Index: ChangeLog
[deliverable/binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
3 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
4 Free Software Foundation, Inc.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
22
23 #include "defs.h"
24 #include "symtab.h"
25 #include "gdbtypes.h"
26 #include "value.h"
27 #include "frame.h"
28 #include "inferior.h"
29 #include "gdbcore.h"
30 #include "target.h"
31 #include "demangle.h"
32 #include "language.h"
33 #include "gdbcmd.h"
34 #include "regcache.h"
35 #include "cp-abi.h"
36 #include "block.h"
37
38 #include <errno.h>
39 #include "gdb_string.h"
40 #include "gdb_assert.h"
41
42 /* Flag indicating HP compilers were used; needed to correctly handle some
43 value operations with HP aCC code/runtime. */
44 extern int hp_som_som_object_present;
45
46 extern int overload_debug;
47 /* Local functions. */
48
49 static int typecmp (int staticp, int varargs, int nargs,
50 struct field t1[], struct value *t2[]);
51
52 static CORE_ADDR find_function_addr (struct value *, struct type **);
53 static struct value *value_arg_coerce (struct value *, struct type *, int);
54
55
56 static CORE_ADDR value_push (CORE_ADDR, struct value *);
57
58 static struct value *search_struct_field (char *, struct value *, int,
59 struct type *, int);
60
61 static struct value *search_struct_method (char *, struct value **,
62 struct value **,
63 int, int *, struct type *);
64
65 static int check_field_in (struct type *, const char *);
66
67 static CORE_ADDR allocate_space_in_inferior (int);
68
69 static struct value *cast_into_complex (struct type *, struct value *);
70
71 static struct fn_field *find_method_list (struct value ** argp, char *method,
72 int offset,
73 struct type *type, int *num_fns,
74 struct type **basetype,
75 int *boffset);
76
77 void _initialize_valops (void);
78
79 /* Flag for whether we want to abandon failed expression evals by default. */
80
81 #if 0
82 static int auto_abandon = 0;
83 #endif
84
85 int overload_resolution = 0;
86
87 /* This boolean tells what gdb should do if a signal is received while in
88 a function called from gdb (call dummy). If set, gdb unwinds the stack
89 and restore the context to what as it was before the call.
90 The default is to stop in the frame where the signal was received. */
91
92 int unwind_on_signal_p = 0;
93
94 /* How you should pass arguments to a function depends on whether it
95 was defined in K&R style or prototype style. If you define a
96 function using the K&R syntax that takes a `float' argument, then
97 callers must pass that argument as a `double'. If you define the
98 function using the prototype syntax, then you must pass the
99 argument as a `float', with no promotion.
100
101 Unfortunately, on certain older platforms, the debug info doesn't
102 indicate reliably how each function was defined. A function type's
103 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
104 defined in prototype style. When calling a function whose
105 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to decide
106 what to do.
107
108 For modern targets, it is proper to assume that, if the prototype
109 flag is clear, that can be trusted: `float' arguments should be
110 promoted to `double'. For some older targets, if the prototype
111 flag is clear, that doesn't tell us anything. The default is to
112 trust the debug information; the user can override this behavior
113 with "set coerce-float-to-double 0". */
114
115 static int coerce_float_to_double;
116 \f
117
118 /* Find the address of function name NAME in the inferior. */
119
120 struct value *
121 find_function_in_inferior (const char *name)
122 {
123 register struct symbol *sym;
124 sym = lookup_symbol (name, 0, VAR_NAMESPACE, 0, NULL);
125 if (sym != NULL)
126 {
127 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
128 {
129 error ("\"%s\" exists in this program but is not a function.",
130 name);
131 }
132 return value_of_variable (sym, NULL);
133 }
134 else
135 {
136 struct minimal_symbol *msymbol = lookup_minimal_symbol (name, NULL, NULL);
137 if (msymbol != NULL)
138 {
139 struct type *type;
140 CORE_ADDR maddr;
141 type = lookup_pointer_type (builtin_type_char);
142 type = lookup_function_type (type);
143 type = lookup_pointer_type (type);
144 maddr = SYMBOL_VALUE_ADDRESS (msymbol);
145 return value_from_pointer (type, maddr);
146 }
147 else
148 {
149 if (!target_has_execution)
150 error ("evaluation of this expression requires the target program to be active");
151 else
152 error ("evaluation of this expression requires the program to have a function \"%s\".", name);
153 }
154 }
155 }
156
157 /* Allocate NBYTES of space in the inferior using the inferior's malloc
158 and return a value that is a pointer to the allocated space. */
159
160 struct value *
161 value_allocate_space_in_inferior (int len)
162 {
163 struct value *blocklen;
164 struct value *val = find_function_in_inferior (NAME_OF_MALLOC);
165
166 blocklen = value_from_longest (builtin_type_int, (LONGEST) len);
167 val = call_function_by_hand (val, 1, &blocklen);
168 if (value_logical_not (val))
169 {
170 if (!target_has_execution)
171 error ("No memory available to program now: you need to start the target first");
172 else
173 error ("No memory available to program: call to malloc failed");
174 }
175 return val;
176 }
177
178 static CORE_ADDR
179 allocate_space_in_inferior (int len)
180 {
181 return value_as_long (value_allocate_space_in_inferior (len));
182 }
183
184 /* Cast value ARG2 to type TYPE and return as a value.
185 More general than a C cast: accepts any two types of the same length,
186 and if ARG2 is an lvalue it can be cast into anything at all. */
187 /* In C++, casts may change pointer or object representations. */
188
189 struct value *
190 value_cast (struct type *type, struct value *arg2)
191 {
192 register enum type_code code1;
193 register enum type_code code2;
194 register int scalar;
195 struct type *type2;
196
197 int convert_to_boolean = 0;
198
199 if (VALUE_TYPE (arg2) == type)
200 return arg2;
201
202 CHECK_TYPEDEF (type);
203 code1 = TYPE_CODE (type);
204 COERCE_REF (arg2);
205 type2 = check_typedef (VALUE_TYPE (arg2));
206
207 /* A cast to an undetermined-length array_type, such as (TYPE [])OBJECT,
208 is treated like a cast to (TYPE [N])OBJECT,
209 where N is sizeof(OBJECT)/sizeof(TYPE). */
210 if (code1 == TYPE_CODE_ARRAY)
211 {
212 struct type *element_type = TYPE_TARGET_TYPE (type);
213 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
214 if (element_length > 0
215 && TYPE_ARRAY_UPPER_BOUND_TYPE (type) == BOUND_CANNOT_BE_DETERMINED)
216 {
217 struct type *range_type = TYPE_INDEX_TYPE (type);
218 int val_length = TYPE_LENGTH (type2);
219 LONGEST low_bound, high_bound, new_length;
220 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
221 low_bound = 0, high_bound = 0;
222 new_length = val_length / element_length;
223 if (val_length % element_length != 0)
224 warning ("array element type size does not divide object size in cast");
225 /* FIXME-type-allocation: need a way to free this type when we are
226 done with it. */
227 range_type = create_range_type ((struct type *) NULL,
228 TYPE_TARGET_TYPE (range_type),
229 low_bound,
230 new_length + low_bound - 1);
231 VALUE_TYPE (arg2) = create_array_type ((struct type *) NULL,
232 element_type, range_type);
233 return arg2;
234 }
235 }
236
237 if (current_language->c_style_arrays
238 && TYPE_CODE (type2) == TYPE_CODE_ARRAY)
239 arg2 = value_coerce_array (arg2);
240
241 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
242 arg2 = value_coerce_function (arg2);
243
244 type2 = check_typedef (VALUE_TYPE (arg2));
245 COERCE_VARYING_ARRAY (arg2, type2);
246 code2 = TYPE_CODE (type2);
247
248 if (code1 == TYPE_CODE_COMPLEX)
249 return cast_into_complex (type, arg2);
250 if (code1 == TYPE_CODE_BOOL)
251 {
252 code1 = TYPE_CODE_INT;
253 convert_to_boolean = 1;
254 }
255 if (code1 == TYPE_CODE_CHAR)
256 code1 = TYPE_CODE_INT;
257 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
258 code2 = TYPE_CODE_INT;
259
260 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
261 || code2 == TYPE_CODE_ENUM || code2 == TYPE_CODE_RANGE);
262
263 if (code1 == TYPE_CODE_STRUCT
264 && code2 == TYPE_CODE_STRUCT
265 && TYPE_NAME (type) != 0)
266 {
267 /* Look in the type of the source to see if it contains the
268 type of the target as a superclass. If so, we'll need to
269 offset the object in addition to changing its type. */
270 struct value *v = search_struct_field (type_name_no_tag (type),
271 arg2, 0, type2, 1);
272 if (v)
273 {
274 VALUE_TYPE (v) = type;
275 return v;
276 }
277 }
278 if (code1 == TYPE_CODE_FLT && scalar)
279 return value_from_double (type, value_as_double (arg2));
280 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
281 || code1 == TYPE_CODE_RANGE)
282 && (scalar || code2 == TYPE_CODE_PTR))
283 {
284 LONGEST longest;
285
286 if (hp_som_som_object_present && /* if target compiled by HP aCC */
287 (code2 == TYPE_CODE_PTR))
288 {
289 unsigned int *ptr;
290 struct value *retvalp;
291
292 switch (TYPE_CODE (TYPE_TARGET_TYPE (type2)))
293 {
294 /* With HP aCC, pointers to data members have a bias */
295 case TYPE_CODE_MEMBER:
296 retvalp = value_from_longest (type, value_as_long (arg2));
297 /* force evaluation */
298 ptr = (unsigned int *) VALUE_CONTENTS (retvalp);
299 *ptr &= ~0x20000000; /* zap 29th bit to remove bias */
300 return retvalp;
301
302 /* While pointers to methods don't really point to a function */
303 case TYPE_CODE_METHOD:
304 error ("Pointers to methods not supported with HP aCC");
305
306 default:
307 break; /* fall out and go to normal handling */
308 }
309 }
310
311 /* When we cast pointers to integers, we mustn't use
312 POINTER_TO_ADDRESS to find the address the pointer
313 represents, as value_as_long would. GDB should evaluate
314 expressions just as the compiler would --- and the compiler
315 sees a cast as a simple reinterpretation of the pointer's
316 bits. */
317 if (code2 == TYPE_CODE_PTR)
318 longest = extract_unsigned_integer (VALUE_CONTENTS (arg2),
319 TYPE_LENGTH (type2));
320 else
321 longest = value_as_long (arg2);
322 return value_from_longest (type, convert_to_boolean ?
323 (LONGEST) (longest ? 1 : 0) : longest);
324 }
325 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT ||
326 code2 == TYPE_CODE_ENUM ||
327 code2 == TYPE_CODE_RANGE))
328 {
329 /* TYPE_LENGTH (type) is the length of a pointer, but we really
330 want the length of an address! -- we are really dealing with
331 addresses (i.e., gdb representations) not pointers (i.e.,
332 target representations) here.
333
334 This allows things like "print *(int *)0x01000234" to work
335 without printing a misleading message -- which would
336 otherwise occur when dealing with a target having two byte
337 pointers and four byte addresses. */
338
339 int addr_bit = TARGET_ADDR_BIT;
340
341 LONGEST longest = value_as_long (arg2);
342 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
343 {
344 if (longest >= ((LONGEST) 1 << addr_bit)
345 || longest <= -((LONGEST) 1 << addr_bit))
346 warning ("value truncated");
347 }
348 return value_from_longest (type, longest);
349 }
350 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
351 {
352 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
353 {
354 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type));
355 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
356 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
357 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
358 && !value_logical_not (arg2))
359 {
360 struct value *v;
361
362 /* Look in the type of the source to see if it contains the
363 type of the target as a superclass. If so, we'll need to
364 offset the pointer rather than just change its type. */
365 if (TYPE_NAME (t1) != NULL)
366 {
367 v = search_struct_field (type_name_no_tag (t1),
368 value_ind (arg2), 0, t2, 1);
369 if (v)
370 {
371 v = value_addr (v);
372 VALUE_TYPE (v) = type;
373 return v;
374 }
375 }
376
377 /* Look in the type of the target to see if it contains the
378 type of the source as a superclass. If so, we'll need to
379 offset the pointer rather than just change its type.
380 FIXME: This fails silently with virtual inheritance. */
381 if (TYPE_NAME (t2) != NULL)
382 {
383 v = search_struct_field (type_name_no_tag (t2),
384 value_zero (t1, not_lval), 0, t1, 1);
385 if (v)
386 {
387 CORE_ADDR addr2 = value_as_address (arg2);
388 addr2 -= (VALUE_ADDRESS (v)
389 + VALUE_OFFSET (v)
390 + VALUE_EMBEDDED_OFFSET (v));
391 return value_from_pointer (type, addr2);
392 }
393 }
394 }
395 /* No superclass found, just fall through to change ptr type. */
396 }
397 VALUE_TYPE (arg2) = type;
398 arg2 = value_change_enclosing_type (arg2, type);
399 VALUE_POINTED_TO_OFFSET (arg2) = 0; /* pai: chk_val */
400 return arg2;
401 }
402 else if (VALUE_LVAL (arg2) == lval_memory)
403 {
404 return value_at_lazy (type, VALUE_ADDRESS (arg2) + VALUE_OFFSET (arg2),
405 VALUE_BFD_SECTION (arg2));
406 }
407 else if (code1 == TYPE_CODE_VOID)
408 {
409 return value_zero (builtin_type_void, not_lval);
410 }
411 else
412 {
413 error ("Invalid cast.");
414 return 0;
415 }
416 }
417
418 /* Create a value of type TYPE that is zero, and return it. */
419
420 struct value *
421 value_zero (struct type *type, enum lval_type lv)
422 {
423 struct value *val = allocate_value (type);
424
425 memset (VALUE_CONTENTS (val), 0, TYPE_LENGTH (check_typedef (type)));
426 VALUE_LVAL (val) = lv;
427
428 return val;
429 }
430
431 /* Return a value with type TYPE located at ADDR.
