2004-11-23 Randolph Chung <tausq@debian.org>
[deliverable/binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
3 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
4 Free Software Foundation, Inc.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
22
23 #include "defs.h"
24 #include "symtab.h"
25 #include "gdbtypes.h"
26 #include "value.h"
27 #include "frame.h"
28 #include "inferior.h"
29 #include "gdbcore.h"
30 #include "target.h"
31 #include "demangle.h"
32 #include "language.h"
33 #include "gdbcmd.h"
34 #include "regcache.h"
35 #include "cp-abi.h"
36 #include "block.h"
37 #include "infcall.h"
38 #include "dictionary.h"
39 #include "cp-support.h"
40
41 #include <errno.h>
42 #include "gdb_string.h"
43 #include "gdb_assert.h"
44 #include "cp-support.h"
45 #include "observer.h"
46
47 extern int overload_debug;
48 /* Local functions. */
49
50 static int typecmp (int staticp, int varargs, int nargs,
51 struct field t1[], struct value *t2[]);
52
53 static struct value *search_struct_field (char *, struct value *, int,
54 struct type *, int);
55
56 static struct value *search_struct_method (char *, struct value **,
57 struct value **,
58 int, int *, struct type *);
59
60 static int find_oload_champ_namespace (struct type **arg_types, int nargs,
61 const char *func_name,
62 const char *qualified_name,
63 struct symbol ***oload_syms,
64 struct badness_vector **oload_champ_bv);
65
66 static
67 int find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
68 const char *func_name,
69 const char *qualified_name,
70 int namespace_len,
71 struct symbol ***oload_syms,
72 struct badness_vector **oload_champ_bv,
73 int *oload_champ);
74
75 static int find_oload_champ (struct type **arg_types, int nargs, int method,
76 int num_fns,
77 struct fn_field *fns_ptr,
78 struct symbol **oload_syms,
79 struct badness_vector **oload_champ_bv);
80
81 static int oload_method_static (int method, struct fn_field *fns_ptr,
82 int index);
83
84 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
85
86 static enum
87 oload_classification classify_oload_match (struct badness_vector
88 * oload_champ_bv,
89 int nargs,
90 int static_offset);
91
92 static int check_field_in (struct type *, const char *);
93
94 static struct value *value_struct_elt_for_reference (struct type *domain,
95 int offset,
96 struct type *curtype,
97 char *name,
98 struct type *intype,
99 enum noside noside);
100
101 static struct value *value_namespace_elt (const struct type *curtype,
102 char *name,
103 enum noside noside);
104
105 static struct value *value_maybe_namespace_elt (const struct type *curtype,
106 char *name,
107 enum noside noside);
108
109 static CORE_ADDR allocate_space_in_inferior (int);
110
111 static struct value *cast_into_complex (struct type *, struct value *);
112
113 static struct fn_field *find_method_list (struct value ** argp, char *method,
114 int offset,
115 struct type *type, int *num_fns,
116 struct type **basetype,
117 int *boffset);
118
119 void _initialize_valops (void);
120
121 /* Flag for whether we want to abandon failed expression evals by default. */
122
123 #if 0
124 static int auto_abandon = 0;
125 #endif
126
127 int overload_resolution = 0;
128
129 /* Find the address of function name NAME in the inferior. */
130
131 struct value *
132 find_function_in_inferior (const char *name)
133 {
134 struct symbol *sym;
135 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0, NULL);
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 return value_of_variable (sym, NULL);
144 }
145 else
146 {
147 struct minimal_symbol *msymbol = lookup_minimal_symbol (name, NULL, NULL);
148 if (msymbol != NULL)
149 {
150 struct type *type;
151 CORE_ADDR maddr;
152 type = lookup_pointer_type (builtin_type_char);
153 type = lookup_function_type (type);
154 type = lookup_pointer_type (type);
155 maddr = SYMBOL_VALUE_ADDRESS (msymbol);
156 return value_from_pointer (type, maddr);
157 }
158 else
159 {
160 if (!target_has_execution)
161 error ("evaluation of this expression requires the target program to be active");
162 else
163 error ("evaluation of this expression requires the program to have a function \"%s\".", name);
164 }
165 }
166 }
167
168 /* Allocate NBYTES of space in the inferior using the inferior's malloc
169 and return a value that is a pointer to the allocated space. */
170
171 struct value *
172 value_allocate_space_in_inferior (int len)
173 {
174 struct value *blocklen;
175 struct value *val = find_function_in_inferior (NAME_OF_MALLOC);
176
177 blocklen = value_from_longest (builtin_type_int, (LONGEST) len);
178 val = call_function_by_hand (val, 1, &blocklen);
179 if (value_logical_not (val))
180 {
181 if (!target_has_execution)
182 error ("No memory available to program now: you need to start the target first");
183 else
184 error ("No memory available to program: call to malloc failed");
185 }
186 return val;
187 }
188
189 static CORE_ADDR
190 allocate_space_in_inferior (int len)
191 {
192 return value_as_long (value_allocate_space_in_inferior (len));
193 }
194
195 /* Cast value ARG2 to type TYPE and return as a value.
196 More general than a C cast: accepts any two types of the same length,
197 and if ARG2 is an lvalue it can be cast into anything at all. */
198 /* In C++, casts may change pointer or object representations. */
199
200 struct value *
201 value_cast (struct type *type, struct value *arg2)
202 {
203 enum type_code code1;
204 enum type_code code2;
205 int scalar;
206 struct type *type2;
207
208 int convert_to_boolean = 0;
209
210 if (value_type (arg2) == type)
211 return arg2;
212
213 CHECK_TYPEDEF (type);
214 code1 = TYPE_CODE (type);
215 arg2 = coerce_ref (arg2);
216 type2 = check_typedef (value_type (arg2));
217
218 /* A cast to an undetermined-length array_type, such as (TYPE [])OBJECT,
219 is treated like a cast to (TYPE [N])OBJECT,
220 where N is sizeof(OBJECT)/sizeof(TYPE). */
221 if (code1 == TYPE_CODE_ARRAY)
222 {
223 struct type *element_type = TYPE_TARGET_TYPE (type);
224 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
225 if (element_length > 0
226 && TYPE_ARRAY_UPPER_BOUND_TYPE (type) == BOUND_CANNOT_BE_DETERMINED)
227 {
228 struct type *range_type = TYPE_INDEX_TYPE (type);
229 int val_length = TYPE_LENGTH (type2);
230 LONGEST low_bound, high_bound, new_length;
231 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
232 low_bound = 0, high_bound = 0;
233 new_length = val_length / element_length;
234 if (val_length % element_length != 0)
235 warning ("array element type size does not divide object size in cast");
236 /* FIXME-type-allocation: need a way to free this type when we are
237 done with it. */
238 range_type = create_range_type ((struct type *) NULL,
239 TYPE_TARGET_TYPE (range_type),
240 low_bound,
241 new_length + low_bound - 1);
242 arg2->type = create_array_type ((struct type *) NULL,
243 element_type, range_type);
244 return arg2;
245 }
246 }
247
248 if (current_language->c_style_arrays
249 && TYPE_CODE (type2) == TYPE_CODE_ARRAY)
250 arg2 = value_coerce_array (arg2);
251
252 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
253 arg2 = value_coerce_function (arg2);
254
255 type2 = check_typedef (value_type (arg2));
256 code2 = TYPE_CODE (type2);
257
258 if (code1 == TYPE_CODE_COMPLEX)
259 return cast_into_complex (type, arg2);
260 if (code1 == TYPE_CODE_BOOL)
261 {
262 code1 = TYPE_CODE_INT;
263 convert_to_boolean = 1;
264 }
265 if (code1 == TYPE_CODE_CHAR)
266 code1 = TYPE_CODE_INT;
267 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
268 code2 = TYPE_CODE_INT;
269
270 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
271 || code2 == TYPE_CODE_ENUM || code2 == TYPE_CODE_RANGE);
272
273 if (code1 == TYPE_CODE_STRUCT
274 && code2 == TYPE_CODE_STRUCT
275 && TYPE_NAME (type) != 0)
276 {
277 /* Look in the type of the source to see if it contains the
278 type of the target as a superclass. If so, we'll need to
279 offset the object in addition to changing its type. */
280 struct value *v = search_struct_field (type_name_no_tag (type),
281 arg2, 0, type2, 1);
282 if (v)
283 {
284 v->type = type;
285 return v;
286 }
287 }
288 if (code1 == TYPE_CODE_FLT && scalar)
289 return value_from_double (type, value_as_double (arg2));
290 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
291 || code1 == TYPE_CODE_RANGE)
292 && (scalar || code2 == TYPE_CODE_PTR))
293 {
294 LONGEST longest;
295
296 if (deprecated_hp_som_som_object_present /* if target compiled by HP aCC */
297 && (code2 == TYPE_CODE_PTR))
298 {
299 unsigned int *ptr;
300 struct value *retvalp;
301
302 switch (TYPE_CODE (TYPE_TARGET_TYPE (type2)))
303 {
304 /* With HP aCC, pointers to data members have a bias */
305 case TYPE_CODE_MEMBER:
306 retvalp = value_from_longest (type, value_as_long (arg2));
307 /* force evaluation */
308 ptr = (unsigned int *) VALUE_CONTENTS (retvalp);
309 *ptr &= ~0x20000000; /* zap 29th bit to remove bias */
310 return retvalp;
311
312 /* While pointers to methods don't really point to a function */
313 case TYPE_CODE_METHOD:
314 error ("Pointers to methods not supported with HP aCC");
315
316 default:
317 break; /* fall out and go to normal handling */
318 }
319 }
320
321 /* When we cast pointers to integers, we mustn't use
322 POINTER_TO_ADDRESS to find the address the pointer
323 represents, as value_as_long would. GDB should evaluate
324 expressions just as the compiler would --- and the compiler
325 sees a cast as a simple reinterpretation of the pointer's
326 bits. */
327 if (code2 == TYPE_CODE_PTR)
328 longest = extract_unsigned_integer (VALUE_CONTENTS (arg2),
329 TYPE_LENGTH (type2));
330 else
331 longest = value_as_long (arg2);
332 return value_from_longest (type, convert_to_boolean ?
333 (LONGEST) (longest ? 1 : 0) : longest);
334 }
335 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT ||
336 code2 == TYPE_CODE_ENUM ||
337 code2 == TYPE_CODE_RANGE))
338 {
339 /* TYPE_LENGTH (type) is the length of a pointer, but we really
340 want the length of an address! -- we are really dealing with
341 addresses (i.e., gdb representations) not pointers (i.e.,
342 target representations) here.
343
344 This allows things like "print *(int *)0x01000234" to work
345 without printing a misleading message -- which would
346 otherwise occur when dealing with a target having two byte
347 pointers and four byte addresses. */
348
349 int addr_bit = TARGET_ADDR_BIT;
350
351 LONGEST longest = value_as_long (arg2);
352 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
353 {
354 if (longest >= ((LONGEST) 1 << addr_bit)
355 || longest <= -((LONGEST) 1 << addr_bit))
356 warning ("value truncated");
357 }
358 return value_from_longest (type, longest);
359 }
360 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
361 {
362 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
363 {
364 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type));
365 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
366 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
367 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
368 && !value_logical_not (arg2))
369 {
370 struct value *v;
371
372 /* Look in the type of the source to see if it contains the
373 type of the target as a superclass. If so, we'll need to
374 offset the pointer rather than just change its type. */
375 if (TYPE_NAME (t1) != NULL)
376 {
377 v = search_struct_field (type_name_no_tag (t1),
378 value_ind (arg2), 0, t2, 1);
379 if (v)
380 {
381 v = value_addr (v);
382 v->type = type;
383 return v;
384 }
385 }
386
387 /* Look in the type of the target to see if it contains the
388 type of the source as a superclass. If so, we'll need to
389 offset the pointer rather than just change its type.
