gdb
[deliverable/binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 2008, 2009 Free Software Foundation, Inc.
6
7 This file is part of GDB.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21
22 #include "defs.h"
23 #include "symtab.h"
24 #include "gdbtypes.h"
25 #include "value.h"
26 #include "frame.h"
27 #include "inferior.h"
28 #include "gdbcore.h"
29 #include "target.h"
30 #include "demangle.h"
31 #include "language.h"
32 #include "gdbcmd.h"
33 #include "regcache.h"
34 #include "cp-abi.h"
35 #include "block.h"
36 #include "infcall.h"
37 #include "dictionary.h"
38 #include "cp-support.h"
39 #include "dfp.h"
40 #include "user-regs.h"
41
42 #include <errno.h>
43 #include "gdb_string.h"
44 #include "gdb_assert.h"
45 #include "cp-support.h"
46 #include "observer.h"
47 #include "objfiles.h"
48 #include "symtab.h"
49
50 extern int overload_debug;
51 /* Local functions. */
52
53 static int typecmp (int staticp, int varargs, int nargs,
54 struct field t1[], struct value *t2[]);
55
56 static struct value *search_struct_field (char *, struct value *,
57 int, struct type *, int);
58
59 static struct value *search_struct_method (char *, struct value **,
60 struct value **,
61 int, int *, struct type *);
62
63 static int find_oload_champ_namespace (struct type **, int,
64 const char *, const char *,
65 struct symbol ***,
66 struct badness_vector **);
67
68 static
69 int find_oload_champ_namespace_loop (struct type **, int,
70 const char *, const char *,
71 int, struct symbol ***,
72 struct badness_vector **, int *);
73
74 static int find_oload_champ (struct type **, int, int, int,
75 struct fn_field *, struct symbol **,
76 struct badness_vector **);
77
78 static int oload_method_static (int, struct fn_field *, int);
79
80 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
81
82 static enum
83 oload_classification classify_oload_match (struct badness_vector *,
84 int, int);
85
86 static struct value *value_struct_elt_for_reference (struct type *,
87 int, struct type *,
88 char *,
89 struct type *,
90 int, enum noside);
91
92 static struct value *value_namespace_elt (const struct type *,
93 char *, int , enum noside);
94
95 static struct value *value_maybe_namespace_elt (const struct type *,
96 char *, int,
97 enum noside);
98
99 static CORE_ADDR allocate_space_in_inferior (int);
100
101 static struct value *cast_into_complex (struct type *, struct value *);
102
103 static struct fn_field *find_method_list (struct value **, char *,
104 int, struct type *, int *,
105 struct type **, int *);
106
107 void _initialize_valops (void);
108
109 #if 0
110 /* Flag for whether we want to abandon failed expression evals by
111 default. */
112
113 static int auto_abandon = 0;
114 #endif
115
116 int overload_resolution = 0;
117 static void
118 show_overload_resolution (struct ui_file *file, int from_tty,
119 struct cmd_list_element *c,
120 const char *value)
121 {
122 fprintf_filtered (file, _("\
123 Overload resolution in evaluating C++ functions is %s.\n"),
124 value);
125 }
126
127 /* Find the address of function name NAME in the inferior. If OBJF_P
128 is non-NULL, *OBJF_P will be set to the OBJFILE where the function
129 is defined. */
130
131 struct value *
132 find_function_in_inferior (const char *name, struct objfile **objf_p)
133 {
134 struct symbol *sym;
135 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0);
136 if (sym != NULL)
137 {
138 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
139 {
140 error (_("\"%s\" exists in this program but is not a function."),
141 name);
142 }
143
144 if (objf_p)
145 *objf_p = SYMBOL_SYMTAB (sym)->objfile;
146
147 return value_of_variable (sym, NULL);
148 }
149 else
150 {
151 struct minimal_symbol *msymbol =
152 lookup_minimal_symbol (name, NULL, NULL);
153 if (msymbol != NULL)
154 {
155 struct objfile *objfile = msymbol_objfile (msymbol);
156 struct gdbarch *gdbarch = get_objfile_arch (objfile);
157
158 struct type *type;
159 CORE_ADDR maddr;
160 type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char);
161 type = lookup_function_type (type);
162 type = lookup_pointer_type (type);
163 maddr = SYMBOL_VALUE_ADDRESS (msymbol);
164
165 if (objf_p)
166 *objf_p = objfile;
167
168 return value_from_pointer (type, maddr);
169 }
170 else
171 {
172 if (!target_has_execution)
173 error (_("evaluation of this expression requires the target program to be active"));
174 else
175 error (_("evaluation of this expression requires the program to have a function \"%s\"."), name);
176 }
177 }
178 }
179
180 /* Allocate NBYTES of space in the inferior using the inferior's
181 malloc and return a value that is a pointer to the allocated
182 space. */
183
184 struct value *
185 value_allocate_space_in_inferior (int len)
186 {
187 struct objfile *objf;
188 struct value *val = find_function_in_inferior ("malloc", &objf);
189 struct gdbarch *gdbarch = get_objfile_arch (objf);
190 struct value *blocklen;
191
192 blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len);
193 val = call_function_by_hand (val, 1, &blocklen);
194 if (value_logical_not (val))
195 {
196 if (!target_has_execution)
197 error (_("No memory available to program now: you need to start the target first"));
198 else
199 error (_("No memory available to program: call to malloc failed"));
200 }
201 return val;
202 }
203
204 static CORE_ADDR
205 allocate_space_in_inferior (int len)
206 {
207 return value_as_long (value_allocate_space_in_inferior (len));
208 }
209
210 /* Cast struct value VAL to type TYPE and return as a value.
211 Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION
212 for this to work. Typedef to one of the codes is permitted.
213 Returns NULL if the cast is neither an upcast nor a downcast. */
214
215 static struct value *
216 value_cast_structs (struct type *type, struct value *v2)
217 {
218 struct type *t1;
219 struct type *t2;
220 struct value *v;
221
222 gdb_assert (type != NULL && v2 != NULL);
223
224 t1 = check_typedef (type);
225 t2 = check_typedef (value_type (v2));
226
227 /* Check preconditions. */
228 gdb_assert ((TYPE_CODE (t1) == TYPE_CODE_STRUCT
229 || TYPE_CODE (t1) == TYPE_CODE_UNION)
230 && !!"Precondition is that type is of STRUCT or UNION kind.");
231 gdb_assert ((TYPE_CODE (t2) == TYPE_CODE_STRUCT
232 || TYPE_CODE (t2) == TYPE_CODE_UNION)
233 && !!"Precondition is that value is of STRUCT or UNION kind");
234
235 /* Upcasting: look in the type of the source to see if it contains the
236 type of the target as a superclass. If so, we'll need to
237 offset the pointer rather than just change its type. */
238 if (TYPE_NAME (t1) != NULL)
239 {
240 v = search_struct_field (type_name_no_tag (t1),
241 v2, 0, t2, 1);
242 if (v)
243 return v;
244 }
245
246 /* Downcasting: look in the type of the target to see if it contains the
247 type of the source as a superclass. If so, we'll need to
248 offset the pointer rather than just change its type.
249 FIXME: This fails silently with virtual inheritance. */
250 if (TYPE_NAME (t2) != NULL)
251 {
252 v = search_struct_field (type_name_no_tag (t2),
253 value_zero (t1, not_lval), 0, t1, 1);
254 if (v)
255 {
256 /* Downcasting is possible (t1 is superclass of v2). */
257 CORE_ADDR addr2 = VALUE_ADDRESS (v2);
258 addr2 -= (VALUE_ADDRESS (v)
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 if (VALUE_LVAL (val) == lval_computed)
731 value_computed_funcs (val)->read (val);
732 else
733 internal_error (__FILE__, __LINE__, "Unexpected lazy value type.");
734
735 set_value_lazy (val, 0);
736 return 0;
737 }
738
739
740 /* Store the contents of FROMVAL into the location of TOVAL.
