* arch-utils.h (legacy_register_to_value): Declare.
[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
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
37 #include <errno.h>
38 #include "gdb_string.h"
39 #include "gdb_assert.h"
40
41 /* Flag indicating HP compilers were used; needed to correctly handle some
42 value operations with HP aCC code/runtime. */
43 extern int hp_som_som_object_present;
44
45 extern int overload_debug;
46 /* Local functions. */
47
48 static int typecmp (int staticp, struct type *t1[], struct value *t2[]);
49
50 static CORE_ADDR find_function_addr (struct value *, struct type **);
51 static struct value *value_arg_coerce (struct value *, struct type *, int);
52
53
54 static CORE_ADDR value_push (CORE_ADDR, struct value *);
55
56 static struct value *search_struct_field (char *, struct value *, int,
57 struct type *, int);
58
59 static struct value *search_struct_method (char *, struct value **,
60 struct value **,
61 int, int *, struct type *);
62
63 static int check_field_in (struct type *, const char *);
64
65 static CORE_ADDR allocate_space_in_inferior (int);
66
67 static struct value *cast_into_complex (struct type *, struct value *);
68
69 static struct fn_field *find_method_list (struct value ** argp, char *method,
70 int offset,
71 struct type *type, int *num_fns,
72 struct type **basetype,
73 int *boffset);
74
75 void _initialize_valops (void);
76
77 /* Flag for whether we want to abandon failed expression evals by default. */
78
79 #if 0
80 static int auto_abandon = 0;
81 #endif
82
83 int overload_resolution = 0;
84
85 /* This boolean tells what gdb should do if a signal is received while in
86 a function called from gdb (call dummy). If set, gdb unwinds the stack
87 and restore the context to what as it was before the call.
88 The default is to stop in the frame where the signal was received. */
89
90 int unwind_on_signal_p = 0;
91 \f
92
93
94 /* Find the address of function name NAME in the inferior. */
95
96 struct value *
97 find_function_in_inferior (char *name)
98 {
99 register struct symbol *sym;
100 sym = lookup_symbol (name, 0, VAR_NAMESPACE, 0, NULL);
101 if (sym != NULL)
102 {
103 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
104 {
105 error ("\"%s\" exists in this program but is not a function.",
106 name);
107 }
108 return value_of_variable (sym, NULL);
109 }
110 else
111 {
112 struct minimal_symbol *msymbol = lookup_minimal_symbol (name, NULL, NULL);
113 if (msymbol != NULL)
114 {
115 struct type *type;
116 CORE_ADDR maddr;
117 type = lookup_pointer_type (builtin_type_char);
118 type = lookup_function_type (type);
119 type = lookup_pointer_type (type);
120 maddr = SYMBOL_VALUE_ADDRESS (msymbol);
121 return value_from_pointer (type, maddr);
122 }
123 else
124 {
125 if (!target_has_execution)
126 error ("evaluation of this expression requires the target program to be active");
127 else
128 error ("evaluation of this expression requires the program to have a function \"%s\".", name);
129 }
130 }
131 }
132
133 /* Allocate NBYTES of space in the inferior using the inferior's malloc
134 and return a value that is a pointer to the allocated space. */
135
136 struct value *
137 value_allocate_space_in_inferior (int len)
138 {
139 struct value *blocklen;
140 struct value *val = find_function_in_inferior ("malloc");
141
142 blocklen = value_from_longest (builtin_type_int, (LONGEST) len);
143 val = call_function_by_hand (val, 1, &blocklen);
144 if (value_logical_not (val))
145 {
146 if (!target_has_execution)
147 error ("No memory available to program now: you need to start the target first");
148 else
149 error ("No memory available to program: call to malloc failed");
150 }
151 return val;
152 }
153
154 static CORE_ADDR
155 allocate_space_in_inferior (int len)
156 {
157 return value_as_long (value_allocate_space_in_inferior (len));
158 }
159
160 /* Cast value ARG2 to type TYPE and return as a value.
161 More general than a C cast: accepts any two types of the same length,
162 and if ARG2 is an lvalue it can be cast into anything at all. */
163 /* In C++, casts may change pointer or object representations. */
164
165 struct value *
166 value_cast (struct type *type, struct value *arg2)
167 {
168 register enum type_code code1;
169 register enum type_code code2;
170 register int scalar;
171 struct type *type2;
172
173 int convert_to_boolean = 0;
174
175 if (VALUE_TYPE (arg2) == type)
176 return arg2;
177
178 CHECK_TYPEDEF (type);
179 code1 = TYPE_CODE (type);
180 COERCE_REF (arg2);
181 type2 = check_typedef (VALUE_TYPE (arg2));
182
183 /* A cast to an undetermined-length array_type, such as (TYPE [])OBJECT,
184 is treated like a cast to (TYPE [N])OBJECT,
185 where N is sizeof(OBJECT)/sizeof(TYPE). */
186 if (code1 == TYPE_CODE_ARRAY)
187 {
188 struct type *element_type = TYPE_TARGET_TYPE (type);
189 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
190 if (element_length > 0
191 && TYPE_ARRAY_UPPER_BOUND_TYPE (type) == BOUND_CANNOT_BE_DETERMINED)
192 {
193 struct type *range_type = TYPE_INDEX_TYPE (type);
194 int val_length = TYPE_LENGTH (type2);
195 LONGEST low_bound, high_bound, new_length;
196 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
197 low_bound = 0, high_bound = 0;
198 new_length = val_length / element_length;
199 if (val_length % element_length != 0)
200 warning ("array element type size does not divide object size in cast");
201 /* FIXME-type-allocation: need a way to free this type when we are
202 done with it. */
203 range_type = create_range_type ((struct type *) NULL,
204 TYPE_TARGET_TYPE (range_type),
205 low_bound,
206 new_length + low_bound - 1);
207 VALUE_TYPE (arg2) = create_array_type ((struct type *) NULL,
208 element_type, range_type);
209 return arg2;
210 }
211 }
212
213 if (current_language->c_style_arrays
214 && TYPE_CODE (type2) == TYPE_CODE_ARRAY)
215 arg2 = value_coerce_array (arg2);
216
217 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
218 arg2 = value_coerce_function (arg2);
219
220 type2 = check_typedef (VALUE_TYPE (arg2));
221 COERCE_VARYING_ARRAY (arg2, type2);
222 code2 = TYPE_CODE (type2);
223
224 if (code1 == TYPE_CODE_COMPLEX)
225 return cast_into_complex (type, arg2);
226 if (code1 == TYPE_CODE_BOOL)
227 {
228 code1 = TYPE_CODE_INT;
229 convert_to_boolean = 1;
230 }
231 if (code1 == TYPE_CODE_CHAR)
232 code1 = TYPE_CODE_INT;
233 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
234 code2 = TYPE_CODE_INT;
235
236 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
237 || code2 == TYPE_CODE_ENUM || code2 == TYPE_CODE_RANGE);
238
239 if (code1 == TYPE_CODE_STRUCT
240 && code2 == TYPE_CODE_STRUCT
241 && TYPE_NAME (type) != 0)
242 {
243 /* Look in the type of the source to see if it contains the
244 type of the target as a superclass. If so, we'll need to
245 offset the object in addition to changing its type. */
246 struct value *v = search_struct_field (type_name_no_tag (type),
247 arg2, 0, type2, 1);
248 if (v)
249 {
250 VALUE_TYPE (v) = type;
251 return v;
252 }
253 }
254 if (code1 == TYPE_CODE_FLT && scalar)
255 return value_from_double (type, value_as_double (arg2));
256 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
257 || code1 == TYPE_CODE_RANGE)
258 && (scalar || code2 == TYPE_CODE_PTR))
259 {
260 LONGEST longest;
261
262 if (hp_som_som_object_present && /* if target compiled by HP aCC */
263 (code2 == TYPE_CODE_PTR))
264 {
265 unsigned int *ptr;
266 struct value *retvalp;
267
268 switch (TYPE_CODE (TYPE_TARGET_TYPE (type2)))
269 {
270 /* With HP aCC, pointers to data members have a bias */
271 case TYPE_CODE_MEMBER:
272 retvalp = value_from_longest (type, value_as_long (arg2));
273 /* force evaluation */
274 ptr = (unsigned int *) VALUE_CONTENTS (retvalp);
275 *ptr &= ~0x20000000; /* zap 29th bit to remove bias */
276 return retvalp;
277
278 /* While pointers to methods don't really point to a function */
279 case TYPE_CODE_METHOD:
280 error ("Pointers to methods not supported with HP aCC");
281
282 default:
283 break; /* fall out and go to normal handling */
284 }
285 }
286
287 /* When we cast pointers to integers, we mustn't use
288 POINTER_TO_ADDRESS to find the address the pointer
289 represents, as value_as_long would. GDB should evaluate
290 expressions just as the compiler would --- and the compiler
291 sees a cast as a simple reinterpretation of the pointer's
292 bits. */
293 if (code2 == TYPE_CODE_PTR)
294 longest = extract_unsigned_integer (VALUE_CONTENTS (arg2),
295 TYPE_LENGTH (type2));
296 else
297 longest = value_as_long (arg2);
298 return value_from_longest (type, convert_to_boolean ?
299 (LONGEST) (longest ? 1 : 0) : longest);
300 }
301 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT ||
302 code2 == TYPE_CODE_ENUM ||
303 code2 == TYPE_CODE_RANGE))
304 {
305 /* TYPE_LENGTH (type) is the length of a pointer, but we really
306 want the length of an address! -- we are really dealing with
307 addresses (i.e., gdb representations) not pointers (i.e.,
308 target representations) here.
309
310 This allows things like "print *(int *)0x01000234" to work
311 without printing a misleading message -- which would
312 otherwise occur when dealing with a target having two byte
313 pointers and four byte addresses. */
314
315 int addr_bit = TARGET_ADDR_BIT;
316
317 LONGEST longest = value_as_long (arg2);
318 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
319 {
320 if (longest >= ((LONGEST) 1 << addr_bit)
321 || longest <= -((LONGEST) 1 << addr_bit))
322 warning ("value truncated");
323 }
324 return value_from_longest (type, longest);
325 }
326 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
327 {
328 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
329 {
330 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type));
331 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
332 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
333 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
334 && !value_logical_not (arg2))
335 {
336 struct value *v;
337
338 /* Look in the type of the source to see if it contains the
339 type of the target as a superclass. If so, we'll need to
340 offset the pointer rather than just change its type. */
341 if (TYPE_NAME (t1) != NULL)
342 {
343 v = search_struct_field (type_name_no_tag (t1),
344 value_ind (arg2), 0, t2, 1);
345 if (v)
346 {
347 v = value_addr (v);
348 VALUE_TYPE (v) = type;
349 return v;
350 }
351 }
352
353 /* Look in the type of the target to see if it contains the
354 type of the source as a superclass. If so, we'll need to
355 offset the pointer rather than just change its type.
356 FIXME: This fails silently with virtual inheritance. */
357 if (TYPE_NAME (t2) != NULL)
358 {
359 v = search_struct_field (type_name_no_tag (t2),
360 value_zero (t1, not_lval), 0, t1, 1);
361 if (v)
362 {
363 struct value *v2 = value_ind (arg2);
364 VALUE_ADDRESS (v2) -= VALUE_ADDRESS (v)
365 + VALUE_OFFSET (v);
366
367 /* JYG: adjust the new pointer value and
368 embedded offset. */
369 v2->aligner.contents[0] -= VALUE_EMBEDDED_OFFSET (v);
370 VALUE_EMBEDDED_OFFSET (v2) = 0;
371
372 v2 = value_addr (v2);
373 VALUE_TYPE (v2) = type;
374 return v2;
375 }
376 }
377 }
378 /* No superclass found, just fall through to change ptr type. */
379 }
380 VALUE_TYPE (arg2) = type;
381 arg2 = value_change_enclosing_type (arg2, type);
382 VALUE_POINTED_TO_OFFSET (arg2) = 0; /* pai: chk_val */
383 return arg2;
384 }
385 else if (chill_varying_type (type))
386 {
387 struct type *range1, *range2, *eltype1, *eltype2;
388 struct value *val;
389 int count1, count2;
390 LONGEST low_bound, high_bound;
391 char *valaddr, *valaddr_data;
392 /* For lint warning about eltype2 possibly uninitialized: */
393 eltype2 = NULL;
394 if (code2 == TYPE_CODE_BITSTRING)
395 error ("not implemented: converting bitstring to varying type");
396 if ((code2 != TYPE_CODE_ARRAY && code2 != TYPE_CODE_STRING)
397 || (eltype1 = check_typedef (TYPE_TARGET_TYPE (TYPE_FIELD_TYPE (type, 1))),
398 eltype2 = check_typedef (TYPE_TARGET_TYPE (type2)),
399 (TYPE_LENGTH (eltype1) != TYPE_LENGTH (eltype2)
400 /* || TYPE_CODE (eltype1) != TYPE_CODE (eltype2) */ )))
401 error ("Invalid conversion to varying type");
402 range1 = TYPE_FIELD_TYPE (TYPE_FIELD_TYPE (type, 1), 0);
403 range2 = TYPE_FIELD_TYPE (type2, 0);
404 if (get_discrete_bounds (range1, &low_bound, &high_bound) < 0)
405 count1 = -1;
406 else
407 count1 = high_bound - low_bound + 1;
408 if (get_discrete_bounds (range2, &low_bound, &high_bound) < 0)
409 count1 = -1, count2 = 0; /* To force error before */
410 else
411 count2 = high_bound - low_bound + 1;
412 if (count2 > count1)
413 error ("target varying type is too small");
414 val = allocate_value (type);
415 valaddr = VALUE_CONTENTS_RAW (val);
416 valaddr_data = valaddr + TYPE_FIELD_BITPOS (type, 1) / 8;
417 /* Set val's __var_length field to count2. */
418 store_signed_integer (valaddr, TYPE_LENGTH (TYPE_FIELD_TYPE (type, 0)),
419 count2);
420 /* Set the __var_data field to count2 elements copied from arg2. */
421 memcpy (valaddr_data, VALUE_CONTENTS (arg2),
422 count2 * TYPE_LENGTH (eltype2));
423 /* Zero the rest of the __var_data field of val. */
424 memset (valaddr_data + count2 * TYPE_LENGTH (eltype2), '\0',
425 (count1 - count2) * TYPE_LENGTH (eltype2));
426 return val;
427 }
428 else if (VALUE_LVAL (arg2) == lval_memory)
429 {
430 return value_at_lazy (type, VALUE_ADDRESS (arg2) + VALUE_OFFSET (arg2),
431 VALUE_BFD_SECTION (arg2));
432 }
433 else if (code1 == TYPE_CODE_VOID)
434 {
435 return value_zero (builtin_type_void, not_lval);
436 }
437 else
438 {
439 error ("Invalid cast.");
440 return 0;
441 }
442 }
443
444 /* Create a value of type TYPE that is zero, and return it. */
445
446 struct value *
447 value_zero (struct type *type, enum lval_type lv)
448 {
449 struct value *val = allocate_value (type);
450
451 memset (VALUE_CONTENTS (val), 0, TYPE_LENGTH (check_typedef (type)));
452 VALUE_LVAL (val) = lv;
453
454 return val;
455 }
456
457 /* Return a value with type TYPE located at ADDR.
