* source.c (openp): Squelch warning about "filename".
[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
37 #include <errno.h>
38 #include "gdb_string.h"
39 #include "gdb_assert.h"
40
41 /* Flag indicating HP compilers were used; needed to correctly handle some
42 value operations with HP aCC code/runtime. */
43 extern int hp_som_som_object_present;
44
45 extern int overload_debug;
46 /* Local functions. */
47
48 static int typecmp (int staticp, int varargs, int nargs,
49 struct field t1[], struct value *t2[]);
50
51 static CORE_ADDR find_function_addr (struct value *, struct type **);
52 static struct value *value_arg_coerce (struct value *, struct type *, int);
53
54
55 static CORE_ADDR value_push (CORE_ADDR, struct value *);
56
57 static struct value *search_struct_field (char *, struct value *, int,
58 struct type *, int);
59
60 static struct value *search_struct_method (char *, struct value **,
61 struct value **,
62 int, int *, struct type *);
63
64 static int check_field_in (struct type *, const char *);
65
66 static CORE_ADDR allocate_space_in_inferior (int);
67
68 static struct value *cast_into_complex (struct type *, struct value *);
69
70 static struct fn_field *find_method_list (struct value ** argp, char *method,
71 int offset,
72 struct type *type, int *num_fns,
73 struct type **basetype,
74 int *boffset);
75
76 void _initialize_valops (void);
77
78 /* Flag for whether we want to abandon failed expression evals by default. */
79
80 #if 0
81 static int auto_abandon = 0;
82 #endif
83
84 int overload_resolution = 0;
85
86 /* This boolean tells what gdb should do if a signal is received while in
87 a function called from gdb (call dummy). If set, gdb unwinds the stack
88 and restore the context to what as it was before the call.
89 The default is to stop in the frame where the signal was received. */
90
91 int unwind_on_signal_p = 0;
92
93 /* How you should pass arguments to a function depends on whether it
94 was defined in K&R style or prototype style. If you define a
95 function using the K&R syntax that takes a `float' argument, then
96 callers must pass that argument as a `double'. If you define the
97 function using the prototype syntax, then you must pass the
98 argument as a `float', with no promotion.
99
100 Unfortunately, on certain older platforms, the debug info doesn't
101 indicate reliably how each function was defined. A function type's
102 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
103 defined in prototype style. When calling a function whose
104 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to decide
105 what to do.
106
107 For modern targets, it is proper to assume that, if the prototype
108 flag is clear, that can be trusted: `float' arguments should be
109 promoted to `double'. For some older targets, if the prototype
110 flag is clear, that doesn't tell us anything. The default is to
111 trust the debug information; the user can override this behavior
112 with "set coerce-float-to-double 0". */
113
114 static int coerce_float_to_double;
115 \f
116
117 /* Find the address of function name NAME in the inferior. */
118
119 struct value *
120 find_function_in_inferior (const char *name)
121 {
122 register struct symbol *sym;
123 sym = lookup_symbol (name, 0, VAR_NAMESPACE, 0, NULL);
124 if (sym != NULL)
125 {
126 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
127 {
128 error ("\"%s\" exists in this program but is not a function.",
129 name);
130 }
131 return value_of_variable (sym, NULL);
132 }
133 else
134 {
135 struct minimal_symbol *msymbol = lookup_minimal_symbol (name, NULL, NULL);
136 if (msymbol != NULL)
137 {
138 struct type *type;
139 CORE_ADDR maddr;
140 type = lookup_pointer_type (builtin_type_char);
141 type = lookup_function_type (type);
142 type = lookup_pointer_type (type);
143 maddr = SYMBOL_VALUE_ADDRESS (msymbol);
144 return value_from_pointer (type, maddr);
145 }
146 else
147 {
148 if (!target_has_execution)
149 error ("evaluation of this expression requires the target program to be active");
150 else
151 error ("evaluation of this expression requires the program to have a function \"%s\".", name);
152 }
153 }
154 }
155
156 /* Allocate NBYTES of space in the inferior using the inferior's malloc
157 and return a value that is a pointer to the allocated space. */
158
159 struct value *
160 value_allocate_space_in_inferior (int len)
161 {
162 struct value *blocklen;
163 struct value *val = find_function_in_inferior (NAME_OF_MALLOC);
164
165 blocklen = value_from_longest (builtin_type_int, (LONGEST) len);
166 val = call_function_by_hand (val, 1, &blocklen);
167 if (value_logical_not (val))
168 {
169 if (!target_has_execution)
170 error ("No memory available to program now: you need to start the target first");
171 else
172 error ("No memory available to program: call to malloc failed");
173 }
174 return val;
175 }
176
177 static CORE_ADDR
178 allocate_space_in_inferior (int len)
179 {
180 return value_as_long (value_allocate_space_in_inferior (len));
181 }
182
183 /* Cast value ARG2 to type TYPE and return as a value.