741 Return a new value with the location of TOVAL and contents of FROMVAL. */
742
743 struct value *
744 value_assign (struct value *toval, struct value *fromval)
745 {
746 struct type *type;
747 struct value *val;
748 struct frame_id old_frame;
749
750 if (!deprecated_value_modifiable (toval))
751 error (_("Left operand of assignment is not a modifiable lvalue."));
752
753 toval = coerce_ref (toval);
754
755 type = value_type (toval);
756 if (VALUE_LVAL (toval) != lval_internalvar)
757 {
758 toval = value_coerce_to_target (toval);
759 fromval = value_cast (type, fromval);
760 }
761 else
762 {
763 /* Coerce arrays and functions to pointers, except for arrays
764 which only live in GDB's storage. */
765 if (!value_must_coerce_to_target (fromval))
766 fromval = coerce_array (fromval);
767 }
768
769 CHECK_TYPEDEF (type);
770
771 /* Since modifying a register can trash the frame chain, and
772 modifying memory can trash the frame cache, we save the old frame
773 and then restore the new frame afterwards. */
774 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
775
776 switch (VALUE_LVAL (toval))
777 {
778 case lval_internalvar:
779 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
780 val = value_copy (VALUE_INTERNALVAR (toval)->value);
781 val = value_change_enclosing_type (val,
782 value_enclosing_type (fromval));
783 set_value_embedded_offset (val, value_embedded_offset (fromval));
784 set_value_pointed_to_offset (val,
785 value_pointed_to_offset (fromval));
786 return val;
787
788 case lval_internalvar_component:
789 set_internalvar_component (VALUE_INTERNALVAR (toval),
790 value_offset (toval),
791 value_bitpos (toval),
792 value_bitsize (toval),
793 fromval);
794 break;
795
796 case lval_memory:
797 {
798 const gdb_byte *dest_buffer;
799 CORE_ADDR changed_addr;
800 int changed_len;
801 gdb_byte buffer[sizeof (LONGEST)];
802
803 if (value_bitsize (toval))
804 {
805 /* We assume that the argument to read_memory is in units
806 of host chars. FIXME: Is that correct? */
807 changed_len = (value_bitpos (toval)
808 + value_bitsize (toval)
809 + HOST_CHAR_BIT - 1)
810 / HOST_CHAR_BIT;
811
812 if (changed_len > (int) sizeof (LONGEST))
813 error (_("Can't handle bitfields which don't fit in a %d bit word."),
814 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
815
816 read_memory (VALUE_ADDRESS (toval) + value_offset (toval),
817 buffer, changed_len);
818 modify_field (buffer, value_as_long (fromval),
819 value_bitpos (toval), value_bitsize (toval));
820 changed_addr = VALUE_ADDRESS (toval) + value_offset (toval);
821 dest_buffer = buffer;
822 }
823 else
824 {
825 changed_addr = VALUE_ADDRESS (toval) + value_offset (toval);
826 changed_len = TYPE_LENGTH (type);
827 dest_buffer = value_contents (fromval);
828 }
829
830 write_memory (changed_addr, dest_buffer, changed_len);
831 if (deprecated_memory_changed_hook)
832 deprecated_memory_changed_hook (changed_addr, changed_len);
833 }
834 break;
835
836 case lval_register:
837 {
838 struct frame_info *frame;
839 int value_reg;
840
841 /* Figure out which frame this is in currently. */
842 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
843 value_reg = VALUE_REGNUM (toval);
844
845 if (!frame)
846 error (_("Value being assigned to is no longer active."));
847
848 if (gdbarch_convert_register_p
849 (current_gdbarch, VALUE_REGNUM (toval), type))
850 {
851 /* If TOVAL is a special machine register requiring
852 conversion of program values to a special raw
853 format. */
854 gdbarch_value_to_register (current_gdbarch, frame,
855 VALUE_REGNUM (toval), type,
856 value_contents (fromval));
857 }
858 else
859 {
860 if (value_bitsize (toval))
861 {
862 int changed_len;
863 gdb_byte buffer[sizeof (LONGEST)];
864
865 changed_len = (value_bitpos (toval)
866 + value_bitsize (toval)
867 + HOST_CHAR_BIT - 1)
868 / HOST_CHAR_BIT;
869
870 if (changed_len > (int) sizeof (LONGEST))
871 error (_("Can't handle bitfields which don't fit in a %d bit word."),
872 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
873
874 get_frame_register_bytes (frame, value_reg,
875 value_offset (toval),
876 changed_len, buffer);
877
878 modify_field (buffer, value_as_long (fromval),
879 value_bitpos (toval),
880 value_bitsize (toval));
881
882 put_frame_register_bytes (frame, value_reg,
883 value_offset (toval),
884 changed_len, buffer);
885 }
886 else
887 {
888 put_frame_register_bytes (frame, value_reg,
889 value_offset (toval),
890 TYPE_LENGTH (type),
891 value_contents (fromval));
892 }
893 }
894
895 if (deprecated_register_changed_hook)
896 deprecated_register_changed_hook (-1);
897 observer_notify_target_changed (&current_target);
898 break;
899 }
900
901 case lval_computed:
902 {
903 struct lval_funcs *funcs = value_computed_funcs (toval);
904
905 funcs->write (toval, fromval);
906 }
907 break;
908
909 default:
910 error (_("Left operand of assignment is not an lvalue."));
911 }
912
913 /* Assigning to the stack pointer, frame pointer, and other
914 (architecture and calling convention specific) registers may
915 cause the frame cache to be out of date. Assigning to memory
916 also can. We just do this on all assignments to registers or
917 memory, for simplicity's sake; I doubt the slowdown matters. */
918 switch (VALUE_LVAL (toval))
919 {
920 case lval_memory:
921 case lval_register:
922
923 reinit_frame_cache ();
924
925 /* Having destroyed the frame cache, restore the selected
926 frame. */
927
928 /* FIXME: cagney/2002-11-02: There has to be a better way of
929 doing this. Instead of constantly saving/restoring the
930 frame. Why not create a get_selected_frame() function that,
931 having saved the selected frame's ID can automatically
932 re-find the previously selected frame automatically. */
933
934 {
935 struct frame_info *fi = frame_find_by_id (old_frame);
936 if (fi != NULL)
937 select_frame (fi);
938 }
939
940 break;
941 default:
942 break;
943 }
944
945 /* If the field does not entirely fill a LONGEST, then zero the sign
946 bits. If the field is signed, and is negative, then sign
947 extend. */
948 if ((value_bitsize (toval) > 0)
949 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
950 {
951 LONGEST fieldval = value_as_long (fromval);
952 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
953
954 fieldval &= valmask;
955 if (!TYPE_UNSIGNED (type)
956 && (fieldval & (valmask ^ (valmask >> 1))))
957 fieldval |= ~valmask;
958
959 fromval = value_from_longest (type, fieldval);
960 }
961
962 val = value_copy (toval);
963 memcpy (value_contents_raw (val), value_contents (fromval),
964 TYPE_LENGTH (type));
965 deprecated_set_value_type (val, type);
966 val = value_change_enclosing_type (val,
967 value_enclosing_type (fromval));
968 set_value_embedded_offset (val, value_embedded_offset (fromval));
969 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
970
971 return val;
972 }
973
974 /* Extend a value VAL to COUNT repetitions of its type. */
975
976 struct value *
977 value_repeat (struct value *arg1, int count)
978 {
979 struct value *val;
980
981 if (VALUE_LVAL (arg1) != lval_memory)
982 error (_("Only values in memory can be extended with '@'."));
983 if (count < 1)
984 error (_("Invalid number %d of repetitions."), count);
985
986 val = allocate_repeat_value (value_enclosing_type (arg1), count);
987
988 read_memory (VALUE_ADDRESS (arg1) + value_offset (arg1),
989 value_contents_all_raw (val),
990 TYPE_LENGTH (value_enclosing_type (val)));
991 VALUE_LVAL (val) = lval_memory;
992 VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + value_offset (arg1);
993
994 return val;
995 }
996
997 struct value *
998 value_of_variable (struct symbol *var, struct block *b)
999 {
1000 struct value *val;
1001 struct frame_info *frame;
1002
1003 if (!symbol_read_needs_frame (var))
1004 frame = NULL;
1005 else if (!b)
1006 frame = get_selected_frame (_("No frame selected."));
1007 else
1008 {
1009 frame = block_innermost_frame (b);
1010 if (!frame)
1011 {
1012 if (BLOCK_FUNCTION (b)
1013 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
1014 error (_("No frame is currently executing in block %s."),
1015 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
1016 else
1017 error (_("No frame is currently executing in specified block"));
1018 }
1019 }
1020
1021 val = read_var_value (var, frame);
1022 if (!val)
1023 error (_("Address of symbol \"%s\" is unknown."), SYMBOL_PRINT_NAME (var));
1024
1025 return val;
1026 }
1027
1028 struct value *
1029 address_of_variable (struct symbol *var, struct block *b)
1030 {
1031 struct type *type = SYMBOL_TYPE (var);
1032 struct value *val;
1033
1034 /* Evaluate it first; if the result is a memory address, we're fine.
1035 Lazy evaluation pays off here. */
1036
1037 val = value_of_variable (var, b);
1038
1039 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1040 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1041 {
1042 CORE_ADDR addr = VALUE_ADDRESS (val);
1043 return value_from_pointer (lookup_pointer_type (type), addr);
1044 }
1045
1046 /* Not a memory address; check what the problem was. */
1047 switch (VALUE_LVAL (val))
1048 {
1049 case lval_register:
1050 {
1051 struct frame_info *frame;
1052 const char *regname;
1053
1054 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1055 gdb_assert (frame);
1056
1057 regname = gdbarch_register_name (get_frame_arch (frame),
1058 VALUE_REGNUM (val));
1059 gdb_assert (regname && *regname);
1060
1061 error (_("Address requested for identifier "
1062 "\"%s\" which is in register $%s"),
1063 SYMBOL_PRINT_NAME (var), regname);
1064 break;
1065 }
1066
1067 default:
1068 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1069 SYMBOL_PRINT_NAME (var));
1070 break;
1071 }
1072
1073 return val;
1074 }
1075
1076 /* Return one if VAL does not live in target memory, but should in order
1077 to operate on it. Otherwise return zero. */
1078
1079 int
1080 value_must_coerce_to_target (struct value *val)
1081 {
1082 struct type *valtype;
1083
1084 /* The only lval kinds which do not live in target memory. */
1085 if (VALUE_LVAL (val) != not_lval
1086 && VALUE_LVAL (val) != lval_internalvar)
1087 return 0;
1088
1089 valtype = check_typedef (value_type (val));
1090
1091 switch (TYPE_CODE (valtype))
1092 {
1093 case TYPE_CODE_ARRAY:
1094 case TYPE_CODE_STRING:
1095 return 1;
1096 default:
1097 return 0;
1098 }
1099 }
1100
1101 /* Make sure that VAL lives in target memory if it's supposed to. For instance,
1102 strings are constructed as character arrays in GDB's storage, and this
1103 function copies them to the target. */
1104
1105 struct value *
1106 value_coerce_to_target (struct value *val)
1107 {
1108 LONGEST length;
1109 CORE_ADDR addr;
1110
1111 if (!value_must_coerce_to_target (val))
1112 return val;
1113
1114 length = TYPE_LENGTH (check_typedef (value_type (val)));
1115 addr = allocate_space_in_inferior (length);
1116 write_memory (addr, value_contents (val), length);
1117 return value_at_lazy (value_type (val), addr);
1118 }
1119
1120 /* Given a value which is an array, return a value which is a pointer
1121 to its first element, regardless of whether or not the array has a
1122 nonzero lower bound.
1123
1124 FIXME: A previous comment here indicated that this routine should
1125 be substracting the array's lower bound. It's not clear to me that
1126 this is correct. Given an array subscripting operation, it would
1127 certainly work to do the adjustment here, essentially computing:
1128
1129 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1130
1131 However I believe a more appropriate and logical place to account
1132 for the lower bound is to do so in value_subscript, essentially
1133 computing:
1134
1135 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1136
1137 As further evidence consider what would happen with operations
1138 other than array subscripting, where the caller would get back a
1139 value that had an address somewhere before the actual first element
1140 of the array, and the information about the lower bound would be
1141 lost because of the coercion to pointer type.