432
433 Call value_at only if the data needs to be fetched immediately;
434 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
435 value_at_lazy instead. value_at_lazy simply records the address of
436 the data and sets the lazy-evaluation-required flag. The lazy flag
437 is tested in the VALUE_CONTENTS macro, which is used if and when
438 the contents are actually required.
439
440 Note: value_at does *NOT* handle embedded offsets; perform such
441 adjustments before or after calling it. */
442
443 struct value *
444 value_at (struct type *type, CORE_ADDR addr, asection *sect)
445 {
446 struct value *val;
447
448 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
449 error ("Attempt to dereference a generic pointer.");
450
451 val = allocate_value (type);
452
453 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), TYPE_LENGTH (type));
454
455 VALUE_LVAL (val) = lval_memory;
456 VALUE_ADDRESS (val) = addr;
457 VALUE_BFD_SECTION (val) = sect;
458
459 return val;
460 }
461
462 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
463
464 struct value *
465 value_at_lazy (struct type *type, CORE_ADDR addr, asection *sect)
466 {
467 struct value *val;
468
469 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
470 error ("Attempt to dereference a generic pointer.");
471
472 val = allocate_value (type);
473
474 VALUE_LVAL (val) = lval_memory;
475 VALUE_ADDRESS (val) = addr;
476 VALUE_LAZY (val) = 1;
477 VALUE_BFD_SECTION (val) = sect;
478
479 return val;
480 }
481
482 /* Called only from the VALUE_CONTENTS and VALUE_CONTENTS_ALL macros,
483 if the current data for a variable needs to be loaded into
484 VALUE_CONTENTS(VAL). Fetches the data from the user's process, and
485 clears the lazy flag to indicate that the data in the buffer is valid.
486
487 If the value is zero-length, we avoid calling read_memory, which would
488 abort. We mark the value as fetched anyway -- all 0 bytes of it.
489
490 This function returns a value because it is used in the VALUE_CONTENTS
491 macro as part of an expression, where a void would not work. The
492 value is ignored. */
493
494 int
495 value_fetch_lazy (struct value *val)
496 {
497 CORE_ADDR addr = VALUE_ADDRESS (val) + VALUE_OFFSET (val);
498 int length = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val));
499
500 struct type *type = VALUE_TYPE (val);
501 if (length)
502 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), length);
503
504 VALUE_LAZY (val) = 0;
505 return 0;
506 }
507
508
509 /* Store the contents of FROMVAL into the location of TOVAL.
510 Return a new value with the location of TOVAL and contents of FROMVAL. */
511
512 struct value *
513 value_assign (struct value *toval, struct value *fromval)
514 {
515 register struct type *type;
516 struct value *val;
517 char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE);
518 int use_buffer = 0;
519 struct frame_id old_frame;
520
521 if (!toval->modifiable)
522 error ("Left operand of assignment is not a modifiable lvalue.");
523
524 COERCE_REF (toval);
525
526 type = VALUE_TYPE (toval);
527 if (VALUE_LVAL (toval) != lval_internalvar)
528 fromval = value_cast (type, fromval);
529 else
530 COERCE_ARRAY (fromval);
531 CHECK_TYPEDEF (type);
532
533 /* If TOVAL is a special machine register requiring conversion
534 of program values to a special raw format,
535 convert FROMVAL's contents now, with result in `raw_buffer',
536 and set USE_BUFFER to the number of bytes to write. */
537
538 if (VALUE_REGNO (toval) >= 0)
539 {
540 int regno = VALUE_REGNO (toval);
541 if (CONVERT_REGISTER_P (regno))
542 {
543 struct type *fromtype = check_typedef (VALUE_TYPE (fromval));
544 VALUE_TO_REGISTER (fromtype, regno, VALUE_CONTENTS (fromval), raw_buffer);
545 use_buffer = REGISTER_RAW_SIZE (regno);
546 }
547 }
548
549 /* Since modifying a register can trash the frame chain, and modifying memory
550 can trash the frame cache, we save the old frame and then restore the new
551 frame afterwards. */
552 old_frame = get_frame_id (deprecated_selected_frame);
553
554 switch (VALUE_LVAL (toval))
555 {
556 case lval_internalvar:
557 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
558 val = value_copy (VALUE_INTERNALVAR (toval)->value);
559 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
560 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
561 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
562 return val;
563
564 case lval_internalvar_component:
565 set_internalvar_component (VALUE_INTERNALVAR (toval),
566 VALUE_OFFSET (toval),
567 VALUE_BITPOS (toval),
568 VALUE_BITSIZE (toval),
569 fromval);
570 break;
571
572 case lval_memory:
573 {
574 char *dest_buffer;
575 CORE_ADDR changed_addr;
576 int changed_len;
577
578 if (VALUE_BITSIZE (toval))
579 {
580 char buffer[sizeof (LONGEST)];
581 /* We assume that the argument to read_memory is in units of
582 host chars. FIXME: Is that correct? */
583 changed_len = (VALUE_BITPOS (toval)
584 + VALUE_BITSIZE (toval)
585 + HOST_CHAR_BIT - 1)
586 / HOST_CHAR_BIT;
587
588 if (changed_len > (int) sizeof (LONGEST))
589 error ("Can't handle bitfields which don't fit in a %d bit word.",
590 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
591
592 read_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
593 buffer, changed_len);
594 modify_field (buffer, value_as_long (fromval),
595 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
596 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
597 dest_buffer = buffer;
598 }
599 else if (use_buffer)
600 {
601 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
602 changed_len = use_buffer;
603 dest_buffer = raw_buffer;
604 }
605 else
606 {
607 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
608 changed_len = TYPE_LENGTH (type);
609 dest_buffer = VALUE_CONTENTS (fromval);
610 }
611
612 write_memory (changed_addr, dest_buffer, changed_len);
613 if (memory_changed_hook)
614 memory_changed_hook (changed_addr, changed_len);
615 target_changed_event ();
616 }
617 break;
618
619 case lval_reg_frame_relative:
620 case lval_register:
621 {
622 /* value is stored in a series of registers in the frame
623 specified by the structure. Copy that value out, modify
624 it, and copy it back in. */
625 int amount_copied;
626 int amount_to_copy;
627 char *buffer;
628 int value_reg;
629 int reg_offset;
630 int byte_offset;
631 int regno;
632 struct frame_info *frame;
633
634 /* Figure out which frame this is in currently. */
635 if (VALUE_LVAL (toval) == lval_register)
636 {
637 frame = get_current_frame ();
638 value_reg = VALUE_REGNO (toval);
639 }
640 else
641 {
642 for (frame = get_current_frame ();
643 frame && get_frame_base (frame) != VALUE_FRAME (toval);
644 frame = get_prev_frame (frame))
645 ;
646 value_reg = VALUE_FRAME_REGNUM (toval);
647 }
648
649 if (!frame)
650 error ("Value being assigned to is no longer active.");
651
652 /* Locate the first register that falls in the value that
653 needs to be transfered. Compute the offset of the value in
654 that register. */
655 {
656 int offset;
657 for (reg_offset = value_reg, offset = 0;
658 offset + REGISTER_RAW_SIZE (reg_offset) <= VALUE_OFFSET (toval);
659 reg_offset++);
660 byte_offset = VALUE_OFFSET (toval) - offset;
661 }
662
663 /* Compute the number of register aligned values that need to
664 be copied. */
665 if (VALUE_BITSIZE (toval))
666 amount_to_copy = byte_offset + 1;
667 else
668 amount_to_copy = byte_offset + TYPE_LENGTH (type);
669
670 /* And a bounce buffer. Be slightly over generous. */
671 buffer = (char *) alloca (amount_to_copy
672 + MAX_REGISTER_RAW_SIZE);
673
674 /* Copy it in. */
675 for (regno = reg_offset, amount_copied = 0;
676 amount_copied < amount_to_copy;
677 amount_copied += REGISTER_RAW_SIZE (regno), regno++)
678 {
679 frame_register_read (frame, regno, buffer + amount_copied);
680 }
681
682 /* Modify what needs to be modified. */
683 if (VALUE_BITSIZE (toval))
684 {
685 modify_field (buffer + byte_offset,
686 value_as_long (fromval),
687 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
688 }
689 else if (use_buffer)
690 {
691 memcpy (buffer + VALUE_OFFSET (toval), raw_buffer, use_buffer);
692 }
693 else
694 {
695 memcpy (buffer + byte_offset, VALUE_CONTENTS (fromval),
696 TYPE_LENGTH (type));
697 /* Do any conversion necessary when storing this type to
698 more than one register. */
699 #ifdef REGISTER_CONVERT_FROM_TYPE
700 REGISTER_CONVERT_FROM_TYPE (value_reg, type,
701 (buffer + byte_offset));
702 #endif
703 }
704
705 /* Copy it out. */
706 for (regno = reg_offset, amount_copied = 0;
707 amount_copied < amount_to_copy;
708 amount_copied += REGISTER_RAW_SIZE (regno), regno++)
709 {
710 enum lval_type lval;
711 CORE_ADDR addr;
712 int optim;
713 int realnum;
714
715 /* Just find out where to put it. */
716 frame_register (frame, regno, &optim, &lval, &addr, &realnum,
717 NULL);
718
719 if (optim)
720 error ("Attempt to assign to a value that was optimized out.");
721 if (lval == lval_memory)
722 write_memory (addr, buffer + amount_copied,
723 REGISTER_RAW_SIZE (regno));
724 else if (lval == lval_register)
725 regcache_cooked_write (current_regcache, realnum,
726 (buffer + amount_copied));
727 else
728 error ("Attempt to assign to an unmodifiable value.");
729 }
730
731 if (register_changed_hook)
732 register_changed_hook (-1);
733 target_changed_event ();
734
735 }
736 break;
737
738
739 default:
740 error ("Left operand of assignment is not an lvalue.");
741 }
742
743 /* Assigning to the stack pointer, frame pointer, and other
744 (architecture and calling convention specific) registers may
745 cause the frame cache to be out of date. Assigning to memory
746 also can. We just do this on all assignments to registers or
747 memory, for simplicity's sake; I doubt the slowdown matters. */
748 switch (VALUE_LVAL (toval))
749 {
750 case lval_memory:
751 case lval_register:
752 case lval_reg_frame_relative:
753
754 reinit_frame_cache ();
755
756 /* Having destoroyed the frame cache, restore the selected frame. */
757
758 /* FIXME: cagney/2002-11-02: There has to be a better way of
759 doing this. Instead of constantly saving/restoring the
760 frame. Why not create a get_selected_frame() function that,
761 having saved the selected frame's ID can automatically
762 re-find the previously selected frame automatically. */
763
764 {
765 struct frame_info *fi = frame_find_by_id (old_frame);
766 if (fi != NULL)
767 select_frame (fi);
768 }
769
770 break;
771 default:
772 break;
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_PRINT_NAME (BLOCK_FUNCTION (b)))
839 error ("No frame is currently executing in block %s.",
840 SYMBOL_PRINT_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_PRINT_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_lazy (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 /* Perform the standard coercions that are specified
1093 for arguments to be passed to C functions.
1094
1095 If PARAM_TYPE is non-NULL, it is the expected parameter type.
1096 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
1097
1098 static struct value *
1099 value_arg_coerce (struct value *arg, struct type *param_type,
1100 int is_prototyped)
1101 {
1102 register struct type *arg_type = check_typedef (VALUE_TYPE (arg));
1103 register struct type *type
1104 = param_type ? check_typedef (param_type) : arg_type;
1105
1106 switch (TYPE_CODE (type))
1107 {
1108 case TYPE_CODE_REF:
1109 if (TYPE_CODE (arg_type) != TYPE_CODE_REF
1110 && TYPE_CODE (arg_type) != TYPE_CODE_PTR)
1111 {
1112 arg = value_addr (arg);
1113 VALUE_TYPE (arg) = param_type;
1114 return arg;
1115 }
1116 break;
1117 case TYPE_CODE_INT:
1118 case TYPE_CODE_CHAR:
1119 case TYPE_CODE_BOOL:
1120 case TYPE_CODE_ENUM:
1121 /* If we don't have a prototype, coerce to integer type if necessary. */
1122 if (!is_prototyped)
1123 {
1124 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
1125 type = builtin_type_int;
1126 }
1127 /* Currently all target ABIs require at least the width of an integer
1128 type for an argument. We may have to conditionalize the following
1129 type coercion for future targets. */
1130 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
1131 type = builtin_type_int;
1132 break;
1133 case TYPE_CODE_FLT:
1134 if (!is_prototyped && coerce_float_to_double)
1135 {
1136 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
1137 type = builtin_type_double;
1138 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double))
1139 type = builtin_type_long_double;
1140 }
1141 break;
1142 case TYPE_CODE_FUNC:
1143 type = lookup_pointer_type (type);
1144 break;
1145 case TYPE_CODE_ARRAY:
1146 /* Arrays are coerced to pointers to their first element, unless
1147 they are vectors, in which case we want to leave them alone,
1148 because they are passed by value. */
1149 if (current_language->c_style_arrays)
1150 if (!TYPE_VECTOR (type))
1151 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
1152 break;
1153 case TYPE_CODE_UNDEF:
1154 case TYPE_CODE_PTR:
1155 case TYPE_CODE_STRUCT:
1156 case TYPE_CODE_UNION:
1157 case TYPE_CODE_VOID:
1158 case TYPE_CODE_SET:
1159 case TYPE_CODE_RANGE:
1160 case TYPE_CODE_STRING:
1161 case TYPE_CODE_BITSTRING:
1162 case TYPE_CODE_ERROR:
1163 case TYPE_CODE_MEMBER:
1164 case TYPE_CODE_METHOD:
1165 case TYPE_CODE_COMPLEX:
1166 default:
1167 break;
1168 }
1169
1170 return value_cast (type, arg);
1171 }
1172
1173 /* Determine a function's address and its return type from its value.