458
459 Call value_at only if the data needs to be fetched immediately;
460 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
461 value_at_lazy instead. value_at_lazy simply records the address of
462 the data and sets the lazy-evaluation-required flag. The lazy flag
463 is tested in the VALUE_CONTENTS macro, which is used if and when
464 the contents are actually required.
465
466 Note: value_at does *NOT* handle embedded offsets; perform such
467 adjustments before or after calling it. */
468
469 struct value *
470 value_at (struct type *type, CORE_ADDR addr, asection *sect)
471 {
472 struct value *val;
473
474 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
475 error ("Attempt to dereference a generic pointer.");
476
477 val = allocate_value (type);
478
479 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), TYPE_LENGTH (type));
480
481 VALUE_LVAL (val) = lval_memory;
482 VALUE_ADDRESS (val) = addr;
483 VALUE_BFD_SECTION (val) = sect;
484
485 return val;
486 }
487
488 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
489
490 struct value *
491 value_at_lazy (struct type *type, CORE_ADDR addr, asection *sect)
492 {
493 struct value *val;
494
495 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
496 error ("Attempt to dereference a generic pointer.");
497
498 val = allocate_value (type);
499
500 VALUE_LVAL (val) = lval_memory;
501 VALUE_ADDRESS (val) = addr;
502 VALUE_LAZY (val) = 1;
503 VALUE_BFD_SECTION (val) = sect;
504
505 return val;
506 }
507
508 /* Called only from the VALUE_CONTENTS and VALUE_CONTENTS_ALL macros,
509 if the current data for a variable needs to be loaded into
510 VALUE_CONTENTS(VAL). Fetches the data from the user's process, and
511 clears the lazy flag to indicate that the data in the buffer is valid.
512
513 If the value is zero-length, we avoid calling read_memory, which would
514 abort. We mark the value as fetched anyway -- all 0 bytes of it.
515
516 This function returns a value because it is used in the VALUE_CONTENTS
517 macro as part of an expression, where a void would not work. The
518 value is ignored. */
519
520 int
521 value_fetch_lazy (struct value *val)
522 {
523 CORE_ADDR addr = VALUE_ADDRESS (val) + VALUE_OFFSET (val);
524 int length = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val));
525
526 struct type *type = VALUE_TYPE (val);
527 if (length)
528 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), length);
529
530 VALUE_LAZY (val) = 0;
531 return 0;
532 }
533
534
535 /* Store the contents of FROMVAL into the location of TOVAL.
536 Return a new value with the location of TOVAL and contents of FROMVAL. */
537
538 struct value *
539 value_assign (struct value *toval, struct value *fromval)
540 {
541 register struct type *type;
542 struct value *val;
543 char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE);
544 int use_buffer = 0;
545
546 if (!toval->modifiable)
547 error ("Left operand of assignment is not a modifiable lvalue.");
548
549 COERCE_REF (toval);
550
551 type = VALUE_TYPE (toval);
552 if (VALUE_LVAL (toval) != lval_internalvar)
553 fromval = value_cast (type, fromval);
554 else
555 COERCE_ARRAY (fromval);
556 CHECK_TYPEDEF (type);
557
558 /* If TOVAL is a special machine register requiring conversion
559 of program values to a special raw format,
560 convert FROMVAL's contents now, with result in `raw_buffer',
561 and set USE_BUFFER to the number of bytes to write. */
562
563 if (VALUE_REGNO (toval) >= 0)
564 {
565 int regno = VALUE_REGNO (toval);
566 if (CONVERT_REGISTER_P (regno))
567 {
568 struct type *fromtype = check_typedef (VALUE_TYPE (fromval));
569 VALUE_TO_REGISTER (fromtype, regno, VALUE_CONTENTS (fromval), raw_buffer);
570 use_buffer = REGISTER_RAW_SIZE (regno);
571 }
572 }
573
574 switch (VALUE_LVAL (toval))
575 {
576 case lval_internalvar:
577 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
578 val = value_copy (VALUE_INTERNALVAR (toval)->value);
579 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
580 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
581 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
582 return val;
583
584 case lval_internalvar_component:
585 set_internalvar_component (VALUE_INTERNALVAR (toval),
586 VALUE_OFFSET (toval),
587 VALUE_BITPOS (toval),
588 VALUE_BITSIZE (toval),
589 fromval);
590 break;
591
592 case lval_memory:
593 {
594 char *dest_buffer;
595 CORE_ADDR changed_addr;
596 int changed_len;
597
598 if (VALUE_BITSIZE (toval))
599 {
600 char buffer[sizeof (LONGEST)];
601 /* We assume that the argument to read_memory is in units of
602 host chars. FIXME: Is that correct? */
603 changed_len = (VALUE_BITPOS (toval)
604 + VALUE_BITSIZE (toval)
605 + HOST_CHAR_BIT - 1)
606 / HOST_CHAR_BIT;
607
608 if (changed_len > (int) sizeof (LONGEST))
609 error ("Can't handle bitfields which don't fit in a %d bit word.",
610 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
611
612 read_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
613 buffer, changed_len);
614 modify_field (buffer, value_as_long (fromval),
615 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
616 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
617 dest_buffer = buffer;
618 }
619 else if (use_buffer)
620 {
621 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
622 changed_len = use_buffer;
623 dest_buffer = raw_buffer;
624 }
625 else
626 {
627 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
628 changed_len = TYPE_LENGTH (type);
629 dest_buffer = VALUE_CONTENTS (fromval);
630 }
631
632 write_memory (changed_addr, dest_buffer, changed_len);
633 if (memory_changed_hook)
634 memory_changed_hook (changed_addr, changed_len);
635 }
636 break;
637
638 case lval_register:
639 if (VALUE_BITSIZE (toval))
640 {
641 char buffer[sizeof (LONGEST)];
642 int len =
643 REGISTER_RAW_SIZE (VALUE_REGNO (toval)) - VALUE_OFFSET (toval);
644
645 if (len > (int) sizeof (LONGEST))
646 error ("Can't handle bitfields in registers larger than %d bits.",
647 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
648
649 if (VALUE_BITPOS (toval) + VALUE_BITSIZE (toval)
650 > len * HOST_CHAR_BIT)
651 /* Getting this right would involve being very careful about
652 byte order. */
653 error ("Can't assign to bitfields that cross register "
654 "boundaries.");
655
656 read_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
657 buffer, len);
658 modify_field (buffer, value_as_long (fromval),
659 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
660 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
661 buffer, len);
662 }
663 else if (use_buffer)
664 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
665 raw_buffer, use_buffer);
666 else
667 {
668 /* Do any conversion necessary when storing this type to more
669 than one register. */
670 #ifdef REGISTER_CONVERT_FROM_TYPE
671 memcpy (raw_buffer, VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
672 REGISTER_CONVERT_FROM_TYPE (VALUE_REGNO (toval), type, raw_buffer);
673 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
674 raw_buffer, TYPE_LENGTH (type));
675 #else
676 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
677 VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
678 #endif
679 }
680 /* Assigning to the stack pointer, frame pointer, and other
681 (architecture and calling convention specific) registers may
682 cause the frame cache to be out of date. We just do this
683 on all assignments to registers for simplicity; I doubt the slowdown
684 matters. */
685 reinit_frame_cache ();
686 break;
687
688 case lval_reg_frame_relative:
689 {
690 /* value is stored in a series of registers in the frame
691 specified by the structure. Copy that value out, modify
692 it, and copy it back in. */
693 int amount_to_copy = (VALUE_BITSIZE (toval) ? 1 : TYPE_LENGTH (type));
694 int reg_size = REGISTER_RAW_SIZE (VALUE_FRAME_REGNUM (toval));
695 int byte_offset = VALUE_OFFSET (toval) % reg_size;
696 int reg_offset = VALUE_OFFSET (toval) / reg_size;
697 int amount_copied;
698
699 /* Make the buffer large enough in all cases. */
700 /* FIXME (alloca): Not safe for very large data types. */
701 char *buffer = (char *) alloca (amount_to_copy
702 + sizeof (LONGEST)
703 + MAX_REGISTER_RAW_SIZE);
704
705 int regno;
706 struct frame_info *frame;
707
708 /* Figure out which frame this is in currently. */
709 for (frame = get_current_frame ();
710 frame && FRAME_FP (frame) != VALUE_FRAME (toval);
711 frame = get_prev_frame (frame))
712 ;
713
714 if (!frame)
715 error ("Value being assigned to is no longer active.");
716
717 amount_to_copy += (reg_size - amount_to_copy % reg_size);
718
719 /* Copy it out. */
720 for ((regno = VALUE_FRAME_REGNUM (toval) + reg_offset,
721 amount_copied = 0);
722 amount_copied < amount_to_copy;
723 amount_copied += reg_size, regno++)
724 {
725 get_saved_register (buffer + amount_copied,
726 (int *) NULL, (CORE_ADDR *) NULL,
727 frame, regno, (enum lval_type *) NULL);
728 }
729
730 /* Modify what needs to be modified. */
731 if (VALUE_BITSIZE (toval))
732 modify_field (buffer + byte_offset,
733 value_as_long (fromval),
734 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
735 else if (use_buffer)
736 memcpy (buffer + byte_offset, raw_buffer, use_buffer);
737 else
738 memcpy (buffer + byte_offset, VALUE_CONTENTS (fromval),
739 TYPE_LENGTH (type));
740
741 /* Copy it back. */
742 for ((regno = VALUE_FRAME_REGNUM (toval) + reg_offset,
743 amount_copied = 0);
744 amount_copied < amount_to_copy;
745 amount_copied += reg_size, regno++)
746 {
747 enum lval_type lval;
748 CORE_ADDR addr;
749 int optim;
750
751 /* Just find out where to put it. */
752 get_saved_register ((char *) NULL,
753 &optim, &addr, frame, regno, &lval);
754
755 if (optim)
756 error ("Attempt to assign to a value that was optimized out.");
757 if (lval == lval_memory)
758 write_memory (addr, buffer + amount_copied, reg_size);
759 else if (lval == lval_register)
760 write_register_bytes (addr, buffer + amount_copied, reg_size);
761 else
762 error ("Attempt to assign to an unmodifiable value.");
763 }
764
765 if (register_changed_hook)
766 register_changed_hook (-1);
767 }
768 break;
769
770
771 default:
772 error ("Left operand of assignment is not an lvalue.");
773 }
774
775 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
776 If the field is signed, and is negative, then sign extend. */
777 if ((VALUE_BITSIZE (toval) > 0)
778 && (VALUE_BITSIZE (toval) < 8 * (int) sizeof (LONGEST)))
779 {
780 LONGEST fieldval = value_as_long (fromval);
781 LONGEST valmask = (((ULONGEST) 1) << VALUE_BITSIZE (toval)) - 1;
782
783 fieldval &= valmask;
784 if (!TYPE_UNSIGNED (type) && (fieldval & (valmask ^ (valmask >> 1))))
785 fieldval |= ~valmask;
786
787 fromval = value_from_longest (type, fieldval);
788 }
789
790 val = value_copy (toval);
791 memcpy (VALUE_CONTENTS_RAW (val), VALUE_CONTENTS (fromval),
792 TYPE_LENGTH (type));
793 VALUE_TYPE (val) = type;
794 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
795 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
796 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
797
798 return val;
799 }
800
801 /* Extend a value VAL to COUNT repetitions of its type. */
802
803 struct value *
804 value_repeat (struct value *arg1, int count)
805 {
806 struct value *val;
807
808 if (VALUE_LVAL (arg1) != lval_memory)
809 error ("Only values in memory can be extended with '@'.");
810 if (count < 1)
811 error ("Invalid number %d of repetitions.", count);
812
813 val = allocate_repeat_value (VALUE_ENCLOSING_TYPE (arg1), count);
814
815 read_memory (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1),
816 VALUE_CONTENTS_ALL_RAW (val),
817 TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val)));
818 VALUE_LVAL (val) = lval_memory;
819 VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1);
820
821 return val;
822 }
823
824 struct value *
825 value_of_variable (struct symbol *var, struct block *b)
826 {
827 struct value *val;
828 struct frame_info *frame = NULL;
829
830 if (!b)
831 frame = NULL; /* Use selected frame. */
832 else if (symbol_read_needs_frame (var))
833 {
834 frame = block_innermost_frame (b);
835 if (!frame)
836 {
837 if (BLOCK_FUNCTION (b)
838 && SYMBOL_SOURCE_NAME (BLOCK_FUNCTION (b)))
839 error ("No frame is currently executing in block %s.",
840 SYMBOL_SOURCE_NAME (BLOCK_FUNCTION (b)));
841 else
842 error ("No frame is currently executing in specified block");
843 }
844 }
845
846 val = read_var_value (var, frame);
847 if (!val)
848 error ("Address of symbol \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var));
849
850 return val;
851 }
852
853 /* Given a value which is an array, return a value which is a pointer to its
854 first element, regardless of whether or not the array has a nonzero lower
855 bound.
856
857 FIXME: A previous comment here indicated that this routine should be
858 substracting the array's lower bound. It's not clear to me that this
859 is correct. Given an array subscripting operation, it would certainly
860 work to do the adjustment here, essentially computing:
861
862 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
863
864 However I believe a more appropriate and logical place to account for
865 the lower bound is to do so in value_subscript, essentially computing:
866
867 (&array[0] + ((index - lowerbound) * sizeof array[0]))
868
869 As further evidence consider what would happen with operations other
870 than array subscripting, where the caller would get back a value that
871 had an address somewhere before the actual first element of the array,
872 and the information about the lower bound would be lost because of
873 the coercion to pointer type.
874 */
875
876 struct value *
877 value_coerce_array (struct value *arg1)
878 {
879 register struct type *type = check_typedef (VALUE_TYPE (arg1));
880
881 if (VALUE_LVAL (arg1) != lval_memory)
882 error ("Attempt to take address of value not located in memory.");
883
884 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
885 (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
886 }
887
888 /* Given a value which is a function, return a value which is a pointer
889 to it. */
890
891 struct value *
892 value_coerce_function (struct value *arg1)
893 {
894 struct value *retval;
895
896 if (VALUE_LVAL (arg1) != lval_memory)
897 error ("Attempt to take address of value not located in memory.");
898
899 retval = value_from_pointer (lookup_pointer_type (VALUE_TYPE (arg1)),
900 (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
901 VALUE_BFD_SECTION (retval) = VALUE_BFD_SECTION (arg1);
902 return retval;
903 }
904
905 /* Return a pointer value for the object for which ARG1 is the contents. */
906
907 struct value *
908 value_addr (struct value *arg1)
909 {
910 struct value *arg2;
911
912 struct type *type = check_typedef (VALUE_TYPE (arg1));
913 if (TYPE_CODE (type) == TYPE_CODE_REF)
914 {
915 /* Copy the value, but change the type from (T&) to (T*).