1142 */
1143
1144 struct value *
1145 value_coerce_array (struct value *arg1)
1146 {
1147 struct type *type = check_typedef (value_type (arg1));
1148
1149 /* If the user tries to do something requiring a pointer with an
1150 array that has not yet been pushed to the target, then this would
1151 be a good time to do so. */
1152 arg1 = value_coerce_to_target (arg1);
1153
1154 if (VALUE_LVAL (arg1) != lval_memory)
1155 error (_("Attempt to take address of value not located in memory."));
1156
1157 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1158 (VALUE_ADDRESS (arg1) + value_offset (arg1)));
1159 }
1160
1161 /* Given a value which is a function, return a value which is a pointer
1162 to it. */
1163
1164 struct value *
1165 value_coerce_function (struct value *arg1)
1166 {
1167 struct value *retval;
1168
1169 if (VALUE_LVAL (arg1) != lval_memory)
1170 error (_("Attempt to take address of value not located in memory."));
1171
1172 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1173 (VALUE_ADDRESS (arg1) + value_offset (arg1)));
1174 return retval;
1175 }
1176
1177 /* Return a pointer value for the object for which ARG1 is the
1178 contents. */
1179
1180 struct value *
1181 value_addr (struct value *arg1)
1182 {
1183 struct value *arg2;
1184
1185 struct type *type = check_typedef (value_type (arg1));
1186 if (TYPE_CODE (type) == TYPE_CODE_REF)
1187 {
1188 /* Copy the value, but change the type from (T&) to (T*). We
1189 keep the same location information, which is efficient, and
1190 allows &(&X) to get the location containing the reference. */
1191 arg2 = value_copy (arg1);
1192 deprecated_set_value_type (arg2,
1193 lookup_pointer_type (TYPE_TARGET_TYPE (type)));
1194 return arg2;
1195 }
1196 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1197 return value_coerce_function (arg1);
1198
1199 /* If this is an array that has not yet been pushed to the target,
1200 then this would be a good time to force it to memory. */
1201 arg1 = value_coerce_to_target (arg1);
1202
1203 if (VALUE_LVAL (arg1) != lval_memory)
1204 error (_("Attempt to take address of value not located in memory."));
1205
1206 /* Get target memory address */
1207 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1208 (VALUE_ADDRESS (arg1)
1209 + value_offset (arg1)
1210 + value_embedded_offset (arg1)));
1211
1212 /* This may be a pointer to a base subobject; so remember the
1213 full derived object's type ... */
1214 arg2 = value_change_enclosing_type (arg2, lookup_pointer_type (value_enclosing_type (arg1)));
1215 /* ... and also the relative position of the subobject in the full
1216 object. */
1217 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1218 return arg2;
1219 }
1220
1221 /* Return a reference value for the object for which ARG1 is the
1222 contents. */
1223
1224 struct value *
1225 value_ref (struct value *arg1)
1226 {
1227 struct value *arg2;
1228
1229 struct type *type = check_typedef (value_type (arg1));
1230 if (TYPE_CODE (type) == TYPE_CODE_REF)
1231 return arg1;
1232
1233 arg2 = value_addr (arg1);
1234 deprecated_set_value_type (arg2, lookup_reference_type (type));
1235 return arg2;
1236 }
1237
1238 /* Given a value of a pointer type, apply the C unary * operator to
1239 it. */
1240
1241 struct value *
1242 value_ind (struct value *arg1)
1243 {
1244 struct type *base_type;
1245 struct value *arg2;
1246
1247 arg1 = coerce_array (arg1);
1248
1249 base_type = check_typedef (value_type (arg1));
1250
1251 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1252 {
1253 struct type *enc_type;
1254 /* We may be pointing to something embedded in a larger object.
1255 Get the real type of the enclosing object. */
1256 enc_type = check_typedef (value_enclosing_type (arg1));
1257 enc_type = TYPE_TARGET_TYPE (enc_type);
1258
1259 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1260 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1261 /* For functions, go through find_function_addr, which knows
1262 how to handle function descriptors. */
1263 arg2 = value_at_lazy (enc_type,
1264 find_function_addr (arg1, NULL));
1265 else
1266 /* Retrieve the enclosing object pointed to */
1267 arg2 = value_at_lazy (enc_type,
1268 (value_as_address (arg1)
1269 - value_pointed_to_offset (arg1)));
1270
1271 /* Re-adjust type. */
1272 deprecated_set_value_type (arg2, TYPE_TARGET_TYPE (base_type));
1273 /* Add embedding info. */
1274 arg2 = value_change_enclosing_type (arg2, enc_type);
1275 set_value_embedded_offset (arg2, value_pointed_to_offset (arg1));
1276
1277 /* We may be pointing to an object of some derived type. */
1278 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
1279 return arg2;
1280 }
1281
1282 error (_("Attempt to take contents of a non-pointer value."));
1283 return 0; /* For lint -- never reached. */
1284 }
1285 \f
1286 /* Create a value for an array by allocating space in GDB, copying
1287 copying the data into that space, and then setting up an array
1288 value.
1289
1290 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1291 is populated from the values passed in ELEMVEC.
1292
1293 The element type of the array is inherited from the type of the
1294 first element, and all elements must have the same size (though we
1295 don't currently enforce any restriction on their types). */
1296
1297 struct value *
1298 value_array (int lowbound, int highbound, struct value **elemvec)
1299 {
1300 int nelem;
1301 int idx;
1302 unsigned int typelength;
1303 struct value *val;
1304 struct type *rangetype;
1305 struct type *arraytype;
1306 CORE_ADDR addr;
1307
1308 /* Validate that the bounds are reasonable and that each of the
1309 elements have the same size. */
1310
1311 nelem = highbound - lowbound + 1;
1312 if (nelem <= 0)
1313 {
1314 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1315 }
1316 typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
1317 for (idx = 1; idx < nelem; idx++)
1318 {
1319 if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
1320 {
1321 error (_("array elements must all be the same size"));
1322 }
1323 }
1324
1325 rangetype = create_range_type ((struct type *) NULL,
1326 builtin_type_int32,
1327 lowbound, highbound);
1328 arraytype = create_array_type ((struct type *) NULL,
1329 value_enclosing_type (elemvec[0]),
1330 rangetype);
1331
1332 if (!current_language->c_style_arrays)
1333 {
1334 val = allocate_value (arraytype);
1335 for (idx = 0; idx < nelem; idx++)
1336 {
1337 memcpy (value_contents_all_raw (val) + (idx * typelength),
1338 value_contents_all (elemvec[idx]),
1339 typelength);
1340 }
1341 return val;
1342 }
1343
1344 /* Allocate space to store the array, and then initialize it by
1345 copying in each element. */
1346
1347 val = allocate_value (arraytype);
1348 for (idx = 0; idx < nelem; idx++)
1349 memcpy (value_contents_writeable (val) + (idx * typelength),
1350 value_contents_all (elemvec[idx]),
1351 typelength);
1352 return val;
1353 }
1354
1355 struct value *
1356 value_typed_string (char *ptr, int len, struct type *char_type)
1357 {
1358 struct value *val;
1359 int lowbound = current_language->string_lower_bound;
1360 int highbound = len / TYPE_LENGTH (char_type);
1361 struct type *rangetype = create_range_type ((struct type *) NULL,
1362 builtin_type_int32,
1363 lowbound,
1364 highbound + lowbound - 1);
1365 struct type *stringtype
1366 = create_array_type ((struct type *) NULL, char_type, rangetype);
1367
1368 val = allocate_value (stringtype);
1369 memcpy (value_contents_raw (val), ptr, len);
1370 return val;
1371 }
1372
1373 /* Create a value for a string constant by allocating space in the
1374 inferior, copying the data into that space, and returning the
1375 address with type TYPE_CODE_STRING. PTR points to the string
1376 constant data; LEN is number of characters.
1377
1378 Note that string types are like array of char types with a lower
1379 bound of zero and an upper bound of LEN - 1. Also note that the
1380 string may contain embedded null bytes. */
1381
1382 struct value *
1383 value_string (char *ptr, int len)
1384 {
1385 struct value *val;
1386 int lowbound = current_language->string_lower_bound;
1387 struct type *rangetype = create_range_type ((struct type *) NULL,
1388 builtin_type_int32,
1389 lowbound,
1390 len + lowbound - 1);
1391 struct type *stringtype
1392 = create_string_type ((struct type *) NULL, rangetype);
1393 CORE_ADDR addr;
1394
1395 if (current_language->c_style_arrays == 0)
1396 {
1397 val = allocate_value (stringtype);
1398 memcpy (value_contents_raw (val), ptr, len);
1399 return val;
1400 }
1401
1402
1403 /* Allocate space to store the string in the inferior, and then copy
1404 LEN bytes from PTR in gdb to that address in the inferior. */
1405
1406 addr = allocate_space_in_inferior (len);
1407 write_memory (addr, (gdb_byte *) ptr, len);
1408
1409 val = value_at_lazy (stringtype, addr);
1410 return (val);
1411 }
1412
1413 struct value *
1414 value_bitstring (char *ptr, int len)
1415 {
1416 struct value *val;
1417 struct type *domain_type = create_range_type (NULL,
1418 builtin_type_int32,
1419 0, len - 1);
1420 struct type *type = create_set_type ((struct type *) NULL,
1421 domain_type);
1422 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1423 val = allocate_value (type);
1424 memcpy (value_contents_raw (val), ptr, TYPE_LENGTH (type));
1425 return val;
1426 }
1427 \f
1428 /* See if we can pass arguments in T2 to a function which takes
1429 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1430 a NULL-terminated vector. If some arguments need coercion of some
1431 sort, then the coerced values are written into T2. Return value is
1432 0 if the arguments could be matched, or the position at which they
1433 differ if not.
1434
1435 STATICP is nonzero if the T1 argument list came from a static
1436 member function. T2 will still include the ``this'' pointer, but
1437 it will be skipped.
1438
1439 For non-static member functions, we ignore the first argument,
1440 which is the type of the instance variable. This is because we
1441 want to handle calls with objects from derived classes. This is
1442 not entirely correct: we should actually check to make sure that a
1443 requested operation is type secure, shouldn't we? FIXME. */
1444
1445 static int
1446 typecmp (int staticp, int varargs, int nargs,
1447 struct field t1[], struct value *t2[])
1448 {
1449 int i;
1450
1451 if (t2 == 0)
1452 internal_error (__FILE__, __LINE__,
1453 _("typecmp: no argument list"));
1454
1455 /* Skip ``this'' argument if applicable. T2 will always include
1456 THIS. */
1457 if (staticp)
1458 t2 ++;
1459
1460 for (i = 0;
1461 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1462 i++)
1463 {
1464 struct type *tt1, *tt2;
1465
1466 if (!t2[i])
1467 return i + 1;
1468
1469 tt1 = check_typedef (t1[i].type);
1470 tt2 = check_typedef (value_type (t2[i]));
1471
1472 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1473 /* We should be doing hairy argument matching, as below. */
1474 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
1475 {
1476 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1477 t2[i] = value_coerce_array (t2[i]);
1478 else
1479 t2[i] = value_ref (t2[i]);
1480 continue;
1481 }
1482
1483 /* djb - 20000715 - Until the new type structure is in the
1484 place, and we can attempt things like implicit conversions,
1485 we need to do this so you can take something like a map<const
1486 char *>, and properly access map["hello"], because the
1487 argument to [] will be a reference to a pointer to a char,
1488 and the argument will be a pointer to a char. */
1489 while (TYPE_CODE(tt1) == TYPE_CODE_REF
1490 || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1491 {
1492 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1493 }
1494 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1495 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1496 || TYPE_CODE(tt2) == TYPE_CODE_REF)
1497 {
1498 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1499 }
1500 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1501 continue;
1502 /* Array to pointer is a `trivial conversion' according to the
1503 ARM. */
1504
1505 /* We should be doing much hairier argument matching (see
1506 section 13.2 of the ARM), but as a quick kludge, just check
1507 for the same type code. */
1508 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1509 return i + 1;
1510 }
1511 if (varargs || t2[i] == NULL)
1512 return 0;
1513 return i + 1;
1514 }
1515
1516 /* Helper function used by value_struct_elt to recurse through
1517 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1518 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1519 TYPE. If found, return value, else return NULL.