1174 Calls error() if the function is not valid for calling. */
1175
1176 static CORE_ADDR
1177 find_function_addr (struct value *function, struct type **retval_type)
1178 {
1179 register struct type *ftype = check_typedef (VALUE_TYPE (function));
1180 register enum type_code code = TYPE_CODE (ftype);
1181 struct type *value_type;
1182 CORE_ADDR funaddr;
1183
1184 /* If it's a member function, just look at the function
1185 part of it. */
1186
1187 /* Determine address to call. */
1188 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
1189 {
1190 funaddr = VALUE_ADDRESS (function);
1191 value_type = TYPE_TARGET_TYPE (ftype);
1192 }
1193 else if (code == TYPE_CODE_PTR)
1194 {
1195 funaddr = value_as_address (function);
1196 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
1197 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
1198 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1199 {
1200 funaddr = CONVERT_FROM_FUNC_PTR_ADDR (funaddr);
1201 value_type = TYPE_TARGET_TYPE (ftype);
1202 }
1203 else
1204 value_type = builtin_type_int;
1205 }
1206 else if (code == TYPE_CODE_INT)
1207 {
1208 /* Handle the case of functions lacking debugging info.
1209 Their values are characters since their addresses are char */
1210 if (TYPE_LENGTH (ftype) == 1)
1211 funaddr = value_as_address (value_addr (function));
1212 else
1213 /* Handle integer used as address of a function. */
1214 funaddr = (CORE_ADDR) value_as_long (function);
1215
1216 value_type = builtin_type_int;
1217 }
1218 else
1219 error ("Invalid data type for function to be called.");
1220
1221 *retval_type = value_type;
1222 return funaddr;
1223 }
1224
1225 /* All this stuff with a dummy frame may seem unnecessarily complicated
1226 (why not just save registers in GDB?). The purpose of pushing a dummy
1227 frame which looks just like a real frame is so that if you call a
1228 function and then hit a breakpoint (get a signal, etc), "backtrace"
1229 will look right. Whether the backtrace needs to actually show the
1230 stack at the time the inferior function was called is debatable, but
1231 it certainly needs to not display garbage. So if you are contemplating
1232 making dummy frames be different from normal frames, consider that. */
1233
1234 /* Perform a function call in the inferior.
1235 ARGS is a vector of values of arguments (NARGS of them).
1236 FUNCTION is a value, the function to be called.
1237 Returns a value representing what the function returned.
1238 May fail to return, if a breakpoint or signal is hit
1239 during the execution of the function.
1240
1241 ARGS is modified to contain coerced values. */
1242
1243 static struct value *
1244 hand_function_call (struct value *function, int nargs, struct value **args)
1245 {
1246 register CORE_ADDR sp;
1247 register int i;
1248 int rc;
1249 CORE_ADDR start_sp;
1250 /* CALL_DUMMY is an array of words (REGISTER_SIZE), but each word
1251 is in host byte order. Before calling FIX_CALL_DUMMY, we byteswap it
1252 and remove any extra bytes which might exist because ULONGEST is
1253 bigger than REGISTER_SIZE.
1254
1255 NOTE: This is pretty wierd, as the call dummy is actually a
1256 sequence of instructions. But CISC machines will have
1257 to pack the instructions into REGISTER_SIZE units (and
1258 so will RISC machines for which INSTRUCTION_SIZE is not
1259 REGISTER_SIZE).
1260
1261 NOTE: This is pretty stupid. CALL_DUMMY should be in strict
1262 target byte order. */
1263
1264 static ULONGEST *dummy;
1265 int sizeof_dummy1;
1266 char *dummy1;
1267 CORE_ADDR old_sp;
1268 struct type *value_type;
1269 unsigned char struct_return;
1270 CORE_ADDR struct_addr = 0;
1271 struct regcache *retbuf;
1272 struct cleanup *retbuf_cleanup;
1273 struct inferior_status *inf_status;
1274 struct cleanup *inf_status_cleanup;
1275 CORE_ADDR funaddr;
1276 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
1277 CORE_ADDR real_pc;
1278 struct type *param_type = NULL;
1279 struct type *ftype = check_typedef (SYMBOL_TYPE (function));
1280 int n_method_args = 0;
1281
1282 dummy = alloca (SIZEOF_CALL_DUMMY_WORDS);
1283 sizeof_dummy1 = REGISTER_SIZE * SIZEOF_CALL_DUMMY_WORDS / sizeof (ULONGEST);
1284 dummy1 = alloca (sizeof_dummy1);
1285 memcpy (dummy, CALL_DUMMY_WORDS, SIZEOF_CALL_DUMMY_WORDS);
1286
1287 if (!target_has_execution)
1288 noprocess ();
1289
1290 /* Create a cleanup chain that contains the retbuf (buffer
1291 containing the register values). This chain is create BEFORE the
1292 inf_status chain so that the inferior status can cleaned up
1293 (restored or discarded) without having the retbuf freed. */
1294 retbuf = regcache_xmalloc (current_gdbarch);
1295 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
1296
1297 /* A cleanup for the inferior status. Create this AFTER the retbuf
1298 so that this can be discarded or applied without interfering with
1299 the regbuf. */
1300 inf_status = save_inferior_status (1);
1301 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
1302
1303 if (DEPRECATED_PUSH_DUMMY_FRAME_P ())
1304 {
1305 /* DEPRECATED_PUSH_DUMMY_FRAME is responsible for saving the
1306 inferior registers (and frame_pop() for restoring them). (At
1307 least on most machines) they are saved on the stack in the
1308 inferior. */
1309 DEPRECATED_PUSH_DUMMY_FRAME;
1310 }
1311 else
1312 {
1313 /* FIXME: cagney/2003-02-26: Step zero of this little tinker is
1314 to extract the generic dummy frame code from the architecture
1315 vector. Hence this direct call.
1316
1317 A follow-on change is to modify this interface so that it takes
1318 thread OR frame OR tpid as a parameter, and returns a dummy
1319 frame handle. The handle can then be used further down as a
1320 parameter SAVE_DUMMY_FRAME_TOS. Hmm, thinking about it, since
1321 everything is ment to be using generic dummy frames, why not
1322 even use some of the dummy frame code to here - do a regcache
1323 dup and then pass the duped regcache, along with all the other
1324 stuff, at one single point.
1325
1326 In fact, you can even save the structure's return address in the
1327 dummy frame and fix one of those nasty lost struct return edge
1328 conditions. */
1329 generic_push_dummy_frame ();
1330 }
1331
1332 old_sp = read_sp ();
1333
1334 /* Ensure that the initial SP is correctly aligned. */
1335 if (gdbarch_frame_align_p (current_gdbarch))
1336 {
1337 /* NOTE: cagney/2002-09-18:
1338
1339 On a RISC architecture, a void parameterless generic dummy
1340 frame (i.e., no parameters, no result) typically does not
1341 need to push anything the stack and hence can leave SP and
1342 FP. Similarly, a framelss (possibly leaf) function does not
1343 push anything on the stack and, hence, that too can leave FP
1344 and SP unchanged. As a consequence, a sequence of void
1345 parameterless generic dummy frame calls to frameless
1346 functions will create a sequence of effectively identical
1347 frames (SP, FP and TOS and PC the same). This, not
1348 suprisingly, results in what appears to be a stack in an
1349 infinite loop --- when GDB tries to find a generic dummy
1350 frame on the internal dummy frame stack, it will always find
1351 the first one.
1352
1353 To avoid this problem, the code below always grows the stack.
1354 That way, two dummy frames can never be identical. It does
1355 burn a few bytes of stack but that is a small price to pay
1356 :-). */
1357 sp = gdbarch_frame_align (current_gdbarch, old_sp);
1358 if (sp == old_sp)
1359 {
1360 if (INNER_THAN (1, 2))
1361 /* Stack grows down. */
1362 sp = gdbarch_frame_align (current_gdbarch, old_sp - 1);
1363 else
1364 /* Stack grows up. */
1365 sp = gdbarch_frame_align (current_gdbarch, old_sp + 1);
1366 }
1367 gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp)
1368 || (INNER_THAN (2, 1) && sp >= old_sp));
1369 }
1370 else
1371 /* FIXME: cagney/2002-09-18: Hey, you loose! Who knows how badly
1372 aligned the SP is! Further, per comment above, if the generic
1373 dummy frame ends up empty (because nothing is pushed) GDB won't
1374 be able to correctly perform back traces. If a target is
1375 having trouble with backtraces, first thing to do is add
1376 FRAME_ALIGN() to its architecture vector. After that, try
1377 adding SAVE_DUMMY_FRAME_TOS() and modifying
1378 DEPRECATED_FRAME_CHAIN so that when the next outer frame is a
1379 generic dummy, it returns the current frame's base. */
1380 sp = old_sp;
1381
1382 if (INNER_THAN (1, 2))
1383 {
1384 /* Stack grows down */
1385 sp -= sizeof_dummy1;
1386 start_sp = sp;
1387 }
1388 else
1389 {
1390 /* Stack grows up */
1391 start_sp = sp;
1392 sp += sizeof_dummy1;
1393 }
1394
1395 /* NOTE: cagney/2002-09-10: Don't bother re-adjusting the stack
1396 after allocating space for the call dummy. A target can specify
1397 a SIZEOF_DUMMY1 (via SIZEOF_CALL_DUMMY_WORDS) such that all local
1398 alignment requirements are met. */
1399
1400 funaddr = find_function_addr (function, &value_type);
1401 CHECK_TYPEDEF (value_type);
1402
1403 {
1404 struct block *b = block_for_pc (funaddr);
1405 /* If compiled without -g, assume GCC 2. */
1406 using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
1407 }
1408
1409 /* Are we returning a value using a structure return or a normal
1410 value return? */
1411
1412 struct_return = using_struct_return (function, funaddr, value_type,
1413 using_gcc);
1414
1415 /* Create a call sequence customized for this function
1416 and the number of arguments for it. */
1417 for (i = 0; i < (int) (SIZEOF_CALL_DUMMY_WORDS / sizeof (dummy[0])); i++)
1418 store_unsigned_integer (&dummy1[i * REGISTER_SIZE],
1419 REGISTER_SIZE,
1420 (ULONGEST) dummy[i]);
1421
1422 #ifdef GDB_TARGET_IS_HPPA
1423 real_pc = FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
1424 value_type, using_gcc);
1425 #else
1426 FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
1427 value_type, using_gcc);
1428 real_pc = start_sp;
1429 #endif
1430
1431 if (CALL_DUMMY_LOCATION == ON_STACK)
1432 {
1433 write_memory (start_sp, (char *) dummy1, sizeof_dummy1);
1434 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
1435 generic_save_call_dummy_addr (start_sp, start_sp + sizeof_dummy1);
1436 }
1437
1438 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
1439 {
1440 real_pc = funaddr;
1441 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
1442 /* NOTE: cagney/2002-04-13: The entry point is going to be
1443 modified with a single breakpoint. */
1444 generic_save_call_dummy_addr (CALL_DUMMY_ADDRESS (),
1445 CALL_DUMMY_ADDRESS () + 1);
1446 }
1447
1448 #ifdef lint
1449 sp = old_sp; /* It really is used, for some ifdef's... */
1450 #endif
1451
1452 if (nargs < TYPE_NFIELDS (ftype))
1453 error ("too few arguments in function call");
1454
1455 for (i = nargs - 1; i >= 0; i--)
1456 {
1457 int prototyped;
1458
1459 /* FIXME drow/2002-05-31: Should just always mark methods as
1460 prototyped. Can we respect TYPE_VARARGS? Probably not. */
1461 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1462 prototyped = 1;
1463 else
1464 prototyped = TYPE_PROTOTYPED (ftype);
1465
1466 if (i < TYPE_NFIELDS (ftype))
1467 args[i] = value_arg_coerce (args[i], TYPE_FIELD_TYPE (ftype, i),
1468 prototyped);
1469 else
1470 args[i] = value_arg_coerce (args[i], NULL, 0);
1471
1472 /*elz: this code is to handle the case in which the function to be called
1473 has a pointer to function as parameter and the corresponding actual argument
1474 is the address of a function and not a pointer to function variable.
1475 In aCC compiled code, the calls through pointers to functions (in the body
1476 of the function called by hand) are made via $$dyncall_external which
1477 requires some registers setting, this is taken care of if we call
1478 via a function pointer variable, but not via a function address.
1479 In cc this is not a problem. */
1480
1481 if (using_gcc == 0)
1482 if (param_type && TYPE_CODE (ftype) != TYPE_CODE_METHOD)
1483 /* if this parameter is a pointer to function */
1484 if (TYPE_CODE (param_type) == TYPE_CODE_PTR)
1485 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type)) == TYPE_CODE_FUNC)
1486 /* elz: FIXME here should go the test about the compiler used
1487 to compile the target. We want to issue the error
1488 message only if the compiler used was HP's aCC.