184 More general than a C cast: accepts any two types of the same length,
185 and if ARG2 is an lvalue it can be cast into anything at all. */
186 /* In C++, casts may change pointer or object representations. */
187
188 struct value *
189 value_cast (struct type *type, struct value *arg2)
190 {
191 register enum type_code code1;
192 register enum type_code code2;
193 register int scalar;
194 struct type *type2;
195
196 int convert_to_boolean = 0;
197
198 if (VALUE_TYPE (arg2) == type)
199 return arg2;
200
201 CHECK_TYPEDEF (type);
202 code1 = TYPE_CODE (type);
203 COERCE_REF (arg2);
204 type2 = check_typedef (VALUE_TYPE (arg2));
205
206 /* A cast to an undetermined-length array_type, such as (TYPE [])OBJECT,
207 is treated like a cast to (TYPE [N])OBJECT,
208 where N is sizeof(OBJECT)/sizeof(TYPE). */
209 if (code1 == TYPE_CODE_ARRAY)
210 {
211 struct type *element_type = TYPE_TARGET_TYPE (type);
212 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
213 if (element_length > 0
214 && TYPE_ARRAY_UPPER_BOUND_TYPE (type) == BOUND_CANNOT_BE_DETERMINED)
215 {
216 struct type *range_type = TYPE_INDEX_TYPE (type);
217 int val_length = TYPE_LENGTH (type2);
218 LONGEST low_bound, high_bound, new_length;
219 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
220 low_bound = 0, high_bound = 0;
221 new_length = val_length / element_length;
222 if (val_length % element_length != 0)
223 warning ("array element type size does not divide object size in cast");
224 /* FIXME-type-allocation: need a way to free this type when we are
225 done with it. */
226 range_type = create_range_type ((struct type *) NULL,
227 TYPE_TARGET_TYPE (range_type),
228 low_bound,
229 new_length + low_bound - 1);
230 VALUE_TYPE (arg2) = create_array_type ((struct type *) NULL,
231 element_type, range_type);
232 return arg2;
233 }
234 }
235
236 if (current_language->c_style_arrays
237 && TYPE_CODE (type2) == TYPE_CODE_ARRAY)
238 arg2 = value_coerce_array (arg2);
239
240 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
241 arg2 = value_coerce_function (arg2);
242
243 type2 = check_typedef (VALUE_TYPE (arg2));
244 COERCE_VARYING_ARRAY (arg2, type2);
245 code2 = TYPE_CODE (type2);
246
247 if (code1 == TYPE_CODE_COMPLEX)
248 return cast_into_complex (type, arg2);
249 if (code1 == TYPE_CODE_BOOL)
250 {
251 code1 = TYPE_CODE_INT;
252 convert_to_boolean = 1;
253 }
254 if (code1 == TYPE_CODE_CHAR)
255 code1 = TYPE_CODE_INT;
256 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
257 code2 = TYPE_CODE_INT;
258
259 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
260 || code2 == TYPE_CODE_ENUM || code2 == TYPE_CODE_RANGE);
261
262 if (code1 == TYPE_CODE_STRUCT
263 && code2 == TYPE_CODE_STRUCT
264 && TYPE_NAME (type) != 0)
265 {
266 /* Look in the type of the source to see if it contains the
267 type of the target as a superclass. If so, we'll need to
268 offset the object in addition to changing its type. */
269 struct value *v = search_struct_field (type_name_no_tag (type),
270 arg2, 0, type2, 1);
271 if (v)
272 {
273 VALUE_TYPE (v) = type;
274 return v;
275 }
276 }
277 if (code1 == TYPE_CODE_FLT && scalar)
278 return value_from_double (type, value_as_double (arg2));
279 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
280 || code1 == TYPE_CODE_RANGE)
281 && (scalar || code2 == TYPE_CODE_PTR))
282 {
283 LONGEST longest;
284
285 if (hp_som_som_object_present && /* if target compiled by HP aCC */
286 (code2 == TYPE_CODE_PTR))
287 {
288 unsigned int *ptr;
289 struct value *retvalp;
290
291 switch (TYPE_CODE (TYPE_TARGET_TYPE (type2)))
292 {
293 /* With HP aCC, pointers to data members have a bias */
294 case TYPE_CODE_MEMBER:
295 retvalp = value_from_longest (type, value_as_long (arg2));
296 /* force evaluation */
297 ptr = (unsigned int *) VALUE_CONTENTS (retvalp);
298 *ptr &= ~0x20000000; /* zap 29th bit to remove bias */
299 return retvalp;
300
301 /* While pointers to methods don't really point to a function */
302 case TYPE_CODE_METHOD:
303 error ("Pointers to methods not supported with HP aCC");
304
305 default:
306 break; /* fall out and go to normal handling */
307 }
308 }
309
310 /* When we cast pointers to integers, we mustn't use
311 POINTER_TO_ADDRESS to find the address the pointer
312 represents, as value_as_long would. GDB should evaluate
313 expressions just as the compiler would --- and the compiler
314 sees a cast as a simple reinterpretation of the pointer's
315 bits. */
316 if (code2 == TYPE_CODE_PTR)
317 longest = extract_unsigned_integer (VALUE_CONTENTS (arg2),
318 TYPE_LENGTH (type2));
319 else
320 longest = value_as_long (arg2);
321 return value_from_longest (type, convert_to_boolean ?