1520
1521 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1522 fields, look for a baseclass named NAME. */
1523
1524 static struct value *
1525 search_struct_field (char *name, struct value *arg1, int offset,
1526 struct type *type, int looking_for_baseclass)
1527 {
1528 int i;
1529 int nbases = TYPE_N_BASECLASSES (type);
1530
1531 CHECK_TYPEDEF (type);
1532
1533 if (!looking_for_baseclass)
1534 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1535 {
1536 char *t_field_name = TYPE_FIELD_NAME (type, i);
1537
1538 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1539 {
1540 struct value *v;
1541 if (field_is_static (&TYPE_FIELD (type, i)))
1542 {
1543 v = value_static_field (type, i);
1544 if (v == 0)
1545 error (_("field %s is nonexistent or has been optimised out"),
1546 name);
1547 }
1548 else
1549 {
1550 v = value_primitive_field (arg1, offset, i, type);
1551 if (v == 0)
1552 error (_("there is no field named %s"), name);
1553 }
1554 return v;
1555 }
1556
1557 if (t_field_name
1558 && (t_field_name[0] == '\0'
1559 || (TYPE_CODE (type) == TYPE_CODE_UNION
1560 && (strcmp_iw (t_field_name, "else") == 0))))
1561 {
1562 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1563 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1564 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1565 {
1566 /* Look for a match through the fields of an anonymous
1567 union, or anonymous struct. C++ provides anonymous
1568 unions.
1569
1570 In the GNU Chill (now deleted from GDB)
1571 implementation of variant record types, each
1572 <alternative field> has an (anonymous) union type,
1573 each member of the union represents a <variant
1574 alternative>. Each <variant alternative> is
1575 represented as a struct, with a member for each
1576 <variant field>. */
1577
1578 struct value *v;
1579 int new_offset = offset;
1580
1581 /* This is pretty gross. In G++, the offset in an
1582 anonymous union is relative to the beginning of the
1583 enclosing struct. In the GNU Chill (now deleted
1584 from GDB) implementation of variant records, the
1585 bitpos is zero in an anonymous union field, so we
1586 have to add the offset of the union here. */
1587 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1588 || (TYPE_NFIELDS (field_type) > 0
1589 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1590 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1591
1592 v = search_struct_field (name, arg1, new_offset,
1593 field_type,
1594 looking_for_baseclass);
1595 if (v)
1596 return v;
1597 }
1598 }
1599 }
1600
1601 for (i = 0; i < nbases; i++)
1602 {
1603 struct value *v;
1604 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1605 /* If we are looking for baseclasses, this is what we get when
1606 we hit them. But it could happen that the base part's member
1607 name is not yet filled in. */
1608 int found_baseclass = (looking_for_baseclass
1609 && TYPE_BASECLASS_NAME (type, i) != NULL
1610 && (strcmp_iw (name,
1611 TYPE_BASECLASS_NAME (type,
1612 i)) == 0));
1613
1614 if (BASETYPE_VIA_VIRTUAL (type, i))
1615 {
1616 int boffset;
1617 struct value *v2;
1618
1619 boffset = baseclass_offset (type, i,
1620 value_contents (arg1) + offset,
1621 VALUE_ADDRESS (arg1)
1622 + value_offset (arg1) + offset);
1623 if (boffset == -1)
1624 error (_("virtual baseclass botch"));
1625
1626 /* The virtual base class pointer might have been clobbered
1627 by the user program. Make sure that it still points to a
1628 valid memory location. */
1629
1630 boffset += offset;
1631 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
1632 {
1633 CORE_ADDR base_addr;
1634
1635 v2 = allocate_value (basetype);
1636 base_addr =
1637 VALUE_ADDRESS (arg1) + value_offset (arg1) + boffset;
1638 if (target_read_memory (base_addr,
1639 value_contents_raw (v2),
1640 TYPE_LENGTH (basetype)) != 0)
1641 error (_("virtual baseclass botch"));
1642 VALUE_LVAL (v2) = lval_memory;
1643 VALUE_ADDRESS (v2) = base_addr;
1644 }
1645 else
1646 {
1647 if (VALUE_LVAL (arg1) == lval_memory && value_lazy (arg1))
1648 v2 = allocate_value_lazy (basetype);
1649 else
1650 {
1651 v2 = allocate_value (basetype);
1652 memcpy (value_contents_raw (v2),
1653 value_contents_raw (arg1) + boffset,
1654 TYPE_LENGTH (basetype));
1655 }
1656 set_value_component_location (v2, arg1);
1657 VALUE_FRAME_ID (v2) = VALUE_FRAME_ID (arg1);
1658 set_value_offset (v2, value_offset (arg1) + boffset);
1659 }
1660
1661 if (found_baseclass)
1662 return v2;
1663 v = search_struct_field (name, v2, 0,
1664 TYPE_BASECLASS (type, i),
1665 looking_for_baseclass);
1666 }
1667 else if (found_baseclass)
1668 v = value_primitive_field (arg1, offset, i, type);
1669 else
1670 v = search_struct_field (name, arg1,
1671 offset + TYPE_BASECLASS_BITPOS (type,
1672 i) / 8,
1673 basetype, looking_for_baseclass);
1674 if (v)
1675 return v;
1676 }
1677 return NULL;
1678 }
1679
1680 /* Helper function used by value_struct_elt to recurse through
1681 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1682 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1683 TYPE.
1684
1685 If found, return value, else if name matched and args not return
1686 (value) -1, else return NULL. */
1687
1688 static struct value *
1689 search_struct_method (char *name, struct value **arg1p,
1690 struct value **args, int offset,
1691 int *static_memfuncp, struct type *type)
1692 {
1693 int i;
1694 struct value *v;
1695 int name_matched = 0;
1696 char dem_opname[64];
1697
1698 CHECK_TYPEDEF (type);
1699 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1700 {
1701 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1702 /* FIXME! May need to check for ARM demangling here */
1703 if (strncmp (t_field_name, "__", 2) == 0 ||
1704 strncmp (t_field_name, "op", 2) == 0 ||
1705 strncmp (t_field_name, "type", 4) == 0)
1706 {
1707 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
1708 t_field_name = dem_opname;
1709 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
1710 t_field_name = dem_opname;
1711 }
1712 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1713 {
1714 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1715 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1716 name_matched = 1;
1717
1718 check_stub_method_group (type, i);
1719 if (j > 0 && args == 0)
1720 error (_("cannot resolve overloaded method `%s': no arguments supplied"), name);
1721 else if (j == 0 && args == 0)
1722 {
1723 v = value_fn_field (arg1p, f, j, type, offset);
1724 if (v != NULL)
1725 return v;
1726 }
1727 else
1728 while (j >= 0)
1729 {
1730 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
1731 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
1732 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
1733 TYPE_FN_FIELD_ARGS (f, j), args))
1734 {
1735 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
1736 return value_virtual_fn_field (arg1p, f, j,
1737 type, offset);
1738 if (TYPE_FN_FIELD_STATIC_P (f, j)
1739 && static_memfuncp)
1740 *static_memfuncp = 1;
1741 v = value_fn_field (arg1p, f, j, type, offset);
1742 if (v != NULL)
1743 return v;
1744 }
1745 j--;
1746 }
1747 }
1748 }
1749
1750 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1751 {
1752 int base_offset;
1753
1754 if (BASETYPE_VIA_VIRTUAL (type, i))
1755 {
1756 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
1757 const gdb_byte *base_valaddr;
1758
1759 /* The virtual base class pointer might have been
1760 clobbered by the user program. Make sure that it
1761 still points to a valid memory location. */
1762
1763 if (offset < 0 || offset >= TYPE_LENGTH (type))
1764 {
1765 gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
1766 if (target_read_memory (VALUE_ADDRESS (*arg1p)
1767 + value_offset (*arg1p) + offset,
1768 tmp, TYPE_LENGTH (baseclass)) != 0)
1769 error (_("virtual baseclass botch"));
1770 base_valaddr = tmp;
1771 }
1772 else
1773 base_valaddr = value_contents (*arg1p) + offset;
1774
1775 base_offset = baseclass_offset (type, i, base_valaddr,
1776 VALUE_ADDRESS (*arg1p)
1777 + value_offset (*arg1p) + offset);
1778 if (base_offset == -1)
1779 error (_("virtual baseclass botch"));
1780 }
1781 else
1782 {
1783 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1784 }
1785 v = search_struct_method (name, arg1p, args, base_offset + offset,
1786 static_memfuncp, TYPE_BASECLASS (type, i));
1787 if (v == (struct value *) - 1)
1788 {
1789 name_matched = 1;
1790 }
1791 else if (v)
1792 {
1793 /* FIXME-bothner: Why is this commented out? Why is it here? */
1794 /* *arg1p = arg1_tmp; */
1795 return v;
1796 }
1797 }
1798 if (name_matched)
1799 return (struct value *) - 1;
1800 else
1801 return NULL;
1802 }
1803
1804 /* Given *ARGP, a value of type (pointer to a)* structure/union,
1805 extract the component named NAME from the ultimate target
1806 structure/union and return it as a value with its appropriate type.
1807 ERR is used in the error message if *ARGP's type is wrong.
1808
1809 C++: ARGS is a list of argument types to aid in the selection of
1810 an appropriate method. Also, handle derived types.
1811
1812 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
1813 where the truthvalue of whether the function that was resolved was
1814 a static member function or not is stored.