1489 If we used HP's cc, then there is no problem and no need
1490 to return at this point */
1491 if (using_gcc == 0) /* && compiler == aCC */
1492 /* go see if the actual parameter is a variable of type
1493 pointer to function or just a function */
1494 if (args[i]->lval == not_lval)
1495 {
1496 char *arg_name;
1497 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL))
1498 error ("\
1499 You cannot use function <%s> as argument. \n\
1500 You must use a pointer to function type variable. Command ignored.", arg_name);
1501 }
1502 }
1503
1504 if (REG_STRUCT_HAS_ADDR_P ())
1505 {
1506 /* This is a machine like the sparc, where we may need to pass a
1507 pointer to the structure, not the structure itself. */
1508 for (i = nargs - 1; i >= 0; i--)
1509 {
1510 struct type *arg_type = check_typedef (VALUE_TYPE (args[i]));
1511 if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT
1512 || TYPE_CODE (arg_type) == TYPE_CODE_UNION
1513 || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
1514 || TYPE_CODE (arg_type) == TYPE_CODE_STRING
1515 || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING
1516 || TYPE_CODE (arg_type) == TYPE_CODE_SET
1517 || (TYPE_CODE (arg_type) == TYPE_CODE_FLT
1518 && TYPE_LENGTH (arg_type) > 8)
1519 )
1520 && REG_STRUCT_HAS_ADDR (using_gcc, arg_type))
1521 {
1522 CORE_ADDR addr;
1523 int len; /* = TYPE_LENGTH (arg_type); */
1524 int aligned_len;
1525 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i]));
1526 len = TYPE_LENGTH (arg_type);
1527
1528 if (STACK_ALIGN_P ())
1529 /* MVS 11/22/96: I think at least some of this
1530 stack_align code is really broken. Better to let
1531 PUSH_ARGUMENTS adjust the stack in a target-defined
1532 manner. */
1533 aligned_len = STACK_ALIGN (len);
1534 else
1535 aligned_len = len;
1536 if (INNER_THAN (1, 2))
1537 {
1538 /* stack grows downward */
1539 sp -= aligned_len;
1540 /* ... so the address of the thing we push is the
1541 stack pointer after we push it. */
1542 addr = sp;
1543 }
1544 else
1545 {
1546 /* The stack grows up, so the address of the thing
1547 we push is the stack pointer before we push it. */
1548 addr = sp;
1549 sp += aligned_len;
1550 }
1551 /* Push the structure. */
1552 write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len);
1553 /* The value we're going to pass is the address of the
1554 thing we just pushed. */
1555 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
1556 (LONGEST) addr); */
1557 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
1558 addr);
1559 }
1560 }
1561 }
1562
1563
1564 /* Reserve space for the return structure to be written on the
1565 stack, if necessary. Make certain that the value is correctly
1566 aligned. */
1567
1568 if (struct_return)
1569 {
1570 int len = TYPE_LENGTH (value_type);
1571 if (STACK_ALIGN_P ())
1572 /* MVS 11/22/96: I think at least some of this stack_align
1573 code is really broken. Better to let PUSH_ARGUMENTS adjust
1574 the stack in a target-defined manner. */
1575 len = STACK_ALIGN (len);
1576 if (INNER_THAN (1, 2))
1577 {
1578 /* Stack grows downward. Align STRUCT_ADDR and SP after
1579 making space for the return value. */
1580 sp -= len;
1581 if (gdbarch_frame_align_p (current_gdbarch))
1582 sp = gdbarch_frame_align (current_gdbarch, sp);
1583 struct_addr = sp;
1584 }
1585 else
1586 {
1587 /* Stack grows upward. Align the frame, allocate space, and
1588 then again, re-align the frame??? */
1589 if (gdbarch_frame_align_p (current_gdbarch))
1590 sp = gdbarch_frame_align (current_gdbarch, sp);
1591 struct_addr = sp;
1592 sp += len;
1593 if (gdbarch_frame_align_p (current_gdbarch))
1594 sp = gdbarch_frame_align (current_gdbarch, sp);
1595 }
1596 }
1597
1598 /* elz: on HPPA no need for this extra alignment, maybe it is needed
1599 on other architectures. This is because all the alignment is
1600 taken care of in the above code (ifdef REG_STRUCT_HAS_ADDR) and
1601 in hppa_push_arguments */
1602 if (EXTRA_STACK_ALIGNMENT_NEEDED)
1603 {
1604 /* MVS 11/22/96: I think at least some of this stack_align code
1605 is really broken. Better to let PUSH_ARGUMENTS adjust the
1606 stack in a target-defined manner. */
1607 if (STACK_ALIGN_P () && INNER_THAN (1, 2))
1608 {
1609 /* If stack grows down, we must leave a hole at the top. */
1610 int len = 0;
1611
1612 for (i = nargs - 1; i >= 0; i--)
1613 len += TYPE_LENGTH (VALUE_ENCLOSING_TYPE (args[i]));
1614 if (CALL_DUMMY_STACK_ADJUST_P)
1615 len += CALL_DUMMY_STACK_ADJUST;
1616 sp -= STACK_ALIGN (len) - len;
1617 }
1618 }
1619
1620 sp = PUSH_ARGUMENTS (nargs, args, sp, struct_return, struct_addr);
1621
1622 if (PUSH_RETURN_ADDRESS_P ())
1623 /* for targets that use no CALL_DUMMY */
1624 /* There are a number of targets now which actually don't write
1625 any CALL_DUMMY instructions into the target, but instead just
1626 save the machine state, push the arguments, and jump directly
1627 to the callee function. Since this doesn't actually involve
1628 executing a JSR/BSR instruction, the return address must be set
1629 up by hand, either by pushing onto the stack or copying into a
1630 return-address register as appropriate. Formerly this has been
1631 done in PUSH_ARGUMENTS, but that's overloading its
1632 functionality a bit, so I'm making it explicit to do it here. */
1633 sp = PUSH_RETURN_ADDRESS (real_pc, sp);
1634
1635 if (STACK_ALIGN_P () && !INNER_THAN (1, 2))
1636 {
1637 /* If stack grows up, we must leave a hole at the bottom, note
1638 that sp already has been advanced for the arguments! */
1639 if (CALL_DUMMY_STACK_ADJUST_P)
1640 sp += CALL_DUMMY_STACK_ADJUST;
1641 sp = STACK_ALIGN (sp);
1642 }
1643
1644 /* XXX This seems wrong. For stacks that grow down we shouldn't do
1645 anything here! */
1646 /* MVS 11/22/96: I think at least some of this stack_align code is
1647 really broken. Better to let PUSH_ARGUMENTS adjust the stack in
1648 a target-defined manner. */
1649 if (CALL_DUMMY_STACK_ADJUST_P)
1650 if (INNER_THAN (1, 2))
1651 {
1652 /* stack grows downward */
1653 sp -= CALL_DUMMY_STACK_ADJUST;
1654 }
1655
1656 /* Store the address at which the structure is supposed to be
1657 written. Note that this (and the code which reserved the space
1658 above) assumes that gcc was used to compile this function. Since
1659 it doesn't cost us anything but space and if the function is pcc
1660 it will ignore this value, we will make that assumption.
1661
1662 Also note that on some machines (like the sparc) pcc uses a
1663 convention like gcc's. */
1664
1665 if (struct_return)
1666 STORE_STRUCT_RETURN (struct_addr, sp);
1667
1668 /* Write the stack pointer. This is here because the statements above
1669 might fool with it. On SPARC, this write also stores the register
1670 window into the right place in the new stack frame, which otherwise
1671 wouldn't happen. (See store_inferior_registers in sparc-nat.c.) */
1672 write_sp (sp);
1673
1674 if (SAVE_DUMMY_FRAME_TOS_P ())
1675 SAVE_DUMMY_FRAME_TOS (sp);
1676
1677 {
1678 char *name;
1679 struct symbol *symbol;
1680
1681 name = NULL;
1682 symbol = find_pc_function (funaddr);
1683 if (symbol)
1684 {
1685 name = SYMBOL_PRINT_NAME (symbol);
1686 }
1687 else
1688 {
1689 /* Try the minimal symbols. */
1690 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
1691
1692 if (msymbol)
1693 {
1694 name = SYMBOL_PRINT_NAME (msymbol);
1695 }
1696 }
1697 if (name == NULL)
1698 {
1699 char format[80];
1700 sprintf (format, "at %s", local_hex_format ());
1701 name = alloca (80);
1702 /* FIXME-32x64: assumes funaddr fits in a long. */
1703 sprintf (name, format, (unsigned long) funaddr);
1704 }
1705
1706 /* Execute the stack dummy routine, calling FUNCTION.
1707 When it is done, discard the empty frame
1708 after storing the contents of all regs into retbuf. */
1709 rc = run_stack_dummy (real_pc + CALL_DUMMY_START_OFFSET, retbuf);
1710
1711 if (rc == 1)
1712 {
1713 /* We stopped inside the FUNCTION because of a random signal.
1714 Further execution of the FUNCTION is not allowed. */
1715
1716 if (unwind_on_signal_p)
1717 {
1718 /* The user wants the context restored. */
1719
1720 /* We must get back to the frame we were before the dummy
1721 call. */
1722 frame_pop (get_current_frame ());
1723
1724 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1725 a C++ name with arguments and stuff. */
1726 error ("\
1727 The program being debugged was signaled while in a function called from GDB.\n\
1728 GDB has restored the context to what it was before the call.\n\
1729 To change this behavior use \"set unwindonsignal off\"\n\
1730 Evaluation of the expression containing the function (%s) will be abandoned.",
1731 name);
1732 }
1733 else
1734 {
1735 /* The user wants to stay in the frame where we stopped (default).*/
1736
1737 /* If we restored the inferior status (via the cleanup),
1738 we would print a spurious error message (Unable to
1739 restore previously selected frame), would write the
1740 registers from the inf_status (which is wrong), and
1741 would do other wrong things. */
1742 discard_cleanups (inf_status_cleanup);
1743 discard_inferior_status (inf_status);
1744
1745 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1746 a C++ name with arguments and stuff. */
1747 error ("\
1748 The program being debugged was signaled while in a function called from GDB.\n\
1749 GDB remains in the frame where the signal was received.\n\
1750 To change this behavior use \"set unwindonsignal on\"\n\
1751 Evaluation of the expression containing the function (%s) will be abandoned.",
1752 name);
1753 }
1754 }
1755
1756 if (rc == 2)
1757 {
1758 /* We hit a breakpoint inside the FUNCTION. */
1759
1760 /* If we restored the inferior status (via the cleanup), we
1761 would print a spurious error message (Unable to restore
1762 previously selected frame), would write the registers from
1763 the inf_status (which is wrong), and would do other wrong
1764 things. */
1765 discard_cleanups (inf_status_cleanup);
1766 discard_inferior_status (inf_status);
1767
1768 /* The following error message used to say "The expression
1769 which contained the function call has been discarded." It
1770 is a hard concept to explain in a few words. Ideally, GDB
1771 would be able to resume evaluation of the expression when
1772 the function finally is done executing. Perhaps someday
1773 this will be implemented (it would not be easy). */
1774
1775 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1776 a C++ name with arguments and stuff. */
1777 error ("\
1778 The program being debugged stopped while in a function called from GDB.\n\
1779 When the function (%s) is done executing, GDB will silently\n\
1780 stop (instead of continuing to evaluate the expression containing\n\
1781 the function call).", name);
1782 }
1783
1784 /* If we get here the called FUNCTION run to completion. */
1785
1786 /* Restore the inferior status, via its cleanup. At this stage,
1787 leave the RETBUF alone. */
1788 do_cleanups (inf_status_cleanup);
1789
1790 /* Figure out the value returned by the function. */
1791 /* elz: I defined this new macro for the hppa architecture only.
1792 this gives us a way to get the value returned by the function
1793 from the stack, at the same address we told the function to put
1794 it. We cannot assume on the pa that r28 still contains the
1795 address of the returned structure. Usually this will be
1796 overwritten by the callee. I don't know about other
1797 architectures, so I defined this macro */
1798 #ifdef VALUE_RETURNED_FROM_STACK
1799 if (struct_return)
1800 {
1801 do_cleanups (retbuf_cleanup);
1802 return VALUE_RETURNED_FROM_STACK (value_type, struct_addr);
1803 }
1804 #endif
1805 /* NOTE: cagney/2002-09-10: Only when the stack has been correctly
1806 aligned (using frame_align()) do we can trust STRUCT_ADDR and
1807 fetch the return value direct from the stack. This lack of
1808 trust comes about because legacy targets have a nasty habit of
1809 silently, and local to PUSH_ARGUMENTS(), moving STRUCT_ADDR.
1810 For such targets, just hope that value_being_returned() can
1811 find the adjusted value. */
1812 if (struct_return && gdbarch_frame_align_p (current_gdbarch))
1813 {
1814 struct value *retval = value_at (value_type, struct_addr, NULL);
1815 do_cleanups (retbuf_cleanup);
1816 return retval;
1817 }
1818 else
1819 {
1820 struct value *retval = value_being_returned (value_type, retbuf,
1821 struct_return);
1822 do_cleanups (retbuf_cleanup);
1823 return retval;
1824 }
1825 }
1826 }
1827
1828 struct value *
1829 call_function_by_hand (struct value *function, int nargs, struct value **args)
1830 {
1831 if (CALL_DUMMY_P)
1832 {
1833 return hand_function_call (function, nargs, args);
1834 }
1835 else
1836 {
1837 error ("Cannot invoke functions on this machine.");
1838 }
1839 }
1840 \f
1841
1842
1843 /* Create a value for an array by allocating space in the inferior, copying
1844 the data into that space, and then setting up an array value.
1845
1846 The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
1847 populated from the values passed in ELEMVEC.