916 We keep the same location information, which is efficient,
917 and allows &(&X) to get the location containing the reference. */
918 arg2 = value_copy (arg1);
919 VALUE_TYPE (arg2) = lookup_pointer_type (TYPE_TARGET_TYPE (type));
920 return arg2;
921 }
922 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
923 return value_coerce_function (arg1);
924
925 if (VALUE_LVAL (arg1) != lval_memory)
926 error ("Attempt to take address of value not located in memory.");
927
928 /* Get target memory address */
929 arg2 = value_from_pointer (lookup_pointer_type (VALUE_TYPE (arg1)),
930 (VALUE_ADDRESS (arg1)
931 + VALUE_OFFSET (arg1)
932 + VALUE_EMBEDDED_OFFSET (arg1)));
933
934 /* This may be a pointer to a base subobject; so remember the
935 full derived object's type ... */
936 arg2 = value_change_enclosing_type (arg2, lookup_pointer_type (VALUE_ENCLOSING_TYPE (arg1)));
937 /* ... and also the relative position of the subobject in the full object */
938 VALUE_POINTED_TO_OFFSET (arg2) = VALUE_EMBEDDED_OFFSET (arg1);
939 VALUE_BFD_SECTION (arg2) = VALUE_BFD_SECTION (arg1);
940 return arg2;
941 }
942
943 /* Given a value of a pointer type, apply the C unary * operator to it. */
944
945 struct value *
946 value_ind (struct value *arg1)
947 {
948 struct type *base_type;
949 struct value *arg2;
950
951 COERCE_ARRAY (arg1);
952
953 base_type = check_typedef (VALUE_TYPE (arg1));
954
955 if (TYPE_CODE (base_type) == TYPE_CODE_MEMBER)
956 error ("not implemented: member types in value_ind");
957
958 /* Allow * on an integer so we can cast it to whatever we want.
959 This returns an int, which seems like the most C-like thing
960 to do. "long long" variables are rare enough that
961 BUILTIN_TYPE_LONGEST would seem to be a mistake. */
962 if (TYPE_CODE (base_type) == TYPE_CODE_INT)
963 return value_at (builtin_type_int,
964 (CORE_ADDR) value_as_long (arg1),
965 VALUE_BFD_SECTION (arg1));
966 else if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
967 {
968 struct type *enc_type;
969 /* We may be pointing to something embedded in a larger object */
970 /* Get the real type of the enclosing object */
971 enc_type = check_typedef (VALUE_ENCLOSING_TYPE (arg1));
972 enc_type = TYPE_TARGET_TYPE (enc_type);
973 /* Retrieve the enclosing object pointed to */
974 arg2 = value_at_lazy (enc_type,
975 value_as_address (arg1) - VALUE_POINTED_TO_OFFSET (arg1),
976 VALUE_BFD_SECTION (arg1));
977 /* Re-adjust type */
978 VALUE_TYPE (arg2) = TYPE_TARGET_TYPE (base_type);
979 /* Add embedding info */
980 arg2 = value_change_enclosing_type (arg2, enc_type);
981 VALUE_EMBEDDED_OFFSET (arg2) = VALUE_POINTED_TO_OFFSET (arg1);
982
983 /* We may be pointing to an object of some derived type */
984 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
985 return arg2;
986 }
987
988 error ("Attempt to take contents of a non-pointer value.");
989 return 0; /* For lint -- never reached */
990 }
991 \f
992 /* Pushing small parts of stack frames. */
993
994 /* Push one word (the size of object that a register holds). */
995
996 CORE_ADDR
997 push_word (CORE_ADDR sp, ULONGEST word)
998 {
999 register int len = REGISTER_SIZE;
1000 char *buffer = alloca (MAX_REGISTER_RAW_SIZE);
1001
1002 store_unsigned_integer (buffer, len, word);
1003 if (INNER_THAN (1, 2))
1004 {
1005 /* stack grows downward */
1006 sp -= len;
1007 write_memory (sp, buffer, len);
1008 }
1009 else
1010 {
1011 /* stack grows upward */
1012 write_memory (sp, buffer, len);
1013 sp += len;
1014 }
1015
1016 return sp;
1017 }
1018
1019 /* Push LEN bytes with data at BUFFER. */
1020
1021 CORE_ADDR
1022 push_bytes (CORE_ADDR sp, char *buffer, int len)
1023 {
1024 if (INNER_THAN (1, 2))
1025 {
1026 /* stack grows downward */
1027 sp -= len;
1028 write_memory (sp, buffer, len);
1029 }
1030 else
1031 {
1032 /* stack grows upward */
1033 write_memory (sp, buffer, len);
1034 sp += len;
1035 }
1036
1037 return sp;
1038 }
1039
1040 #ifndef PARM_BOUNDARY
1041 #define PARM_BOUNDARY (0)
1042 #endif
1043
1044 /* Push onto the stack the specified value VALUE. Pad it correctly for
1045 it to be an argument to a function. */
1046
1047 static CORE_ADDR
1048 value_push (register CORE_ADDR sp, struct value *arg)
1049 {
1050 register int len = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg));
1051 register int container_len = len;
1052 register int offset;
1053
1054 /* How big is the container we're going to put this value in? */
1055 if (PARM_BOUNDARY)
1056 container_len = ((len + PARM_BOUNDARY / TARGET_CHAR_BIT - 1)
1057 & ~(PARM_BOUNDARY / TARGET_CHAR_BIT - 1));
1058
1059 /* Are we going to put it at the high or low end of the container? */
1060 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
1061 offset = container_len - len;
1062 else
1063 offset = 0;
1064
1065 if (INNER_THAN (1, 2))
1066 {
1067 /* stack grows downward */
1068 sp -= container_len;
1069 write_memory (sp + offset, VALUE_CONTENTS_ALL (arg), len);
1070 }
1071 else
1072 {
1073 /* stack grows upward */
1074 write_memory (sp + offset, VALUE_CONTENTS_ALL (arg), len);
1075 sp += container_len;
1076 }
1077
1078 return sp;
1079 }
1080
1081 CORE_ADDR
1082 default_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
1083 int struct_return, CORE_ADDR struct_addr)
1084 {
1085 /* ASSERT ( !struct_return); */
1086 int i;
1087 for (i = nargs - 1; i >= 0; i--)
1088 sp = value_push (sp, args[i]);
1089 return sp;
1090 }
1091
1092
1093 /* Functions to use for the COERCE_FLOAT_TO_DOUBLE gdbarch method.
1094
1095 How you should pass arguments to a function depends on whether it
1096 was defined in K&R style or prototype style. If you define a
1097 function using the K&R syntax that takes a `float' argument, then
1098 callers must pass that argument as a `double'. If you define the
1099 function using the prototype syntax, then you must pass the
1100 argument as a `float', with no promotion.
1101
1102 Unfortunately, on certain older platforms, the debug info doesn't
1103 indicate reliably how each function was defined. A function type's
1104 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
1105 defined in prototype style. When calling a function whose
1106 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults the
1107 COERCE_FLOAT_TO_DOUBLE gdbarch method to decide what to do.
1108
1109 For modern targets, it is proper to assume that, if the prototype
1110 flag is clear, that can be trusted: `float' arguments should be
1111 promoted to `double'. You should register the function
1112 `standard_coerce_float_to_double' to get this behavior.
1113
1114 For some older targets, if the prototype flag is clear, that
1115 doesn't tell us anything. So we guess that, if we don't have a
1116 type for the formal parameter (i.e., the first argument to
1117 COERCE_FLOAT_TO_DOUBLE is null), then we should promote it;
1118 otherwise, we should leave it alone. The function
1119 `default_coerce_float_to_double' provides this behavior; it is the
1120 default value, for compatibility with older configurations. */
1121 int
1122 default_coerce_float_to_double (struct type *formal, struct type *actual)
1123 {
1124 return formal == NULL;
1125 }
1126
1127
1128 int
1129 standard_coerce_float_to_double (struct type *formal, struct type *actual)
1130 {
1131 return 1;
1132 }
1133
1134
1135 /* Perform the standard coercions that are specified
1136 for arguments to be passed to C functions.
1137
1138 If PARAM_TYPE is non-NULL, it is the expected parameter type.
1139 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
1140
1141 static struct value *
1142 value_arg_coerce (struct value *arg, struct type *param_type,
1143 int is_prototyped)
1144 {
1145 register struct type *arg_type = check_typedef (VALUE_TYPE (arg));
1146 register struct type *type
1147 = param_type ? check_typedef (param_type) : arg_type;
1148
1149 switch (TYPE_CODE (type))
1150 {
1151 case TYPE_CODE_REF:
1152 if (TYPE_CODE (arg_type) != TYPE_CODE_REF
1153 && TYPE_CODE (arg_type) != TYPE_CODE_PTR)
1154 {
1155 arg = value_addr (arg);
1156 VALUE_TYPE (arg) = param_type;
1157 return arg;
1158 }
1159 break;
1160 case TYPE_CODE_INT:
1161 case TYPE_CODE_CHAR:
1162 case TYPE_CODE_BOOL:
1163 case TYPE_CODE_ENUM:
1164 /* If we don't have a prototype, coerce to integer type if necessary. */
1165 if (!is_prototyped)
1166 {
1167 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
1168 type = builtin_type_int;
1169 }
1170 /* Currently all target ABIs require at least the width of an integer
1171 type for an argument. We may have to conditionalize the following
1172 type coercion for future targets. */
1173 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
1174 type = builtin_type_int;
1175 break;
1176 case TYPE_CODE_FLT:
1177 /* FIXME: We should always convert floats to doubles in the
1178 non-prototyped case. As many debugging formats include
1179 no information about prototyping, we have to live with
1180 COERCE_FLOAT_TO_DOUBLE for now. */
1181 if (!is_prototyped && COERCE_FLOAT_TO_DOUBLE (param_type, arg_type))
1182 {
1183 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
1184 type = builtin_type_double;
1185 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double))
1186 type = builtin_type_long_double;
1187 }
1188 break;
1189 case TYPE_CODE_FUNC:
1190 type = lookup_pointer_type (type);
1191 break;
1192 case TYPE_CODE_ARRAY:
1193 /* Arrays are coerced to pointers to their first element, unless
1194 they are vectors, in which case we want to leave them alone,
1195 because they are passed by value. */
1196 if (current_language->c_style_arrays)
1197 if (!TYPE_VECTOR (type))
1198 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
1199 break;
1200 case TYPE_CODE_UNDEF:
1201 case TYPE_CODE_PTR:
1202 case TYPE_CODE_STRUCT:
1203 case TYPE_CODE_UNION:
1204 case TYPE_CODE_VOID:
1205 case TYPE_CODE_SET:
1206 case TYPE_CODE_RANGE:
1207 case TYPE_CODE_STRING:
1208 case TYPE_CODE_BITSTRING:
1209 case TYPE_CODE_ERROR:
1210 case TYPE_CODE_MEMBER:
1211 case TYPE_CODE_METHOD:
1212 case TYPE_CODE_COMPLEX:
1213 default:
1214 break;
1215 }
1216
1217 return value_cast (type, arg);
1218 }
1219
1220 /* Determine a function's address and its return type from its value.
1221 Calls error() if the function is not valid for calling. */
1222
1223 static CORE_ADDR
1224 find_function_addr (struct value *function, struct type **retval_type)
1225 {
1226 register struct type *ftype = check_typedef (VALUE_TYPE (function));
1227 register enum type_code code = TYPE_CODE (ftype);
1228 struct type *value_type;
1229 CORE_ADDR funaddr;
1230
1231 /* If it's a member function, just look at the function
1232 part of it. */
1233
1234 /* Determine address to call. */
1235 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
1236 {
1237 funaddr = VALUE_ADDRESS (function);
1238 value_type = TYPE_TARGET_TYPE (ftype);
1239 }
1240 else if (code == TYPE_CODE_PTR)
1241 {
1242 funaddr = value_as_address (function);
1243 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
1244 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
1245 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1246 {
1247 funaddr = CONVERT_FROM_FUNC_PTR_ADDR (funaddr);
1248 value_type = TYPE_TARGET_TYPE (ftype);
1249 }
1250 else
1251 value_type = builtin_type_int;
1252 }
1253 else if (code == TYPE_CODE_INT)
1254 {
1255 /* Handle the case of functions lacking debugging info.
1256 Their values are characters since their addresses are char */
1257 if (TYPE_LENGTH (ftype) == 1)
1258 funaddr = value_as_address (value_addr (function));
1259 else
1260 /* Handle integer used as address of a function. */
1261 funaddr = (CORE_ADDR) value_as_long (function);
1262
1263 value_type = builtin_type_int;
1264 }
1265 else
1266 error ("Invalid data type for function to be called.");
1267
1268 *retval_type = value_type;
1269 return funaddr;
1270 }
1271
1272 /* All this stuff with a dummy frame may seem unnecessarily complicated
1273 (why not just save registers in GDB?). The purpose of pushing a dummy
1274 frame which looks just like a real frame is so that if you call a
1275 function and then hit a breakpoint (get a signal, etc), "backtrace"
1276 will look right. Whether the backtrace needs to actually show the
1277 stack at the time the inferior function was called is debatable, but
1278 it certainly needs to not display garbage. So if you are contemplating
1279 making dummy frames be different from normal frames, consider that. */
1280
1281 /* Perform a function call in the inferior.
1282 ARGS is a vector of values of arguments (NARGS of them).
1283 FUNCTION is a value, the function to be called.
1284 Returns a value representing what the function returned.
1285 May fail to return, if a breakpoint or signal is hit
1286 during the execution of the function.
1287
1288 ARGS is modified to contain coerced values. */
1289
1290 static struct value *
1291 hand_function_call (struct value *function, int nargs, struct value **args)
1292 {
1293 register CORE_ADDR sp;
1294 register int i;
1295 int rc;
1296 CORE_ADDR start_sp;
1297 /* CALL_DUMMY is an array of words (REGISTER_SIZE), but each word
1298 is in host byte order. Before calling FIX_CALL_DUMMY, we byteswap it
1299 and remove any extra bytes which might exist because ULONGEST is
1300 bigger than REGISTER_SIZE.