1815
1816 ERR is an error message to be printed in case the field is not
1817 found. */
1818
1819 struct value *
1820 value_struct_elt (struct value **argp, struct value **args,
1821 char *name, int *static_memfuncp, char *err)
1822 {
1823 struct type *t;
1824 struct value *v;
1825
1826 *argp = coerce_array (*argp);
1827
1828 t = check_typedef (value_type (*argp));
1829
1830 /* Follow pointers until we get to a non-pointer. */
1831
1832 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1833 {
1834 *argp = value_ind (*argp);
1835 /* Don't coerce fn pointer to fn and then back again! */
1836 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
1837 *argp = coerce_array (*argp);
1838 t = check_typedef (value_type (*argp));
1839 }
1840
1841 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
1842 && TYPE_CODE (t) != TYPE_CODE_UNION)
1843 error (_("Attempt to extract a component of a value that is not a %s."), err);
1844
1845 /* Assume it's not, unless we see that it is. */
1846 if (static_memfuncp)
1847 *static_memfuncp = 0;
1848
1849 if (!args)
1850 {
1851 /* if there are no arguments ...do this... */
1852
1853 /* Try as a field first, because if we succeed, there is less
1854 work to be done. */
1855 v = search_struct_field (name, *argp, 0, t, 0);
1856 if (v)
1857 return v;
1858
1859 /* C++: If it was not found as a data field, then try to
1860 return it as a pointer to a method. */
1861
1862 if (destructor_name_p (name, t))
1863 error (_("Cannot get value of destructor"));
1864
1865 v = search_struct_method (name, argp, args, 0,
1866 static_memfuncp, t);
1867
1868 if (v == (struct value *) - 1)
1869 error (_("Cannot take address of method %s."), name);
1870 else if (v == 0)
1871 {
1872 if (TYPE_NFN_FIELDS (t))
1873 error (_("There is no member or method named %s."), name);
1874 else
1875 error (_("There is no member named %s."), name);
1876 }
1877 return v;
1878 }
1879
1880 if (destructor_name_p (name, t))
1881 {
1882 if (!args[1])
1883 {
1884 /* Destructors are a special case. */
1885 int m_index, f_index;
1886
1887 v = NULL;
1888 if (get_destructor_fn_field (t, &m_index, &f_index))
1889 {
1890 v = value_fn_field (NULL,
1891 TYPE_FN_FIELDLIST1 (t, m_index),
1892 f_index, NULL, 0);
1893 }
1894 if (v == NULL)
1895 error (_("could not find destructor function named %s."),
1896 name);
1897 else
1898 return v;
1899 }
1900 else
1901 {
1902 error (_("destructor should not have any argument"));
1903 }
1904 }
1905 else
1906 v = search_struct_method (name, argp, args, 0,
1907 static_memfuncp, t);
1908
1909 if (v == (struct value *) - 1)
1910 {
1911 error (_("One of the arguments you tried to pass to %s could not be converted to what the function wants."), name);
1912 }
1913 else if (v == 0)
1914 {
1915 /* See if user tried to invoke data as function. If so, hand it
1916 back. If it's not callable (i.e., a pointer to function),
1917 gdb should give an error. */
1918 v = search_struct_field (name, *argp, 0, t, 0);
1919 /* If we found an ordinary field, then it is not a method call.
1920 So, treat it as if it were a static member function. */
1921 if (v && static_memfuncp)
1922 *static_memfuncp = 1;
1923 }
1924
1925 if (!v)
1926 error (_("Structure has no component named %s."), name);
1927 return v;
1928 }
1929
1930 /* Search through the methods of an object (and its bases) to find a
1931 specified method. Return the pointer to the fn_field list of
1932 overloaded instances.
1933
1934 Helper function for value_find_oload_list.
1935 ARGP is a pointer to a pointer to a value (the object).
1936 METHOD is a string containing the method name.
1937 OFFSET is the offset within the value.
1938 TYPE is the assumed type of the object.
1939 NUM_FNS is the number of overloaded instances.
1940 BASETYPE is set to the actual type of the subobject where the
1941 method is found.
1942 BOFFSET is the offset of the base subobject where the method is found.
1943 */
1944
1945 static struct fn_field *
1946 find_method_list (struct value **argp, char *method,
1947 int offset, struct type *type, int *num_fns,
1948 struct type **basetype, int *boffset)
1949 {
1950 int i;
1951 struct fn_field *f;
1952 CHECK_TYPEDEF (type);
1953
1954 *num_fns = 0;
1955
1956 /* First check in object itself. */
1957 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1958 {
1959 /* pai: FIXME What about operators and type conversions? */
1960 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1961 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
1962 {
1963 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
1964 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1965
1966 *num_fns = len;
1967 *basetype = type;
1968 *boffset = offset;
1969
1970 /* Resolve any stub methods. */
1971 check_stub_method_group (type, i);
1972
1973 return f;
1974 }
1975 }
1976
1977 /* Not found in object, check in base subobjects. */
1978 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1979 {
1980 int base_offset;
1981 if (BASETYPE_VIA_VIRTUAL (type, i))
1982 {
1983 base_offset = value_offset (*argp) + offset;
1984 base_offset = baseclass_offset (type, i,
1985 value_contents (*argp) + base_offset,
1986 VALUE_ADDRESS (*argp) + base_offset);
1987 if (base_offset == -1)
1988 error (_("virtual baseclass botch"));
1989 }
1990 else /* Non-virtual base, simply use bit position from debug
1991 info. */
1992 {
1993 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1994 }
1995 f = find_method_list (argp, method, base_offset + offset,
1996 TYPE_BASECLASS (type, i), num_fns,
1997 basetype, boffset);
1998 if (f)
1999 return f;
2000 }
2001 return NULL;
2002 }
2003
2004 /* Return the list of overloaded methods of a specified name.
2005
2006 ARGP is a pointer to a pointer to a value (the object).
2007 METHOD is the method name.
2008 OFFSET is the offset within the value contents.
2009 NUM_FNS is the number of overloaded instances.
2010 BASETYPE is set to the type of the base subobject that defines the
2011 method.
2012 BOFFSET is the offset of the base subobject which defines the method.
2013 */
2014
2015 struct fn_field *
2016 value_find_oload_method_list (struct value **argp, char *method,
2017 int offset, int *num_fns,
2018 struct type **basetype, int *boffset)
2019 {
2020 struct type *t;
2021
2022 t = check_typedef (value_type (*argp));
2023
2024 /* Code snarfed from value_struct_elt. */
2025 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2026 {
2027 *argp = value_ind (*argp);
2028 /* Don't coerce fn pointer to fn and then back again! */
2029 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
2030 *argp = coerce_array (*argp);
2031 t = check_typedef (value_type (*argp));
2032 }
2033
2034 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2035 && TYPE_CODE (t) != TYPE_CODE_UNION)
2036 error (_("Attempt to extract a component of a value that is not a struct or union"));
2037
2038 return find_method_list (argp, method, 0, t, num_fns,
2039 basetype, boffset);
2040 }
2041
2042 /* Given an array of argument types (ARGTYPES) (which includes an
2043 entry for "this" in the case of C++ methods), the number of
2044 arguments NARGS, the NAME of a function whether it's a method or
2045 not (METHOD), and the degree of laxness (LAX) in conforming to
2046 overload resolution rules in ANSI C++, find the best function that
2047 matches on the argument types according to the overload resolution
2048 rules.
2049
2050 In the case of class methods, the parameter OBJ is an object value
2051 in which to search for overloaded methods.
2052
2053 In the case of non-method functions, the parameter FSYM is a symbol
2054 corresponding to one of the overloaded functions.
2055
2056 Return value is an integer: 0 -> good match, 10 -> debugger applied
2057 non-standard coercions, 100 -> incompatible.
2058
2059 If a method is being searched for, VALP will hold the value.
2060 If a non-method is being searched for, SYMP will hold the symbol
2061 for it.
2062
2063 If a method is being searched for, and it is a static method,
2064 then STATICP will point to a non-zero value.
2065
2066 Note: This function does *not* check the value of
2067 overload_resolution. Caller must check it to see whether overload
2068 resolution is permitted.
2069 */
2070
2071 int
2072 find_overload_match (struct type **arg_types, int nargs,
2073 char *name, int method, int lax,
2074 struct value **objp, struct symbol *fsym,
2075 struct value **valp, struct symbol **symp,
2076 int *staticp)
2077 {
2078 struct value *obj = (objp ? *objp : NULL);
2079 /* Index of best overloaded function. */
2080 int oload_champ;
2081 /* The measure for the current best match. */
2082 struct badness_vector *oload_champ_bv = NULL;
2083 struct value *temp = obj;
2084 /* For methods, the list of overloaded methods. */
2085 struct fn_field *fns_ptr = NULL;
2086 /* For non-methods, the list of overloaded function symbols. */
2087 struct symbol **oload_syms = NULL;
2088 /* Number of overloaded instances being considered. */
2089 int num_fns = 0;
2090 struct type *basetype = NULL;
2091 int boffset;
2092 int ix;
2093 int static_offset;
2094 struct cleanup *old_cleanups = NULL;
2095
2096 const char *obj_type_name = NULL;
2097 char *func_name = NULL;
2098 enum oload_classification match_quality;
2099
2100 /* Get the list of overloaded methods or functions. */
2101 if (method)
2102 {
2103 gdb_assert (obj);
2104 obj_type_name = TYPE_NAME (value_type (obj));
2105 /* Hack: evaluate_subexp_standard often passes in a pointer
2106 value rather than the object itself, so try again. */
2107 if ((!obj_type_name || !*obj_type_name)
2108 && (TYPE_CODE (value_type (obj)) == TYPE_CODE_PTR))
2109 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (value_type (obj)));
2110
2111 fns_ptr = value_find_oload_method_list (&temp, name,
2112 0, &num_fns,
2113 &basetype, &boffset);
2114 if (!fns_ptr || !num_fns)
2115 error (_("Couldn't find method %s%s%s"),
2116 obj_type_name,
2117 (obj_type_name && *obj_type_name) ? "::" : "",
2118 name);
2119 /* If we are dealing with stub method types, they should have
2120 been resolved by find_method_list via
2121 value_find_oload_method_list above. */
2122 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2123 oload_champ = find_oload_champ (arg_types, nargs, method,
2124 num_fns, fns_ptr,
2125 oload_syms, &oload_champ_bv);
2126 }
2127 else
2128 {
2129 const char *qualified_name = SYMBOL_CPLUS_DEMANGLED_NAME (fsym);
2130
2131 /* If we have a C++ name, try to extract just the function
2132 part. */
2133 if (qualified_name)
2134 func_name = cp_func_name (qualified_name);
2135
2136 /* If there was no C++ name, this must be a C-style function.