1848
1849 The element type of the array is inherited from the type of the
1850 first element, and all elements must have the same size (though we
1851 don't currently enforce any restriction on their types). */
1852
1853 struct value *
1854 value_array (int lowbound, int highbound, struct value **elemvec)
1855 {
1856 int nelem;
1857 int idx;
1858 unsigned int typelength;
1859 struct value *val;
1860 struct type *rangetype;
1861 struct type *arraytype;
1862 CORE_ADDR addr;
1863
1864 /* Validate that the bounds are reasonable and that each of the elements
1865 have the same size. */
1866
1867 nelem = highbound - lowbound + 1;
1868 if (nelem <= 0)
1869 {
1870 error ("bad array bounds (%d, %d)", lowbound, highbound);
1871 }
1872 typelength = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[0]));
1873 for (idx = 1; idx < nelem; idx++)
1874 {
1875 if (TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[idx])) != typelength)
1876 {
1877 error ("array elements must all be the same size");
1878 }
1879 }
1880
1881 rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
1882 lowbound, highbound);
1883 arraytype = create_array_type ((struct type *) NULL,
1884 VALUE_ENCLOSING_TYPE (elemvec[0]), rangetype);
1885
1886 if (!current_language->c_style_arrays)
1887 {
1888 val = allocate_value (arraytype);
1889 for (idx = 0; idx < nelem; idx++)
1890 {
1891 memcpy (VALUE_CONTENTS_ALL_RAW (val) + (idx * typelength),
1892 VALUE_CONTENTS_ALL (elemvec[idx]),
1893 typelength);
1894 }
1895 VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (elemvec[0]);
1896 return val;
1897 }
1898
1899 /* Allocate space to store the array in the inferior, and then initialize
1900 it by copying in each element. FIXME: Is it worth it to create a
1901 local buffer in which to collect each value and then write all the
1902 bytes in one operation? */
1903
1904 addr = allocate_space_in_inferior (nelem * typelength);
1905 for (idx = 0; idx < nelem; idx++)
1906 {
1907 write_memory (addr + (idx * typelength), VALUE_CONTENTS_ALL (elemvec[idx]),
1908 typelength);
1909 }
1910
1911 /* Create the array type and set up an array value to be evaluated lazily. */
1912
1913 val = value_at_lazy (arraytype, addr, VALUE_BFD_SECTION (elemvec[0]));
1914 return (val);
1915 }
1916
1917 /* Create a value for a string constant by allocating space in the inferior,
1918 copying the data into that space, and returning the address with type
1919 TYPE_CODE_STRING. PTR points to the string constant data; LEN is number
1920 of characters.
1921 Note that string types are like array of char types with a lower bound of
1922 zero and an upper bound of LEN - 1. Also note that the string may contain
1923 embedded null bytes. */
1924
1925 struct value *
1926 value_string (char *ptr, int len)
1927 {
1928 struct value *val;
1929 int lowbound = current_language->string_lower_bound;
1930 struct type *rangetype = create_range_type ((struct type *) NULL,
1931 builtin_type_int,
1932 lowbound, len + lowbound - 1);
1933 struct type *stringtype
1934 = create_string_type ((struct type *) NULL, rangetype);
1935 CORE_ADDR addr;
1936
1937 if (current_language->c_style_arrays == 0)
1938 {
1939 val = allocate_value (stringtype);
1940 memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
1941 return val;
1942 }
1943
1944
1945 /* Allocate space to store the string in the inferior, and then
1946 copy LEN bytes from PTR in gdb to that address in the inferior. */
1947
1948 addr = allocate_space_in_inferior (len);
1949 write_memory (addr, ptr, len);
1950
1951 val = value_at_lazy (stringtype, addr, NULL);
1952 return (val);
1953 }
1954
1955 struct value *
1956 value_bitstring (char *ptr, int len)
1957 {
1958 struct value *val;
1959 struct type *domain_type = create_range_type (NULL, builtin_type_int,
1960 0, len - 1);
1961 struct type *type = create_set_type ((struct type *) NULL, domain_type);
1962 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1963 val = allocate_value (type);
1964 memcpy (VALUE_CONTENTS_RAW (val), ptr, TYPE_LENGTH (type));
1965 return val;
1966 }
1967 \f
1968 /* See if we can pass arguments in T2 to a function which takes arguments
1969 of types T1. T1 is a list of NARGS arguments, and T2 is a NULL-terminated
1970 vector. If some arguments need coercion of some sort, then the coerced
1971 values are written into T2. Return value is 0 if the arguments could be
1972 matched, or the position at which they differ if not.
1973
1974 STATICP is nonzero if the T1 argument list came from a
1975 static member function. T2 will still include the ``this'' pointer,
1976 but it will be skipped.
1977
1978 For non-static member functions, we ignore the first argument,
1979 which is the type of the instance variable. This is because we want
1980 to handle calls with objects from derived classes. This is not
1981 entirely correct: we should actually check to make sure that a
1982 requested operation is type secure, shouldn't we? FIXME. */
1983
1984 static int
1985 typecmp (int staticp, int varargs, int nargs,
1986 struct field t1[], struct value *t2[])
1987 {
1988 int i;
1989
1990 if (t2 == 0)
1991 internal_error (__FILE__, __LINE__, "typecmp: no argument list");
1992
1993 /* Skip ``this'' argument if applicable. T2 will always include THIS. */
1994 if (staticp)
1995 t2 ++;
1996
1997 for (i = 0;
1998 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1999 i++)
2000 {
2001 struct type *tt1, *tt2;
2002
2003 if (!t2[i])
2004 return i + 1;
2005
2006 tt1 = check_typedef (t1[i].type);
2007 tt2 = check_typedef (VALUE_TYPE (t2[i]));
2008
2009 if (TYPE_CODE (tt1) == TYPE_CODE_REF
2010 /* We should be doing hairy argument matching, as below. */
2011 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
2012 {
2013 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
2014 t2[i] = value_coerce_array (t2[i]);
2015 else
2016 t2[i] = value_addr (t2[i]);
2017 continue;
2018 }
2019
2020 /* djb - 20000715 - Until the new type structure is in the
2021 place, and we can attempt things like implicit conversions,
2022 we need to do this so you can take something like a map<const
2023 char *>, and properly access map["hello"], because the
2024 argument to [] will be a reference to a pointer to a char,
2025 and the argument will be a pointer to a char. */
2026 while ( TYPE_CODE(tt1) == TYPE_CODE_REF ||
2027 TYPE_CODE (tt1) == TYPE_CODE_PTR)
2028 {
2029 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
2030 }
2031 while ( TYPE_CODE(tt2) == TYPE_CODE_ARRAY ||
2032 TYPE_CODE(tt2) == TYPE_CODE_PTR ||
2033 TYPE_CODE(tt2) == TYPE_CODE_REF)
2034 {
2035 tt2 = check_typedef( TYPE_TARGET_TYPE(tt2) );
2036 }
2037 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
2038 continue;
2039 /* Array to pointer is a `trivial conversion' according to the ARM. */
2040
2041 /* We should be doing much hairier argument matching (see section 13.2
2042 of the ARM), but as a quick kludge, just check for the same type
2043 code. */
2044 if (TYPE_CODE (t1[i].type) != TYPE_CODE (VALUE_TYPE (t2[i])))
2045 return i + 1;
2046 }
2047 if (varargs || t2[i] == NULL)
2048 return 0;
2049 return i + 1;
2050 }
2051
2052 /* Helper function used by value_struct_elt to recurse through baseclasses.
2053 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
2054 and search in it assuming it has (class) type TYPE.
2055 If found, return value, else return NULL.
2056
2057 If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
2058 look for a baseclass named NAME. */
2059
2060 static struct value *
2061 search_struct_field (char *name, struct value *arg1, int offset,
2062 register struct type *type, int looking_for_baseclass)
2063 {
2064 int i;
2065 int nbases = TYPE_N_BASECLASSES (type);
2066
2067 CHECK_TYPEDEF (type);
2068
2069 if (!looking_for_baseclass)
2070 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
2071 {
2072 char *t_field_name = TYPE_FIELD_NAME (type, i);
2073
2074 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2075 {
2076 struct value *v;
2077 if (TYPE_FIELD_STATIC (type, i))
2078 {
2079 v = value_static_field (type, i);
2080 if (v == 0)
2081 error ("field %s is nonexistent or has been optimised out",
2082 name);
2083 }
2084 else
2085 {
2086 v = value_primitive_field (arg1, offset, i, type);
2087 if (v == 0)
2088 error ("there is no field named %s", name);
2089 }
2090 return v;
2091 }
2092
2093 if (t_field_name
2094 && (t_field_name[0] == '\0'
2095 || (TYPE_CODE (type) == TYPE_CODE_UNION
2096 && (strcmp_iw (t_field_name, "else") == 0))))
2097 {
2098 struct type *field_type = TYPE_FIELD_TYPE (type, i);
2099 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
2100 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
2101 {
2102 /* Look for a match through the fields of an anonymous union,
2103 or anonymous struct. C++ provides anonymous unions.
2104
2105 In the GNU Chill (now deleted from GDB)
2106 implementation of variant record types, each
2107 <alternative field> has an (anonymous) union type,
2108 each member of the union represents a <variant
2109 alternative>. Each <variant alternative> is
2110 represented as a struct, with a member for each
2111 <variant field>. */
2112
2113 struct value *v;
2114 int new_offset = offset;
2115
2116 /* This is pretty gross. In G++, the offset in an
2117 anonymous union is relative to the beginning of the
2118 enclosing struct. In the GNU Chill (now deleted
2119 from GDB) implementation of variant records, the
2120 bitpos is zero in an anonymous union field, so we
2121 have to add the offset of the union here. */
2122 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
2123 || (TYPE_NFIELDS (field_type) > 0
2124 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
2125 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
2126
2127 v = search_struct_field (name, arg1, new_offset, field_type,
2128 looking_for_baseclass);
2129 if (v)
2130 return v;
2131 }
2132 }
2133 }
2134
2135 for (i = 0; i < nbases; i++)
2136 {
2137 struct value *v;
2138 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
2139 /* If we are looking for baseclasses, this is what we get when we
2140 hit them. But it could happen that the base part's member name
2141 is not yet filled in. */
2142 int found_baseclass = (looking_for_baseclass
2143 && TYPE_BASECLASS_NAME (type, i) != NULL
2144 && (strcmp_iw (name, TYPE_BASECLASS_NAME (type, i)) == 0));
2145
2146 if (BASETYPE_VIA_VIRTUAL (type, i))
2147 {
2148 int boffset;
2149 struct value *v2 = allocate_value (basetype);
2150
2151 boffset = baseclass_offset (type, i,
2152 VALUE_CONTENTS (arg1) + offset,
2153 VALUE_ADDRESS (arg1)
2154 + VALUE_OFFSET (arg1) + offset);
2155 if (boffset == -1)
2156 error ("virtual baseclass botch");
2157
2158 /* The virtual base class pointer might have been clobbered by the
2159 user program. Make sure that it still points to a valid memory
2160 location. */
2161
2162 boffset += offset;
2163 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
2164 {
2165 CORE_ADDR base_addr;
2166
2167 base_addr = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1) + boffset;
2168 if (target_read_memory (base_addr, VALUE_CONTENTS_RAW (v2),
2169 TYPE_LENGTH (basetype)) != 0)
2170 error ("virtual baseclass botch");
2171 VALUE_LVAL (v2) = lval_memory;
2172 VALUE_ADDRESS (v2) = base_addr;
2173 }
2174 else
2175 {
2176 VALUE_LVAL (v2) = VALUE_LVAL (arg1);
2177 VALUE_ADDRESS (v2) = VALUE_ADDRESS (arg1);
2178 VALUE_OFFSET (v2) = VALUE_OFFSET (arg1) + boffset;
2179 if (VALUE_LAZY (arg1))
2180 VALUE_LAZY (v2) = 1;
2181 else
2182 memcpy (VALUE_CONTENTS_RAW (v2),
2183 VALUE_CONTENTS_RAW (arg1) + boffset,
2184 TYPE_LENGTH (basetype));
2185 }
2186
2187 if (found_baseclass)
2188 return v2;
2189 v = search_struct_field (name, v2, 0, TYPE_BASECLASS (type, i),
2190 looking_for_baseclass);
2191 }
2192 else if (found_baseclass)
2193 v = value_primitive_field (arg1, offset, i, type);
2194 else
2195 v = search_struct_field (name, arg1,
2196 offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
2197 basetype, looking_for_baseclass);
2198 if (v)
2199 return v;
2200 }
2201 return NULL;
2202 }
2203
2204
2205 /* Return the offset (in bytes) of the virtual base of type BASETYPE
2206 * in an object pointed to by VALADDR (on the host), assumed to be of
2207 * type TYPE. OFFSET is number of bytes beyond start of ARG to start
2208 * looking (in case VALADDR is the contents of an enclosing object).
2209 *
2210 * This routine recurses on the primary base of the derived class because
2211 * the virtual base entries of the primary base appear before the other
2212 * virtual base entries.
2213 *
2214 * If the virtual base is not found, a negative integer is returned.
2215 * The magnitude of the negative integer is the number of entries in
2216 * the virtual table to skip over (entries corresponding to various
2217 * ancestral classes in the chain of primary bases).
2218 *
2219 * Important: This assumes the HP / Taligent C++ runtime
2220 * conventions. Use baseclass_offset() instead to deal with g++
2221 * conventions. */
2222
2223 void
2224 find_rt_vbase_offset (struct type *type, struct type *basetype, char *valaddr,
2225 int offset, int *boffset_p, int *skip_p)
2226 {
2227 int boffset; /* offset of virtual base */
2228 int index; /* displacement to use in virtual table */
2229 int skip;
2230
2231 struct value *vp;
2232 CORE_ADDR vtbl; /* the virtual table pointer */
2233 struct type *pbc; /* the primary base class */
2234
2235 /* Look for the virtual base recursively in the primary base, first.
2236 * This is because the derived class object and its primary base
2237 * subobject share the primary virtual table. */
2238
2239 boffset = 0;
2240 pbc = TYPE_PRIMARY_BASE (type);
2241 if (pbc)
2242 {
2243 find_rt_vbase_offset (pbc, basetype, valaddr, offset, &boffset, &skip);
2244 if (skip < 0)
2245 {
2246 *boffset_p = boffset;
2247 *skip_p = -1;
2248 return;
2249 }
2250 }
2251 else
2252 skip = 0;
2253
2254
2255 /* Find the index of the virtual base according to HP/Taligent
2256 runtime spec. (Depth-first, left-to-right.) */
2257 index = virtual_base_index_skip_primaries (basetype, type);
2258
2259 if (index < 0)
2260 {
2261 *skip_p = skip + virtual_base_list_length_skip_primaries (type);
2262 *boffset_p = 0;
2263 return;
2264 }
2265
2266 /* pai: FIXME -- 32x64 possible problem */
2267 /* First word (4 bytes) in object layout is the vtable pointer */
2268 vtbl = *(CORE_ADDR *) (valaddr + offset);
2269
2270 /* Before the constructor is invoked, things are usually zero'd out. */
2271 if (vtbl == 0)
2272 error ("Couldn't find virtual table -- object may not be constructed yet.");
2273
2274
2275 /* Find virtual base's offset -- jump over entries for primary base
2276 * ancestors, then use the index computed above. But also adjust by
2277 * HP_ACC_VBASE_START for the vtable slots before the start of the
2278 * virtual base entries. Offset is negative -- virtual base entries
2279 * appear _before_ the address point of the virtual table. */
2280
2281 /* pai: FIXME -- 32x64 problem, if word = 8 bytes, change multiplier
2282 & use long type */
2283
2284 /* epstein : FIXME -- added param for overlay section. May not be correct */
2285 vp = value_at (builtin_type_int, vtbl + 4 * (-skip - index - HP_ACC_VBASE_START), NULL);
2286 boffset = value_as_long (vp);
2287 *skip_p = -1;
2288 *boffset_p = boffset;
2289 return;
2290 }
2291
2292
2293 /* Helper function used by value_struct_elt to recurse through baseclasses.