390 FIXME: This fails silently with virtual inheritance. */
391 if (TYPE_NAME (t2) != NULL)
392 {
393 v = search_struct_field (type_name_no_tag (t2),
394 value_zero (t1, not_lval), 0, t1, 1);
395 if (v)
396 {
397 CORE_ADDR addr2 = value_as_address (arg2);
398 addr2 -= (VALUE_ADDRESS (v)
399 + value_offset (v)
400 + VALUE_EMBEDDED_OFFSET (v));
401 return value_from_pointer (type, addr2);
402 }
403 }
404 }
405 /* No superclass found, just fall through to change ptr type. */
406 }
407 arg2->type = type;
408 arg2 = value_change_enclosing_type (arg2, type);
409 VALUE_POINTED_TO_OFFSET (arg2) = 0; /* pai: chk_val */
410 return arg2;
411 }
412 else if (VALUE_LVAL (arg2) == lval_memory)
413 return value_at_lazy (type, VALUE_ADDRESS (arg2) + value_offset (arg2));
414 else if (code1 == TYPE_CODE_VOID)
415 {
416 return value_zero (builtin_type_void, not_lval);
417 }
418 else
419 {
420 error ("Invalid cast.");
421 return 0;
422 }
423 }
424
425 /* Create a value of type TYPE that is zero, and return it. */
426
427 struct value *
428 value_zero (struct type *type, enum lval_type lv)
429 {
430 struct value *val = allocate_value (type);
431
432 memset (VALUE_CONTENTS (val), 0, TYPE_LENGTH (check_typedef (type)));
433 VALUE_LVAL (val) = lv;
434
435 return val;
436 }
437
438 /* Return a value with type TYPE located at ADDR.
439
440 Call value_at only if the data needs to be fetched immediately;
441 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
442 value_at_lazy instead. value_at_lazy simply records the address of
443 the data and sets the lazy-evaluation-required flag. The lazy flag
444 is tested in the VALUE_CONTENTS macro, which is used if and when
445 the contents are actually required.
446
447 Note: value_at does *NOT* handle embedded offsets; perform such
448 adjustments before or after calling it. */
449
450 struct value *
451 value_at (struct type *type, CORE_ADDR addr)
452 {
453 struct value *val;
454
455 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
456 error ("Attempt to dereference a generic pointer.");
457
458 val = allocate_value (type);
459
460 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), TYPE_LENGTH (type));
461
462 VALUE_LVAL (val) = lval_memory;
463 VALUE_ADDRESS (val) = addr;
464
465 return val;
466 }
467
468 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
469
470 struct value *
471 value_at_lazy (struct type *type, CORE_ADDR addr)
472 {
473 struct value *val;
474
475 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
476 error ("Attempt to dereference a generic pointer.");
477
478 val = allocate_value (type);
479
480 VALUE_LVAL (val) = lval_memory;
481 VALUE_ADDRESS (val) = addr;
482 VALUE_LAZY (val) = 1;
483
484 return val;
485 }
486
487 /* Called only from the VALUE_CONTENTS and VALUE_CONTENTS_ALL macros,
488 if the current data for a variable needs to be loaded into
489 VALUE_CONTENTS(VAL). Fetches the data from the user's process, and
490 clears the lazy flag to indicate that the data in the buffer is valid.
491
492 If the value is zero-length, we avoid calling read_memory, which would
493 abort. We mark the value as fetched anyway -- all 0 bytes of it.
494
495 This function returns a value because it is used in the VALUE_CONTENTS
496 macro as part of an expression, where a void would not work. The
497 value is ignored. */
498
499 int
500 value_fetch_lazy (struct value *val)
501 {
502 CORE_ADDR addr = VALUE_ADDRESS (val) + value_offset (val);
503 int length = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val));
504
505 struct type *type = value_type (val);
506 if (length)
507 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), length);
508
509 VALUE_LAZY (val) = 0;
510 return 0;
511 }
512
513
514 /* Store the contents of FROMVAL into the location of TOVAL.
515 Return a new value with the location of TOVAL and contents of FROMVAL. */
516
517 struct value *
518 value_assign (struct value *toval, struct value *fromval)
519 {
520 struct type *type;
521 struct value *val;
522 struct frame_id old_frame;
523
524 if (!toval->modifiable)
525 error ("Left operand of assignment is not a modifiable lvalue.");
526
527 toval = coerce_ref (toval);
528
529 type = value_type (toval);
530 if (VALUE_LVAL (toval) != lval_internalvar)
531 fromval = value_cast (type, fromval);
532 else
533 fromval = coerce_array (fromval);
534 CHECK_TYPEDEF (type);
535
536 /* Since modifying a register can trash the frame chain, and modifying memory
537 can trash the frame cache, we save the old frame and then restore the new
538 frame afterwards. */
539 old_frame = get_frame_id (deprecated_selected_frame);
540
541 switch (VALUE_LVAL (toval))
542 {
543 case lval_internalvar:
544 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
545 val = value_copy (VALUE_INTERNALVAR (toval)->value);
546 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
547 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
548 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
549 return val;
550
551 case lval_internalvar_component:
552 set_internalvar_component (VALUE_INTERNALVAR (toval),
553 value_offset (toval),
554 value_bitpos (toval),
555 value_bitsize (toval),
556 fromval);
557 break;
558
559 case lval_memory:
560 {
561 char *dest_buffer;
562 CORE_ADDR changed_addr;
563 int changed_len;
564 char buffer[sizeof (LONGEST)];
565
566 if (value_bitsize (toval))
567 {
568 /* We assume that the argument to read_memory is in units of
569 host chars. FIXME: Is that correct? */
570 changed_len = (value_bitpos (toval)
571 + value_bitsize (toval)
572 + HOST_CHAR_BIT - 1)
573 / HOST_CHAR_BIT;
574
575 if (changed_len > (int) sizeof (LONGEST))
576 error ("Can't handle bitfields which don't fit in a %d bit word.",
577 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
578
579 read_memory (VALUE_ADDRESS (toval) + value_offset (toval),
580 buffer, changed_len);
581 modify_field (buffer, value_as_long (fromval),
582 value_bitpos (toval), value_bitsize (toval));
583 changed_addr = VALUE_ADDRESS (toval) + value_offset (toval);
584 dest_buffer = buffer;
585 }
586 else
587 {
588 changed_addr = VALUE_ADDRESS (toval) + value_offset (toval);
589 changed_len = TYPE_LENGTH (type);
590 dest_buffer = VALUE_CONTENTS (fromval);
591 }
592
593 write_memory (changed_addr, dest_buffer, changed_len);
594 if (deprecated_memory_changed_hook)
595 deprecated_memory_changed_hook (changed_addr, changed_len);
596 }
597 break;
598
599 case lval_register:
600 {
601 struct frame_info *frame;
602 int value_reg;
603
604 /* Figure out which frame this is in currently. */
605 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
606 value_reg = VALUE_REGNUM (toval);
607
608 if (!frame)
609 error ("Value being assigned to is no longer active.");
610
611 if (VALUE_LVAL (toval) == lval_register
612 && CONVERT_REGISTER_P (VALUE_REGNUM (toval), type))
613 {
614 /* If TOVAL is a special machine register requiring
615 conversion of program values to a special raw format. */
616 VALUE_TO_REGISTER (frame, VALUE_REGNUM (toval),
617 type, VALUE_CONTENTS (fromval));
618 }
619 else
620 {
621 /* TOVAL is stored in a series of registers in the frame
622 specified by the structure. Copy that value out,
623 modify it, and copy it back in. */
624 int amount_copied;
625 int amount_to_copy;
626 char *buffer;
627 int reg_offset;
628 int byte_offset;
629 int regno;
630
631 /* Locate the first register that falls in the value that
632 needs to be transfered. Compute the offset of the
633 value in that register. */
634 {
635 int offset;
636 for (reg_offset = value_reg, offset = 0;
637 offset + register_size (current_gdbarch, reg_offset) <= value_offset (toval);
638 reg_offset++);
639 byte_offset = value_offset (toval) - offset;
640 }
641
642 /* Compute the number of register aligned values that need
643 to be copied. */
644 if (value_bitsize (toval))
645 amount_to_copy = byte_offset + 1;
646 else
647 amount_to_copy = byte_offset + TYPE_LENGTH (type);
648
649 /* And a bounce buffer. Be slightly over generous. */
650 buffer = (char *) alloca (amount_to_copy + MAX_REGISTER_SIZE);
651
652 /* Copy it in. */
653 for (regno = reg_offset, amount_copied = 0;
654 amount_copied < amount_to_copy;
655 amount_copied += register_size (current_gdbarch, regno), regno++)
656 frame_register_read (frame, regno, buffer + amount_copied);
657
658 /* Modify what needs to be modified. */
659 if (value_bitsize (toval))
660 modify_field (buffer + byte_offset,
661 value_as_long (fromval),
662 value_bitpos (toval), value_bitsize (toval));
663 else
664 memcpy (buffer + byte_offset, VALUE_CONTENTS (fromval),
665 TYPE_LENGTH (type));
666
667 /* Copy it out. */
668 for (regno = reg_offset, amount_copied = 0;
669 amount_copied < amount_to_copy;
670 amount_copied += register_size (current_gdbarch, regno), regno++)
671 put_frame_register (frame, regno, buffer + amount_copied);
672
673 }
674 if (deprecated_register_changed_hook)
675 deprecated_register_changed_hook (-1);
676 observer_notify_target_changed (&current_target);
677 break;
678 }
679
680 default:
681 error ("Left operand of assignment is not an lvalue.");
682 }
683
684 /* Assigning to the stack pointer, frame pointer, and other
685 (architecture and calling convention specific) registers may
686 cause the frame cache to be out of date. Assigning to memory
687 also can. We just do this on all assignments to registers or
688 memory, for simplicity's sake; I doubt the slowdown matters. */
689 switch (VALUE_LVAL (toval))
690 {
691 case lval_memory:
692 case lval_register:
693
694 reinit_frame_cache ();
695
696 /* Having destoroyed the frame cache, restore the selected frame. */
697
698 /* FIXME: cagney/2002-11-02: There has to be a better way of
699 doing this. Instead of constantly saving/restoring the
700 frame. Why not create a get_selected_frame() function that,
701 having saved the selected frame's ID can automatically
702 re-find the previously selected frame automatically. */
703
704 {
705 struct frame_info *fi = frame_find_by_id (old_frame);
706 if (fi != NULL)
707 select_frame (fi);
708 }
709
710 break;
711 default:
712 break;
713 }
714
715 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
716 If the field is signed, and is negative, then sign extend. */
717 if ((value_bitsize (toval) > 0)
718 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
719 {
720 LONGEST fieldval = value_as_long (fromval);
721 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
722
723 fieldval &= valmask;
724 if (!TYPE_UNSIGNED (type) && (fieldval & (valmask ^ (valmask >> 1))))
725 fieldval |= ~valmask;
726
727 fromval = value_from_longest (type, fieldval);
728 }
729
730 val = value_copy (toval);
731 memcpy (VALUE_CONTENTS_RAW (val), VALUE_CONTENTS (fromval),
732 TYPE_LENGTH (type));
733 val->type = type;
734 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
735 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
736 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
737
738 return val;
739 }
740
741 /* Extend a value VAL to COUNT repetitions of its type. */
742
743 struct value *
744 value_repeat (struct value *arg1, int count)
745 {
746 struct value *val;
747
748 if (VALUE_LVAL (arg1) != lval_memory)
749 error ("Only values in memory can be extended with '@'.");
750 if (count < 1)
751 error ("Invalid number %d of repetitions.", count);
752
753 val = allocate_repeat_value (VALUE_ENCLOSING_TYPE (arg1), count);
754
755 read_memory (VALUE_ADDRESS (arg1) + value_offset (arg1),
756 VALUE_CONTENTS_ALL_RAW (val),
757 TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val)));
758 VALUE_LVAL (val) = lval_memory;
759 VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + value_offset (arg1);
760
761 return val;
762 }
763
764 struct value *
765 value_of_variable (struct symbol *var, struct block *b)
766 {
767 struct value *val;
768 struct frame_info *frame = NULL;
769
770 if (!b)
771 frame = NULL; /* Use selected frame. */
772 else if (symbol_read_needs_frame (var))
773 {
774 frame = block_innermost_frame (b);
775 if (!frame)
776 {
777 if (BLOCK_FUNCTION (b)
778 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
779 error ("No frame is currently executing in block %s.",
780 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
781 else
782 error ("No frame is currently executing in specified block");
783 }
784 }
785
786 val = read_var_value (var, frame);
787 if (!val)
788 error ("Address of symbol \"%s\" is unknown.", SYMBOL_PRINT_NAME (var));
789
790 return val;
791 }
792
793 /* Given a value which is an array, return a value which is a pointer to its
794 first element, regardless of whether or not the array has a nonzero lower
795 bound.