1301
1302 NOTE: This is pretty wierd, as the call dummy is actually a
1303 sequence of instructions. But CISC machines will have
1304 to pack the instructions into REGISTER_SIZE units (and
1305 so will RISC machines for which INSTRUCTION_SIZE is not
1306 REGISTER_SIZE).
1307
1308 NOTE: This is pretty stupid. CALL_DUMMY should be in strict
1309 target byte order. */
1310
1311 static ULONGEST *dummy;
1312 int sizeof_dummy1;
1313 char *dummy1;
1314 CORE_ADDR old_sp;
1315 struct type *value_type;
1316 unsigned char struct_return;
1317 CORE_ADDR struct_addr = 0;
1318 struct inferior_status *inf_status;
1319 struct cleanup *old_chain;
1320 CORE_ADDR funaddr;
1321 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
1322 CORE_ADDR real_pc;
1323 struct type *param_type = NULL;
1324 struct type *ftype = check_typedef (SYMBOL_TYPE (function));
1325 int n_method_args = 0;
1326
1327 dummy = alloca (SIZEOF_CALL_DUMMY_WORDS);
1328 sizeof_dummy1 = REGISTER_SIZE * SIZEOF_CALL_DUMMY_WORDS / sizeof (ULONGEST);
1329 dummy1 = alloca (sizeof_dummy1);
1330 memcpy (dummy, CALL_DUMMY_WORDS, SIZEOF_CALL_DUMMY_WORDS);
1331
1332 if (!target_has_execution)
1333 noprocess ();
1334
1335 inf_status = save_inferior_status (1);
1336 old_chain = make_cleanup_restore_inferior_status (inf_status);
1337
1338 /* PUSH_DUMMY_FRAME is responsible for saving the inferior registers
1339 (and POP_FRAME for restoring them). (At least on most machines)
1340 they are saved on the stack in the inferior. */
1341 PUSH_DUMMY_FRAME;
1342
1343 old_sp = sp = read_sp ();
1344
1345 if (INNER_THAN (1, 2))
1346 {
1347 /* Stack grows down */
1348 sp -= sizeof_dummy1;
1349 start_sp = sp;
1350 }
1351 else
1352 {
1353 /* Stack grows up */
1354 start_sp = sp;
1355 sp += sizeof_dummy1;
1356 }
1357
1358 funaddr = find_function_addr (function, &value_type);
1359 CHECK_TYPEDEF (value_type);
1360
1361 {
1362 struct block *b = block_for_pc (funaddr);
1363 /* If compiled without -g, assume GCC 2. */
1364 using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
1365 }
1366
1367 /* Are we returning a value using a structure return or a normal
1368 value return? */
1369
1370 struct_return = using_struct_return (function, funaddr, value_type,
1371 using_gcc);
1372
1373 /* Create a call sequence customized for this function
1374 and the number of arguments for it. */
1375 for (i = 0; i < (int) (SIZEOF_CALL_DUMMY_WORDS / sizeof (dummy[0])); i++)
1376 store_unsigned_integer (&dummy1[i * REGISTER_SIZE],
1377 REGISTER_SIZE,
1378 (ULONGEST) dummy[i]);
1379
1380 #ifdef GDB_TARGET_IS_HPPA
1381 real_pc = FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
1382 value_type, using_gcc);
1383 #else
1384 FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
1385 value_type, using_gcc);
1386 real_pc = start_sp;
1387 #endif
1388
1389 if (CALL_DUMMY_LOCATION == ON_STACK)
1390 {
1391 write_memory (start_sp, (char *) dummy1, sizeof_dummy1);
1392 if (USE_GENERIC_DUMMY_FRAMES)
1393 generic_save_call_dummy_addr (start_sp, start_sp + sizeof_dummy1);
1394 }
1395
1396 if (CALL_DUMMY_LOCATION == BEFORE_TEXT_END)
1397 {
1398 /* Convex Unix prohibits executing in the stack segment. */
1399 /* Hope there is empty room at the top of the text segment. */
1400 extern CORE_ADDR text_end;
1401 static int checked = 0;
1402 if (!checked)
1403 for (start_sp = text_end - sizeof_dummy1; start_sp < text_end; ++start_sp)
1404 if (read_memory_integer (start_sp, 1) != 0)
1405 error ("text segment full -- no place to put call");
1406 checked = 1;
1407 sp = old_sp;
1408 real_pc = text_end - sizeof_dummy1;
1409 write_memory (real_pc, (char *) dummy1, sizeof_dummy1);
1410 if (USE_GENERIC_DUMMY_FRAMES)
1411 generic_save_call_dummy_addr (real_pc, real_pc + sizeof_dummy1);
1412 }
1413
1414 if (CALL_DUMMY_LOCATION == AFTER_TEXT_END)
1415 {
1416 extern CORE_ADDR text_end;
1417 int errcode;
1418 sp = old_sp;
1419 real_pc = text_end;
1420 errcode = target_write_memory (real_pc, (char *) dummy1, sizeof_dummy1);
1421 if (errcode != 0)
1422 error ("Cannot write text segment -- call_function failed");
1423 if (USE_GENERIC_DUMMY_FRAMES)
1424 generic_save_call_dummy_addr (real_pc, real_pc + sizeof_dummy1);
1425 }
1426
1427 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
1428 {
1429 real_pc = funaddr;
1430 if (USE_GENERIC_DUMMY_FRAMES)
1431 /* NOTE: cagney/2002-04-13: The entry point is going to be
1432 modified with a single breakpoint. */
1433 generic_save_call_dummy_addr (CALL_DUMMY_ADDRESS (),
1434 CALL_DUMMY_ADDRESS () + 1);
1435 }
1436
1437 #ifdef lint
1438 sp = old_sp; /* It really is used, for some ifdef's... */
1439 #endif
1440
1441 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1442 {
1443 i = 0;
1444 while (TYPE_CODE (TYPE_ARG_TYPES (ftype)[i]) != TYPE_CODE_VOID)
1445 i++;
1446 n_method_args = i;
1447 if (nargs < i)
1448 error ("too few arguments in method call");
1449 }
1450 else if (nargs < TYPE_NFIELDS (ftype))
1451 error ("too few arguments in function call");
1452
1453 for (i = nargs - 1; i >= 0; i--)
1454 {
1455 /* Assume that methods are always prototyped, unless they are off the
1456 end (which we should only be allowing if there is a ``...'').
1457 FIXME. */
1458 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1459 {
1460 if (i < n_method_args)
1461 args[i] = value_arg_coerce (args[i], TYPE_ARG_TYPES (ftype)[i], 1);
1462 else
1463 args[i] = value_arg_coerce (args[i], NULL, 0);
1464 }
1465
1466 /* If we're off the end of the known arguments, do the standard
1467 promotions. FIXME: if we had a prototype, this should only
1468 be allowed if ... were present. */
1469 if (i >= TYPE_NFIELDS (ftype))
1470 args[i] = value_arg_coerce (args[i], NULL, 0);
1471
1472 else
1473 {
1474 param_type = TYPE_FIELD_TYPE (ftype, i);
1475 args[i] = value_arg_coerce (args[i], param_type, TYPE_PROTOTYPED (ftype));
1476 }
1477
1478 /*elz: this code is to handle the case in which the function to be called
1479 has a pointer to function as parameter and the corresponding actual argument
1480 is the address of a function and not a pointer to function variable.
1481 In aCC compiled code, the calls through pointers to functions (in the body
1482 of the function called by hand) are made via $$dyncall_external which
1483 requires some registers setting, this is taken care of if we call
1484 via a function pointer variable, but not via a function address.
1485 In cc this is not a problem. */
1486
1487 if (using_gcc == 0)
1488 if (param_type)
1489 /* if this parameter is a pointer to function */
1490 if (TYPE_CODE (param_type) == TYPE_CODE_PTR)
1491 if (TYPE_CODE (param_type->target_type) == TYPE_CODE_FUNC)
1492 /* elz: FIXME here should go the test about the compiler used
1493 to compile the target. We want to issue the error
1494 message only if the compiler used was HP's aCC.
1495 If we used HP's cc, then there is no problem and no need
1496 to return at this point */
1497 if (using_gcc == 0) /* && compiler == aCC */
1498 /* go see if the actual parameter is a variable of type
1499 pointer to function or just a function */
1500 if (args[i]->lval == not_lval)
1501 {
1502 char *arg_name;
1503 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL))
1504 error ("\
1505 You cannot use function <%s> as argument. \n\
1506 You must use a pointer to function type variable. Command ignored.", arg_name);
1507 }
1508 }
1509
1510 if (REG_STRUCT_HAS_ADDR_P ())
1511 {
1512 /* This is a machine like the sparc, where we may need to pass a
1513 pointer to the structure, not the structure itself. */
1514 for (i = nargs - 1; i >= 0; i--)
1515 {
1516 struct type *arg_type = check_typedef (VALUE_TYPE (args[i]));
1517 if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT
1518 || TYPE_CODE (arg_type) == TYPE_CODE_UNION
1519 || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
1520 || TYPE_CODE (arg_type) == TYPE_CODE_STRING
1521 || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING
1522 || TYPE_CODE (arg_type) == TYPE_CODE_SET
1523 || (TYPE_CODE (arg_type) == TYPE_CODE_FLT
1524 && TYPE_LENGTH (arg_type) > 8)
1525 )
1526 && REG_STRUCT_HAS_ADDR (using_gcc, arg_type))
1527 {
1528 CORE_ADDR addr;
1529 int len; /* = TYPE_LENGTH (arg_type); */
1530 int aligned_len;
1531 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i]));
1532 len = TYPE_LENGTH (arg_type);
1533
1534 if (STACK_ALIGN_P ())
1535 /* MVS 11/22/96: I think at least some of this
1536 stack_align code is really broken. Better to let
1537 PUSH_ARGUMENTS adjust the stack in a target-defined
1538 manner. */
1539 aligned_len = STACK_ALIGN (len);
1540 else
1541 aligned_len = len;
1542 if (INNER_THAN (1, 2))
1543 {
1544 /* stack grows downward */
1545 sp -= aligned_len;
1546 /* ... so the address of the thing we push is the
1547 stack pointer after we push it. */
1548 addr = sp;
1549 }
1550 else
1551 {
1552 /* The stack grows up, so the address of the thing
1553 we push is the stack pointer before we push it. */
1554 addr = sp;
1555 sp += aligned_len;
1556 }
1557 /* Push the structure. */
1558 write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len);
1559 /* The value we're going to pass is the address of the
1560 thing we just pushed. */
1561 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
1562 (LONGEST) addr); */
1563 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
1564 addr);
1565 }
1566 }
1567 }
1568
1569
1570 /* Reserve space for the return structure to be written on the
1571 stack, if necessary */
1572
1573 if (struct_return)
1574 {
1575 int len = TYPE_LENGTH (value_type);
1576 if (STACK_ALIGN_P ())
1577 /* MVS 11/22/96: I think at least some of this stack_align
1578 code is really broken. Better to let PUSH_ARGUMENTS adjust
1579 the stack in a target-defined manner. */
1580 len = STACK_ALIGN (len);
1581 if (INNER_THAN (1, 2))
1582 {
1583 /* stack grows downward */
1584 sp -= len;
1585 struct_addr = sp;
1586 }
1587 else
1588 {
1589 /* stack grows upward */
1590 struct_addr = sp;
1591 sp += len;
1592 }
1593 }
1594
1595 /* elz: on HPPA no need for this extra alignment, maybe it is needed
1596 on other architectures. This is because all the alignment is
1597 taken care of in the above code (ifdef REG_STRUCT_HAS_ADDR) and
1598 in hppa_push_arguments */
1599 if (EXTRA_STACK_ALIGNMENT_NEEDED)
1600 {
1601 /* MVS 11/22/96: I think at least some of this stack_align code
1602 is really broken. Better to let PUSH_ARGUMENTS adjust the
1603 stack in a target-defined manner. */
1604 if (STACK_ALIGN_P () && INNER_THAN (1, 2))
1605 {
1606 /* If stack grows down, we must leave a hole at the top. */
1607 int len = 0;
1608
1609 for (i = nargs - 1; i >= 0; i--)
1610 len += TYPE_LENGTH (VALUE_ENCLOSING_TYPE (args[i]));
1611 if (CALL_DUMMY_STACK_ADJUST_P)
1612 len += CALL_DUMMY_STACK_ADJUST;
1613 sp -= STACK_ALIGN (len) - len;
1614 }
1615 }
1616
1617 sp = PUSH_ARGUMENTS (nargs, args, sp, struct_return, struct_addr);
1618
1619 if (PUSH_RETURN_ADDRESS_P ())
1620 /* for targets that use no CALL_DUMMY */
1621 /* There are a number of targets now which actually don't write
1622 any CALL_DUMMY instructions into the target, but instead just
1623 save the machine state, push the arguments, and jump directly
1624 to the callee function. Since this doesn't actually involve
1625 executing a JSR/BSR instruction, the return address must be set
1626 up by hand, either by pushing onto the stack or copying into a
1627 return-address register as appropriate. Formerly this has been
1628 done in PUSH_ARGUMENTS, but that's overloading its
1629 functionality a bit, so I'm making it explicit to do it here. */
1630 sp = PUSH_RETURN_ADDRESS (real_pc, sp);
1631
1632 if (STACK_ALIGN_P () && !INNER_THAN (1, 2))
1633 {
1634 /* If stack grows up, we must leave a hole at the bottom, note
1635 that sp already has been advanced for the arguments! */
1636 if (CALL_DUMMY_STACK_ADJUST_P)
1637 sp += CALL_DUMMY_STACK_ADJUST;
1638 sp = STACK_ALIGN (sp);
1639 }
1640
1641 /* XXX This seems wrong. For stacks that grow down we shouldn't do
1642 anything here! */
1643 /* MVS 11/22/96: I think at least some of this stack_align code is
1644 really broken. Better to let PUSH_ARGUMENTS adjust the stack in
1645 a target-defined manner. */
1646 if (CALL_DUMMY_STACK_ADJUST_P)
1647 if (INNER_THAN (1, 2))
1648 {
1649 /* stack grows downward */
1650 sp -= CALL_DUMMY_STACK_ADJUST;
1651 }
1652
1653 /* Store the address at which the structure is supposed to be
1654 written. Note that this (and the code which reserved the space
1655 above) assumes that gcc was used to compile this function. Since
1656 it doesn't cost us anything but space and if the function is pcc
1657 it will ignore this value, we will make that assumption.
1658
1659 Also note that on some machines (like the sparc) pcc uses a
1660 convention like gcc's. */
1661
1662 if (struct_return)
1663 STORE_STRUCT_RETURN (struct_addr, sp);
1664
1665 /* Write the stack pointer. This is here because the statements above
1666 might fool with it. On SPARC, this write also stores the register
1667 window into the right place in the new stack frame, which otherwise
1668 wouldn't happen. (See store_inferior_registers in sparc-nat.c.) */
1669 write_sp (sp);
1670
1671 if (SAVE_DUMMY_FRAME_TOS_P ())
1672 SAVE_DUMMY_FRAME_TOS (sp);
1673
1674 {
1675 char *retbuf = (char*) alloca (REGISTER_BYTES);
1676 char *name;
1677 struct symbol *symbol;
1678
1679 name = NULL;
1680 symbol = find_pc_function (funaddr);
1681 if (symbol)
1682 {
1683 name = SYMBOL_SOURCE_NAME (symbol);
1684 }
1685 else
1686 {
1687 /* Try the minimal symbols. */
1688 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
1689
1690 if (msymbol)
1691 {
1692 name = SYMBOL_SOURCE_NAME (msymbol);
1693 }
1694 }
1695 if (name == NULL)
1696 {
1697 char format[80];
1698 sprintf (format, "at %s", local_hex_format ());
1699 name = alloca (80);
1700 /* FIXME-32x64: assumes funaddr fits in a long. */
1701 sprintf (name, format, (unsigned long) funaddr);
1702 }
1703
1704 /* Execute the stack dummy routine, calling FUNCTION.
1705 When it is done, discard the empty frame
1706 after storing the contents of all regs into retbuf. */
1707 rc = run_stack_dummy (real_pc + CALL_DUMMY_START_OFFSET, retbuf);
1708
1709 if (rc == 1)
1710 {
1711 /* We stopped inside the FUNCTION because of a random signal.