2294 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
2295 and search in it assuming it has (class) type TYPE.
2296 If found, return value, else if name matched and args not return (value)-1,
2297 else return NULL. */
2298
2299 static struct value *
2300 search_struct_method (char *name, struct value **arg1p,
2301 struct value **args, int offset,
2302 int *static_memfuncp, register struct type *type)
2303 {
2304 int i;
2305 struct value *v;
2306 int name_matched = 0;
2307 char dem_opname[64];
2308
2309 CHECK_TYPEDEF (type);
2310 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2311 {
2312 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2313 /* FIXME! May need to check for ARM demangling here */
2314 if (strncmp (t_field_name, "__", 2) == 0 ||
2315 strncmp (t_field_name, "op", 2) == 0 ||
2316 strncmp (t_field_name, "type", 4) == 0)
2317 {
2318 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2319 t_field_name = dem_opname;
2320 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2321 t_field_name = dem_opname;
2322 }
2323 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2324 {
2325 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2326 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2327 name_matched = 1;
2328
2329 check_stub_method_group (type, i);
2330 if (j > 0 && args == 0)
2331 error ("cannot resolve overloaded method `%s': no arguments supplied", name);
2332 else if (j == 0 && args == 0)
2333 {
2334 v = value_fn_field (arg1p, f, j, type, offset);
2335 if (v != NULL)
2336 return v;
2337 }
2338 else
2339 while (j >= 0)
2340 {
2341 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2342 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2343 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2344 TYPE_FN_FIELD_ARGS (f, j), args))
2345 {
2346 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2347 return value_virtual_fn_field (arg1p, f, j, type, offset);
2348 if (TYPE_FN_FIELD_STATIC_P (f, j) && static_memfuncp)
2349 *static_memfuncp = 1;
2350 v = value_fn_field (arg1p, f, j, type, offset);
2351 if (v != NULL)
2352 return v;
2353 }
2354 j--;
2355 }
2356 }
2357 }
2358
2359 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2360 {
2361 int base_offset;
2362
2363 if (BASETYPE_VIA_VIRTUAL (type, i))
2364 {
2365 if (TYPE_HAS_VTABLE (type))
2366 {
2367 /* HP aCC compiled type, search for virtual base offset
2368 according to HP/Taligent runtime spec. */
2369 int skip;
2370 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
2371 VALUE_CONTENTS_ALL (*arg1p),
2372 offset + VALUE_EMBEDDED_OFFSET (*arg1p),
2373 &base_offset, &skip);
2374 if (skip >= 0)
2375 error ("Virtual base class offset not found in vtable");
2376 }
2377 else
2378 {
2379 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2380 char *base_valaddr;
2381
2382 /* The virtual base class pointer might have been clobbered by the
2383 user program. Make sure that it still points to a valid memory
2384 location. */
2385
2386 if (offset < 0 || offset >= TYPE_LENGTH (type))
2387 {
2388 base_valaddr = (char *) alloca (TYPE_LENGTH (baseclass));
2389 if (target_read_memory (VALUE_ADDRESS (*arg1p)
2390 + VALUE_OFFSET (*arg1p) + offset,
2391 base_valaddr,
2392 TYPE_LENGTH (baseclass)) != 0)
2393 error ("virtual baseclass botch");
2394 }
2395 else
2396 base_valaddr = VALUE_CONTENTS (*arg1p) + offset;
2397
2398 base_offset =
2399 baseclass_offset (type, i, base_valaddr,
2400 VALUE_ADDRESS (*arg1p)
2401 + VALUE_OFFSET (*arg1p) + offset);
2402 if (base_offset == -1)
2403 error ("virtual baseclass botch");
2404 }
2405 }
2406 else
2407 {
2408 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2409 }
2410 v = search_struct_method (name, arg1p, args, base_offset + offset,
2411 static_memfuncp, TYPE_BASECLASS (type, i));
2412 if (v == (struct value *) - 1)
2413 {
2414 name_matched = 1;
2415 }
2416 else if (v)
2417 {
2418 /* FIXME-bothner: Why is this commented out? Why is it here? */
2419 /* *arg1p = arg1_tmp; */
2420 return v;
2421 }
2422 }
2423 if (name_matched)
2424 return (struct value *) - 1;
2425 else
2426 return NULL;
2427 }
2428
2429 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2430 extract the component named NAME from the ultimate target structure/union
2431 and return it as a value with its appropriate type.
2432 ERR is used in the error message if *ARGP's type is wrong.
2433
2434 C++: ARGS is a list of argument types to aid in the selection of
2435 an appropriate method. Also, handle derived types.
2436
2437 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2438 where the truthvalue of whether the function that was resolved was
2439 a static member function or not is stored.
2440
2441 ERR is an error message to be printed in case the field is not found. */
2442
2443 struct value *
2444 value_struct_elt (struct value **argp, struct value **args,
2445 char *name, int *static_memfuncp, char *err)
2446 {
2447 register struct type *t;
2448 struct value *v;
2449
2450 COERCE_ARRAY (*argp);
2451
2452 t = check_typedef (VALUE_TYPE (*argp));
2453
2454 /* Follow pointers until we get to a non-pointer. */
2455
2456 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2457 {
2458 *argp = value_ind (*argp);
2459 /* Don't coerce fn pointer to fn and then back again! */
2460 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
2461 COERCE_ARRAY (*argp);
2462 t = check_typedef (VALUE_TYPE (*argp));
2463 }
2464
2465 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2466 error ("not implemented: member type in value_struct_elt");
2467
2468 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2469 && TYPE_CODE (t) != TYPE_CODE_UNION)
2470 error ("Attempt to extract a component of a value that is not a %s.", err);
2471
2472 /* Assume it's not, unless we see that it is. */
2473 if (static_memfuncp)
2474 *static_memfuncp = 0;
2475
2476 if (!args)
2477 {
2478 /* if there are no arguments ...do this... */
2479
2480 /* Try as a field first, because if we succeed, there
2481 is less work to be done. */
2482 v = search_struct_field (name, *argp, 0, t, 0);
2483 if (v)
2484 return v;
2485
2486 /* C++: If it was not found as a data field, then try to
2487 return it as a pointer to a method. */
2488
2489 if (destructor_name_p (name, t))
2490 error ("Cannot get value of destructor");
2491
2492 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
2493
2494 if (v == (struct value *) - 1)
2495 error ("Cannot take address of a method");
2496 else if (v == 0)
2497 {
2498 if (TYPE_NFN_FIELDS (t))
2499 error ("There is no member or method named %s.", name);
2500 else
2501 error ("There is no member named %s.", name);
2502 }
2503 return v;
2504 }
2505
2506 if (destructor_name_p (name, t))
2507 {
2508 if (!args[1])
2509 {
2510 /* Destructors are a special case. */
2511 int m_index, f_index;
2512
2513 v = NULL;
2514 if (get_destructor_fn_field (t, &m_index, &f_index))
2515 {
2516 v = value_fn_field (NULL, TYPE_FN_FIELDLIST1 (t, m_index),
2517 f_index, NULL, 0);
2518 }
2519 if (v == NULL)
2520 error ("could not find destructor function named %s.", name);
2521 else
2522 return v;
2523 }
2524 else
2525 {
2526 error ("destructor should not have any argument");
2527 }
2528 }
2529 else
2530 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
2531
2532 if (v == (struct value *) - 1)
2533 {
2534 error ("One of the arguments you tried to pass to %s could not be converted to what the function wants.", name);
2535 }
2536 else if (v == 0)
2537 {
2538 /* See if user tried to invoke data as function. If so,
2539 hand it back. If it's not callable (i.e., a pointer to function),
2540 gdb should give an error. */
2541 v = search_struct_field (name, *argp, 0, t, 0);
2542 }
2543
2544 if (!v)
2545 error ("Structure has no component named %s.", name);
2546 return v;
2547 }
2548
2549 /* Search through the methods of an object (and its bases)
2550 * to find a specified method. Return the pointer to the
2551 * fn_field list of overloaded instances.
2552 * Helper function for value_find_oload_list.
2553 * ARGP is a pointer to a pointer to a value (the object)
2554 * METHOD is a string containing the method name
2555 * OFFSET is the offset within the value
2556 * TYPE is the assumed type of the object
2557 * NUM_FNS is the number of overloaded instances
2558 * BASETYPE is set to the actual type of the subobject where the method is found
2559 * BOFFSET is the offset of the base subobject where the method is found */
2560
2561 static struct fn_field *
2562 find_method_list (struct value **argp, char *method, int offset,
2563 struct type *type, int *num_fns,
2564 struct type **basetype, int *boffset)
2565 {
2566 int i;
2567 struct fn_field *f;
2568 CHECK_TYPEDEF (type);
2569
2570 *num_fns = 0;
2571
2572 /* First check in object itself */
2573 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2574 {
2575 /* pai: FIXME What about operators and type conversions? */
2576 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2577 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2578 {
2579 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2580 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2581
2582 *num_fns = len;
2583 *basetype = type;
2584 *boffset = offset;
2585
2586 /* Resolve any stub methods. */
2587 check_stub_method_group (type, i);
2588
2589 return f;
2590 }
2591 }
2592
2593 /* Not found in object, check in base subobjects */
2594 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2595 {
2596 int base_offset;
2597 if (BASETYPE_VIA_VIRTUAL (type, i))
2598 {
2599 if (TYPE_HAS_VTABLE (type))
2600 {
2601 /* HP aCC compiled type, search for virtual base offset
2602 * according to HP/Taligent runtime spec. */
2603 int skip;
2604 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
2605 VALUE_CONTENTS_ALL (*argp),
2606 offset + VALUE_EMBEDDED_OFFSET (*argp),
2607 &base_offset, &skip);
2608 if (skip >= 0)
2609 error ("Virtual base class offset not found in vtable");
2610 }
2611 else
2612 {
2613 /* probably g++ runtime model */
2614 base_offset = VALUE_OFFSET (*argp) + offset;
2615 base_offset =
2616 baseclass_offset (type, i,
2617 VALUE_CONTENTS (*argp) + base_offset,
2618 VALUE_ADDRESS (*argp) + base_offset);
2619 if (base_offset == -1)
2620 error ("virtual baseclass botch");
2621 }
2622 }
2623 else
2624 /* non-virtual base, simply use bit position from debug info */
2625 {
2626 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2627 }
2628 f = find_method_list (argp, method, base_offset + offset,
2629 TYPE_BASECLASS (type, i), num_fns, basetype,
2630 boffset);
2631 if (f)
2632 return f;
2633 }
2634 return NULL;
2635 }
2636
2637 /* Return the list of overloaded methods of a specified name.
2638 * ARGP is a pointer to a pointer to a value (the object)
2639 * METHOD is the method name
2640 * OFFSET is the offset within the value contents
2641 * NUM_FNS is the number of overloaded instances
2642 * BASETYPE is set to the type of the base subobject that defines the method
2643 * BOFFSET is the offset of the base subobject which defines the method */
2644
2645 struct fn_field *
2646 value_find_oload_method_list (struct value **argp, char *method, int offset,
2647 int *num_fns, struct type **basetype,
2648 int *boffset)
2649 {
2650 struct type *t;
2651
2652 t = check_typedef (VALUE_TYPE (*argp));
2653
2654 /* code snarfed from value_struct_elt */
2655 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2656 {
2657 *argp = value_ind (*argp);
2658 /* Don't coerce fn pointer to fn and then back again! */
2659 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
2660 COERCE_ARRAY (*argp);
2661 t = check_typedef (VALUE_TYPE (*argp));
2662 }
2663
2664 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2665 error ("Not implemented: member type in value_find_oload_lis");
2666
2667 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2668 && TYPE_CODE (t) != TYPE_CODE_UNION)
2669 error ("Attempt to extract a component of a value that is not a struct or union");
2670
2671 return find_method_list (argp, method, 0, t, num_fns, basetype, boffset);
2672 }
2673
2674 /* Given an array of argument types (ARGTYPES) (which includes an
2675 entry for "this" in the case of C++ methods), the number of
2676 arguments NARGS, the NAME of a function whether it's a method or
2677 not (METHOD), and the degree of laxness (LAX) in conforming to
2678 overload resolution rules in ANSI C++, find the best function that
2679 matches on the argument types according to the overload resolution
2680 rules.
2681
2682 In the case of class methods, the parameter OBJ is an object value
2683 in which to search for overloaded methods.
2684
2685 In the case of non-method functions, the parameter FSYM is a symbol
2686 corresponding to one of the overloaded functions.
2687
2688 Return value is an integer: 0 -> good match, 10 -> debugger applied
2689 non-standard coercions, 100 -> incompatible.
2690
2691 If a method is being searched for, VALP will hold the value.
2692 If a non-method is being searched for, SYMP will hold the symbol for it.
2693
2694 If a method is being searched for, and it is a static method,
2695 then STATICP will point to a non-zero value.