796
797 FIXME: A previous comment here indicated that this routine should be
798 substracting the array's lower bound. It's not clear to me that this
799 is correct. Given an array subscripting operation, it would certainly
800 work to do the adjustment here, essentially computing:
801
802 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
803
804 However I believe a more appropriate and logical place to account for
805 the lower bound is to do so in value_subscript, essentially computing:
806
807 (&array[0] + ((index - lowerbound) * sizeof array[0]))
808
809 As further evidence consider what would happen with operations other
810 than array subscripting, where the caller would get back a value that
811 had an address somewhere before the actual first element of the array,
812 and the information about the lower bound would be lost because of
813 the coercion to pointer type.
814 */
815
816 struct value *
817 value_coerce_array (struct value *arg1)
818 {
819 struct type *type = check_typedef (value_type (arg1));
820
821 if (VALUE_LVAL (arg1) != lval_memory)
822 error ("Attempt to take address of value not located in memory.");
823
824 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
825 (VALUE_ADDRESS (arg1) + value_offset (arg1)));
826 }
827
828 /* Given a value which is a function, return a value which is a pointer
829 to it. */
830
831 struct value *
832 value_coerce_function (struct value *arg1)
833 {
834 struct value *retval;
835
836 if (VALUE_LVAL (arg1) != lval_memory)
837 error ("Attempt to take address of value not located in memory.");
838
839 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
840 (VALUE_ADDRESS (arg1) + value_offset (arg1)));
841 return retval;
842 }
843
844 /* Return a pointer value for the object for which ARG1 is the contents. */
845
846 struct value *
847 value_addr (struct value *arg1)
848 {
849 struct value *arg2;
850
851 struct type *type = check_typedef (value_type (arg1));
852 if (TYPE_CODE (type) == TYPE_CODE_REF)
853 {
854 /* Copy the value, but change the type from (T&) to (T*).
855 We keep the same location information, which is efficient,
856 and allows &(&X) to get the location containing the reference. */
857 arg2 = value_copy (arg1);
858 arg2->type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
859 return arg2;
860 }
861 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
862 return value_coerce_function (arg1);
863
864 if (VALUE_LVAL (arg1) != lval_memory)
865 error ("Attempt to take address of value not located in memory.");
866
867 /* Get target memory address */
868 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
869 (VALUE_ADDRESS (arg1)
870 + value_offset (arg1)
871 + VALUE_EMBEDDED_OFFSET (arg1)));
872
873 /* This may be a pointer to a base subobject; so remember the
874 full derived object's type ... */
875 arg2 = value_change_enclosing_type (arg2, lookup_pointer_type (VALUE_ENCLOSING_TYPE (arg1)));
876 /* ... and also the relative position of the subobject in the full object */
877 VALUE_POINTED_TO_OFFSET (arg2) = VALUE_EMBEDDED_OFFSET (arg1);
878 return arg2;
879 }
880
881 /* Given a value of a pointer type, apply the C unary * operator to it. */
882
883 struct value *
884 value_ind (struct value *arg1)
885 {
886 struct type *base_type;
887 struct value *arg2;
888
889 arg1 = coerce_array (arg1);
890
891 base_type = check_typedef (value_type (arg1));
892
893 if (TYPE_CODE (base_type) == TYPE_CODE_MEMBER)
894 error ("not implemented: member types in value_ind");
895
896 /* Allow * on an integer so we can cast it to whatever we want.
897 This returns an int, which seems like the most C-like thing
898 to do. "long long" variables are rare enough that
899 BUILTIN_TYPE_LONGEST would seem to be a mistake. */
900 if (TYPE_CODE (base_type) == TYPE_CODE_INT)
901 return value_at_lazy (builtin_type_int,
902 (CORE_ADDR) value_as_long (arg1));
903 else if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
904 {
905 struct type *enc_type;
906 /* We may be pointing to something embedded in a larger object */
907 /* Get the real type of the enclosing object */
908 enc_type = check_typedef (VALUE_ENCLOSING_TYPE (arg1));
909 enc_type = TYPE_TARGET_TYPE (enc_type);
910 /* Retrieve the enclosing object pointed to */
911 arg2 = value_at_lazy (enc_type, (value_as_address (arg1)
912 - VALUE_POINTED_TO_OFFSET (arg1)));
913 /* Re-adjust type */
914 arg2->type = TYPE_TARGET_TYPE (base_type);
915 /* Add embedding info */
916 arg2 = value_change_enclosing_type (arg2, enc_type);
917 VALUE_EMBEDDED_OFFSET (arg2) = VALUE_POINTED_TO_OFFSET (arg1);
918
919 /* We may be pointing to an object of some derived type */
920 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
921 return arg2;
922 }
923
924 error ("Attempt to take contents of a non-pointer value.");
925 return 0; /* For lint -- never reached */
926 }
927 \f
928 /* Pushing small parts of stack frames. */
929
930 /* Push one word (the size of object that a register holds). */
931
932 CORE_ADDR
933 push_word (CORE_ADDR sp, ULONGEST word)
934 {
935 int len = DEPRECATED_REGISTER_SIZE;
936 char buffer[MAX_REGISTER_SIZE];
937
938 store_unsigned_integer (buffer, len, word);
939 if (INNER_THAN (1, 2))
940 {
941 /* stack grows downward */
942 sp -= len;
943 write_memory (sp, buffer, len);
944 }
945 else
946 {
947 /* stack grows upward */
948 write_memory (sp, buffer, len);
949 sp += len;
950 }
951
952 return sp;
953 }
954
955 /* Push LEN bytes with data at BUFFER. */
956
957 CORE_ADDR
958 push_bytes (CORE_ADDR sp, char *buffer, int len)
959 {
960 if (INNER_THAN (1, 2))
961 {
962 /* stack grows downward */
963 sp -= len;
964 write_memory (sp, buffer, len);
965 }
966 else
967 {
968 /* stack grows upward */
969 write_memory (sp, buffer, len);
970 sp += len;
971 }
972
973 return sp;
974 }
975
976 /* Create a value for an array by allocating space in the inferior, copying
977 the data into that space, and then setting up an array value.
978
979 The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
980 populated from the values passed in ELEMVEC.
981
982 The element type of the array is inherited from the type of the
983 first element, and all elements must have the same size (though we
984 don't currently enforce any restriction on their types). */
985
986 struct value *
987 value_array (int lowbound, int highbound, struct value **elemvec)
988 {
989 int nelem;
990 int idx;
991 unsigned int typelength;
992 struct value *val;
993 struct type *rangetype;
994 struct type *arraytype;
995 CORE_ADDR addr;
996
997 /* Validate that the bounds are reasonable and that each of the elements
998 have the same size. */
999
1000 nelem = highbound - lowbound + 1;
1001 if (nelem <= 0)
1002 {
1003 error ("bad array bounds (%d, %d)", lowbound, highbound);
1004 }
1005 typelength = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[0]));
1006 for (idx = 1; idx < nelem; idx++)
1007 {
1008 if (TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[idx])) != typelength)
1009 {
1010 error ("array elements must all be the same size");
1011 }
1012 }
1013
1014 rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
1015 lowbound, highbound);
1016 arraytype = create_array_type ((struct type *) NULL,
1017 VALUE_ENCLOSING_TYPE (elemvec[0]), rangetype);
1018
1019 if (!current_language->c_style_arrays)
1020 {
1021 val = allocate_value (arraytype);
1022 for (idx = 0; idx < nelem; idx++)
1023 {
1024 memcpy (VALUE_CONTENTS_ALL_RAW (val) + (idx * typelength),
1025 VALUE_CONTENTS_ALL (elemvec[idx]),
1026 typelength);
1027 }
1028 return val;
1029 }
1030
1031 /* Allocate space to store the array in the inferior, and then initialize
1032 it by copying in each element. FIXME: Is it worth it to create a
1033 local buffer in which to collect each value and then write all the
1034 bytes in one operation? */
1035
1036 addr = allocate_space_in_inferior (nelem * typelength);
1037 for (idx = 0; idx < nelem; idx++)
1038 {
1039 write_memory (addr + (idx * typelength), VALUE_CONTENTS_ALL (elemvec[idx]),
1040 typelength);
1041 }
1042
1043 /* Create the array type and set up an array value to be evaluated lazily. */
1044
1045 val = value_at_lazy (arraytype, addr);
1046 return (val);
1047 }
1048
1049 /* Create a value for a string constant by allocating space in the inferior,
1050 copying the data into that space, and returning the address with type
1051 TYPE_CODE_STRING. PTR points to the string constant data; LEN is number
1052 of characters.
1053 Note that string types are like array of char types with a lower bound of
1054 zero and an upper bound of LEN - 1. Also note that the string may contain
1055 embedded null bytes. */
1056
1057 struct value *
1058 value_string (char *ptr, int len)
1059 {
1060 struct value *val;
1061 int lowbound = current_language->string_lower_bound;
1062 struct type *rangetype = create_range_type ((struct type *) NULL,
1063 builtin_type_int,
1064 lowbound, len + lowbound - 1);
1065 struct type *stringtype
1066 = create_string_type ((struct type *) NULL, rangetype);
1067 CORE_ADDR addr;
1068
1069 if (current_language->c_style_arrays == 0)
1070 {
1071 val = allocate_value (stringtype);
1072 memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
1073 return val;
1074 }
1075
1076
1077 /* Allocate space to store the string in the inferior, and then
1078 copy LEN bytes from PTR in gdb to that address in the inferior. */
1079
1080 addr = allocate_space_in_inferior (len);
1081 write_memory (addr, ptr, len);
1082
1083 val = value_at_lazy (stringtype, addr);
1084 return (val);
1085 }
1086
1087 struct value *
1088 value_bitstring (char *ptr, int len)
1089 {
1090 struct value *val;
1091 struct type *domain_type = create_range_type (NULL, builtin_type_int,
1092 0, len - 1);
1093 struct type *type = create_set_type ((struct type *) NULL, domain_type);
1094 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1095 val = allocate_value (type);
1096 memcpy (VALUE_CONTENTS_RAW (val), ptr, TYPE_LENGTH (type));
1097 return val;
1098 }
1099 \f
1100 /* See if we can pass arguments in T2 to a function which takes arguments
1101 of types T1. T1 is a list of NARGS arguments, and T2 is a NULL-terminated
1102 vector. If some arguments need coercion of some sort, then the coerced
1103 values are written into T2. Return value is 0 if the arguments could be
1104 matched, or the position at which they differ if not.