1712 Further execution of the FUNCTION is not allowed. */
1713
1714 if (unwind_on_signal_p)
1715 {
1716 /* The user wants the context restored. */
1717
1718 /* We must get back to the frame we were before the dummy call. */
1719 POP_FRAME;
1720
1721 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1722 a C++ name with arguments and stuff. */
1723 error ("\
1724 The program being debugged was signaled while in a function called from GDB.\n\
1725 GDB has restored the context to what it was before the call.\n\
1726 To change this behavior use \"set unwindonsignal off\"\n\
1727 Evaluation of the expression containing the function (%s) will be abandoned.",
1728 name);
1729 }
1730 else
1731 {
1732 /* The user wants to stay in the frame where we stopped (default).*/
1733
1734 /* If we did the cleanups, we would print a spurious error
1735 message (Unable to restore previously selected frame),
1736 would write the registers from the inf_status (which is
1737 wrong), and would do other wrong things. */
1738 discard_cleanups (old_chain);
1739 discard_inferior_status (inf_status);
1740
1741 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1742 a C++ name with arguments and stuff. */
1743 error ("\
1744 The program being debugged was signaled while in a function called from GDB.\n\
1745 GDB remains in the frame where the signal was received.\n\
1746 To change this behavior use \"set unwindonsignal on\"\n\
1747 Evaluation of the expression containing the function (%s) will be abandoned.",
1748 name);
1749 }
1750 }
1751
1752 if (rc == 2)
1753 {
1754 /* We hit a breakpoint inside the FUNCTION. */
1755
1756 /* If we did the cleanups, we would print a spurious error
1757 message (Unable to restore previously selected frame),
1758 would write the registers from the inf_status (which is
1759 wrong), and would do other wrong things. */
1760 discard_cleanups (old_chain);
1761 discard_inferior_status (inf_status);
1762
1763 /* The following error message used to say "The expression
1764 which contained the function call has been discarded." It
1765 is a hard concept to explain in a few words. Ideally, GDB
1766 would be able to resume evaluation of the expression when
1767 the function finally is done executing. Perhaps someday
1768 this will be implemented (it would not be easy). */
1769
1770 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1771 a C++ name with arguments and stuff. */
1772 error ("\
1773 The program being debugged stopped while in a function called from GDB.\n\
1774 When the function (%s) is done executing, GDB will silently\n\
1775 stop (instead of continuing to evaluate the expression containing\n\
1776 the function call).", name);
1777 }
1778
1779 /* If we get here the called FUNCTION run to completion. */
1780 do_cleanups (old_chain);
1781
1782 /* Figure out the value returned by the function. */
1783 /* elz: I defined this new macro for the hppa architecture only.
1784 this gives us a way to get the value returned by the function from the stack,
1785 at the same address we told the function to put it.
1786 We cannot assume on the pa that r28 still contains the address of the returned
1787 structure. Usually this will be overwritten by the callee.
1788 I don't know about other architectures, so I defined this macro
1789 */
1790
1791 #ifdef VALUE_RETURNED_FROM_STACK
1792 if (struct_return)
1793 return (struct value *) VALUE_RETURNED_FROM_STACK (value_type, struct_addr);
1794 #endif
1795
1796 return value_being_returned (value_type, retbuf, struct_return);
1797 }
1798 }
1799
1800 struct value *
1801 call_function_by_hand (struct value *function, int nargs, struct value **args)
1802 {
1803 if (CALL_DUMMY_P)
1804 {
1805 return hand_function_call (function, nargs, args);
1806 }
1807 else
1808 {
1809 error ("Cannot invoke functions on this machine.");
1810 }
1811 }
1812 \f
1813
1814
1815 /* Create a value for an array by allocating space in the inferior, copying
1816 the data into that space, and then setting up an array value.
1817
1818 The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
1819 populated from the values passed in ELEMVEC.
1820
1821 The element type of the array is inherited from the type of the
1822 first element, and all elements must have the same size (though we
1823 don't currently enforce any restriction on their types). */
1824
1825 struct value *
1826 value_array (int lowbound, int highbound, struct value **elemvec)
1827 {
1828 int nelem;
1829 int idx;
1830 unsigned int typelength;
1831 struct value *val;
1832 struct type *rangetype;
1833 struct type *arraytype;
1834 CORE_ADDR addr;
1835
1836 /* Validate that the bounds are reasonable and that each of the elements
1837 have the same size. */
1838
1839 nelem = highbound - lowbound + 1;
1840 if (nelem <= 0)
1841 {
1842 error ("bad array bounds (%d, %d)", lowbound, highbound);
1843 }
1844 typelength = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[0]));
1845 for (idx = 1; idx < nelem; idx++)
1846 {
1847 if (TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[idx])) != typelength)
1848 {
1849 error ("array elements must all be the same size");
1850 }
1851 }
1852
1853 rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
1854 lowbound, highbound);
1855 arraytype = create_array_type ((struct type *) NULL,
1856 VALUE_ENCLOSING_TYPE (elemvec[0]), rangetype);
1857
1858 if (!current_language->c_style_arrays)
1859 {
1860 val = allocate_value (arraytype);
1861 for (idx = 0; idx < nelem; idx++)
1862 {
1863 memcpy (VALUE_CONTENTS_ALL_RAW (val) + (idx * typelength),
1864 VALUE_CONTENTS_ALL (elemvec[idx]),
1865 typelength);
1866 }
1867 VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (elemvec[0]);
1868 return val;
1869 }
1870
1871 /* Allocate space to store the array in the inferior, and then initialize
1872 it by copying in each element. FIXME: Is it worth it to create a
1873 local buffer in which to collect each value and then write all the
1874 bytes in one operation? */
1875
1876 addr = allocate_space_in_inferior (nelem * typelength);
1877 for (idx = 0; idx < nelem; idx++)
1878 {
1879 write_memory (addr + (idx * typelength), VALUE_CONTENTS_ALL (elemvec[idx]),
1880 typelength);
1881 }
1882
1883 /* Create the array type and set up an array value to be evaluated lazily. */
1884
1885 val = value_at_lazy (arraytype, addr, VALUE_BFD_SECTION (elemvec[0]));
1886 return (val);
1887 }
1888
1889 /* Create a value for a string constant by allocating space in the inferior,
1890 copying the data into that space, and returning the address with type
1891 TYPE_CODE_STRING. PTR points to the string constant data; LEN is number
1892 of characters.
1893 Note that string types are like array of char types with a lower bound of
1894 zero and an upper bound of LEN - 1. Also note that the string may contain
1895 embedded null bytes. */
1896
1897 struct value *
1898 value_string (char *ptr, int len)
1899 {
1900 struct value *val;
1901 int lowbound = current_language->string_lower_bound;
1902 struct type *rangetype = create_range_type ((struct type *) NULL,
1903 builtin_type_int,
1904 lowbound, len + lowbound - 1);
1905 struct type *stringtype
1906 = create_string_type ((struct type *) NULL, rangetype);
1907 CORE_ADDR addr;
1908
1909 if (current_language->c_style_arrays == 0)
1910 {
1911 val = allocate_value (stringtype);
1912 memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
1913 return val;
1914 }
1915
1916
1917 /* Allocate space to store the string in the inferior, and then
1918 copy LEN bytes from PTR in gdb to that address in the inferior. */
1919
1920 addr = allocate_space_in_inferior (len);
1921 write_memory (addr, ptr, len);
1922
1923 val = value_at_lazy (stringtype, addr, NULL);
1924 return (val);
1925 }
1926
1927 struct value *
1928 value_bitstring (char *ptr, int len)
1929 {
1930 struct value *val;
1931 struct type *domain_type = create_range_type (NULL, builtin_type_int,
1932 0, len - 1);
1933 struct type *type = create_set_type ((struct type *) NULL, domain_type);
1934 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1935 val = allocate_value (type);
1936 memcpy (VALUE_CONTENTS_RAW (val), ptr, TYPE_LENGTH (type));
1937 return val;
1938 }
1939 \f
1940 /* See if we can pass arguments in T2 to a function which takes arguments
1941 of types T1. Both t1 and t2 are NULL-terminated vectors. If some
1942 arguments need coercion of some sort, then the coerced values are written
1943 into T2. Return value is 0 if the arguments could be matched, or the
1944 position at which they differ if not.
1945
1946 STATICP is nonzero if the T1 argument list came from a
1947 static member function.
1948
1949 For non-static member functions, we ignore the first argument,
1950 which is the type of the instance variable. This is because we want
1951 to handle calls with objects from derived classes. This is not
1952 entirely correct: we should actually check to make sure that a
1953 requested operation is type secure, shouldn't we? FIXME. */
1954
1955 static int
1956 typecmp (int staticp, struct type *t1[], struct value *t2[])
1957 {
1958 int i;
1959
1960 if (t2 == 0)
1961 return 1;
1962 if (staticp && t1 == 0)
1963 return t2[1] != 0;
1964 if (t1 == 0)
1965 return 1;
1966 if (t1[!staticp] == 0)
1967 return 0;
1968 if (TYPE_CODE (t1[0]) == TYPE_CODE_VOID)
1969 return 0;
1970 /* Skip ``this'' argument if applicable. T2 will always include THIS. */
1971 if (staticp)
1972 t2++;
1973 for (i = !staticp; t1[i] && TYPE_CODE (t1[i]) != TYPE_CODE_VOID; i++)
1974 {
1975 struct type *tt1, *tt2;
1976 if (!t2[i])
1977 return i + 1;
1978 tt1 = check_typedef (t1[i]);
1979 tt2 = check_typedef (VALUE_TYPE (t2[i]));
1980 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1981 /* We should be doing hairy argument matching, as below. */
1982 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
1983 {
1984 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1985 t2[i] = value_coerce_array (t2[i]);
1986 else
1987 t2[i] = value_addr (t2[i]);
1988 continue;
1989 }
1990
1991 /* djb - 20000715 - Until the new type structure is in the
1992 place, and we can attempt things like implicit conversions,
1993 we need to do this so you can take something like a map<const
1994 char *>, and properly access map["hello"], because the
1995 argument to [] will be a reference to a pointer to a char,
1996 and the argument will be a pointer to a char. */
1997 while ( TYPE_CODE(tt1) == TYPE_CODE_REF ||
1998 TYPE_CODE (tt1) == TYPE_CODE_PTR)
1999 {
2000 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
2001 }
2002 while ( TYPE_CODE(tt2) == TYPE_CODE_ARRAY ||
2003 TYPE_CODE(tt2) == TYPE_CODE_PTR ||
2004 TYPE_CODE(tt2) == TYPE_CODE_REF)
2005 {
2006 tt2 = check_typedef( TYPE_TARGET_TYPE(tt2) );
2007 }
2008 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
2009 continue;
2010 /* Array to pointer is a `trivial conversion' according to the ARM. */
2011
2012 /* We should be doing much hairier argument matching (see section 13.2
2013 of the ARM), but as a quick kludge, just check for the same type
2014 code. */
2015 if (TYPE_CODE (t1[i]) != TYPE_CODE (VALUE_TYPE (t2[i])))
2016 return i + 1;
2017 }
2018 if (!t1[i])
2019 return 0;
2020 return t2[i] ? i + 1 : 0;
2021 }
2022
2023 /* Helper function used by value_struct_elt to recurse through baseclasses.
2024 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
2025 and search in it assuming it has (class) type TYPE.
2026 If found, return value, else return NULL.
2027
2028 If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
2029 look for a baseclass named NAME. */
2030
2031 static struct value *
2032 search_struct_field (char *name, struct value *arg1, int offset,
2033 register struct type *type, int looking_for_baseclass)
2034 {
2035 int i;
2036 int nbases = TYPE_N_BASECLASSES (type);
2037
2038 CHECK_TYPEDEF (type);
2039
2040 if (!looking_for_baseclass)
2041 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
2042 {
2043 char *t_field_name = TYPE_FIELD_NAME (type, i);
2044
2045 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2046 {
2047 struct value *v;
2048 if (TYPE_FIELD_STATIC (type, i))
2049 v = value_static_field (type, i);
2050 else
2051 v = value_primitive_field (arg1, offset, i, type);
2052 if (v == 0)
2053 error ("there is no field named %s", name);
2054 return v;
2055 }
2056
2057 if (t_field_name
2058 && (t_field_name[0] == '\0'
2059 || (TYPE_CODE (type) == TYPE_CODE_UNION
2060 && (strcmp_iw (t_field_name, "else") == 0))))
2061 {
2062 struct type *field_type = TYPE_FIELD_TYPE (type, i);
2063 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
2064 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
2065 {
2066 /* Look for a match through the fields of an anonymous union,
2067 or anonymous struct. C++ provides anonymous unions.
2068
2069 In the GNU Chill implementation of variant record types,
2070 each <alternative field> has an (anonymous) union type,
2071 each member of the union represents a <variant alternative>.
2072 Each <variant alternative> is represented as a struct,
2073 with a member for each <variant field>. */
2074
2075 struct value *v;
2076 int new_offset = offset;
2077
2078 /* This is pretty gross. In G++, the offset in an anonymous
2079 union is relative to the beginning of the enclosing struct.
2080 In the GNU Chill implementation of variant records,
2081 the bitpos is zero in an anonymous union field, so we
2082 have to add the offset of the union here. */
2083 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
2084 || (TYPE_NFIELDS (field_type) > 0
2085 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
2086 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
2087
2088 v = search_struct_field (name, arg1, new_offset, field_type,
2089 looking_for_baseclass);
2090 if (v)
2091 return v;
2092 }
2093 }
2094 }
2095
2096 for (i = 0; i < nbases; i++)
2097 {
2098 struct value *v;
2099 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
2100 /* If we are looking for baseclasses, this is what we get when we
2101 hit them. But it could happen that the base part's member name
2102 is not yet filled in. */
2103 int found_baseclass = (looking_for_baseclass
2104 && TYPE_BASECLASS_NAME (type, i) != NULL
2105 && (strcmp_iw (name, TYPE_BASECLASS_NAME (type, i)) == 0));
2106
2107 if (BASETYPE_VIA_VIRTUAL (type, i))
2108 {
2109 int boffset;
2110 struct value *v2 = allocate_value (basetype);
2111
2112 boffset = baseclass_offset (type, i,
2113 VALUE_CONTENTS (arg1) + offset,
2114 VALUE_ADDRESS (arg1)
2115 + VALUE_OFFSET (arg1) + offset);
2116 if (boffset == -1)
2117 error ("virtual baseclass botch");
2118
2119 /* The virtual base class pointer might have been clobbered by the
2120 user program. Make sure that it still points to a valid memory
2121 location. */
2122
2123 boffset += offset;
2124 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
2125 {
2126 CORE_ADDR base_addr;
2127
2128 base_addr = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1) + boffset;
2129 if (target_read_memory (base_addr, VALUE_CONTENTS_RAW (v2),
2130 TYPE_LENGTH (basetype)) != 0)
2131 error ("virtual baseclass botch");
2132 VALUE_LVAL (v2) = lval_memory;
2133 VALUE_ADDRESS (v2) = base_addr;
2134 }
2135 else
2136 {
2137 VALUE_LVAL (v2) = VALUE_LVAL (arg1);
2138 VALUE_ADDRESS (v2) = VALUE_ADDRESS (arg1);
2139 VALUE_OFFSET (v2) = VALUE_OFFSET (arg1) + boffset;
2140 if (VALUE_LAZY (arg1))
2141 VALUE_LAZY (v2) = 1;
2142 else
2143 memcpy (VALUE_CONTENTS_RAW (v2),
2144 VALUE_CONTENTS_RAW (arg1) + boffset,
2145 TYPE_LENGTH (basetype));
2146 }
2147
2148 if (found_baseclass)
2149 return v2;
2150 v = search_struct_field (name, v2, 0, TYPE_BASECLASS (type, i),
2151 looking_for_baseclass);
2152 }
2153 else if (found_baseclass)
2154 v = value_primitive_field (arg1, offset, i, type);
2155 else
2156 v = search_struct_field (name, arg1,
2157 offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
2158 basetype, looking_for_baseclass);
2159 if (v)
2160 return v;
2161 }
2162 return NULL;
2163 }
2164
2165
2166 /* Return the offset (in bytes) of the virtual base of type BASETYPE
2167 * in an object pointed to by VALADDR (on the host), assumed to be of
2168 * type TYPE. OFFSET is number of bytes beyond start of ARG to start
2169 * looking (in case VALADDR is the contents of an enclosing object).