2696
2697 Note: This function does *not* check the value of
2698 overload_resolution. Caller must check it to see whether overload
2699 resolution is permitted.
2700 */
2701
2702 int
2703 find_overload_match (struct type **arg_types, int nargs, char *name, int method,
2704 int lax, struct value **objp, struct symbol *fsym,
2705 struct value **valp, struct symbol **symp, int *staticp)
2706 {
2707 int nparms;
2708 struct type **parm_types;
2709 int champ_nparms = 0;
2710 struct value *obj = (objp ? *objp : NULL);
2711
2712 short oload_champ = -1; /* Index of best overloaded function */
2713 short oload_ambiguous = 0; /* Current ambiguity state for overload resolution */
2714 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs */
2715 short oload_ambig_champ = -1; /* 2nd contender for best match */
2716 short oload_non_standard = 0; /* did we have to use non-standard conversions? */
2717 short oload_incompatible = 0; /* are args supplied incompatible with any function? */
2718
2719 struct badness_vector *bv; /* A measure of how good an overloaded instance is */
2720 struct badness_vector *oload_champ_bv = NULL; /* The measure for the current best match */
2721
2722 struct value *temp = obj;
2723 struct fn_field *fns_ptr = NULL; /* For methods, the list of overloaded methods */
2724 struct symbol **oload_syms = NULL; /* For non-methods, the list of overloaded function symbols */
2725 int num_fns = 0; /* Number of overloaded instances being considered */
2726 struct type *basetype = NULL;
2727 int boffset;
2728 register int jj;
2729 register int ix;
2730 int static_offset;
2731 struct cleanup *cleanups = NULL;
2732
2733 char *obj_type_name = NULL;
2734 char *func_name = NULL;
2735
2736 /* Get the list of overloaded methods or functions */
2737 if (method)
2738 {
2739 obj_type_name = TYPE_NAME (VALUE_TYPE (obj));
2740 /* Hack: evaluate_subexp_standard often passes in a pointer
2741 value rather than the object itself, so try again */
2742 if ((!obj_type_name || !*obj_type_name) &&
2743 (TYPE_CODE (VALUE_TYPE (obj)) == TYPE_CODE_PTR))
2744 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (VALUE_TYPE (obj)));
2745
2746 fns_ptr = value_find_oload_method_list (&temp, name, 0,
2747 &num_fns,
2748 &basetype, &boffset);
2749 if (!fns_ptr || !num_fns)
2750 error ("Couldn't find method %s%s%s",
2751 obj_type_name,
2752 (obj_type_name && *obj_type_name) ? "::" : "",
2753 name);
2754 /* If we are dealing with stub method types, they should have
2755 been resolved by find_method_list via value_find_oload_method_list
2756 above. */
2757 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2758 }
2759 else
2760 {
2761 int i = -1;
2762 func_name = cplus_demangle (DEPRECATED_SYMBOL_NAME (fsym), DMGL_NO_OPTS);
2763
2764 /* If the name is NULL this must be a C-style function.
2765 Just return the same symbol. */
2766 if (!func_name)
2767 {
2768 *symp = fsym;
2769 return 0;
2770 }
2771
2772 oload_syms = make_symbol_overload_list (fsym);
2773 cleanups = make_cleanup (xfree, oload_syms);
2774 while (oload_syms[++i])
2775 num_fns++;
2776 if (!num_fns)
2777 error ("Couldn't find function %s", func_name);
2778 }
2779
2780 oload_champ_bv = NULL;
2781
2782 /* Consider each candidate in turn */
2783 for (ix = 0; ix < num_fns; ix++)
2784 {
2785 static_offset = 0;
2786 if (method)
2787 {
2788 if (TYPE_FN_FIELD_STATIC_P (fns_ptr, ix))
2789 static_offset = 1;
2790 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2791 }
2792 else
2793 {
2794 /* If it's not a method, this is the proper place */
2795 nparms=TYPE_NFIELDS(SYMBOL_TYPE(oload_syms[ix]));
2796 }
2797
2798 /* Prepare array of parameter types */
2799 parm_types = (struct type **) xmalloc (nparms * (sizeof (struct type *)));
2800 for (jj = 0; jj < nparms; jj++)
2801 parm_types[jj] = (method
2802 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2803 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]), jj));
2804
2805 /* Compare parameter types to supplied argument types. Skip THIS for
2806 static methods. */
2807 bv = rank_function (parm_types, nparms, arg_types + static_offset,
2808 nargs - static_offset);
2809
2810 if (!oload_champ_bv)
2811 {
2812 oload_champ_bv = bv;
2813 oload_champ = 0;
2814 champ_nparms = nparms;
2815 }
2816 else
2817 /* See whether current candidate is better or worse than previous best */
2818 switch (compare_badness (bv, oload_champ_bv))
2819 {
2820 case 0:
2821 oload_ambiguous = 1; /* top two contenders are equally good */
2822 oload_ambig_champ = ix;
2823 break;
2824 case 1:
2825 oload_ambiguous = 2; /* incomparable top contenders */
2826 oload_ambig_champ = ix;
2827 break;
2828 case 2:
2829 oload_champ_bv = bv; /* new champion, record details */
2830 oload_ambiguous = 0;
2831 oload_champ = ix;
2832 oload_ambig_champ = -1;
2833 champ_nparms = nparms;
2834 break;
2835 case 3:
2836 default:
2837 break;
2838 }
2839 xfree (parm_types);
2840 if (overload_debug)
2841 {
2842 if (method)
2843 fprintf_filtered (gdb_stderr,"Overloaded method instance %s, # of parms %d\n", fns_ptr[ix].physname, nparms);
2844 else
2845 fprintf_filtered (gdb_stderr,"Overloaded function instance %s # of parms %d\n", SYMBOL_DEMANGLED_NAME (oload_syms[ix]), nparms);
2846 for (jj = 0; jj < nargs - static_offset; jj++)
2847 fprintf_filtered (gdb_stderr,"...Badness @ %d : %d\n", jj, bv->rank[jj]);
2848 fprintf_filtered (gdb_stderr,"Overload resolution champion is %d, ambiguous? %d\n", oload_champ, oload_ambiguous);
2849 }
2850 } /* end loop over all candidates */
2851 /* NOTE: dan/2000-03-10: Seems to be a better idea to just pick one
2852 if they have the exact same goodness. This is because there is no
2853 way to differentiate based on return type, which we need to in
2854 cases like overloads of .begin() <It's both const and non-const> */
2855 #if 0
2856 if (oload_ambiguous)
2857 {
2858 if (method)
2859 error ("Cannot resolve overloaded method %s%s%s to unique instance; disambiguate by specifying function signature",
2860 obj_type_name,
2861 (obj_type_name && *obj_type_name) ? "::" : "",
2862 name);
2863 else
2864 error ("Cannot resolve overloaded function %s to unique instance; disambiguate by specifying function signature",
2865 func_name);
2866 }
2867 #endif
2868
2869 /* Check how bad the best match is. */
2870 static_offset = 0;
2871 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
2872 static_offset = 1;
2873 for (ix = 1; ix <= nargs - static_offset; ix++)
2874 {
2875 if (oload_champ_bv->rank[ix] >= 100)
2876 oload_incompatible = 1; /* truly mismatched types */
2877
2878 else if (oload_champ_bv->rank[ix] >= 10)
2879 oload_non_standard = 1; /* non-standard type conversions needed */
2880 }
2881 if (oload_incompatible)
2882 {
2883 if (method)
2884 error ("Cannot resolve method %s%s%s to any overloaded instance",
2885 obj_type_name,
2886 (obj_type_name && *obj_type_name) ? "::" : "",
2887 name);
2888 else
2889 error ("Cannot resolve function %s to any overloaded instance",
2890 func_name);
2891 }
2892 else if (oload_non_standard)
2893 {
2894 if (method)
2895 warning ("Using non-standard conversion to match method %s%s%s to supplied arguments",
2896 obj_type_name,
2897 (obj_type_name && *obj_type_name) ? "::" : "",
2898 name);
2899 else
2900 warning ("Using non-standard conversion to match function %s to supplied arguments",
2901 func_name);
2902 }
2903
2904 if (method)
2905 {
2906 if (staticp && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
2907 *staticp = 1;
2908 else if (staticp)
2909 *staticp = 0;
2910 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
2911 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
2912 else
2913 *valp = value_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
2914 }
2915 else
2916 {
2917 *symp = oload_syms[oload_champ];
2918 xfree (func_name);
2919 }
2920
2921 if (objp)
2922 {
2923 if (TYPE_CODE (VALUE_TYPE (temp)) != TYPE_CODE_PTR
2924 && TYPE_CODE (VALUE_TYPE (*objp)) == TYPE_CODE_PTR)
2925 {
2926 temp = value_addr (temp);
2927 }
2928 *objp = temp;
2929 }
2930 if (cleanups != NULL)
2931 do_cleanups (cleanups);
2932
2933 return oload_incompatible ? 100 : (oload_non_standard ? 10 : 0);
2934 }
2935
2936 /* C++: return 1 is NAME is a legitimate name for the destructor
2937 of type TYPE. If TYPE does not have a destructor, or
2938 if NAME is inappropriate for TYPE, an error is signaled. */
2939 int
2940 destructor_name_p (const char *name, const struct type *type)
2941 {
2942 /* destructors are a special case. */
2943
2944 if (name[0] == '~')
2945 {
2946 char *dname = type_name_no_tag (type);
2947 char *cp = strchr (dname, '<');
2948 unsigned int len;
2949
2950 /* Do not compare the template part for template classes. */
2951 if (cp == NULL)
2952 len = strlen (dname);
2953 else
2954 len = cp - dname;
2955 if (strlen (name + 1) != len || !STREQN (dname, name + 1, len))
2956 error ("name of destructor must equal name of class");
2957 else
2958 return 1;
2959 }
2960 return 0;
2961 }
2962
2963 /* Helper function for check_field: Given TYPE, a structure/union,
2964 return 1 if the component named NAME from the ultimate
2965 target structure/union is defined, otherwise, return 0. */
2966
2967 static int
2968 check_field_in (register struct type *type, const char *name)
2969 {
2970 register int i;
2971
2972 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2973 {
2974 char *t_field_name = TYPE_FIELD_NAME (type, i);
2975 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2976 return 1;
2977 }
2978
2979 /* C++: If it was not found as a data field, then try to
2980 return it as a pointer to a method. */
2981
2982 /* Destructors are a special case. */
2983 if (destructor_name_p (name, type))
2984 {
2985 int m_index, f_index;
2986
2987 return get_destructor_fn_field (type, &m_index, &f_index);
2988 }
2989
2990 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2991 {
2992 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2993 return 1;
2994 }
2995
2996 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2997 if (check_field_in (TYPE_BASECLASS (type, i), name))
2998 return 1;
2999
3000 return 0;
3001 }
3002
3003
3004 /* C++: Given ARG1, a value of type (pointer to a)* structure/union,
3005 return 1 if the component named NAME from the ultimate
3006 target structure/union is defined, otherwise, return 0. */
3007
3008 int
3009 check_field (struct value *arg1, const char *name)
3010 {
3011 register struct type *t;
3012
3013 COERCE_ARRAY (arg1);
3014
3015 t = VALUE_TYPE (arg1);
3016
3017 /* Follow pointers until we get to a non-pointer. */
3018
3019 for (;;)
3020 {
3021 CHECK_TYPEDEF (t);
3022 if (TYPE_CODE (t) != TYPE_CODE_PTR && TYPE_CODE (t) != TYPE_CODE_REF)
3023 break;
3024 t = TYPE_TARGET_TYPE (t);
3025 }
3026
3027 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
3028 error ("not implemented: member type in check_field");
3029
3030 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3031 && TYPE_CODE (t) != TYPE_CODE_UNION)
3032 error ("Internal error: `this' is not an aggregate");
3033
3034 return check_field_in (t, name);
3035 }
3036
3037 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3038 return the address of this member as a "pointer to member"
3039 type. If INTYPE is non-null, then it will be the type
3040 of the member we are looking for. This will help us resolve
3041 "pointers to member functions". This function is used
3042 to resolve user expressions of the form "DOMAIN::NAME". */
3043
3044 struct value *
3045 value_struct_elt_for_reference (struct type *domain, int offset,
3046 struct type *curtype, char *name,
3047 struct type *intype)
3048 {
3049 register struct type *t = curtype;
3050 register int i;
3051 struct value *v;
3052
3053 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3054 && TYPE_CODE (t) != TYPE_CODE_UNION)
3055 error ("Internal error: non-aggregate type to value_struct_elt_for_reference");
3056
3057 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3058 {
3059 char *t_field_name = TYPE_FIELD_NAME (t, i);
3060
3061 if (t_field_name && STREQ (t_field_name, name))
3062 {
3063 if (TYPE_FIELD_STATIC (t, i))
3064 {
3065 v = value_static_field (t, i);
3066 if (v == NULL)
3067 error ("static field %s has been optimized out",
3068 name);
3069 return v;
3070 }
3071 if (TYPE_FIELD_PACKED (t, i))
3072 error ("pointers to bitfield members not allowed");
3073
3074 return value_from_longest
3075 (lookup_reference_type (lookup_member_type (TYPE_FIELD_TYPE (t, i),
3076 domain)),
3077 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3078 }
3079 }
3080
3081 /* C++: If it was not found as a data field, then try to
3082 return it as a pointer to a method. */
3083
3084 /* Destructors are a special case. */
3085 if (destructor_name_p (name, t))
3086 {
3087 error ("member pointers to destructors not implemented yet");
3088 }
3089
3090 /* Perform all necessary dereferencing. */
3091 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3092 intype = TYPE_TARGET_TYPE (intype);
3093
3094 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3095 {
3096 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3097 char dem_opname[64];
3098
3099 if (strncmp (t_field_name, "__", 2) == 0 ||
3100 strncmp (t_field_name, "op", 2) == 0 ||
3101 strncmp (t_field_name, "type", 4) == 0)
3102 {
3103 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
3104 t_field_name = dem_opname;
3105 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
3106 t_field_name = dem_opname;
3107 }
3108 if (t_field_name && STREQ (t_field_name, name))
3109 {
3110 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
3111 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3112
3113 check_stub_method_group (t, i);
3114
3115 if (intype == 0 && j > 1)
3116 error ("non-unique member `%s' requires type instantiation", name);
3117 if (intype)
3118 {
3119 while (j--)
3120 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
3121 break;
3122 if (j < 0)
3123 error ("no member function matches that type instantiation");
3124 }
3125 else
3126 j = 0;
3127
3128 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3129 {
3130 return value_from_longest
3131 (lookup_reference_type
3132 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
3133 domain)),
3134 (LONGEST) METHOD_PTR_FROM_VOFFSET (TYPE_FN_FIELD_VOFFSET (f, j)));
3135 }
3136 else
3137 {
3138 struct symbol *s = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3139 0, VAR_NAMESPACE, 0, NULL);
3140 if (s == NULL)
3141 {
3142 v = 0;
3143 }
3144 else
3145 {
3146 v = read_var_value (s, 0);
3147 #if 0
3148 VALUE_TYPE (v) = lookup_reference_type
3149 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
3150 domain));
3151 #endif
3152 }
3153 return v;
3154 }
3155 }
3156 }
3157 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3158 {
3159 struct value *v;
3160 int base_offset;
3161
3162 if (BASETYPE_VIA_VIRTUAL (t, i))
3163 base_offset = 0;
3164 else
3165 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3166 v = value_struct_elt_for_reference (domain,
3167 offset + base_offset,
3168 TYPE_BASECLASS (t, i),
3169 name,
3170 intype);
3171 if (v)
3172 return v;
3173 }
3174 return 0;
3175 }
3176
3177
3178 /* Given a pointer value V, find the real (RTTI) type
3179 of the object it points to.