1105
1106 STATICP is nonzero if the T1 argument list came from a
1107 static member function. T2 will still include the ``this'' pointer,
1108 but it will be skipped.
1109
1110 For non-static member functions, we ignore the first argument,
1111 which is the type of the instance variable. This is because we want
1112 to handle calls with objects from derived classes. This is not
1113 entirely correct: we should actually check to make sure that a
1114 requested operation is type secure, shouldn't we? FIXME. */
1115
1116 static int
1117 typecmp (int staticp, int varargs, int nargs,
1118 struct field t1[], struct value *t2[])
1119 {
1120 int i;
1121
1122 if (t2 == 0)
1123 internal_error (__FILE__, __LINE__, "typecmp: no argument list");
1124
1125 /* Skip ``this'' argument if applicable. T2 will always include THIS. */
1126 if (staticp)
1127 t2 ++;
1128
1129 for (i = 0;
1130 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1131 i++)
1132 {
1133 struct type *tt1, *tt2;
1134
1135 if (!t2[i])
1136 return i + 1;
1137
1138 tt1 = check_typedef (t1[i].type);
1139 tt2 = check_typedef (value_type (t2[i]));
1140
1141 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1142 /* We should be doing hairy argument matching, as below. */
1143 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
1144 {
1145 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1146 t2[i] = value_coerce_array (t2[i]);
1147 else
1148 t2[i] = value_addr (t2[i]);
1149 continue;
1150 }
1151
1152 /* djb - 20000715 - Until the new type structure is in the
1153 place, and we can attempt things like implicit conversions,
1154 we need to do this so you can take something like a map<const
1155 char *>, and properly access map["hello"], because the
1156 argument to [] will be a reference to a pointer to a char,
1157 and the argument will be a pointer to a char. */
1158 while ( TYPE_CODE(tt1) == TYPE_CODE_REF ||
1159 TYPE_CODE (tt1) == TYPE_CODE_PTR)
1160 {
1161 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1162 }
1163 while ( TYPE_CODE(tt2) == TYPE_CODE_ARRAY ||
1164 TYPE_CODE(tt2) == TYPE_CODE_PTR ||
1165 TYPE_CODE(tt2) == TYPE_CODE_REF)
1166 {
1167 tt2 = check_typedef( TYPE_TARGET_TYPE(tt2) );
1168 }
1169 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1170 continue;
1171 /* Array to pointer is a `trivial conversion' according to the ARM. */
1172
1173 /* We should be doing much hairier argument matching (see section 13.2
1174 of the ARM), but as a quick kludge, just check for the same type
1175 code. */
1176 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1177 return i + 1;
1178 }
1179 if (varargs || t2[i] == NULL)
1180 return 0;
1181 return i + 1;
1182 }
1183
1184 /* Helper function used by value_struct_elt to recurse through baseclasses.
1185 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
1186 and search in it assuming it has (class) type TYPE.
1187 If found, return value, else return NULL.
1188
1189 If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
1190 look for a baseclass named NAME. */
1191
1192 static struct value *
1193 search_struct_field (char *name, struct value *arg1, int offset,
1194 struct type *type, int looking_for_baseclass)
1195 {
1196 int i;
1197 int nbases = TYPE_N_BASECLASSES (type);
1198
1199 CHECK_TYPEDEF (type);
1200
1201 if (!looking_for_baseclass)
1202 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1203 {
1204 char *t_field_name = TYPE_FIELD_NAME (type, i);
1205
1206 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1207 {
1208 struct value *v;
1209 if (TYPE_FIELD_STATIC (type, i))
1210 {
1211 v = value_static_field (type, i);
1212 if (v == 0)
1213 error ("field %s is nonexistent or has been optimised out",
1214 name);
1215 }
1216 else
1217 {
1218 v = value_primitive_field (arg1, offset, i, type);
1219 if (v == 0)
1220 error ("there is no field named %s", name);
1221 }
1222 return v;
1223 }
1224
1225 if (t_field_name
1226 && (t_field_name[0] == '\0'
1227 || (TYPE_CODE (type) == TYPE_CODE_UNION
1228 && (strcmp_iw (t_field_name, "else") == 0))))
1229 {
1230 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1231 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1232 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1233 {
1234 /* Look for a match through the fields of an anonymous union,
1235 or anonymous struct. C++ provides anonymous unions.
1236
1237 In the GNU Chill (now deleted from GDB)
1238 implementation of variant record types, each
1239 <alternative field> has an (anonymous) union type,
1240 each member of the union represents a <variant
1241 alternative>. Each <variant alternative> is
1242 represented as a struct, with a member for each
1243 <variant field>. */
1244
1245 struct value *v;
1246 int new_offset = offset;
1247
1248 /* This is pretty gross. In G++, the offset in an
1249 anonymous union is relative to the beginning of the
1250 enclosing struct. In the GNU Chill (now deleted
1251 from GDB) implementation of variant records, the
1252 bitpos is zero in an anonymous union field, so we
1253 have to add the offset of the union here. */
1254 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1255 || (TYPE_NFIELDS (field_type) > 0
1256 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1257 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1258
1259 v = search_struct_field (name, arg1, new_offset, field_type,
1260 looking_for_baseclass);
1261 if (v)
1262 return v;
1263 }
1264 }
1265 }
1266
1267 for (i = 0; i < nbases; i++)
1268 {
1269 struct value *v;
1270 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1271 /* If we are looking for baseclasses, this is what we get when we
1272 hit them. But it could happen that the base part's member name
1273 is not yet filled in. */
1274 int found_baseclass = (looking_for_baseclass
1275 && TYPE_BASECLASS_NAME (type, i) != NULL
1276 && (strcmp_iw (name, TYPE_BASECLASS_NAME (type, i)) == 0));
1277
1278 if (BASETYPE_VIA_VIRTUAL (type, i))
1279 {
1280 int boffset;
1281 struct value *v2 = allocate_value (basetype);
1282
1283 boffset = baseclass_offset (type, i,
1284 VALUE_CONTENTS (arg1) + offset,
1285 VALUE_ADDRESS (arg1)
1286 + value_offset (arg1) + offset);
1287 if (boffset == -1)
1288 error ("virtual baseclass botch");
1289
1290 /* The virtual base class pointer might have been clobbered by the
1291 user program. Make sure that it still points to a valid memory
1292 location. */
1293
1294 boffset += offset;
1295 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
1296 {
1297 CORE_ADDR base_addr;
1298
1299 base_addr = VALUE_ADDRESS (arg1) + value_offset (arg1) + boffset;
1300 if (target_read_memory (base_addr, VALUE_CONTENTS_RAW (v2),
1301 TYPE_LENGTH (basetype)) != 0)
1302 error ("virtual baseclass botch");
1303 VALUE_LVAL (v2) = lval_memory;
1304 VALUE_ADDRESS (v2) = base_addr;
1305 }
1306 else
1307 {
1308 VALUE_LVAL (v2) = VALUE_LVAL (arg1);
1309 VALUE_ADDRESS (v2) = VALUE_ADDRESS (arg1);
1310 VALUE_FRAME_ID (v2) = VALUE_FRAME_ID (arg1);
1311 v2->offset = value_offset (arg1) + boffset;
1312 if (VALUE_LAZY (arg1))
1313 VALUE_LAZY (v2) = 1;
1314 else
1315 memcpy (VALUE_CONTENTS_RAW (v2),
1316 VALUE_CONTENTS_RAW (arg1) + boffset,
1317 TYPE_LENGTH (basetype));
1318 }
1319
1320 if (found_baseclass)
1321 return v2;
1322 v = search_struct_field (name, v2, 0, TYPE_BASECLASS (type, i),
1323 looking_for_baseclass);
1324 }
1325 else if (found_baseclass)
1326 v = value_primitive_field (arg1, offset, i, type);
1327 else
1328 v = search_struct_field (name, arg1,
1329 offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
1330 basetype, looking_for_baseclass);
1331 if (v)
1332 return v;
1333 }
1334 return NULL;
1335 }
1336
1337
1338 /* Return the offset (in bytes) of the virtual base of type BASETYPE
1339 * in an object pointed to by VALADDR (on the host), assumed to be of
1340 * type TYPE. OFFSET is number of bytes beyond start of ARG to start
1341 * looking (in case VALADDR is the contents of an enclosing object).
1342 *
1343 * This routine recurses on the primary base of the derived class because
1344 * the virtual base entries of the primary base appear before the other
1345 * virtual base entries.
1346 *
1347 * If the virtual base is not found, a negative integer is returned.
1348 * The magnitude of the negative integer is the number of entries in
1349 * the virtual table to skip over (entries corresponding to various
1350 * ancestral classes in the chain of primary bases).
1351 *
1352 * Important: This assumes the HP / Taligent C++ runtime
1353 * conventions. Use baseclass_offset() instead to deal with g++
1354 * conventions. */
1355
1356 void
1357 find_rt_vbase_offset (struct type *type, struct type *basetype, char *valaddr,
1358 int offset, int *boffset_p, int *skip_p)
1359 {
1360 int boffset; /* offset of virtual base */
1361 int index; /* displacement to use in virtual table */
1362 int skip;
1363
1364 struct value *vp;
1365 CORE_ADDR vtbl; /* the virtual table pointer */
1366 struct type *pbc; /* the primary base class */
1367
1368 /* Look for the virtual base recursively in the primary base, first.
1369 * This is because the derived class object and its primary base
1370 * subobject share the primary virtual table. */
1371
1372 boffset = 0;
1373 pbc = TYPE_PRIMARY_BASE (type);
1374 if (pbc)
1375 {
1376 find_rt_vbase_offset (pbc, basetype, valaddr, offset, &boffset, &skip);
1377 if (skip < 0)
1378 {
1379 *boffset_p = boffset;
1380 *skip_p = -1;
1381 return;
1382 }
1383 }
1384 else
1385 skip = 0;
1386
1387
1388 /* Find the index of the virtual base according to HP/Taligent
1389 runtime spec. (Depth-first, left-to-right.) */
1390 index = virtual_base_index_skip_primaries (basetype, type);
1391
1392 if (index < 0)
1393 {
1394 *skip_p = skip + virtual_base_list_length_skip_primaries (type);
1395 *boffset_p = 0;
1396 return;
1397 }
1398
1399 /* pai: FIXME -- 32x64 possible problem */
1400 /* First word (4 bytes) in object layout is the vtable pointer */
1401 vtbl = *(CORE_ADDR *) (valaddr + offset);
1402
1403 /* Before the constructor is invoked, things are usually zero'd out. */
1404 if (vtbl == 0)
1405 error ("Couldn't find virtual table -- object may not be constructed yet.");
1406
1407
1408 /* Find virtual base's offset -- jump over entries for primary base
1409 * ancestors, then use the index computed above. But also adjust by
1410 * HP_ACC_VBASE_START for the vtable slots before the start of the
1411 * virtual base entries. Offset is negative -- virtual base entries
1412 * appear _before_ the address point of the virtual table. */
1413
1414 /* pai: FIXME -- 32x64 problem, if word = 8 bytes, change multiplier
1415 & use long type */
1416
1417 /* epstein : FIXME -- added param for overlay section. May not be correct */
1418 vp = value_at (builtin_type_int, vtbl + 4 * (-skip - index - HP_ACC_VBASE_START));
1419 boffset = value_as_long (vp);
1420 *skip_p = -1;
1421 *boffset_p = boffset;
1422 return;
1423 }
1424
1425
1426 /* Helper function used by value_struct_elt to recurse through baseclasses.
1427 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
1428 and search in it assuming it has (class) type TYPE.