2170 *
2171 * This routine recurses on the primary base of the derived class because
2172 * the virtual base entries of the primary base appear before the other
2173 * virtual base entries.
2174 *
2175 * If the virtual base is not found, a negative integer is returned.
2176 * The magnitude of the negative integer is the number of entries in
2177 * the virtual table to skip over (entries corresponding to various
2178 * ancestral classes in the chain of primary bases).
2179 *
2180 * Important: This assumes the HP / Taligent C++ runtime
2181 * conventions. Use baseclass_offset() instead to deal with g++
2182 * conventions. */
2183
2184 void
2185 find_rt_vbase_offset (struct type *type, struct type *basetype, char *valaddr,
2186 int offset, int *boffset_p, int *skip_p)
2187 {
2188 int boffset; /* offset of virtual base */
2189 int index; /* displacement to use in virtual table */
2190 int skip;
2191
2192 struct value *vp;
2193 CORE_ADDR vtbl; /* the virtual table pointer */
2194 struct type *pbc; /* the primary base class */
2195
2196 /* Look for the virtual base recursively in the primary base, first.
2197 * This is because the derived class object and its primary base
2198 * subobject share the primary virtual table. */
2199
2200 boffset = 0;
2201 pbc = TYPE_PRIMARY_BASE (type);
2202 if (pbc)
2203 {
2204 find_rt_vbase_offset (pbc, basetype, valaddr, offset, &boffset, &skip);
2205 if (skip < 0)
2206 {
2207 *boffset_p = boffset;
2208 *skip_p = -1;
2209 return;
2210 }
2211 }
2212 else
2213 skip = 0;
2214
2215
2216 /* Find the index of the virtual base according to HP/Taligent
2217 runtime spec. (Depth-first, left-to-right.) */
2218 index = virtual_base_index_skip_primaries (basetype, type);
2219
2220 if (index < 0)
2221 {
2222 *skip_p = skip + virtual_base_list_length_skip_primaries (type);
2223 *boffset_p = 0;
2224 return;
2225 }
2226
2227 /* pai: FIXME -- 32x64 possible problem */
2228 /* First word (4 bytes) in object layout is the vtable pointer */
2229 vtbl = *(CORE_ADDR *) (valaddr + offset);
2230
2231 /* Before the constructor is invoked, things are usually zero'd out. */
2232 if (vtbl == 0)
2233 error ("Couldn't find virtual table -- object may not be constructed yet.");
2234
2235
2236 /* Find virtual base's offset -- jump over entries for primary base
2237 * ancestors, then use the index computed above. But also adjust by
2238 * HP_ACC_VBASE_START for the vtable slots before the start of the
2239 * virtual base entries. Offset is negative -- virtual base entries
2240 * appear _before_ the address point of the virtual table. */
2241
2242 /* pai: FIXME -- 32x64 problem, if word = 8 bytes, change multiplier
2243 & use long type */
2244
2245 /* epstein : FIXME -- added param for overlay section. May not be correct */
2246 vp = value_at (builtin_type_int, vtbl + 4 * (-skip - index - HP_ACC_VBASE_START), NULL);
2247 boffset = value_as_long (vp);
2248 *skip_p = -1;
2249 *boffset_p = boffset;
2250 return;
2251 }
2252
2253
2254 /* Helper function used by value_struct_elt to recurse through baseclasses.
2255 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
2256 and search in it assuming it has (class) type TYPE.
2257 If found, return value, else if name matched and args not return (value)-1,
2258 else return NULL. */
2259
2260 static struct value *
2261 search_struct_method (char *name, struct value **arg1p,
2262 struct value **args, int offset,
2263 int *static_memfuncp, register struct type *type)
2264 {
2265 int i;
2266 struct value *v;
2267 int name_matched = 0;
2268 char dem_opname[64];
2269
2270 CHECK_TYPEDEF (type);
2271 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2272 {
2273 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2274 /* FIXME! May need to check for ARM demangling here */
2275 if (strncmp (t_field_name, "__", 2) == 0 ||
2276 strncmp (t_field_name, "op", 2) == 0 ||
2277 strncmp (t_field_name, "type", 4) == 0)
2278 {
2279 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2280 t_field_name = dem_opname;
2281 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2282 t_field_name = dem_opname;
2283 }
2284 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2285 {
2286 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2287 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2288 name_matched = 1;
2289
2290 if (j > 0 && args == 0)
2291 error ("cannot resolve overloaded method `%s': no arguments supplied", name);
2292 else if (j == 0 && args == 0)
2293 {
2294 if (TYPE_FN_FIELD_STUB (f, j))
2295 check_stub_method (type, i, j);
2296 v = value_fn_field (arg1p, f, j, type, offset);
2297 if (v != NULL)
2298 return v;
2299 }
2300 else
2301 while (j >= 0)
2302 {
2303 if (TYPE_FN_FIELD_STUB (f, j))
2304 check_stub_method (type, i, j);
2305 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2306 TYPE_FN_FIELD_ARGS (f, j), args))
2307 {
2308 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2309 return value_virtual_fn_field (arg1p, f, j, type, offset);
2310 if (TYPE_FN_FIELD_STATIC_P (f, j) && static_memfuncp)
2311 *static_memfuncp = 1;
2312 v = value_fn_field (arg1p, f, j, type, offset);
2313 if (v != NULL)
2314 return v;
2315 }
2316 j--;
2317 }
2318 }
2319 }
2320
2321 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2322 {
2323 int base_offset;
2324
2325 if (BASETYPE_VIA_VIRTUAL (type, i))
2326 {
2327 if (TYPE_HAS_VTABLE (type))
2328 {
2329 /* HP aCC compiled type, search for virtual base offset
2330 according to HP/Taligent runtime spec. */
2331 int skip;
2332 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
2333 VALUE_CONTENTS_ALL (*arg1p),
2334 offset + VALUE_EMBEDDED_OFFSET (*arg1p),
2335 &base_offset, &skip);
2336 if (skip >= 0)
2337 error ("Virtual base class offset not found in vtable");
2338 }
2339 else
2340 {
2341 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2342 char *base_valaddr;
2343
2344 /* The virtual base class pointer might have been clobbered by the
2345 user program. Make sure that it still points to a valid memory
2346 location. */
2347
2348 if (offset < 0 || offset >= TYPE_LENGTH (type))
2349 {
2350 base_valaddr = (char *) alloca (TYPE_LENGTH (baseclass));
2351 if (target_read_memory (VALUE_ADDRESS (*arg1p)
2352 + VALUE_OFFSET (*arg1p) + offset,
2353 base_valaddr,
2354 TYPE_LENGTH (baseclass)) != 0)
2355 error ("virtual baseclass botch");
2356 }
2357 else
2358 base_valaddr = VALUE_CONTENTS (*arg1p) + offset;
2359
2360 base_offset =
2361 baseclass_offset (type, i, base_valaddr,
2362 VALUE_ADDRESS (*arg1p)
2363 + VALUE_OFFSET (*arg1p) + offset);
2364 if (base_offset == -1)
2365 error ("virtual baseclass botch");
2366 }
2367 }
2368 else
2369 {
2370 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2371 }
2372 v = search_struct_method (name, arg1p, args, base_offset + offset,
2373 static_memfuncp, TYPE_BASECLASS (type, i));
2374 if (v == (struct value *) - 1)
2375 {
2376 name_matched = 1;
2377 }
2378 else if (v)
2379 {
2380 /* FIXME-bothner: Why is this commented out? Why is it here? */
2381 /* *arg1p = arg1_tmp; */
2382 return v;
2383 }
2384 }
2385 if (name_matched)
2386 return (struct value *) - 1;
2387 else
2388 return NULL;
2389 }
2390
2391 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2392 extract the component named NAME from the ultimate target structure/union
2393 and return it as a value with its appropriate type.
2394 ERR is used in the error message if *ARGP's type is wrong.
2395
2396 C++: ARGS is a list of argument types to aid in the selection of
2397 an appropriate method. Also, handle derived types.
2398
2399 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2400 where the truthvalue of whether the function that was resolved was
2401 a static member function or not is stored.
2402
2403 ERR is an error message to be printed in case the field is not found. */
2404
2405 struct value *
2406 value_struct_elt (struct value **argp, struct value **args,
2407 char *name, int *static_memfuncp, char *err)
2408 {
2409 register struct type *t;
2410 struct value *v;
2411
2412 COERCE_ARRAY (*argp);
2413
2414 t = check_typedef (VALUE_TYPE (*argp));
2415
2416 /* Follow pointers until we get to a non-pointer. */
2417
2418 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2419 {
2420 *argp = value_ind (*argp);
2421 /* Don't coerce fn pointer to fn and then back again! */
2422 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
2423 COERCE_ARRAY (*argp);
2424 t = check_typedef (VALUE_TYPE (*argp));
2425 }
2426
2427 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2428 error ("not implemented: member type in value_struct_elt");
2429
2430 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2431 && TYPE_CODE (t) != TYPE_CODE_UNION)
2432 error ("Attempt to extract a component of a value that is not a %s.", err);
2433
2434 /* Assume it's not, unless we see that it is. */
2435 if (static_memfuncp)
2436 *static_memfuncp = 0;
2437
2438 if (!args)
2439 {
2440 /* if there are no arguments ...do this... */
2441
2442 /* Try as a field first, because if we succeed, there
2443 is less work to be done. */
2444 v = search_struct_field (name, *argp, 0, t, 0);
2445 if (v)
2446 return v;
2447
2448 /* C++: If it was not found as a data field, then try to
2449 return it as a pointer to a method. */
2450
2451 if (destructor_name_p (name, t))
2452 error ("Cannot get value of destructor");
2453
2454 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
2455
2456 if (v == (struct value *) - 1)
2457 error ("Cannot take address of a method");
2458 else if (v == 0)
2459 {
2460 if (TYPE_NFN_FIELDS (t))
2461 error ("There is no member or method named %s.", name);
2462 else
2463 error ("There is no member named %s.", name);
2464 }
2465 return v;
2466 }
2467
2468 if (destructor_name_p (name, t))
2469 {
2470 if (!args[1])
2471 {
2472 /* Destructors are a special case. */
2473 int m_index, f_index;
2474
2475 v = NULL;
2476 if (get_destructor_fn_field (t, &m_index, &f_index))
2477 {
2478 v = value_fn_field (NULL, TYPE_FN_FIELDLIST1 (t, m_index),
2479 f_index, NULL, 0);
2480 }
2481 if (v == NULL)
2482 error ("could not find destructor function named %s.", name);
2483 else
2484 return v;
2485 }
2486 else
2487 {
2488 error ("destructor should not have any argument");
2489 }
2490 }
2491 else
2492 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
2493
2494 if (v == (struct value *) - 1)
2495 {
2496 error ("One of the arguments you tried to pass to %s could not be converted to what the function wants.", name);
2497 }
2498 else if (v == 0)
2499 {
2500 /* See if user tried to invoke data as function. If so,
2501 hand it back. If it's not callable (i.e., a pointer to function),
2502 gdb should give an error. */
2503 v = search_struct_field (name, *argp, 0, t, 0);
2504 }
2505
2506 if (!v)
2507 error ("Structure has no component named %s.", name);
2508 return v;
2509 }
2510
2511 /* Search through the methods of an object (and its bases)
2512 * to find a specified method. Return the pointer to the
2513 * fn_field list of overloaded instances.
2514 * Helper function for value_find_oload_list.
2515 * ARGP is a pointer to a pointer to a value (the object)
2516 * METHOD is a string containing the method name
2517 * OFFSET is the offset within the value
2518 * STATIC_MEMFUNCP is set if the method is static
2519 * TYPE is the assumed type of the object
2520 * NUM_FNS is the number of overloaded instances
2521 * BASETYPE is set to the actual type of the subobject where the method is found
2522 * BOFFSET is the offset of the base subobject where the method is found */
2523
2524 static struct fn_field *
2525 find_method_list (struct value **argp, char *method, int offset,
2526 struct type *type, int *num_fns,
2527 struct type **basetype, int *boffset)
2528 {
2529 int i;
2530 struct fn_field *f;
2531 CHECK_TYPEDEF (type);
2532
2533 *num_fns = 0;
2534
2535 /* First check in object itself */
2536 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2537 {
2538 /* pai: FIXME What about operators and type conversions? */
2539 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2540 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2541 {
2542 /* Resolve any stub methods. */
2543 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2544 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2545 int j;
2546
2547 *num_fns = len;
2548 *basetype = type;
2549 *boffset = offset;
2550
2551 for (j = 0; j < len; j++)
2552 {
2553 if (TYPE_FN_FIELD_STUB (f, j))
2554 check_stub_method (type, i, j);
2555 }
2556
2557 return f;
2558 }
2559 }
2560
2561 /* Not found in object, check in base subobjects */
2562 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2563 {
2564 int base_offset;
2565 if (BASETYPE_VIA_VIRTUAL (type, i))
2566 {
2567 if (TYPE_HAS_VTABLE (type))
2568 {
2569 /* HP aCC compiled type, search for virtual base offset
2570 * according to HP/Taligent runtime spec. */
2571 int skip;
2572 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
2573 VALUE_CONTENTS_ALL (*argp),
2574 offset + VALUE_EMBEDDED_OFFSET (*argp),
2575 &base_offset, &skip);
2576 if (skip >= 0)
2577 error ("Virtual base class offset not found in vtable");
2578 }
2579 else
2580 {
2581 /* probably g++ runtime model */
2582 base_offset = VALUE_OFFSET (*argp) + offset;
2583 base_offset =
2584 baseclass_offset (type, i,
2585 VALUE_CONTENTS (*argp) + base_offset,
2586 VALUE_ADDRESS (*argp) + base_offset);
2587 if (base_offset == -1)
2588 error ("virtual baseclass botch");
2589 }
2590 }
2591 else
2592 /* non-virtual base, simply use bit position from debug info */
2593 {
2594 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2595 }
2596 f = find_method_list (argp, method, base_offset + offset,
2597 TYPE_BASECLASS (type, i), num_fns, basetype,
2598 boffset);
2599 if (f)
2600 return f;
2601 }
2602 return NULL;
2603 }
2604
2605 /* Return the list of overloaded methods of a specified name.