2137 Just return the same symbol. Do the same if cp_func_name
2138 fails for some reason. */
2139 if (func_name == NULL)
2140 {
2141 *symp = fsym;
2142 return 0;
2143 }
2144
2145 old_cleanups = make_cleanup (xfree, func_name);
2146 make_cleanup (xfree, oload_syms);
2147 make_cleanup (xfree, oload_champ_bv);
2148
2149 oload_champ = find_oload_champ_namespace (arg_types, nargs,
2150 func_name,
2151 qualified_name,
2152 &oload_syms,
2153 &oload_champ_bv);
2154 }
2155
2156 /* Check how bad the best match is. */
2157
2158 match_quality =
2159 classify_oload_match (oload_champ_bv, nargs,
2160 oload_method_static (method, fns_ptr,
2161 oload_champ));
2162
2163 if (match_quality == INCOMPATIBLE)
2164 {
2165 if (method)
2166 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2167 obj_type_name,
2168 (obj_type_name && *obj_type_name) ? "::" : "",
2169 name);
2170 else
2171 error (_("Cannot resolve function %s to any overloaded instance"),
2172 func_name);
2173 }
2174 else if (match_quality == NON_STANDARD)
2175 {
2176 if (method)
2177 warning (_("Using non-standard conversion to match method %s%s%s to supplied arguments"),
2178 obj_type_name,
2179 (obj_type_name && *obj_type_name) ? "::" : "",
2180 name);
2181 else
2182 warning (_("Using non-standard conversion to match function %s to supplied arguments"),
2183 func_name);
2184 }
2185
2186 if (method)
2187 {
2188 if (staticp != NULL)
2189 *staticp = oload_method_static (method, fns_ptr, oload_champ);
2190 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
2191 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ,
2192 basetype, boffset);
2193 else
2194 *valp = value_fn_field (&temp, fns_ptr, oload_champ,
2195 basetype, boffset);
2196 }
2197 else
2198 {
2199 *symp = oload_syms[oload_champ];
2200 }
2201
2202 if (objp)
2203 {
2204 struct type *temp_type = check_typedef (value_type (temp));
2205 struct type *obj_type = check_typedef (value_type (*objp));
2206 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2207 && (TYPE_CODE (obj_type) == TYPE_CODE_PTR
2208 || TYPE_CODE (obj_type) == TYPE_CODE_REF))
2209 {
2210 temp = value_addr (temp);
2211 }
2212 *objp = temp;
2213 }
2214 if (old_cleanups != NULL)
2215 do_cleanups (old_cleanups);
2216
2217 switch (match_quality)
2218 {
2219 case INCOMPATIBLE:
2220 return 100;
2221 case NON_STANDARD:
2222 return 10;
2223 default: /* STANDARD */
2224 return 0;
2225 }
2226 }
2227
2228 /* Find the best overload match, searching for FUNC_NAME in namespaces
2229 contained in QUALIFIED_NAME until it either finds a good match or
2230 runs out of namespaces. It stores the overloaded functions in
2231 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
2232 calling function is responsible for freeing *OLOAD_SYMS and
2233 *OLOAD_CHAMP_BV. */
2234
2235 static int
2236 find_oload_champ_namespace (struct type **arg_types, int nargs,
2237 const char *func_name,
2238 const char *qualified_name,
2239 struct symbol ***oload_syms,
2240 struct badness_vector **oload_champ_bv)
2241 {
2242 int oload_champ;
2243
2244 find_oload_champ_namespace_loop (arg_types, nargs,
2245 func_name,
2246 qualified_name, 0,
2247 oload_syms, oload_champ_bv,
2248 &oload_champ);
2249
2250 return oload_champ;
2251 }
2252
2253 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2254 how deep we've looked for namespaces, and the champ is stored in
2255 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2256 if it isn't.
2257
2258 It is the caller's responsibility to free *OLOAD_SYMS and
2259 *OLOAD_CHAMP_BV. */
2260
2261 static int
2262 find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
2263 const char *func_name,
2264 const char *qualified_name,
2265 int namespace_len,
2266 struct symbol ***oload_syms,
2267 struct badness_vector **oload_champ_bv,
2268 int *oload_champ)
2269 {
2270 int next_namespace_len = namespace_len;
2271 int searched_deeper = 0;
2272 int num_fns = 0;
2273 struct cleanup *old_cleanups;
2274 int new_oload_champ;
2275 struct symbol **new_oload_syms;
2276 struct badness_vector *new_oload_champ_bv;
2277 char *new_namespace;
2278
2279 if (next_namespace_len != 0)
2280 {
2281 gdb_assert (qualified_name[next_namespace_len] == ':');
2282 next_namespace_len += 2;
2283 }
2284 next_namespace_len +=
2285 cp_find_first_component (qualified_name + next_namespace_len);
2286
2287 /* Initialize these to values that can safely be xfree'd. */
2288 *oload_syms = NULL;
2289 *oload_champ_bv = NULL;
2290
2291 /* First, see if we have a deeper namespace we can search in.
2292 If we get a good match there, use it. */
2293
2294 if (qualified_name[next_namespace_len] == ':')
2295 {
2296 searched_deeper = 1;
2297
2298 if (find_oload_champ_namespace_loop (arg_types, nargs,
2299 func_name, qualified_name,
2300 next_namespace_len,
2301 oload_syms, oload_champ_bv,
2302 oload_champ))
2303 {
2304 return 1;
2305 }
2306 };
2307
2308 /* If we reach here, either we're in the deepest namespace or we
2309 didn't find a good match in a deeper namespace. But, in the
2310 latter case, we still have a bad match in a deeper namespace;
2311 note that we might not find any match at all in the current
2312 namespace. (There's always a match in the deepest namespace,
2313 because this overload mechanism only gets called if there's a
2314 function symbol to start off with.) */
2315
2316 old_cleanups = make_cleanup (xfree, *oload_syms);
2317 old_cleanups = make_cleanup (xfree, *oload_champ_bv);
2318 new_namespace = alloca (namespace_len + 1);
2319 strncpy (new_namespace, qualified_name, namespace_len);
2320 new_namespace[namespace_len] = '\0';
2321 new_oload_syms = make_symbol_overload_list (func_name,
2322 new_namespace);
2323 while (new_oload_syms[num_fns])
2324 ++num_fns;
2325
2326 new_oload_champ = find_oload_champ (arg_types, nargs, 0, num_fns,
2327 NULL, new_oload_syms,
2328 &new_oload_champ_bv);
2329
2330 /* Case 1: We found a good match. Free earlier matches (if any),
2331 and return it. Case 2: We didn't find a good match, but we're
2332 not the deepest function. Then go with the bad match that the
2333 deeper function found. Case 3: We found a bad match, and we're
2334 the deepest function. Then return what we found, even though
2335 it's a bad match. */
2336
2337 if (new_oload_champ != -1
2338 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2339 {
2340 *oload_syms = new_oload_syms;
2341 *oload_champ = new_oload_champ;
2342 *oload_champ_bv = new_oload_champ_bv;
2343 do_cleanups (old_cleanups);
2344 return 1;
2345 }
2346 else if (searched_deeper)
2347 {
2348 xfree (new_oload_syms);
2349 xfree (new_oload_champ_bv);
2350 discard_cleanups (old_cleanups);
2351 return 0;
2352 }
2353 else
2354 {
2355 gdb_assert (new_oload_champ != -1);
2356 *oload_syms = new_oload_syms;
2357 *oload_champ = new_oload_champ;
2358 *oload_champ_bv = new_oload_champ_bv;
2359 discard_cleanups (old_cleanups);
2360 return 0;
2361 }
2362 }
2363
2364 /* Look for a function to take NARGS args of types ARG_TYPES. Find
2365 the best match from among the overloaded methods or functions
2366 (depending on METHOD) given by FNS_PTR or OLOAD_SYMS, respectively.
2367 The number of methods/functions in the list is given by NUM_FNS.
2368 Return the index of the best match; store an indication of the
2369 quality of the match in OLOAD_CHAMP_BV.