1429 If found, return value, else if name matched and args not return (value)-1,
1430 else return NULL. */
1431
1432 static struct value *
1433 search_struct_method (char *name, struct value **arg1p,
1434 struct value **args, int offset,
1435 int *static_memfuncp, struct type *type)
1436 {
1437 int i;
1438 struct value *v;
1439 int name_matched = 0;
1440 char dem_opname[64];
1441
1442 CHECK_TYPEDEF (type);
1443 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1444 {
1445 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1446 /* FIXME! May need to check for ARM demangling here */
1447 if (strncmp (t_field_name, "__", 2) == 0 ||
1448 strncmp (t_field_name, "op", 2) == 0 ||
1449 strncmp (t_field_name, "type", 4) == 0)
1450 {
1451 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
1452 t_field_name = dem_opname;
1453 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
1454 t_field_name = dem_opname;
1455 }
1456 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1457 {
1458 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1459 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1460 name_matched = 1;
1461
1462 check_stub_method_group (type, i);
1463 if (j > 0 && args == 0)
1464 error ("cannot resolve overloaded method `%s': no arguments supplied", name);
1465 else if (j == 0 && args == 0)
1466 {
1467 v = value_fn_field (arg1p, f, j, type, offset);
1468 if (v != NULL)
1469 return v;
1470 }
1471 else
1472 while (j >= 0)
1473 {
1474 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
1475 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
1476 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
1477 TYPE_FN_FIELD_ARGS (f, j), args))
1478 {
1479 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
1480 return value_virtual_fn_field (arg1p, f, j, type, offset);
1481 if (TYPE_FN_FIELD_STATIC_P (f, j) && static_memfuncp)
1482 *static_memfuncp = 1;
1483 v = value_fn_field (arg1p, f, j, type, offset);
1484 if (v != NULL)
1485 return v;
1486 }
1487 j--;
1488 }
1489 }
1490 }
1491
1492 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1493 {
1494 int base_offset;
1495
1496 if (BASETYPE_VIA_VIRTUAL (type, i))
1497 {
1498 if (TYPE_HAS_VTABLE (type))
1499 {
1500 /* HP aCC compiled type, search for virtual base offset
1501 according to HP/Taligent runtime spec. */
1502 int skip;
1503 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
1504 VALUE_CONTENTS_ALL (*arg1p),
1505 offset + VALUE_EMBEDDED_OFFSET (*arg1p),
1506 &base_offset, &skip);
1507 if (skip >= 0)
1508 error ("Virtual base class offset not found in vtable");
1509 }
1510 else
1511 {
1512 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
1513 char *base_valaddr;
1514
1515 /* The virtual base class pointer might have been clobbered by the
1516 user program. Make sure that it still points to a valid memory
1517 location. */
1518
1519 if (offset < 0 || offset >= TYPE_LENGTH (type))
1520 {
1521 base_valaddr = (char *) alloca (TYPE_LENGTH (baseclass));
1522 if (target_read_memory (VALUE_ADDRESS (*arg1p)
1523 + value_offset (*arg1p) + offset,
1524 base_valaddr,
1525 TYPE_LENGTH (baseclass)) != 0)
1526 error ("virtual baseclass botch");
1527 }
1528 else
1529 base_valaddr = VALUE_CONTENTS (*arg1p) + offset;
1530
1531 base_offset =
1532 baseclass_offset (type, i, base_valaddr,
1533 VALUE_ADDRESS (*arg1p)
1534 + value_offset (*arg1p) + offset);
1535 if (base_offset == -1)
1536 error ("virtual baseclass botch");
1537 }
1538 }
1539 else
1540 {
1541 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1542 }
1543 v = search_struct_method (name, arg1p, args, base_offset + offset,
1544 static_memfuncp, TYPE_BASECLASS (type, i));
1545 if (v == (struct value *) - 1)
1546 {
1547 name_matched = 1;
1548 }
1549 else if (v)
1550 {
1551 /* FIXME-bothner: Why is this commented out? Why is it here? */
1552 /* *arg1p = arg1_tmp; */
1553 return v;
1554 }
1555 }
1556 if (name_matched)
1557 return (struct value *) - 1;
1558 else
1559 return NULL;
1560 }
1561
1562 /* Given *ARGP, a value of type (pointer to a)* structure/union,
1563 extract the component named NAME from the ultimate target structure/union
1564 and return it as a value with its appropriate type.
1565 ERR is used in the error message if *ARGP's type is wrong.
1566
1567 C++: ARGS is a list of argument types to aid in the selection of
1568 an appropriate method. Also, handle derived types.
1569
1570 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
1571 where the truthvalue of whether the function that was resolved was
1572 a static member function or not is stored.
1573
1574 ERR is an error message to be printed in case the field is not found. */
1575
1576 struct value *
1577 value_struct_elt (struct value **argp, struct value **args,
1578 char *name, int *static_memfuncp, char *err)
1579 {
1580 struct type *t;
1581 struct value *v;
1582
1583 *argp = coerce_array (*argp);
1584
1585 t = check_typedef (value_type (*argp));
1586
1587 /* Follow pointers until we get to a non-pointer. */
1588
1589 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1590 {
1591 *argp = value_ind (*argp);
1592 /* Don't coerce fn pointer to fn and then back again! */
1593 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
1594 *argp = coerce_array (*argp);
1595 t = check_typedef (value_type (*argp));
1596 }
1597
1598 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
1599 error ("not implemented: member type in value_struct_elt");
1600
1601 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
1602 && TYPE_CODE (t) != TYPE_CODE_UNION)
1603 error ("Attempt to extract a component of a value that is not a %s.", err);
1604
1605 /* Assume it's not, unless we see that it is. */
1606 if (static_memfuncp)
1607 *static_memfuncp = 0;
1608
1609 if (!args)
1610 {
1611 /* if there are no arguments ...do this... */
1612
1613 /* Try as a field first, because if we succeed, there
1614 is less work to be done. */
1615 v = search_struct_field (name, *argp, 0, t, 0);
1616 if (v)
1617 return v;
1618
1619 /* C++: If it was not found as a data field, then try to
1620 return it as a pointer to a method. */
1621
1622 if (destructor_name_p (name, t))
1623 error ("Cannot get value of destructor");
1624
1625 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
1626
1627 if (v == (struct value *) - 1)
1628 error ("Cannot take address of a method");
1629 else if (v == 0)
1630 {
1631 if (TYPE_NFN_FIELDS (t))
1632 error ("There is no member or method named %s.", name);
1633 else
1634 error ("There is no member named %s.", name);
1635 }
1636 return v;
1637 }
1638
1639 if (destructor_name_p (name, t))
1640 {
1641 if (!args[1])
1642 {
1643 /* Destructors are a special case. */
1644 int m_index, f_index;
1645
1646 v = NULL;
1647 if (get_destructor_fn_field (t, &m_index, &f_index))
1648 {
1649 v = value_fn_field (NULL, TYPE_FN_FIELDLIST1 (t, m_index),
1650 f_index, NULL, 0);
1651 }
1652 if (v == NULL)
1653 error ("could not find destructor function named %s.", name);
1654 else
1655 return v;
1656 }
1657 else
1658 {
1659 error ("destructor should not have any argument");
1660 }
1661 }
1662 else
1663 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
1664
1665 if (v == (struct value *) - 1)
1666 {
1667 error ("One of the arguments you tried to pass to %s could not be converted to what the function wants.", name);
1668 }
1669 else if (v == 0)
1670 {
1671 /* See if user tried to invoke data as function. If so,
1672 hand it back. If it's not callable (i.e., a pointer to function),
1673 gdb should give an error. */
1674 v = search_struct_field (name, *argp, 0, t, 0);
1675 }
1676
1677 if (!v)
1678 error ("Structure has no component named %s.", name);
1679 return v;
1680 }
1681
1682 /* Search through the methods of an object (and its bases)
1683 * to find a specified method. Return the pointer to the
1684 * fn_field list of overloaded instances.
1685 * Helper function for value_find_oload_list.
1686 * ARGP is a pointer to a pointer to a value (the object)
1687 * METHOD is a string containing the method name
1688 * OFFSET is the offset within the value
1689 * TYPE is the assumed type of the object
1690 * NUM_FNS is the number of overloaded instances
1691 * BASETYPE is set to the actual type of the subobject where the method is found
1692 * BOFFSET is the offset of the base subobject where the method is found */
1693
1694 static struct fn_field *
1695 find_method_list (struct value **argp, char *method, int offset,
1696 struct type *type, int *num_fns,
1697 struct type **basetype, int *boffset)
1698 {
1699 int i;
1700 struct fn_field *f;
1701 CHECK_TYPEDEF (type);
1702
1703 *num_fns = 0;
1704
1705 /* First check in object itself */
1706 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1707 {
1708 /* pai: FIXME What about operators and type conversions? */
1709 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1710 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
1711 {
1712 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
1713 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1714
1715 *num_fns = len;
1716 *basetype = type;
1717 *boffset = offset;
1718
1719 /* Resolve any stub methods. */
1720 check_stub_method_group (type, i);
1721
1722 return f;
1723 }
1724 }
1725
1726 /* Not found in object, check in base subobjects */
1727 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1728 {
1729 int base_offset;
1730 if (BASETYPE_VIA_VIRTUAL (type, i))
1731 {
1732 if (TYPE_HAS_VTABLE (type))
1733 {
1734 /* HP aCC compiled type, search for virtual base offset
1735 * according to HP/Taligent runtime spec. */
1736 int skip;
1737 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
1738 VALUE_CONTENTS_ALL (*argp),
1739 offset + VALUE_EMBEDDED_OFFSET (*argp),
1740 &base_offset, &skip);
1741 if (skip >= 0)
1742 error ("Virtual base class offset not found in vtable");
1743 }
1744 else
1745 {
1746 /* probably g++ runtime model */
1747 base_offset = value_offset (*argp) + offset;
1748 base_offset =
1749 baseclass_offset (type, i,
1750 VALUE_CONTENTS (*argp) + base_offset,
1751 VALUE_ADDRESS (*argp) + base_offset);
1752 if (base_offset == -1)
1753 error ("virtual baseclass botch");
1754 }
1755 }
1756 else
1757 /* non-virtual base, simply use bit position from debug info */
1758 {
1759 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1760 }
1761 f = find_method_list (argp, method, base_offset + offset,
1762 TYPE_BASECLASS (type, i), num_fns, basetype,
1763 boffset);
1764 if (f)
1765 return f;
1766 }
1767 return NULL;
1768 }
1769
1770 /* Return the list of overloaded methods of a specified name.
1771 * ARGP is a pointer to a pointer to a value (the object)
1772 * METHOD is the method name
1773 * OFFSET is the offset within the value contents
1774 * NUM_FNS is the number of overloaded instances
1775 * BASETYPE is set to the type of the base subobject that defines the method
1776 * BOFFSET is the offset of the base subobject which defines the method */
1777
1778 struct fn_field *
1779 value_find_oload_method_list (struct value **argp, char *method, int offset,
1780 int *num_fns, struct type **basetype,
1781 int *boffset)
1782 {
1783 struct type *t;
1784
1785 t = check_typedef (value_type (*argp));
1786
1787 /* code snarfed from value_struct_elt */
1788 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1789 {
1790 *argp = value_ind (*argp);
1791 /* Don't coerce fn pointer to fn and then back again! */
1792 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
1793 *argp = coerce_array (*argp);
1794 t = check_typedef (value_type (*argp));
1795 }
1796
1797 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
1798 error ("Not implemented: member type in value_find_oload_lis");
1799
1800 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
1801 && TYPE_CODE (t) != TYPE_CODE_UNION)
1802 error ("Attempt to extract a component of a value that is not a struct or union");
1803
1804 return find_method_list (argp, method, 0, t, num_fns, basetype, boffset);
1805 }
1806
1807 /* Given an array of argument types (ARGTYPES) (which includes an
1808 entry for "this" in the case of C++ methods), the number of
1809 arguments NARGS, the NAME of a function whether it's a method or
1810 not (METHOD), and the degree of laxness (LAX) in conforming to
1811 overload resolution rules in ANSI C++, find the best function that
1812 matches on the argument types according to the overload resolution
1813 rules.