2606 * ARGP is a pointer to a pointer to a value (the object)
2607 * METHOD is the method name
2608 * OFFSET is the offset within the value contents
2609 * STATIC_MEMFUNCP is set if the method is static
2610 * NUM_FNS is the number of overloaded instances
2611 * BASETYPE is set to the type of the base subobject that defines the method
2612 * BOFFSET is the offset of the base subobject which defines the method */
2613
2614 struct fn_field *
2615 value_find_oload_method_list (struct value **argp, char *method, int offset,
2616 int *num_fns, struct type **basetype,
2617 int *boffset)
2618 {
2619 struct type *t;
2620
2621 t = check_typedef (VALUE_TYPE (*argp));
2622
2623 /* code snarfed from value_struct_elt */
2624 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2625 {
2626 *argp = value_ind (*argp);
2627 /* Don't coerce fn pointer to fn and then back again! */
2628 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
2629 COERCE_ARRAY (*argp);
2630 t = check_typedef (VALUE_TYPE (*argp));
2631 }
2632
2633 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2634 error ("Not implemented: member type in value_find_oload_lis");
2635
2636 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2637 && TYPE_CODE (t) != TYPE_CODE_UNION)
2638 error ("Attempt to extract a component of a value that is not a struct or union");
2639
2640 return find_method_list (argp, method, 0, t, num_fns, basetype, boffset);
2641 }
2642
2643 /* Given an array of argument types (ARGTYPES) (which includes an
2644 entry for "this" in the case of C++ methods), the number of
2645 arguments NARGS, the NAME of a function whether it's a method or
2646 not (METHOD), and the degree of laxness (LAX) in conforming to
2647 overload resolution rules in ANSI C++, find the best function that
2648 matches on the argument types according to the overload resolution
2649 rules.
2650
2651 In the case of class methods, the parameter OBJ is an object value
2652 in which to search for overloaded methods.
2653
2654 In the case of non-method functions, the parameter FSYM is a symbol
2655 corresponding to one of the overloaded functions.
2656
2657 Return value is an integer: 0 -> good match, 10 -> debugger applied
2658 non-standard coercions, 100 -> incompatible.
2659
2660 If a method is being searched for, VALP will hold the value.
2661 If a non-method is being searched for, SYMP will hold the symbol for it.
2662
2663 If a method is being searched for, and it is a static method,
2664 then STATICP will point to a non-zero value.
2665
2666 Note: This function does *not* check the value of
2667 overload_resolution. Caller must check it to see whether overload
2668 resolution is permitted.
2669 */
2670
2671 int
2672 find_overload_match (struct type **arg_types, int nargs, char *name, int method,
2673 int lax, struct value **objp, struct symbol *fsym,
2674 struct value **valp, struct symbol **symp, int *staticp)
2675 {
2676 int nparms;
2677 struct type **parm_types;
2678 int champ_nparms = 0;
2679 struct value *obj = (objp ? *objp : NULL);
2680
2681 short oload_champ = -1; /* Index of best overloaded function */
2682 short oload_ambiguous = 0; /* Current ambiguity state for overload resolution */
2683 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs */
2684 short oload_ambig_champ = -1; /* 2nd contender for best match */
2685 short oload_non_standard = 0; /* did we have to use non-standard conversions? */
2686 short oload_incompatible = 0; /* are args supplied incompatible with any function? */
2687
2688 struct badness_vector *bv; /* A measure of how good an overloaded instance is */
2689 struct badness_vector *oload_champ_bv = NULL; /* The measure for the current best match */
2690
2691 struct value *temp = obj;
2692 struct fn_field *fns_ptr = NULL; /* For methods, the list of overloaded methods */
2693 struct symbol **oload_syms = NULL; /* For non-methods, the list of overloaded function symbols */
2694 int num_fns = 0; /* Number of overloaded instances being considered */
2695 struct type *basetype = NULL;
2696 int boffset;
2697 register int jj;
2698 register int ix;
2699 int static_offset;
2700
2701 char *obj_type_name = NULL;
2702 char *func_name = NULL;
2703
2704 /* Get the list of overloaded methods or functions */
2705 if (method)
2706 {
2707 obj_type_name = TYPE_NAME (VALUE_TYPE (obj));
2708 /* Hack: evaluate_subexp_standard often passes in a pointer
2709 value rather than the object itself, so try again */
2710 if ((!obj_type_name || !*obj_type_name) &&
2711 (TYPE_CODE (VALUE_TYPE (obj)) == TYPE_CODE_PTR))
2712 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (VALUE_TYPE (obj)));
2713
2714 fns_ptr = value_find_oload_method_list (&temp, name, 0,
2715 &num_fns,
2716 &basetype, &boffset);
2717 if (!fns_ptr || !num_fns)
2718 error ("Couldn't find method %s%s%s",
2719 obj_type_name,
2720 (obj_type_name && *obj_type_name) ? "::" : "",
2721 name);
2722 /* If we are dealing with stub method types, they should have
2723 been resolved by find_method_list via value_find_oload_method_list
2724 above. */
2725 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2726 }
2727 else
2728 {
2729 int i = -1;
2730 func_name = cplus_demangle (SYMBOL_NAME (fsym), DMGL_NO_OPTS);
2731
2732 /* If the name is NULL this must be a C-style function.
2733 Just return the same symbol. */
2734 if (!func_name)
2735 {
2736 *symp = fsym;
2737 return 0;
2738 }
2739
2740 oload_syms = make_symbol_overload_list (fsym);
2741 while (oload_syms[++i])
2742 num_fns++;
2743 if (!num_fns)
2744 error ("Couldn't find function %s", func_name);
2745 }
2746
2747 oload_champ_bv = NULL;
2748
2749 /* Consider each candidate in turn */
2750 for (ix = 0; ix < num_fns; ix++)
2751 {
2752 static_offset = 0;
2753 if (method)
2754 {
2755 if (TYPE_FN_FIELD_STATIC_P (fns_ptr, ix))
2756 static_offset = 1;
2757 nparms=0;
2758
2759 if (TYPE_FN_FIELD_ARGS(fns_ptr,ix))
2760 {
2761 while (TYPE_CODE(TYPE_FN_FIELD_ARGS(fns_ptr,ix)[nparms]) != TYPE_CODE_VOID)
2762 nparms++;
2763 }
2764 }
2765 else
2766 {
2767 /* If it's not a method, this is the proper place */
2768 nparms=TYPE_NFIELDS(SYMBOL_TYPE(oload_syms[ix]));
2769 }
2770
2771 /* Prepare array of parameter types */
2772 parm_types = (struct type **) xmalloc (nparms * (sizeof (struct type *)));
2773 for (jj = 0; jj < nparms; jj++)
2774 parm_types[jj] = (method
2775 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj])
2776 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]), jj));
2777
2778 /* Compare parameter types to supplied argument types. Skip THIS for
2779 static methods. */
2780 bv = rank_function (parm_types, nparms, arg_types + static_offset,
2781 nargs - static_offset);
2782
2783 if (!oload_champ_bv)
2784 {
2785 oload_champ_bv = bv;
2786 oload_champ = 0;
2787 champ_nparms = nparms;
2788 }
2789 else
2790 /* See whether current candidate is better or worse than previous best */
2791 switch (compare_badness (bv, oload_champ_bv))
2792 {
2793 case 0:
2794 oload_ambiguous = 1; /* top two contenders are equally good */
2795 oload_ambig_champ = ix;
2796 break;
2797 case 1:
2798 oload_ambiguous = 2; /* incomparable top contenders */
2799 oload_ambig_champ = ix;
2800 break;
2801 case 2:
2802 oload_champ_bv = bv; /* new champion, record details */
2803 oload_ambiguous = 0;
2804 oload_champ = ix;
2805 oload_ambig_champ = -1;
2806 champ_nparms = nparms;
2807 break;
2808 case 3:
2809 default:
2810 break;
2811 }
2812 xfree (parm_types);
2813 if (overload_debug)
2814 {
2815 if (method)
2816 fprintf_filtered (gdb_stderr,"Overloaded method instance %s, # of parms %d\n", fns_ptr[ix].physname, nparms);
2817 else
2818 fprintf_filtered (gdb_stderr,"Overloaded function instance %s # of parms %d\n", SYMBOL_DEMANGLED_NAME (oload_syms[ix]), nparms);
2819 for (jj = 0; jj < nargs - static_offset; jj++)
2820 fprintf_filtered (gdb_stderr,"...Badness @ %d : %d\n", jj, bv->rank[jj]);
2821 fprintf_filtered (gdb_stderr,"Overload resolution champion is %d, ambiguous? %d\n", oload_champ, oload_ambiguous);
2822 }
2823 } /* end loop over all candidates */
2824 /* NOTE: dan/2000-03-10: Seems to be a better idea to just pick one
2825 if they have the exact same goodness. This is because there is no
2826 way to differentiate based on return type, which we need to in
2827 cases like overloads of .begin() <It's both const and non-const> */
2828 #if 0
2829 if (oload_ambiguous)
2830 {
2831 if (method)
2832 error ("Cannot resolve overloaded method %s%s%s to unique instance; disambiguate by specifying function signature",
2833 obj_type_name,
2834 (obj_type_name && *obj_type_name) ? "::" : "",
2835 name);
2836 else
2837 error ("Cannot resolve overloaded function %s to unique instance; disambiguate by specifying function signature",
2838 func_name);
2839 }
2840 #endif
2841
2842 /* Check how bad the best match is. */
2843 static_offset = 0;
2844 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
2845 static_offset = 1;
2846 for (ix = 1; ix <= nargs - static_offset; ix++)
2847 {
2848 if (oload_champ_bv->rank[ix] >= 100)
2849 oload_incompatible = 1; /* truly mismatched types */
2850
2851 else if (oload_champ_bv->rank[ix] >= 10)
2852 oload_non_standard = 1; /* non-standard type conversions needed */
2853 }
2854 if (oload_incompatible)
2855 {
2856 if (method)
2857 error ("Cannot resolve method %s%s%s to any overloaded instance",
2858 obj_type_name,
2859 (obj_type_name && *obj_type_name) ? "::" : "",
2860 name);
2861 else
2862 error ("Cannot resolve function %s to any overloaded instance",
2863 func_name);
2864 }
2865 else if (oload_non_standard)
2866 {
2867 if (method)
2868 warning ("Using non-standard conversion to match method %s%s%s to supplied arguments",
2869 obj_type_name,
2870 (obj_type_name && *obj_type_name) ? "::" : "",
2871 name);
2872 else
2873 warning ("Using non-standard conversion to match function %s to supplied arguments",
2874 func_name);
2875 }
2876
2877 if (method)
2878 {
2879 if (staticp && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
2880 *staticp = 1;
2881 else if (staticp)
2882 *staticp = 0;
2883 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
2884 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
2885 else
2886 *valp = value_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
2887 }
2888 else
2889 {
2890 *symp = oload_syms[oload_champ];
2891 xfree (func_name);
2892 }
2893
2894 if (objp)
2895 {
2896 if (TYPE_CODE (VALUE_TYPE (temp)) != TYPE_CODE_PTR
2897 && TYPE_CODE (VALUE_TYPE (*objp)) == TYPE_CODE_PTR)
2898 {
2899 temp = value_addr (temp);
2900 }
2901 *objp = temp;
2902 }
2903 return oload_incompatible ? 100 : (oload_non_standard ? 10 : 0);
2904 }
2905
2906 /* C++: return 1 is NAME is a legitimate name for the destructor
2907 of type TYPE. If TYPE does not have a destructor, or
2908 if NAME is inappropriate for TYPE, an error is signaled. */
2909 int
2910 destructor_name_p (const char *name, const struct type *type)
2911 {
2912 /* destructors are a special case. */
2913
2914 if (name[0] == '~')
2915 {
2916 char *dname = type_name_no_tag (type);
2917 char *cp = strchr (dname, '<');
2918 unsigned int len;
2919
2920 /* Do not compare the template part for template classes. */
2921 if (cp == NULL)
2922 len = strlen (dname);
2923 else
2924 len = cp - dname;
2925 if (strlen (name + 1) != len || !STREQN (dname, name + 1, len))
2926 error ("name of destructor must equal name of class");
2927 else
2928 return 1;
2929 }
2930 return 0;
2931 }
2932
2933 /* Helper function for check_field: Given TYPE, a structure/union,
2934 return 1 if the component named NAME from the ultimate
2935 target structure/union is defined, otherwise, return 0. */
2936
2937 static int
2938 check_field_in (register struct type *type, const char *name)
2939 {
2940 register int i;
2941
2942 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2943 {
2944 char *t_field_name = TYPE_FIELD_NAME (type, i);
2945 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2946 return 1;
2947 }
2948
2949 /* C++: If it was not found as a data field, then try to
2950 return it as a pointer to a method. */
2951
2952 /* Destructors are a special case. */
2953 if (destructor_name_p (name, type))
2954 {
2955 int m_index, f_index;
2956
2957 return get_destructor_fn_field (type, &m_index, &f_index);
2958 }
2959
2960 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2961 {
2962 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2963 return 1;
2964 }
2965
2966 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2967 if (check_field_in (TYPE_BASECLASS (type, i), name))
2968 return 1;
2969
2970 return 0;
2971 }
2972
2973
2974 /* C++: Given ARG1, a value of type (pointer to a)* structure/union,
2975 return 1 if the component named NAME from the ultimate
2976 target structure/union is defined, otherwise, return 0. */
2977
2978 int
2979 check_field (struct value *arg1, const char *name)
2980 {
2981 register struct type *t;
2982
2983 COERCE_ARRAY (arg1);
2984
2985 t = VALUE_TYPE (arg1);
2986
2987 /* Follow pointers until we get to a non-pointer. */
2988
2989 for (;;)
2990 {
2991 CHECK_TYPEDEF (t);
2992 if (TYPE_CODE (t) != TYPE_CODE_PTR && TYPE_CODE (t) != TYPE_CODE_REF)
2993 break;
2994 t = TYPE_TARGET_TYPE (t);
2995 }
2996
2997 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2998 error ("not implemented: member type in check_field");
2999
3000 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3001 && TYPE_CODE (t) != TYPE_CODE_UNION)
3002 error ("Internal error: `this' is not an aggregate");
3003
3004 return check_field_in (t, name);
3005 }
3006
3007 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3008 return the address of this member as a "pointer to member"
3009 type. If INTYPE is non-null, then it will be the type
3010 of the member we are looking for. This will help us resolve
3011 "pointers to member functions". This function is used
3012 to resolve user expressions of the form "DOMAIN::NAME". */
3013
3014 struct value *
3015 value_struct_elt_for_reference (struct type *domain, int offset,
3016 struct type *curtype, char *name,
3017 struct type *intype)
3018 {
3019 register struct type *t = curtype;
3020 register int i;
3021 struct value *v;
3022
3023 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3024 && TYPE_CODE (t) != TYPE_CODE_UNION)
3025 error ("Internal error: non-aggregate type to value_struct_elt_for_reference");
3026
3027 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3028 {
3029 char *t_field_name = TYPE_FIELD_NAME (t, i);
3030
3031 if (t_field_name && STREQ (t_field_name, name))
3032 {
3033 if (TYPE_FIELD_STATIC (t, i))
3034 {
3035 v = value_static_field (t, i);
3036 if (v == NULL)
3037 error ("Internal error: could not find static variable %s",
3038 name);
3039 return v;
3040 }
3041 if (TYPE_FIELD_PACKED (t, i))
3042 error ("pointers to bitfield members not allowed");
3043
3044 return value_from_longest
3045 (lookup_reference_type (lookup_member_type (TYPE_FIELD_TYPE (t, i),
3046 domain)),
3047 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3048 }
3049 }
3050
3051 /* C++: If it was not found as a data field, then try to
3052 return it as a pointer to a method. */
3053
3054 /* Destructors are a special case. */
3055 if (destructor_name_p (name, t))
3056 {
3057 error ("member pointers to destructors not implemented yet");
3058 }
3059
3060 /* Perform all necessary dereferencing. */
3061 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3062 intype = TYPE_TARGET_TYPE (intype);
3063
3064 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3065 {
3066 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3067 char dem_opname[64];
3068
3069 if (strncmp (t_field_name, "__", 2) == 0 ||
3070 strncmp (t_field_name, "op", 2) == 0 ||
3071 strncmp (t_field_name, "type", 4) == 0)
3072 {
3073 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
3074 t_field_name = dem_opname;
3075 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
3076 t_field_name = dem_opname;
3077 }
3078 if (t_field_name && STREQ (t_field_name, name))
3079 {
3080 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
3081 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3082
3083 if (intype == 0 && j > 1)
3084 error ("non-unique member `%s' requires type instantiation", name);
3085 if (intype)
3086 {
3087 while (j--)
3088 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
3089 break;
3090 if (j < 0)
3091 error ("no member function matches that type instantiation");
3092 }
3093 else
3094 j = 0;
3095
3096 if (TYPE_FN_FIELD_STUB (f, j))
3097 check_stub_method (t, i, j);
3098 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3099 {
3100 return value_from_longest
3101 (lookup_reference_type
3102 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
3103 domain)),
3104 (LONGEST) METHOD_PTR_FROM_VOFFSET (TYPE_FN_FIELD_VOFFSET (f, j)));
3105 }
3106 else
3107 {
3108 struct symbol *s = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3109 0, VAR_NAMESPACE, 0, NULL);
3110 if (s == NULL)
3111 {
3112 v = 0;
3113 }
3114 else
3115 {
3116 v = read_var_value (s, 0);
3117 #if 0
3118 VALUE_TYPE (v) = lookup_reference_type
3119 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
3120 domain));
3121 #endif
3122 }
3123 return v;
3124 }
3125 }
3126 }
3127 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3128 {
3129 struct value *v;
3130 int base_offset;
3131
3132 if (BASETYPE_VIA_VIRTUAL (t, i))
3133 base_offset = 0;
3134 else
3135 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3136 v = value_struct_elt_for_reference (domain,
3137 offset + base_offset,
3138 TYPE_BASECLASS (t, i),
3139 name,
3140 intype);
3141 if (v)
3142 return v;
3143 }
3144 return 0;
3145 }
3146
3147
3148 /* Given a pointer value V, find the real (RTTI) type
3149 of the object it points to.