2370
2371 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2372
2373 static int
2374 find_oload_champ (struct type **arg_types, int nargs, int method,
2375 int num_fns, struct fn_field *fns_ptr,
2376 struct symbol **oload_syms,
2377 struct badness_vector **oload_champ_bv)
2378 {
2379 int ix;
2380 /* A measure of how good an overloaded instance is. */
2381 struct badness_vector *bv;
2382 /* Index of best overloaded function. */
2383 int oload_champ = -1;
2384 /* Current ambiguity state for overload resolution. */
2385 int oload_ambiguous = 0;
2386 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2387
2388 *oload_champ_bv = NULL;
2389
2390 /* Consider each candidate in turn. */
2391 for (ix = 0; ix < num_fns; ix++)
2392 {
2393 int jj;
2394 int static_offset = oload_method_static (method, fns_ptr, ix);
2395 int nparms;
2396 struct type **parm_types;
2397
2398 if (method)
2399 {
2400 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2401 }
2402 else
2403 {
2404 /* If it's not a method, this is the proper place. */
2405 nparms = TYPE_NFIELDS (SYMBOL_TYPE (oload_syms[ix]));
2406 }
2407
2408 /* Prepare array of parameter types. */
2409 parm_types = (struct type **)
2410 xmalloc (nparms * (sizeof (struct type *)));
2411 for (jj = 0; jj < nparms; jj++)
2412 parm_types[jj] = (method
2413 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2414 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]),
2415 jj));
2416
2417 /* Compare parameter types to supplied argument types. Skip
2418 THIS for static methods. */
2419 bv = rank_function (parm_types, nparms,
2420 arg_types + static_offset,
2421 nargs - static_offset);
2422
2423 if (!*oload_champ_bv)
2424 {
2425 *oload_champ_bv = bv;
2426 oload_champ = 0;
2427 }
2428 else /* See whether current candidate is better or worse than
2429 previous best. */
2430 switch (compare_badness (bv, *oload_champ_bv))
2431 {
2432 case 0: /* Top two contenders are equally good. */
2433 oload_ambiguous = 1;
2434 break;
2435 case 1: /* Incomparable top contenders. */
2436 oload_ambiguous = 2;
2437 break;
2438 case 2: /* New champion, record details. */
2439 *oload_champ_bv = bv;
2440 oload_ambiguous = 0;
2441 oload_champ = ix;
2442 break;
2443 case 3:
2444 default:
2445 break;
2446 }
2447 xfree (parm_types);
2448 if (overload_debug)
2449 {
2450 if (method)
2451 fprintf_filtered (gdb_stderr,
2452 "Overloaded method instance %s, # of parms %d\n",
2453 fns_ptr[ix].physname, nparms);
2454 else
2455 fprintf_filtered (gdb_stderr,
2456 "Overloaded function instance %s # of parms %d\n",
2457 SYMBOL_DEMANGLED_NAME (oload_syms[ix]),
2458 nparms);
2459 for (jj = 0; jj < nargs - static_offset; jj++)
2460 fprintf_filtered (gdb_stderr,
2461 "...Badness @ %d : %d\n",
2462 jj, bv->rank[jj]);
2463 fprintf_filtered (gdb_stderr,
2464 "Overload resolution champion is %d, ambiguous? %d\n",
2465 oload_champ, oload_ambiguous);
2466 }
2467 }
2468
2469 return oload_champ;
2470 }
2471
2472 /* Return 1 if we're looking at a static method, 0 if we're looking at
2473 a non-static method or a function that isn't a method. */
2474
2475 static int
2476 oload_method_static (int method, struct fn_field *fns_ptr, int index)
2477 {
2478 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
2479 return 1;
2480 else
2481 return 0;
2482 }
2483
2484 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
2485
2486 static enum oload_classification
2487 classify_oload_match (struct badness_vector *oload_champ_bv,
2488 int nargs,
2489 int static_offset)
2490 {
2491 int ix;
2492
2493 for (ix = 1; ix <= nargs - static_offset; ix++)
2494 {
2495 if (oload_champ_bv->rank[ix] >= 100)
2496 return INCOMPATIBLE; /* Truly mismatched types. */
2497 else if (oload_champ_bv->rank[ix] >= 10)
2498 return NON_STANDARD; /* Non-standard type conversions
2499 needed. */
2500 }
2501
2502 return STANDARD; /* Only standard conversions needed. */
2503 }
2504
2505 /* C++: return 1 is NAME is a legitimate name for the destructor of
2506 type TYPE. If TYPE does not have a destructor, or if NAME is
2507 inappropriate for TYPE, an error is signaled. */
2508 int
2509 destructor_name_p (const char *name, const struct type *type)
2510 {
2511 /* Destructors are a special case. */
2512
2513 if (name[0] == '~')
2514 {
2515 char *dname = type_name_no_tag (type);
2516 char *cp = strchr (dname, '<');
2517 unsigned int len;
2518
2519 /* Do not compare the template part for template classes. */
2520 if (cp == NULL)
2521 len = strlen (dname);
2522 else
2523 len = cp - dname;
2524 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
2525 error (_("name of destructor must equal name of class"));
2526 else
2527 return 1;
2528 }
2529 return 0;
2530 }
2531
2532 /* Given TYPE, a structure/union,
2533 return 1 if the component named NAME from the ultimate target
2534 structure/union is defined, otherwise, return 0. */
2535
2536 int
2537 check_field (struct type *type, const char *name)
2538 {
2539 int i;
2540
2541 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2542 {
2543 char *t_field_name = TYPE_FIELD_NAME (type, i);
2544 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2545 return 1;
2546 }
2547
2548 /* C++: If it was not found as a data field, then try to return it
2549 as a pointer to a method. */
2550
2551 /* Destructors are a special case. */
2552 if (destructor_name_p (name, type))
2553 {
2554 int m_index, f_index;
2555
2556 return get_destructor_fn_field (type, &m_index, &f_index);
2557 }
2558
2559 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2560 {
2561 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2562 return 1;
2563 }
2564
2565 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2566 if (check_field (TYPE_BASECLASS (type, i), name))
2567 return 1;
2568
2569 return 0;
2570 }
2571
2572 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2573 return the appropriate member (or the address of the member, if
2574 WANT_ADDRESS). This function is used to resolve user expressions
2575 of the form "DOMAIN::NAME". For more details on what happens, see
2576 the comment before value_struct_elt_for_reference. */
2577
2578 struct value *
2579 value_aggregate_elt (struct type *curtype,
2580 char *name, int want_address,
2581 enum noside noside)
2582 {
2583 switch (TYPE_CODE (curtype))
2584 {
2585 case TYPE_CODE_STRUCT:
2586 case TYPE_CODE_UNION:
2587 return value_struct_elt_for_reference (curtype, 0, curtype,
2588 name, NULL,
2589 want_address, noside);
2590 case TYPE_CODE_NAMESPACE:
2591 return value_namespace_elt (curtype, name,
2592 want_address, noside);
2593 default:
2594 internal_error (__FILE__, __LINE__,
2595 _("non-aggregate type in value_aggregate_elt"));
2596 }
2597 }
2598
2599 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2600 return the address of this member as a "pointer to member" type.
2601 If INTYPE is non-null, then it will be the type of the member we
2602 are looking for. This will help us resolve "pointers to member
2603 functions". This function is used to resolve user expressions of
2604 the form "DOMAIN::NAME". */
2605
2606 static struct value *
2607 value_struct_elt_for_reference (struct type *domain, int offset,
2608 struct type *curtype, char *name,
2609 struct type *intype,
2610 int want_address,
2611 enum noside noside)
2612 {
2613 struct type *t = curtype;
2614 int i;
2615 struct value *v, *result;
2616
2617 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2618 && TYPE_CODE (t) != TYPE_CODE_UNION)
2619 error (_("Internal error: non-aggregate type to value_struct_elt_for_reference"));
2620
2621 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
2622 {
2623 char *t_field_name = TYPE_FIELD_NAME (t, i);
2624
2625 if (t_field_name && strcmp (t_field_name, name) == 0)
2626 {
2627 if (field_is_static (&TYPE_FIELD (t, i)))
2628 {
2629 v = value_static_field (t, i);
2630 if (v == NULL)
2631 error (_("static field %s has been optimized out"),
2632 name);
2633 if (want_address)
2634 v = value_addr (v);
2635 return v;
2636 }
2637 if (TYPE_FIELD_PACKED (t, i))
2638 error (_("pointers to bitfield members not allowed"));
2639
2640 if (want_address)
2641 return value_from_longest
2642 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
2643 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
2644 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
2645 return allocate_value (TYPE_FIELD_TYPE (t, i));
2646 else
2647 error (_("Cannot reference non-static field \"%s\""), name);
2648 }
2649 }
2650
2651 /* C++: If it was not found as a data field, then try to return it
2652 as a pointer to a method. */
2653
2654 /* Destructors are a special case. */
2655 if (destructor_name_p (name, t))
2656 {
2657 error (_("member pointers to destructors not implemented yet"));
2658 }
2659
2660 /* Perform all necessary dereferencing. */
2661 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
2662 intype = TYPE_TARGET_TYPE (intype);
2663
2664 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
2665 {
2666 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
2667 char dem_opname[64];
2668
2669 if (strncmp (t_field_name, "__", 2) == 0
2670 || strncmp (t_field_name, "op", 2) == 0
2671 || strncmp (t_field_name, "type", 4) == 0)
2672 {
2673 if (cplus_demangle_opname (t_field_name,
2674 dem_opname, DMGL_ANSI))
2675 t_field_name = dem_opname;
2676 else if (cplus_demangle_opname (t_field_name,
2677 dem_opname, 0))
2678 t_field_name = dem_opname;
2679 }
2680 if (t_field_name && strcmp (t_field_name, name) == 0)
2681 {
2682 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
2683 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
2684
2685 check_stub_method_group (t, i);
2686
2687 if (intype == 0 && j > 1)
2688 error (_("non-unique member `%s' requires type instantiation"), name);
2689 if (intype)
2690 {
2691 while (j--)
2692 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
2693 break;
2694 if (j < 0)
2695 error (_("no member function matches that type instantiation"));
2696 }
2697 else
2698 j = 0;
2699
2700 if (TYPE_FN_FIELD_STATIC_P (f, j))
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 if (want_address)
2709 return value_addr (read_var_value (s, 0));
2710 else
2711 return read_var_value (s, 0);
2712 }
2713
2714 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2715 {
2716 if (want_address)
2717 {
2718 result = allocate_value
2719 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
2720 cplus_make_method_ptr (value_type (result),
2721 value_contents_writeable (result),
2722 TYPE_FN_FIELD_VOFFSET (f, j), 1);
2723 }
2724 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
2725 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
2726 else
2727 error (_("Cannot reference virtual member function \"%s\""),
2728 name);
2729 }
2730 else
2731 {
2732 struct symbol *s =
2733 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
2734 0, VAR_DOMAIN, 0);
2735 if (s == NULL)
2736 return NULL;
2737
2738 v = read_var_value (s, 0);
2739 if (!want_address)
2740 result = v;
2741 else
2742 {
2743 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
2744 cplus_make_method_ptr (value_type (result),
2745 value_contents_writeable (result),
2746 VALUE_ADDRESS (v), 0);
2747 }
2748 }
2749 return result;
2750 }
2751 }
2752 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
2753 {
2754 struct value *v;
2755 int base_offset;
2756
2757 if (BASETYPE_VIA_VIRTUAL (t, i))
2758 base_offset = 0;
2759 else
2760 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
2761 v = value_struct_elt_for_reference (domain,
2762 offset + base_offset,
2763 TYPE_BASECLASS (t, i),
2764 name, intype,
2765 want_address, noside);
2766 if (v)
2767 return v;
2768 }
2769
2770 /* As a last chance, pretend that CURTYPE is a namespace, and look
2771 it up that way; this (frequently) works for types nested inside
2772 classes. */
2773
2774 return value_maybe_namespace_elt (curtype, name,
2775 want_address, noside);
2776 }
2777
2778 /* C++: Return the member NAME of the namespace given by the type
2779 CURTYPE. */
2780
2781 static struct value *
2782 value_namespace_elt (const struct type *curtype,
2783 char *name, int want_address,
2784 enum noside noside)
2785 {
2786 struct value *retval = value_maybe_namespace_elt (curtype, name,
2787 want_address,
2788 noside);
2789
2790 if (retval == NULL)
2791 error (_("No symbol \"%s\" in namespace \"%s\"."),
2792 name, TYPE_TAG_NAME (curtype));
2793
2794 return retval;
2795 }
2796
2797 /* A helper function used by value_namespace_elt and
2798 value_struct_elt_for_reference. It looks up NAME inside the
2799 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
2800 is a class and NAME refers to a type in CURTYPE itself (as opposed
2801 to, say, some base class of CURTYPE). */
2802
2803 static struct value *
2804 value_maybe_namespace_elt (const struct type *curtype,
2805 char *name, int want_address,
2806 enum noside noside)
2807 {
2808 const char *namespace_name = TYPE_TAG_NAME (curtype);
2809 struct symbol *sym;
2810 struct value *result;
2811
2812 sym = cp_lookup_symbol_namespace (namespace_name, name, NULL,
2813 get_selected_block (0),
2814 VAR_DOMAIN);
2815
2816 if (sym == NULL)
2817 return NULL;
2818 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
2819 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
2820 result = allocate_value (SYMBOL_TYPE (sym));
2821 else
2822 result = value_of_variable (sym, get_selected_block (0));
2823
2824 if (result && want_address)
2825 result = value_addr (result);
2826
2827 return result;
2828 }
2829
2830 /* Given a pointer value V, find the real (RTTI) type of the object it
2831 points to.