1814
1815 In the case of class methods, the parameter OBJ is an object value
1816 in which to search for overloaded methods.
1817
1818 In the case of non-method functions, the parameter FSYM is a symbol
1819 corresponding to one of the overloaded functions.
1820
1821 Return value is an integer: 0 -> good match, 10 -> debugger applied
1822 non-standard coercions, 100 -> incompatible.
1823
1824 If a method is being searched for, VALP will hold the value.
1825 If a non-method is being searched for, SYMP will hold the symbol for it.
1826
1827 If a method is being searched for, and it is a static method,
1828 then STATICP will point to a non-zero value.
1829
1830 Note: This function does *not* check the value of
1831 overload_resolution. Caller must check it to see whether overload
1832 resolution is permitted.
1833 */
1834
1835 int
1836 find_overload_match (struct type **arg_types, int nargs, char *name, int method,
1837 int lax, struct value **objp, struct symbol *fsym,
1838 struct value **valp, struct symbol **symp, int *staticp)
1839 {
1840 struct value *obj = (objp ? *objp : NULL);
1841
1842 int oload_champ; /* Index of best overloaded function */
1843
1844 struct badness_vector *oload_champ_bv = NULL; /* The measure for the current best match */
1845
1846 struct value *temp = obj;
1847 struct fn_field *fns_ptr = NULL; /* For methods, the list of overloaded methods */
1848 struct symbol **oload_syms = NULL; /* For non-methods, the list of overloaded function symbols */
1849 int num_fns = 0; /* Number of overloaded instances being considered */
1850 struct type *basetype = NULL;
1851 int boffset;
1852 int ix;
1853 int static_offset;
1854 struct cleanup *old_cleanups = NULL;
1855
1856 const char *obj_type_name = NULL;
1857 char *func_name = NULL;
1858 enum oload_classification match_quality;
1859
1860 /* Get the list of overloaded methods or functions */
1861 if (method)
1862 {
1863 obj_type_name = TYPE_NAME (value_type (obj));
1864 /* Hack: evaluate_subexp_standard often passes in a pointer
1865 value rather than the object itself, so try again */
1866 if ((!obj_type_name || !*obj_type_name) &&
1867 (TYPE_CODE (value_type (obj)) == TYPE_CODE_PTR))
1868 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (value_type (obj)));
1869
1870 fns_ptr = value_find_oload_method_list (&temp, name, 0,
1871 &num_fns,
1872 &basetype, &boffset);
1873 if (!fns_ptr || !num_fns)
1874 error ("Couldn't find method %s%s%s",
1875 obj_type_name,
1876 (obj_type_name && *obj_type_name) ? "::" : "",
1877 name);
1878 /* If we are dealing with stub method types, they should have
1879 been resolved by find_method_list via value_find_oload_method_list
1880 above. */
1881 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
1882 oload_champ = find_oload_champ (arg_types, nargs, method, num_fns,
1883 fns_ptr, oload_syms, &oload_champ_bv);
1884 }
1885 else
1886 {
1887 const char *qualified_name = SYMBOL_CPLUS_DEMANGLED_NAME (fsym);
1888 func_name = cp_func_name (qualified_name);
1889
1890 /* If the name is NULL this must be a C-style function.
1891 Just return the same symbol. */
1892 if (func_name == NULL)
1893 {
1894 *symp = fsym;
1895 return 0;
1896 }
1897
1898 old_cleanups = make_cleanup (xfree, func_name);
1899 make_cleanup (xfree, oload_syms);
1900 make_cleanup (xfree, oload_champ_bv);
1901
1902 oload_champ = find_oload_champ_namespace (arg_types, nargs,
1903 func_name,
1904 qualified_name,
1905 &oload_syms,
1906 &oload_champ_bv);
1907 }
1908
1909 /* Check how bad the best match is. */
1910
1911 match_quality
1912 = classify_oload_match (oload_champ_bv, nargs,
1913 oload_method_static (method, fns_ptr,
1914 oload_champ));
1915
1916 if (match_quality == INCOMPATIBLE)
1917 {
1918 if (method)
1919 error ("Cannot resolve method %s%s%s to any overloaded instance",
1920 obj_type_name,
1921 (obj_type_name && *obj_type_name) ? "::" : "",
1922 name);
1923 else
1924 error ("Cannot resolve function %s to any overloaded instance",
1925 func_name);
1926 }
1927 else if (match_quality == NON_STANDARD)
1928 {
1929 if (method)
1930 warning ("Using non-standard conversion to match method %s%s%s to supplied arguments",
1931 obj_type_name,
1932 (obj_type_name && *obj_type_name) ? "::" : "",
1933 name);
1934 else
1935 warning ("Using non-standard conversion to match function %s to supplied arguments",
1936 func_name);
1937 }
1938
1939 if (method)
1940 {
1941 if (staticp != NULL)
1942 *staticp = oload_method_static (method, fns_ptr, oload_champ);
1943 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
1944 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
1945 else
1946 *valp = value_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
1947 }
1948 else
1949 {
1950 *symp = oload_syms[oload_champ];
1951 }
1952
1953 if (objp)
1954 {
1955 if (TYPE_CODE (value_type (temp)) != TYPE_CODE_PTR
1956 && TYPE_CODE (value_type (*objp)) == TYPE_CODE_PTR)
1957 {
1958 temp = value_addr (temp);
1959 }
1960 *objp = temp;
1961 }
1962 if (old_cleanups != NULL)
1963 do_cleanups (old_cleanups);
1964
1965 switch (match_quality)
1966 {
1967 case INCOMPATIBLE:
1968 return 100;
1969 case NON_STANDARD:
1970 return 10;
1971 default: /* STANDARD */
1972 return 0;
1973 }
1974 }
1975
1976 /* Find the best overload match, searching for FUNC_NAME in namespaces
1977 contained in QUALIFIED_NAME until it either finds a good match or
1978 runs out of namespaces. It stores the overloaded functions in
1979 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
1980 calling function is responsible for freeing *OLOAD_SYMS and
1981 *OLOAD_CHAMP_BV. */
1982
1983 static int
1984 find_oload_champ_namespace (struct type **arg_types, int nargs,
1985 const char *func_name,
1986 const char *qualified_name,
1987 struct symbol ***oload_syms,
1988 struct badness_vector **oload_champ_bv)
1989 {
1990 int oload_champ;
1991
1992 find_oload_champ_namespace_loop (arg_types, nargs,
1993 func_name,
1994 qualified_name, 0,
1995 oload_syms, oload_champ_bv,
1996 &oload_champ);
1997
1998 return oload_champ;
1999 }
2000
2001 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2002 how deep we've looked for namespaces, and the champ is stored in
2003 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2004 if it isn't.
2005
2006 It is the caller's responsibility to free *OLOAD_SYMS and
2007 *OLOAD_CHAMP_BV. */
2008
2009 static int
2010 find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
2011 const char *func_name,
2012 const char *qualified_name,
2013 int namespace_len,
2014 struct symbol ***oload_syms,
2015 struct badness_vector **oload_champ_bv,
2016 int *oload_champ)
2017 {
2018 int next_namespace_len = namespace_len;
2019 int searched_deeper = 0;
2020 int num_fns = 0;
2021 struct cleanup *old_cleanups;
2022 int new_oload_champ;
2023 struct symbol **new_oload_syms;
2024 struct badness_vector *new_oload_champ_bv;
2025 char *new_namespace;
2026
2027 if (next_namespace_len != 0)
2028 {
2029 gdb_assert (qualified_name[next_namespace_len] == ':');
2030 next_namespace_len += 2;
2031 }
2032 next_namespace_len
2033 += cp_find_first_component (qualified_name + next_namespace_len);
2034
2035 /* Initialize these to values that can safely be xfree'd. */
2036 *oload_syms = NULL;
2037 *oload_champ_bv = NULL;
2038
2039 /* First, see if we have a deeper namespace we can search in. If we
2040 get a good match there, use it. */
2041
2042 if (qualified_name[next_namespace_len] == ':')
2043 {
2044 searched_deeper = 1;
2045
2046 if (find_oload_champ_namespace_loop (arg_types, nargs,
2047 func_name, qualified_name,
2048 next_namespace_len,
2049 oload_syms, oload_champ_bv,
2050 oload_champ))
2051 {
2052 return 1;
2053 }
2054 };
2055
2056 /* If we reach here, either we're in the deepest namespace or we
2057 didn't find a good match in a deeper namespace. But, in the
2058 latter case, we still have a bad match in a deeper namespace;
2059 note that we might not find any match at all in the current
2060 namespace. (There's always a match in the deepest namespace,
2061 because this overload mechanism only gets called if there's a
2062 function symbol to start off with.) */
2063
2064 old_cleanups = make_cleanup (xfree, *oload_syms);
2065 old_cleanups = make_cleanup (xfree, *oload_champ_bv);
2066 new_namespace = alloca (namespace_len + 1);
2067 strncpy (new_namespace, qualified_name, namespace_len);
2068 new_namespace[namespace_len] = '\0';
2069 new_oload_syms = make_symbol_overload_list (func_name,
2070 new_namespace);
2071 while (new_oload_syms[num_fns])
2072 ++num_fns;
2073
2074 new_oload_champ = find_oload_champ (arg_types, nargs, 0, num_fns,
2075 NULL, new_oload_syms,
2076 &new_oload_champ_bv);
2077
2078 /* Case 1: We found a good match. Free earlier matches (if any),
2079 and return it. Case 2: We didn't find a good match, but we're
2080 not the deepest function. Then go with the bad match that the
2081 deeper function found. Case 3: We found a bad match, and we're
2082 the deepest function. Then return what we found, even though
2083 it's a bad match. */
2084
2085 if (new_oload_champ != -1
2086 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2087 {
2088 *oload_syms = new_oload_syms;
2089 *oload_champ = new_oload_champ;
2090 *oload_champ_bv = new_oload_champ_bv;
2091 do_cleanups (old_cleanups);
2092 return 1;
2093 }
2094 else if (searched_deeper)
2095 {
2096 xfree (new_oload_syms);
2097 xfree (new_oload_champ_bv);
2098 discard_cleanups (old_cleanups);
2099 return 0;
2100 }
2101 else
2102 {
2103 gdb_assert (new_oload_champ != -1);
2104 *oload_syms = new_oload_syms;
2105 *oload_champ = new_oload_champ;
2106 *oload_champ_bv = new_oload_champ_bv;
2107 discard_cleanups (old_cleanups);
2108 return 0;
2109 }
2110 }
2111
2112 /* Look for a function to take NARGS args of types ARG_TYPES. Find
2113 the best match from among the overloaded methods or functions
2114 (depending on METHOD) given by FNS_PTR or OLOAD_SYMS, respectively.
2115 The number of methods/functions in the list is given by NUM_FNS.
2116 Return the index of the best match; store an indication of the
2117 quality of the match in OLOAD_CHAMP_BV.