3180 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3181 and refer to the values computed for the object pointed to. */
3182
3183 struct type *
3184 value_rtti_target_type (struct value *v, int *full, int *top, int *using_enc)
3185 {
3186 struct value *target;
3187
3188 target = value_ind (v);
3189
3190 return value_rtti_type (target, full, top, using_enc);
3191 }
3192
3193 /* Given a value pointed to by ARGP, check its real run-time type, and
3194 if that is different from the enclosing type, create a new value
3195 using the real run-time type as the enclosing type (and of the same
3196 type as ARGP) and return it, with the embedded offset adjusted to
3197 be the correct offset to the enclosed object
3198 RTYPE is the type, and XFULL, XTOP, and XUSING_ENC are the other
3199 parameters, computed by value_rtti_type(). If these are available,
3200 they can be supplied and a second call to value_rtti_type() is avoided.
3201 (Pass RTYPE == NULL if they're not available */
3202
3203 struct value *
3204 value_full_object (struct value *argp, struct type *rtype, int xfull, int xtop,
3205 int xusing_enc)
3206 {
3207 struct type *real_type;
3208 int full = 0;
3209 int top = -1;
3210 int using_enc = 0;
3211 struct value *new_val;
3212
3213 if (rtype)
3214 {
3215 real_type = rtype;
3216 full = xfull;
3217 top = xtop;
3218 using_enc = xusing_enc;
3219 }
3220 else
3221 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3222
3223 /* If no RTTI data, or if object is already complete, do nothing */
3224 if (!real_type || real_type == VALUE_ENCLOSING_TYPE (argp))
3225 return argp;
3226
3227 /* If we have the full object, but for some reason the enclosing
3228 type is wrong, set it *//* pai: FIXME -- sounds iffy */
3229 if (full)
3230 {
3231 argp = value_change_enclosing_type (argp, real_type);
3232 return argp;
3233 }
3234
3235 /* Check if object is in memory */
3236 if (VALUE_LVAL (argp) != lval_memory)
3237 {
3238 warning ("Couldn't retrieve complete object of RTTI type %s; object may be in register(s).", TYPE_NAME (real_type));
3239
3240 return argp;
3241 }
3242
3243 /* All other cases -- retrieve the complete object */
3244 /* Go back by the computed top_offset from the beginning of the object,
3245 adjusting for the embedded offset of argp if that's what value_rtti_type
3246 used for its computation. */
3247 new_val = value_at_lazy (real_type, VALUE_ADDRESS (argp) - top +
3248 (using_enc ? 0 : VALUE_EMBEDDED_OFFSET (argp)),
3249 VALUE_BFD_SECTION (argp));
3250 VALUE_TYPE (new_val) = VALUE_TYPE (argp);
3251 VALUE_EMBEDDED_OFFSET (new_val) = using_enc ? top + VALUE_EMBEDDED_OFFSET (argp) : top;
3252 return new_val;
3253 }
3254
3255
3256
3257
3258 /* Return the value of the local variable, if one exists.
3259 Flag COMPLAIN signals an error if the request is made in an
3260 inappropriate context. */
3261
3262 struct value *
3263 value_of_local (const char *name, int complain)
3264 {
3265 struct symbol *func, *sym;
3266 struct block *b;
3267 int i;
3268 struct value * ret;
3269
3270 if (deprecated_selected_frame == 0)
3271 {
3272 if (complain)
3273 error ("no frame selected");
3274 else
3275 return 0;
3276 }
3277
3278 func = get_frame_function (deprecated_selected_frame);
3279 if (!func)
3280 {
3281 if (complain)
3282 error ("no `%s' in nameless context", name);
3283 else
3284 return 0;
3285 }
3286
3287 b = SYMBOL_BLOCK_VALUE (func);
3288 i = BLOCK_NSYMS (b);
3289 if (i <= 0)
3290 {
3291 if (complain)
3292 error ("no args, no `%s'", name);
3293 else
3294 return 0;
3295 }
3296
3297 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
3298 symbol instead of the LOC_ARG one (if both exist). */
3299 sym = lookup_block_symbol (b, name, NULL, VAR_NAMESPACE);
3300 if (sym == NULL)
3301 {
3302 if (complain)
3303 error ("current stack frame does not contain a variable named `%s'", name);
3304 else
3305 return NULL;
3306 }
3307
3308 ret = read_var_value (sym, deprecated_selected_frame);
3309 if (ret == 0 && complain)
3310 error ("`%s' argument unreadable", name);
3311 return ret;
3312 }
3313
3314 /* C++/Objective-C: return the value of the class instance variable,
3315 if one exists. Flag COMPLAIN signals an error if the request is
3316 made in an inappropriate context. */
3317
3318 struct value *
3319 value_of_this (int complain)
3320 {
3321 if (current_language->la_language == language_objc)
3322 return value_of_local ("self", complain);
3323 else
3324 return value_of_local ("this", complain);
3325 }
3326
3327 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH elements
3328 long, starting at LOWBOUND. The result has the same lower bound as
3329 the original ARRAY. */
3330
3331 struct value *
3332 value_slice (struct value *array, int lowbound, int length)
3333 {
3334 struct type *slice_range_type, *slice_type, *range_type;
3335 LONGEST lowerbound, upperbound;
3336 struct value *slice;
3337 struct type *array_type;
3338 array_type = check_typedef (VALUE_TYPE (array));
3339 COERCE_VARYING_ARRAY (array, array_type);
3340 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3341 && TYPE_CODE (array_type) != TYPE_CODE_STRING
3342 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
3343 error ("cannot take slice of non-array");
3344 range_type = TYPE_INDEX_TYPE (array_type);
3345 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3346 error ("slice from bad array or bitstring");
3347 if (lowbound < lowerbound || length < 0
3348 || lowbound + length - 1 > upperbound)
3349 error ("slice out of range");
3350 /* FIXME-type-allocation: need a way to free this type when we are
3351 done with it. */
3352 slice_range_type = create_range_type ((struct type *) NULL,
3353 TYPE_TARGET_TYPE (range_type),
3354 lowbound, lowbound + length - 1);
3355 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
3356 {
3357 int i;
3358 slice_type = create_set_type ((struct type *) NULL, slice_range_type);
3359 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
3360 slice = value_zero (slice_type, not_lval);
3361 for (i = 0; i < length; i++)
3362 {
3363 int element = value_bit_index (array_type,
3364 VALUE_CONTENTS (array),
3365 lowbound + i);
3366 if (element < 0)
3367 error ("internal error accessing bitstring");
3368 else if (element > 0)
3369 {
3370 int j = i % TARGET_CHAR_BIT;
3371 if (BITS_BIG_ENDIAN)
3372 j = TARGET_CHAR_BIT - 1 - j;
3373 VALUE_CONTENTS_RAW (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3374 }
3375 }
3376 /* We should set the address, bitssize, and bitspos, so the clice
3377 can be used on the LHS, but that may require extensions to
3378 value_assign. For now, just leave as a non_lval. FIXME. */
3379 }
3380 else
3381 {
3382 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3383 LONGEST offset
3384 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3385 slice_type = create_array_type ((struct type *) NULL, element_type,
3386 slice_range_type);
3387 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3388 slice = allocate_value (slice_type);
3389 if (VALUE_LAZY (array))
3390 VALUE_LAZY (slice) = 1;
3391 else
3392 memcpy (VALUE_CONTENTS (slice), VALUE_CONTENTS (array) + offset,
3393 TYPE_LENGTH (slice_type));
3394 if (VALUE_LVAL (array) == lval_internalvar)
3395 VALUE_LVAL (slice) = lval_internalvar_component;
3396 else
3397 VALUE_LVAL (slice) = VALUE_LVAL (array);
3398 VALUE_ADDRESS (slice) = VALUE_ADDRESS (array);
3399 VALUE_OFFSET (slice) = VALUE_OFFSET (array) + offset;
3400 }
3401 return slice;
3402 }
3403
3404 /* Create a value for a FORTRAN complex number. Currently most of
3405 the time values are coerced to COMPLEX*16 (i.e. a complex number
3406 composed of 2 doubles. This really should be a smarter routine
3407 that figures out precision inteligently as opposed to assuming
3408 doubles. FIXME: fmb */
3409
3410 struct value *
3411 value_literal_complex (struct value *arg1, struct value *arg2, struct type *type)
3412 {
3413 struct value *val;
3414 struct type *real_type = TYPE_TARGET_TYPE (type);
3415
3416 val = allocate_value (type);
3417 arg1 = value_cast (real_type, arg1);
3418 arg2 = value_cast (real_type, arg2);
3419
3420 memcpy (VALUE_CONTENTS_RAW (val),
3421 VALUE_CONTENTS (arg1), TYPE_LENGTH (real_type));
3422 memcpy (VALUE_CONTENTS_RAW (val) + TYPE_LENGTH (real_type),
3423 VALUE_CONTENTS (arg2), TYPE_LENGTH (real_type));
3424 return val;
3425 }
3426
3427 /* Cast a value into the appropriate complex data type. */
3428
3429 static struct value *
3430 cast_into_complex (struct type *type, struct value *val)
3431 {
3432 struct type *real_type = TYPE_TARGET_TYPE (type);
3433 if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_COMPLEX)
3434 {
3435 struct type *val_real_type = TYPE_TARGET_TYPE (VALUE_TYPE (val));
3436 struct value *re_val = allocate_value (val_real_type);
3437 struct value *im_val = allocate_value (val_real_type);
3438
3439 memcpy (VALUE_CONTENTS_RAW (re_val),
3440 VALUE_CONTENTS (val), TYPE_LENGTH (val_real_type));
3441 memcpy (VALUE_CONTENTS_RAW (im_val),
3442 VALUE_CONTENTS (val) + TYPE_LENGTH (val_real_type),
3443 TYPE_LENGTH (val_real_type));
3444
3445 return value_literal_complex (re_val, im_val, type);
3446 }
3447 else if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FLT
3448 || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT)
3449 return value_literal_complex (val, value_zero (real_type, not_lval), type);
3450 else
3451 error ("cannot cast non-number to complex");
3452 }
3453
3454 void
3455 _initialize_valops (void)
3456 {
3457 #if 0
3458 add_show_from_set
3459 (add_set_cmd ("abandon", class_support, var_boolean, (char *) &auto_abandon,
3460 "Set automatic abandonment of expressions upon failure.",
3461 &setlist),
3462 &showlist);
3463 #endif
3464
3465 add_show_from_set
3466 (add_set_cmd ("overload-resolution", class_support, var_boolean, (char *) &overload_resolution,
3467 "Set overload resolution in evaluating C++ functions.",
3468 &setlist),
3469 &showlist);
3470 overload_resolution = 1;
3471
3472 add_show_from_set (
3473 add_set_cmd ("unwindonsignal", no_class, var_boolean,
3474 (char *) &unwind_on_signal_p,
3475 "Set unwinding of stack if a signal is received while in a call dummy.\n\
3476 The unwindonsignal lets the user determine what gdb should do if a signal\n\
3477 is received while in a function called from gdb (call dummy). If set, gdb\n\
3478 unwinds the stack and restore the context to what as it was before the call.\n\
3479 The default is to stop in the frame where the signal was received.", &setlist),
3480 &showlist);
3481
3482 add_show_from_set
3483 (add_set_cmd ("coerce-float-to-double", class_obscure, var_boolean,
3484 (char *) &coerce_float_to_double,
3485 "Set coercion of floats to doubles when calling functions\n"
3486 "Variables of type float should generally be converted to doubles before\n"
3487 "calling an unprototyped function, and left alone when calling a prototyped\n"
3488 "function. However, some older debug info formats do not provide enough\n"
3489 "information to determine that a function is prototyped. If this flag is\n"
3490 "set, GDB will perform the conversion for a function it considers\n"
3491 "unprototyped.\n"
3492 "The default is to perform the conversion.\n",
3493 &setlist),
3494 &showlist);
3495 coerce_float_to_double = 1;
3496 }
This page took 0.097908 seconds and 5 git commands to generate.