3150 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3151 and refer to the values computed for the object pointed to. */
3152
3153 struct type *
3154 value_rtti_target_type (struct value *v, int *full, int *top, int *using_enc)
3155 {
3156 struct value *target;
3157
3158 target = value_ind (v);
3159
3160 return value_rtti_type (target, full, top, using_enc);
3161 }
3162
3163 /* Given a value pointed to by ARGP, check its real run-time type, and
3164 if that is different from the enclosing type, create a new value
3165 using the real run-time type as the enclosing type (and of the same
3166 type as ARGP) and return it, with the embedded offset adjusted to
3167 be the correct offset to the enclosed object
3168 RTYPE is the type, and XFULL, XTOP, and XUSING_ENC are the other
3169 parameters, computed by value_rtti_type(). If these are available,
3170 they can be supplied and a second call to value_rtti_type() is avoided.
3171 (Pass RTYPE == NULL if they're not available */
3172
3173 struct value *
3174 value_full_object (struct value *argp, struct type *rtype, int xfull, int xtop,
3175 int xusing_enc)
3176 {
3177 struct type *real_type;
3178 int full = 0;
3179 int top = -1;
3180 int using_enc = 0;
3181 struct value *new_val;
3182
3183 if (rtype)
3184 {
3185 real_type = rtype;
3186 full = xfull;
3187 top = xtop;
3188 using_enc = xusing_enc;
3189 }
3190 else
3191 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3192
3193 /* If no RTTI data, or if object is already complete, do nothing */
3194 if (!real_type || real_type == VALUE_ENCLOSING_TYPE (argp))
3195 return argp;
3196
3197 /* If we have the full object, but for some reason the enclosing
3198 type is wrong, set it *//* pai: FIXME -- sounds iffy */
3199 if (full)
3200 {
3201 argp = value_change_enclosing_type (argp, real_type);
3202 return argp;
3203 }
3204
3205 /* Check if object is in memory */
3206 if (VALUE_LVAL (argp) != lval_memory)
3207 {
3208 warning ("Couldn't retrieve complete object of RTTI type %s; object may be in register(s).", TYPE_NAME (real_type));
3209
3210 return argp;
3211 }
3212
3213 /* All other cases -- retrieve the complete object */
3214 /* Go back by the computed top_offset from the beginning of the object,
3215 adjusting for the embedded offset of argp if that's what value_rtti_type
3216 used for its computation. */
3217 new_val = value_at_lazy (real_type, VALUE_ADDRESS (argp) - top +
3218 (using_enc ? 0 : VALUE_EMBEDDED_OFFSET (argp)),
3219 VALUE_BFD_SECTION (argp));
3220 VALUE_TYPE (new_val) = VALUE_TYPE (argp);
3221 VALUE_EMBEDDED_OFFSET (new_val) = using_enc ? top + VALUE_EMBEDDED_OFFSET (argp) : top;
3222 return new_val;
3223 }
3224
3225
3226
3227
3228 /* C++: return the value of the class instance variable, if one exists.
3229 Flag COMPLAIN signals an error if the request is made in an
3230 inappropriate context. */
3231
3232 struct value *
3233 value_of_this (int complain)
3234 {
3235 struct symbol *func, *sym;
3236 struct block *b;
3237 int i;
3238 static const char funny_this[] = "this";
3239 struct value *this;
3240
3241 if (selected_frame == 0)
3242 {
3243 if (complain)
3244 error ("no frame selected");
3245 else
3246 return 0;
3247 }
3248
3249 func = get_frame_function (selected_frame);
3250 if (!func)
3251 {
3252 if (complain)
3253 error ("no `this' in nameless context");
3254 else
3255 return 0;
3256 }
3257
3258 b = SYMBOL_BLOCK_VALUE (func);
3259 i = BLOCK_NSYMS (b);
3260 if (i <= 0)
3261 {
3262 if (complain)
3263 error ("no args, no `this'");
3264 else
3265 return 0;
3266 }
3267
3268 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
3269 symbol instead of the LOC_ARG one (if both exist). */
3270 sym = lookup_block_symbol (b, funny_this, NULL, VAR_NAMESPACE);
3271 if (sym == NULL)
3272 {
3273 if (complain)
3274 error ("current stack frame not in method");
3275 else
3276 return NULL;
3277 }
3278
3279 this = read_var_value (sym, selected_frame);
3280 if (this == 0 && complain)
3281 error ("`this' argument at unknown address");
3282 return this;
3283 }
3284
3285 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH elements
3286 long, starting at LOWBOUND. The result has the same lower bound as
3287 the original ARRAY. */
3288
3289 struct value *
3290 value_slice (struct value *array, int lowbound, int length)
3291 {
3292 struct type *slice_range_type, *slice_type, *range_type;
3293 LONGEST lowerbound, upperbound, offset;
3294 struct value *slice;
3295 struct type *array_type;
3296 array_type = check_typedef (VALUE_TYPE (array));
3297 COERCE_VARYING_ARRAY (array, array_type);
3298 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3299 && TYPE_CODE (array_type) != TYPE_CODE_STRING
3300 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
3301 error ("cannot take slice of non-array");
3302 range_type = TYPE_INDEX_TYPE (array_type);
3303 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3304 error ("slice from bad array or bitstring");
3305 if (lowbound < lowerbound || length < 0
3306 || lowbound + length - 1 > upperbound
3307 /* Chill allows zero-length strings but not arrays. */
3308 || (current_language->la_language == language_chill
3309 && length == 0 && TYPE_CODE (array_type) == TYPE_CODE_ARRAY))
3310 error ("slice out of range");
3311 /* FIXME-type-allocation: need a way to free this type when we are
3312 done with it. */
3313 slice_range_type = create_range_type ((struct type *) NULL,
3314 TYPE_TARGET_TYPE (range_type),
3315 lowbound, lowbound + length - 1);
3316 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
3317 {
3318 int i;
3319 slice_type = create_set_type ((struct type *) NULL, slice_range_type);
3320 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
3321 slice = value_zero (slice_type, not_lval);
3322 for (i = 0; i < length; i++)
3323 {
3324 int element = value_bit_index (array_type,
3325 VALUE_CONTENTS (array),
3326 lowbound + i);
3327 if (element < 0)
3328 error ("internal error accessing bitstring");
3329 else if (element > 0)
3330 {
3331 int j = i % TARGET_CHAR_BIT;
3332 if (BITS_BIG_ENDIAN)
3333 j = TARGET_CHAR_BIT - 1 - j;
3334 VALUE_CONTENTS_RAW (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3335 }
3336 }
3337 /* We should set the address, bitssize, and bitspos, so the clice
3338 can be used on the LHS, but that may require extensions to
3339 value_assign. For now, just leave as a non_lval. FIXME. */
3340 }
3341 else
3342 {
3343 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3344 offset
3345 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3346 slice_type = create_array_type ((struct type *) NULL, element_type,
3347 slice_range_type);
3348 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3349 slice = allocate_value (slice_type);
3350 if (VALUE_LAZY (array))
3351 VALUE_LAZY (slice) = 1;
3352 else
3353 memcpy (VALUE_CONTENTS (slice), VALUE_CONTENTS (array) + offset,
3354 TYPE_LENGTH (slice_type));
3355 if (VALUE_LVAL (array) == lval_internalvar)
3356 VALUE_LVAL (slice) = lval_internalvar_component;
3357 else
3358 VALUE_LVAL (slice) = VALUE_LVAL (array);
3359 VALUE_ADDRESS (slice) = VALUE_ADDRESS (array);
3360 VALUE_OFFSET (slice) = VALUE_OFFSET (array) + offset;
3361 }
3362 return slice;
3363 }
3364
3365 /* Assuming chill_varying_type (VARRAY) is true, return an equivalent
3366 value as a fixed-length array. */
3367
3368 struct value *
3369 varying_to_slice (struct value *varray)
3370 {
3371 struct type *vtype = check_typedef (VALUE_TYPE (varray));
3372 LONGEST length = unpack_long (TYPE_FIELD_TYPE (vtype, 0),
3373 VALUE_CONTENTS (varray)
3374 + TYPE_FIELD_BITPOS (vtype, 0) / 8);
3375 return value_slice (value_primitive_field (varray, 0, 1, vtype), 0, length);
3376 }
3377
3378 /* Create a value for a FORTRAN complex number. Currently most of
3379 the time values are coerced to COMPLEX*16 (i.e. a complex number
3380 composed of 2 doubles. This really should be a smarter routine
3381 that figures out precision inteligently as opposed to assuming
3382 doubles. FIXME: fmb */
3383
3384 struct value *
3385 value_literal_complex (struct value *arg1, struct value *arg2, struct type *type)
3386 {
3387 struct value *val;
3388 struct type *real_type = TYPE_TARGET_TYPE (type);
3389
3390 val = allocate_value (type);
3391 arg1 = value_cast (real_type, arg1);
3392 arg2 = value_cast (real_type, arg2);
3393
3394 memcpy (VALUE_CONTENTS_RAW (val),
3395 VALUE_CONTENTS (arg1), TYPE_LENGTH (real_type));
3396 memcpy (VALUE_CONTENTS_RAW (val) + TYPE_LENGTH (real_type),
3397 VALUE_CONTENTS (arg2), TYPE_LENGTH (real_type));
3398 return val;
3399 }
3400
3401 /* Cast a value into the appropriate complex data type. */
3402
3403 static struct value *
3404 cast_into_complex (struct type *type, struct value *val)
3405 {
3406 struct type *real_type = TYPE_TARGET_TYPE (type);
3407 if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_COMPLEX)
3408 {
3409 struct type *val_real_type = TYPE_TARGET_TYPE (VALUE_TYPE (val));
3410 struct value *re_val = allocate_value (val_real_type);
3411 struct value *im_val = allocate_value (val_real_type);
3412
3413 memcpy (VALUE_CONTENTS_RAW (re_val),
3414 VALUE_CONTENTS (val), TYPE_LENGTH (val_real_type));
3415 memcpy (VALUE_CONTENTS_RAW (im_val),
3416 VALUE_CONTENTS (val) + TYPE_LENGTH (val_real_type),
3417 TYPE_LENGTH (val_real_type));
3418
3419 return value_literal_complex (re_val, im_val, type);
3420 }
3421 else if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FLT
3422 || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT)
3423 return value_literal_complex (val, value_zero (real_type, not_lval), type);
3424 else
3425 error ("cannot cast non-number to complex");
3426 }
3427
3428 void
3429 _initialize_valops (void)
3430 {
3431 #if 0
3432 add_show_from_set
3433 (add_set_cmd ("abandon", class_support, var_boolean, (char *) &auto_abandon,
3434 "Set automatic abandonment of expressions upon failure.",
3435 &setlist),
3436 &showlist);
3437 #endif
3438
3439 add_show_from_set
3440 (add_set_cmd ("overload-resolution", class_support, var_boolean, (char *) &overload_resolution,
3441 "Set overload resolution in evaluating C++ functions.",
3442 &setlist),
3443 &showlist);
3444 overload_resolution = 1;
3445
3446 add_show_from_set (
3447 add_set_cmd ("unwindonsignal", no_class, var_boolean,
3448 (char *) &unwind_on_signal_p,
3449 "Set unwinding of stack if a signal is received while in a call dummy.\n\
3450 The unwindonsignal lets the user determine what gdb should do if a signal\n\
3451 is received while in a function called from gdb (call dummy). If set, gdb\n\
3452 unwinds the stack and restore the context to what as it was before the call.\n\
3453 The default is to stop in the frame where the signal was received.", &setlist),
3454 &showlist);
3455 }
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