2118
2119 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2120
2121 static int
2122 find_oload_champ (struct type **arg_types, int nargs, int method,
2123 int num_fns, struct fn_field *fns_ptr,
2124 struct symbol **oload_syms,
2125 struct badness_vector **oload_champ_bv)
2126 {
2127 int ix;
2128 struct badness_vector *bv; /* A measure of how good an overloaded instance is */
2129 int oload_champ = -1; /* Index of best overloaded function */
2130 int oload_ambiguous = 0; /* Current ambiguity state for overload resolution */
2131 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs */
2132
2133 *oload_champ_bv = NULL;
2134
2135 /* Consider each candidate in turn */
2136 for (ix = 0; ix < num_fns; ix++)
2137 {
2138 int jj;
2139 int static_offset = oload_method_static (method, fns_ptr, ix);
2140 int nparms;
2141 struct type **parm_types;
2142
2143 if (method)
2144 {
2145 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2146 }
2147 else
2148 {
2149 /* If it's not a method, this is the proper place */
2150 nparms=TYPE_NFIELDS(SYMBOL_TYPE(oload_syms[ix]));
2151 }
2152
2153 /* Prepare array of parameter types */
2154 parm_types = (struct type **) xmalloc (nparms * (sizeof (struct type *)));
2155 for (jj = 0; jj < nparms; jj++)
2156 parm_types[jj] = (method
2157 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2158 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]), jj));
2159
2160 /* Compare parameter types to supplied argument types. Skip THIS for
2161 static methods. */
2162 bv = rank_function (parm_types, nparms, arg_types + static_offset,
2163 nargs - static_offset);
2164
2165 if (!*oload_champ_bv)
2166 {
2167 *oload_champ_bv = bv;
2168 oload_champ = 0;
2169 }
2170 else
2171 /* See whether current candidate is better or worse than previous best */
2172 switch (compare_badness (bv, *oload_champ_bv))
2173 {
2174 case 0:
2175 oload_ambiguous = 1; /* top two contenders are equally good */
2176 break;
2177 case 1:
2178 oload_ambiguous = 2; /* incomparable top contenders */
2179 break;
2180 case 2:
2181 *oload_champ_bv = bv; /* new champion, record details */
2182 oload_ambiguous = 0;
2183 oload_champ = ix;
2184 break;
2185 case 3:
2186 default:
2187 break;
2188 }
2189 xfree (parm_types);
2190 if (overload_debug)
2191 {
2192 if (method)
2193 fprintf_filtered (gdb_stderr,"Overloaded method instance %s, # of parms %d\n", fns_ptr[ix].physname, nparms);
2194 else
2195 fprintf_filtered (gdb_stderr,"Overloaded function instance %s # of parms %d\n", SYMBOL_DEMANGLED_NAME (oload_syms[ix]), nparms);
2196 for (jj = 0; jj < nargs - static_offset; jj++)
2197 fprintf_filtered (gdb_stderr,"...Badness @ %d : %d\n", jj, bv->rank[jj]);
2198 fprintf_filtered (gdb_stderr,"Overload resolution champion is %d, ambiguous? %d\n", oload_champ, oload_ambiguous);
2199 }
2200 }
2201
2202 return oload_champ;
2203 }
2204
2205 /* Return 1 if we're looking at a static method, 0 if we're looking at
2206 a non-static method or a function that isn't a method. */
2207
2208 static int
2209 oload_method_static (int method, struct fn_field *fns_ptr, int index)
2210 {
2211 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
2212 return 1;
2213 else
2214 return 0;
2215 }
2216
2217 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
2218
2219 static enum oload_classification
2220 classify_oload_match (struct badness_vector *oload_champ_bv,
2221 int nargs,
2222 int static_offset)
2223 {
2224 int ix;
2225
2226 for (ix = 1; ix <= nargs - static_offset; ix++)
2227 {
2228 if (oload_champ_bv->rank[ix] >= 100)
2229 return INCOMPATIBLE; /* truly mismatched types */
2230 else if (oload_champ_bv->rank[ix] >= 10)
2231 return NON_STANDARD; /* non-standard type conversions needed */
2232 }
2233
2234 return STANDARD; /* Only standard conversions needed. */
2235 }
2236
2237 /* C++: return 1 is NAME is a legitimate name for the destructor
2238 of type TYPE. If TYPE does not have a destructor, or
2239 if NAME is inappropriate for TYPE, an error is signaled. */
2240 int
2241 destructor_name_p (const char *name, const struct type *type)
2242 {
2243 /* destructors are a special case. */
2244
2245 if (name[0] == '~')
2246 {
2247 char *dname = type_name_no_tag (type);
2248 char *cp = strchr (dname, '<');
2249 unsigned int len;
2250
2251 /* Do not compare the template part for template classes. */
2252 if (cp == NULL)
2253 len = strlen (dname);
2254 else
2255 len = cp - dname;
2256 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
2257 error ("name of destructor must equal name of class");
2258 else
2259 return 1;
2260 }
2261 return 0;
2262 }
2263
2264 /* Helper function for check_field: Given TYPE, a structure/union,
2265 return 1 if the component named NAME from the ultimate
2266 target structure/union is defined, otherwise, return 0. */
2267
2268 static int
2269 check_field_in (struct type *type, const char *name)
2270 {
2271 int i;
2272
2273 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2274 {
2275 char *t_field_name = TYPE_FIELD_NAME (type, i);
2276 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2277 return 1;
2278 }
2279
2280 /* C++: If it was not found as a data field, then try to
2281 return it as a pointer to a method. */
2282
2283 /* Destructors are a special case. */
2284 if (destructor_name_p (name, type))
2285 {
2286 int m_index, f_index;
2287
2288 return get_destructor_fn_field (type, &m_index, &f_index);
2289 }
2290
2291 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2292 {
2293 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2294 return 1;
2295 }
2296
2297 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2298 if (check_field_in (TYPE_BASECLASS (type, i), name))
2299 return 1;
2300
2301 return 0;
2302 }
2303
2304
2305 /* C++: Given ARG1, a value of type (pointer to a)* structure/union,
2306 return 1 if the component named NAME from the ultimate
2307 target structure/union is defined, otherwise, return 0. */
2308
2309 int
2310 check_field (struct value *arg1, const char *name)
2311 {
2312 struct type *t;
2313
2314 arg1 = coerce_array (arg1);
2315
2316 t = value_type (arg1);
2317
2318 /* Follow pointers until we get to a non-pointer. */
2319
2320 for (;;)
2321 {
2322 CHECK_TYPEDEF (t);
2323 if (TYPE_CODE (t) != TYPE_CODE_PTR && TYPE_CODE (t) != TYPE_CODE_REF)
2324 break;
2325 t = TYPE_TARGET_TYPE (t);
2326 }
2327
2328 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2329 error ("not implemented: member type in check_field");
2330
2331 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2332 && TYPE_CODE (t) != TYPE_CODE_UNION)
2333 error ("Internal error: `this' is not an aggregate");
2334
2335 return check_field_in (t, name);
2336 }
2337
2338 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2339 return the appropriate member. This function is used to resolve
2340 user expressions of the form "DOMAIN::NAME". For more details on
2341 what happens, see the comment before
2342 value_struct_elt_for_reference. */
2343
2344 struct value *
2345 value_aggregate_elt (struct type *curtype,
2346 char *name,
2347 enum noside noside)
2348 {
2349 switch (TYPE_CODE (curtype))
2350 {
2351 case TYPE_CODE_STRUCT:
2352 case TYPE_CODE_UNION:
2353 return value_struct_elt_for_reference (curtype, 0, curtype, name, NULL,
2354 noside);
2355 case TYPE_CODE_NAMESPACE:
2356 return value_namespace_elt (curtype, name, noside);
2357 default:
2358 internal_error (__FILE__, __LINE__,
2359 "non-aggregate type in value_aggregate_elt");
2360 }
2361 }
2362
2363 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2364 return the address of this member as a "pointer to member"
2365 type. If INTYPE is non-null, then it will be the type
2366 of the member we are looking for. This will help us resolve
2367 "pointers to member functions". This function is used
2368 to resolve user expressions of the form "DOMAIN::NAME". */
2369
2370 static struct value *
2371 value_struct_elt_for_reference (struct type *domain, int offset,
2372 struct type *curtype, char *name,
2373 struct type *intype,
2374 enum noside noside)
2375 {
2376 struct type *t = curtype;
2377 int i;
2378 struct value *v;
2379
2380 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2381 && TYPE_CODE (t) != TYPE_CODE_UNION)
2382 error ("Internal error: non-aggregate type to value_struct_elt_for_reference");
2383
2384 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
2385 {
2386 char *t_field_name = TYPE_FIELD_NAME (t, i);
2387
2388 if (t_field_name && strcmp (t_field_name, name) == 0)
2389 {
2390 if (TYPE_FIELD_STATIC (t, i))
2391 {
2392 v = value_static_field (t, i);
2393 if (v == NULL)
2394 error ("static field %s has been optimized out",
2395 name);
2396 return v;
2397 }
2398 if (TYPE_FIELD_PACKED (t, i))
2399 error ("pointers to bitfield members not allowed");
2400
2401 return value_from_longest
2402 (lookup_reference_type (lookup_member_type (TYPE_FIELD_TYPE (t, i),
2403 domain)),
2404 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
2405 }
2406 }
2407
2408 /* C++: If it was not found as a data field, then try to
2409 return it as a pointer to a method. */
2410
2411 /* Destructors are a special case. */
2412 if (destructor_name_p (name, t))
2413 {
2414 error ("member pointers to destructors not implemented yet");
2415 }
2416
2417 /* Perform all necessary dereferencing. */
2418 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
2419 intype = TYPE_TARGET_TYPE (intype);
2420
2421 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
2422 {
2423 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
2424 char dem_opname[64];
2425
2426 if (strncmp (t_field_name, "__", 2) == 0 ||
2427 strncmp (t_field_name, "op", 2) == 0 ||
2428 strncmp (t_field_name, "type", 4) == 0)
2429 {
2430 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2431 t_field_name = dem_opname;
2432 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2433 t_field_name = dem_opname;
2434 }
2435 if (t_field_name && strcmp (t_field_name, name) == 0)
2436 {
2437 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
2438 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
2439
2440 check_stub_method_group (t, i);
2441
2442 if (intype == 0 && j > 1)
2443 error ("non-unique member `%s' requires type instantiation", name);
2444 if (intype)
2445 {
2446 while (j--)
2447 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
2448 break;
2449 if (j < 0)
2450 error ("no member function matches that type instantiation");
2451 }
2452 else
2453 j = 0;
2454
2455 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2456 {
2457 return value_from_longest
2458 (lookup_reference_type
2459 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
2460 domain)),
2461 (LONGEST) METHOD_PTR_FROM_VOFFSET (TYPE_FN_FIELD_VOFFSET (f, j)));
2462 }
2463 else
2464 {
2465 struct symbol *s = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
2466 0, VAR_DOMAIN, 0, NULL);
2467 if (s == NULL)
2468 {
2469 v = 0;
2470 }
2471 else
2472 {
2473 v = read_var_value (s, 0);
2474 #if 0
2475 VALUE_TYPE (v) = lookup_reference_type
2476 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
2477 domain));
2478 #endif
2479 }
2480 return v;
2481 }
2482 }
2483 }
2484 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
2485 {
2486 struct value *v;
2487 int base_offset;
2488
2489 if (BASETYPE_VIA_VIRTUAL (t, i))
2490 base_offset = 0;
2491 else
2492 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
2493 v = value_struct_elt_for_reference (domain,
2494 offset + base_offset,
2495 TYPE_BASECLASS (t, i),
2496 name,
2497 intype,
2498 noside);
2499 if (v)
2500 return v;
2501 }
2502
2503 /* As a last chance, pretend that CURTYPE is a namespace, and look
2504 it up that way; this (frequently) works for types nested inside
2505 classes. */
2506
2507 return value_maybe_namespace_elt (curtype, name, noside);
2508 }
2509
2510 /* C++: Return the member NAME of the namespace given by the type
2511 CURTYPE. */
2512
2513 static struct value *
2514 value_namespace_elt (const struct type *curtype,
2515 char *name,
2516 enum noside noside)
2517 {
2518 struct value *retval = value_maybe_namespace_elt (curtype, name,
2519 noside);
2520
2521 if (retval == NULL)
2522 error ("No symbol \"%s\" in namespace \"%s\".", name,
2523 TYPE_TAG_NAME (curtype));
2524
2525 return retval;
2526 }
2527
2528 /* A helper function used by value_namespace_elt and
2529 value_struct_elt_for_reference. It looks up NAME inside the
2530 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
2531 is a class and NAME refers to a type in CURTYPE itself (as opposed
2532 to, say, some base class of CURTYPE). */
2533
2534 static struct value *
2535 value_maybe_namespace_elt (const struct type *curtype,
2536 char *name,
2537 enum noside noside)
2538 {
2539 const char *namespace_name = TYPE_TAG_NAME (curtype);
2540 struct symbol *sym;
2541
2542 sym = cp_lookup_symbol_namespace (namespace_name, name, NULL,
2543 get_selected_block (0), VAR_DOMAIN,
2544 NULL);
2545
2546 if (sym == NULL)
2547 return NULL;
2548 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
2549 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
2550 return allocate_value (SYMBOL_TYPE (sym));
2551 else
2552 return value_of_variable (sym, get_selected_block (0));
2553 }
2554
2555 /* Given a pointer value V, find the real (RTTI) type
2556 of the object it points to.