2832
2833 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
2834 and refer to the values computed for the object pointed to. */
2835
2836 struct type *
2837 value_rtti_target_type (struct value *v, int *full,
2838 int *top, int *using_enc)
2839 {
2840 struct value *target;
2841
2842 target = value_ind (v);
2843
2844 return value_rtti_type (target, full, top, using_enc);
2845 }
2846
2847 /* Given a value pointed to by ARGP, check its real run-time type, and
2848 if that is different from the enclosing type, create a new value
2849 using the real run-time type as the enclosing type (and of the same
2850 type as ARGP) and return it, with the embedded offset adjusted to
2851 be the correct offset to the enclosed object. RTYPE is the type,
2852 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
2853 by value_rtti_type(). If these are available, they can be supplied
2854 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
2855 NULL if they're not available. */
2856
2857 struct value *
2858 value_full_object (struct value *argp,
2859 struct type *rtype,
2860 int xfull, int xtop,
2861 int xusing_enc)
2862 {
2863 struct type *real_type;
2864 int full = 0;
2865 int top = -1;
2866 int using_enc = 0;
2867 struct value *new_val;
2868
2869 if (rtype)
2870 {
2871 real_type = rtype;
2872 full = xfull;
2873 top = xtop;
2874 using_enc = xusing_enc;
2875 }
2876 else
2877 real_type = value_rtti_type (argp, &full, &top, &using_enc);
2878
2879 /* If no RTTI data, or if object is already complete, do nothing. */
2880 if (!real_type || real_type == value_enclosing_type (argp))
2881 return argp;
2882
2883 /* If we have the full object, but for some reason the enclosing
2884 type is wrong, set it. */
2885 /* pai: FIXME -- sounds iffy */
2886 if (full)
2887 {
2888 argp = value_change_enclosing_type (argp, real_type);
2889 return argp;
2890 }
2891
2892 /* Check if object is in memory */
2893 if (VALUE_LVAL (argp) != lval_memory)
2894 {
2895 warning (_("Couldn't retrieve complete object of RTTI type %s; object may be in register(s)."),
2896 TYPE_NAME (real_type));
2897
2898 return argp;
2899 }
2900
2901 /* All other cases -- retrieve the complete object. */
2902 /* Go back by the computed top_offset from the beginning of the
2903 object, adjusting for the embedded offset of argp if that's what
2904 value_rtti_type used for its computation. */
2905 new_val = value_at_lazy (real_type, VALUE_ADDRESS (argp) - top +
2906 (using_enc ? 0 : value_embedded_offset (argp)));
2907 deprecated_set_value_type (new_val, value_type (argp));
2908 set_value_embedded_offset (new_val, (using_enc
2909 ? top + value_embedded_offset (argp)
2910 : top));
2911 return new_val;
2912 }
2913
2914
2915 /* Return the value of the local variable, if one exists.
2916 Flag COMPLAIN signals an error if the request is made in an
2917 inappropriate context. */
2918
2919 struct value *
2920 value_of_local (const char *name, int complain)
2921 {
2922 struct symbol *func, *sym;
2923 struct block *b;
2924 struct value * ret;
2925 struct frame_info *frame;
2926
2927 if (complain)
2928 frame = get_selected_frame (_("no frame selected"));
2929 else
2930 {
2931 frame = deprecated_safe_get_selected_frame ();
2932 if (frame == 0)
2933 return 0;
2934 }
2935
2936 func = get_frame_function (frame);
2937 if (!func)
2938 {
2939 if (complain)
2940 error (_("no `%s' in nameless context"), name);
2941 else
2942 return 0;
2943 }
2944
2945 b = SYMBOL_BLOCK_VALUE (func);
2946 if (dict_empty (BLOCK_DICT (b)))
2947 {
2948 if (complain)
2949 error (_("no args, no `%s'"), name);
2950 else
2951 return 0;
2952 }
2953
2954 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
2955 symbol instead of the LOC_ARG one (if both exist). */
2956 sym = lookup_block_symbol (b, name, NULL, VAR_DOMAIN);
2957 if (sym == NULL)
2958 {
2959 if (complain)
2960 error (_("current stack frame does not contain a variable named `%s'"),
2961 name);
2962 else
2963 return NULL;
2964 }
2965
2966 ret = read_var_value (sym, frame);
2967 if (ret == 0 && complain)
2968 error (_("`%s' argument unreadable"), name);
2969 return ret;
2970 }
2971
2972 /* C++/Objective-C: return the value of the class instance variable,
2973 if one exists. Flag COMPLAIN signals an error if the request is
2974 made in an inappropriate context. */
2975
2976 struct value *
2977 value_of_this (int complain)
2978 {
2979 if (!current_language->la_name_of_this)
2980 return 0;
2981 return value_of_local (current_language->la_name_of_this, complain);
2982 }
2983
2984 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
2985 elements long, starting at LOWBOUND. The result has the same lower
2986 bound as the original ARRAY. */
2987
2988 struct value *
2989 value_slice (struct value *array, int lowbound, int length)
2990 {
2991 struct type *slice_range_type, *slice_type, *range_type;
2992 LONGEST lowerbound, upperbound;
2993 struct value *slice;
2994 struct type *array_type;
2995
2996 array_type = check_typedef (value_type (array));
2997 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
2998 && TYPE_CODE (array_type) != TYPE_CODE_STRING
2999 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
3000 error (_("cannot take slice of non-array"));
3001
3002 range_type = TYPE_INDEX_TYPE (array_type);
3003 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3004 error (_("slice from bad array or bitstring"));
3005
3006 if (lowbound < lowerbound || length < 0
3007 || lowbound + length - 1 > upperbound)
3008 error (_("slice out of range"));
3009
3010 /* FIXME-type-allocation: need a way to free this type when we are
3011 done with it. */
3012 slice_range_type = create_range_type ((struct type *) NULL,
3013 TYPE_TARGET_TYPE (range_type),
3014 lowbound,
3015 lowbound + length - 1);
3016 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
3017 {
3018 int i;
3019
3020 slice_type = create_set_type ((struct type *) NULL,
3021 slice_range_type);
3022 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
3023 slice = value_zero (slice_type, not_lval);
3024
3025 for (i = 0; i < length; i++)
3026 {
3027 int element = value_bit_index (array_type,
3028 value_contents (array),
3029 lowbound + i);
3030 if (element < 0)
3031 error (_("internal error accessing bitstring"));
3032 else if (element > 0)
3033 {
3034 int j = i % TARGET_CHAR_BIT;
3035 if (gdbarch_bits_big_endian (current_gdbarch))
3036 j = TARGET_CHAR_BIT - 1 - j;
3037 value_contents_raw (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3038 }
3039 }
3040 /* We should set the address, bitssize, and bitspos, so the
3041 slice can be used on the LHS, but that may require extensions
3042 to value_assign. For now, just leave as a non_lval.
3043 FIXME. */
3044 }
3045 else
3046 {
3047 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3048 LONGEST offset =
3049 (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3050
3051 slice_type = create_array_type ((struct type *) NULL,
3052 element_type,
3053 slice_range_type);
3054 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3055
3056 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3057 slice = allocate_value_lazy (slice_type);
3058 else
3059 {
3060 slice = allocate_value (slice_type);
3061 memcpy (value_contents_writeable (slice),
3062 value_contents (array) + offset,
3063 TYPE_LENGTH (slice_type));
3064 }
3065
3066 set_value_component_location (slice, array);
3067 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
3068 set_value_offset (slice, value_offset (array) + offset);
3069 }
3070 return slice;
3071 }
3072
3073 /* Create a value for a FORTRAN complex number. Currently most of the
3074 time values are coerced to COMPLEX*16 (i.e. a complex number
3075 composed of 2 doubles. This really should be a smarter routine
3076 that figures out precision inteligently as opposed to assuming
3077 doubles. FIXME: fmb */
3078
3079 struct value *
3080 value_literal_complex (struct value *arg1,
3081 struct value *arg2,
3082 struct type *type)
3083 {
3084 struct value *val;
3085 struct type *real_type = TYPE_TARGET_TYPE (type);
3086
3087 val = allocate_value (type);
3088 arg1 = value_cast (real_type, arg1);
3089 arg2 = value_cast (real_type, arg2);
3090
3091 memcpy (value_contents_raw (val),
3092 value_contents (arg1), TYPE_LENGTH (real_type));
3093 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3094 value_contents (arg2), TYPE_LENGTH (real_type));
3095 return val;
3096 }
3097
3098 /* Cast a value into the appropriate complex data type. */
3099
3100 static struct value *
3101 cast_into_complex (struct type *type, struct value *val)
3102 {
3103 struct type *real_type = TYPE_TARGET_TYPE (type);
3104
3105 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3106 {
3107 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3108 struct value *re_val = allocate_value (val_real_type);
3109 struct value *im_val = allocate_value (val_real_type);
3110
3111 memcpy (value_contents_raw (re_val),
3112 value_contents (val), TYPE_LENGTH (val_real_type));
3113 memcpy (value_contents_raw (im_val),
3114 value_contents (val) + TYPE_LENGTH (val_real_type),
3115 TYPE_LENGTH (val_real_type));
3116
3117 return value_literal_complex (re_val, im_val, type);
3118 }
3119 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3120 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3121 return value_literal_complex (val,
3122 value_zero (real_type, not_lval),
3123 type);
3124 else
3125 error (_("cannot cast non-number to complex"));
3126 }
3127
3128 void
3129 _initialize_valops (void)
3130 {
3131 add_setshow_boolean_cmd ("overload-resolution", class_support,
3132 &overload_resolution, _("\
3133 Set overload resolution in evaluating C++ functions."), _("\
3134 Show overload resolution in evaluating C++ functions."),
3135 NULL, NULL,
3136 show_overload_resolution,
3137 &setlist, &showlist);
3138 overload_resolution = 1;
3139 }
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