2557 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
2558 and refer to the values computed for the object pointed to. */
2559
2560 struct type *
2561 value_rtti_target_type (struct value *v, int *full, int *top, int *using_enc)
2562 {
2563 struct value *target;
2564
2565 target = value_ind (v);
2566
2567 return value_rtti_type (target, full, top, using_enc);
2568 }
2569
2570 /* Given a value pointed to by ARGP, check its real run-time type, and
2571 if that is different from the enclosing type, create a new value
2572 using the real run-time type as the enclosing type (and of the same
2573 type as ARGP) and return it, with the embedded offset adjusted to
2574 be the correct offset to the enclosed object
2575 RTYPE is the type, and XFULL, XTOP, and XUSING_ENC are the other
2576 parameters, computed by value_rtti_type(). If these are available,
2577 they can be supplied and a second call to value_rtti_type() is avoided.
2578 (Pass RTYPE == NULL if they're not available */
2579
2580 struct value *
2581 value_full_object (struct value *argp, struct type *rtype, int xfull, int xtop,
2582 int xusing_enc)
2583 {
2584 struct type *real_type;
2585 int full = 0;
2586 int top = -1;
2587 int using_enc = 0;
2588 struct value *new_val;
2589
2590 if (rtype)
2591 {
2592 real_type = rtype;
2593 full = xfull;
2594 top = xtop;
2595 using_enc = xusing_enc;
2596 }
2597 else
2598 real_type = value_rtti_type (argp, &full, &top, &using_enc);
2599
2600 /* If no RTTI data, or if object is already complete, do nothing */
2601 if (!real_type || real_type == VALUE_ENCLOSING_TYPE (argp))
2602 return argp;
2603
2604 /* If we have the full object, but for some reason the enclosing
2605 type is wrong, set it *//* pai: FIXME -- sounds iffy */
2606 if (full)
2607 {
2608 argp = value_change_enclosing_type (argp, real_type);
2609 return argp;
2610 }
2611
2612 /* Check if object is in memory */
2613 if (VALUE_LVAL (argp) != lval_memory)
2614 {
2615 warning ("Couldn't retrieve complete object of RTTI type %s; object may be in register(s).", TYPE_NAME (real_type));
2616
2617 return argp;
2618 }
2619
2620 /* All other cases -- retrieve the complete object */
2621 /* Go back by the computed top_offset from the beginning of the object,
2622 adjusting for the embedded offset of argp if that's what value_rtti_type
2623 used for its computation. */
2624 new_val = value_at_lazy (real_type, VALUE_ADDRESS (argp) - top +
2625 (using_enc ? 0 : VALUE_EMBEDDED_OFFSET (argp)));
2626 new_val->type = value_type (argp);
2627 VALUE_EMBEDDED_OFFSET (new_val) = using_enc ? top + VALUE_EMBEDDED_OFFSET (argp) : top;
2628 return new_val;
2629 }
2630
2631
2632
2633
2634 /* Return the value of the local variable, if one exists.
2635 Flag COMPLAIN signals an error if the request is made in an
2636 inappropriate context. */
2637
2638 struct value *
2639 value_of_local (const char *name, int complain)
2640 {
2641 struct symbol *func, *sym;
2642 struct block *b;
2643 struct value * ret;
2644
2645 if (deprecated_selected_frame == 0)
2646 {
2647 if (complain)
2648 error ("no frame selected");
2649 else
2650 return 0;
2651 }
2652
2653 func = get_frame_function (deprecated_selected_frame);
2654 if (!func)
2655 {
2656 if (complain)
2657 error ("no `%s' in nameless context", name);
2658 else
2659 return 0;
2660 }
2661
2662 b = SYMBOL_BLOCK_VALUE (func);
2663 if (dict_empty (BLOCK_DICT (b)))
2664 {
2665 if (complain)
2666 error ("no args, no `%s'", name);
2667 else
2668 return 0;
2669 }
2670
2671 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
2672 symbol instead of the LOC_ARG one (if both exist). */
2673 sym = lookup_block_symbol (b, name, NULL, VAR_DOMAIN);
2674 if (sym == NULL)
2675 {
2676 if (complain)
2677 error ("current stack frame does not contain a variable named `%s'", name);
2678 else
2679 return NULL;
2680 }
2681
2682 ret = read_var_value (sym, deprecated_selected_frame);
2683 if (ret == 0 && complain)
2684 error ("`%s' argument unreadable", name);
2685 return ret;
2686 }
2687
2688 /* C++/Objective-C: return the value of the class instance variable,
2689 if one exists. Flag COMPLAIN signals an error if the request is
2690 made in an inappropriate context. */
2691
2692 struct value *
2693 value_of_this (int complain)
2694 {
2695 if (current_language->la_language == language_objc)
2696 return value_of_local ("self", complain);
2697 else
2698 return value_of_local ("this", complain);
2699 }
2700
2701 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH elements
2702 long, starting at LOWBOUND. The result has the same lower bound as
2703 the original ARRAY. */
2704
2705 struct value *
2706 value_slice (struct value *array, int lowbound, int length)
2707 {
2708 struct type *slice_range_type, *slice_type, *range_type;
2709 LONGEST lowerbound, upperbound;
2710 struct value *slice;
2711 struct type *array_type;
2712 array_type = check_typedef (value_type (array));
2713 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
2714 && TYPE_CODE (array_type) != TYPE_CODE_STRING
2715 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
2716 error ("cannot take slice of non-array");
2717 range_type = TYPE_INDEX_TYPE (array_type);
2718 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
2719 error ("slice from bad array or bitstring");
2720 if (lowbound < lowerbound || length < 0
2721 || lowbound + length - 1 > upperbound)
2722 error ("slice out of range");
2723 /* FIXME-type-allocation: need a way to free this type when we are
2724 done with it. */
2725 slice_range_type = create_range_type ((struct type *) NULL,
2726 TYPE_TARGET_TYPE (range_type),
2727 lowbound, lowbound + length - 1);
2728 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
2729 {
2730 int i;
2731 slice_type = create_set_type ((struct type *) NULL, slice_range_type);
2732 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
2733 slice = value_zero (slice_type, not_lval);
2734 for (i = 0; i < length; i++)
2735 {
2736 int element = value_bit_index (array_type,
2737 VALUE_CONTENTS (array),
2738 lowbound + i);
2739 if (element < 0)
2740 error ("internal error accessing bitstring");
2741 else if (element > 0)
2742 {
2743 int j = i % TARGET_CHAR_BIT;
2744 if (BITS_BIG_ENDIAN)
2745 j = TARGET_CHAR_BIT - 1 - j;
2746 VALUE_CONTENTS_RAW (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
2747 }
2748 }
2749 /* We should set the address, bitssize, and bitspos, so the clice
2750 can be used on the LHS, but that may require extensions to
2751 value_assign. For now, just leave as a non_lval. FIXME. */
2752 }
2753 else
2754 {
2755 struct type *element_type = TYPE_TARGET_TYPE (array_type);
2756 LONGEST offset
2757 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
2758 slice_type = create_array_type ((struct type *) NULL, element_type,
2759 slice_range_type);
2760 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
2761 slice = allocate_value (slice_type);
2762 if (VALUE_LAZY (array))
2763 VALUE_LAZY (slice) = 1;
2764 else
2765 memcpy (VALUE_CONTENTS (slice), VALUE_CONTENTS (array) + offset,
2766 TYPE_LENGTH (slice_type));
2767 if (VALUE_LVAL (array) == lval_internalvar)
2768 VALUE_LVAL (slice) = lval_internalvar_component;
2769 else
2770 VALUE_LVAL (slice) = VALUE_LVAL (array);
2771 VALUE_ADDRESS (slice) = VALUE_ADDRESS (array);
2772 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
2773 slice->offset = value_offset (array) + offset;
2774 }
2775 return slice;
2776 }
2777
2778 /* Create a value for a FORTRAN complex number. Currently most of
2779 the time values are coerced to COMPLEX*16 (i.e. a complex number
2780 composed of 2 doubles. This really should be a smarter routine
2781 that figures out precision inteligently as opposed to assuming
2782 doubles. FIXME: fmb */
2783
2784 struct value *
2785 value_literal_complex (struct value *arg1, struct value *arg2, struct type *type)
2786 {
2787 struct value *val;
2788 struct type *real_type = TYPE_TARGET_TYPE (type);
2789
2790 val = allocate_value (type);
2791 arg1 = value_cast (real_type, arg1);
2792 arg2 = value_cast (real_type, arg2);
2793
2794 memcpy (VALUE_CONTENTS_RAW (val),
2795 VALUE_CONTENTS (arg1), TYPE_LENGTH (real_type));
2796 memcpy (VALUE_CONTENTS_RAW (val) + TYPE_LENGTH (real_type),
2797 VALUE_CONTENTS (arg2), TYPE_LENGTH (real_type));
2798 return val;
2799 }
2800
2801 /* Cast a value into the appropriate complex data type. */
2802
2803 static struct value *
2804 cast_into_complex (struct type *type, struct value *val)
2805 {
2806 struct type *real_type = TYPE_TARGET_TYPE (type);
2807 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
2808 {
2809 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
2810 struct value *re_val = allocate_value (val_real_type);
2811 struct value *im_val = allocate_value (val_real_type);
2812
2813 memcpy (VALUE_CONTENTS_RAW (re_val),
2814 VALUE_CONTENTS (val), TYPE_LENGTH (val_real_type));
2815 memcpy (VALUE_CONTENTS_RAW (im_val),
2816 VALUE_CONTENTS (val) + TYPE_LENGTH (val_real_type),
2817 TYPE_LENGTH (val_real_type));
2818
2819 return value_literal_complex (re_val, im_val, type);
2820 }
2821 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
2822 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
2823 return value_literal_complex (val, value_zero (real_type, not_lval), type);
2824 else
2825 error ("cannot cast non-number to complex");
2826 }
2827
2828 void
2829 _initialize_valops (void)
2830 {
2831 #if 0
2832 deprecated_add_show_from_set
2833 (add_set_cmd ("abandon", class_support, var_boolean, (char *) &auto_abandon,
2834 "Set automatic abandonment of expressions upon failure.",
2835 &setlist),
2836 &showlist);
2837 #endif
2838
2839 deprecated_add_show_from_set
2840 (add_set_cmd ("overload-resolution", class_support, var_boolean, (char *) &overload_resolution,
2841 "Set overload resolution in evaluating C++ functions.",
2842 &setlist),
2843 &showlist);
2844 overload_resolution = 1;
2845 }
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