322 (LONGEST) (longest ? 1 : 0) : longest);
323 }
324 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT ||
325 code2 == TYPE_CODE_ENUM ||
326 code2 == TYPE_CODE_RANGE))
327 {
328 /* TYPE_LENGTH (type) is the length of a pointer, but we really
329 want the length of an address! -- we are really dealing with
330 addresses (i.e., gdb representations) not pointers (i.e.,
331 target representations) here.
332
333 This allows things like "print *(int *)0x01000234" to work
334 without printing a misleading message -- which would
335 otherwise occur when dealing with a target having two byte
336 pointers and four byte addresses. */
337
338 int addr_bit = TARGET_ADDR_BIT;
339
340 LONGEST longest = value_as_long (arg2);
341 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
342 {
343 if (longest >= ((LONGEST) 1 << addr_bit)
344 || longest <= -((LONGEST) 1 << addr_bit))
345 warning ("value truncated");
346 }
347 return value_from_longest (type, longest);
348 }
349 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
350 {
351 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
352 {
353 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type));
354 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
355 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
356 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
357 && !value_logical_not (arg2))
358 {
359 struct value *v;
360
361 /* Look in the type of the source to see if it contains the
362 type of the target as a superclass. If so, we'll need to
363 offset the pointer rather than just change its type. */
364 if (TYPE_NAME (t1) != NULL)
365 {
366 v = search_struct_field (type_name_no_tag (t1),
367 value_ind (arg2), 0, t2, 1);
368 if (v)
369 {
370 v = value_addr (v);
371 VALUE_TYPE (v) = type;
372 return v;
373 }
374 }
375
376 /* Look in the type of the target to see if it contains the
377 type of the source as a superclass. If so, we'll need to
378 offset the pointer rather than just change its type.
379 FIXME: This fails silently with virtual inheritance. */
380 if (TYPE_NAME (t2) != NULL)
381 {
382 v = search_struct_field (type_name_no_tag (t2),
383 value_zero (t1, not_lval), 0, t1, 1);
384 if (v)
385 {
386 CORE_ADDR addr2 = value_as_address (arg2);
387 addr2 -= (VALUE_ADDRESS (v)
388 + VALUE_OFFSET (v)
389 + VALUE_EMBEDDED_OFFSET (v));
390 return value_from_pointer (type, addr2);
391 }
392 }
393 }
394 /* No superclass found, just fall through to change ptr type. */
395 }
396 VALUE_TYPE (arg2) = type;
397 arg2 = value_change_enclosing_type (arg2, type);
398 VALUE_POINTED_TO_OFFSET (arg2) = 0; /* pai: chk_val */
399 return arg2;
400 }
401 else if (VALUE_LVAL (arg2) == lval_memory)
402 {
403 return value_at_lazy (type, VALUE_ADDRESS (arg2) + VALUE_OFFSET (arg2),
404 VALUE_BFD_SECTION (arg2));
405 }
406 else if (code1 == TYPE_CODE_VOID)
407 {
408 return value_zero (builtin_type_void, not_lval);
409 }
410 else
411 {
412 error ("Invalid cast.");
413 return 0;
414 }
415 }
416
417 /* Create a value of type TYPE that is zero, and return it. */
418
419 struct value *
420 value_zero (struct type *type, enum lval_type lv)
421 {
422 struct value *val = allocate_value (type);
423
424 memset (VALUE_CONTENTS (val), 0, TYPE_LENGTH (check_typedef (type)));
425 VALUE_LVAL (val) = lv;
426
427 return val;
428 }
429
430 /* Return a value with type TYPE located at ADDR.
431
432 Call value_at only if the data needs to be fetched immediately;
433 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
434 value_at_lazy instead. value_at_lazy simply records the address of
435 the data and sets the lazy-evaluation-required flag. The lazy flag
436 is tested in the VALUE_CONTENTS macro, which is used if and when
437 the contents are actually required.
438
439 Note: value_at does *NOT* handle embedded offsets; perform such
440 adjustments before or after calling it. */
441
442 struct value *
443 value_at (struct type *type, CORE_ADDR addr, asection *sect)
444 {
445 struct value *val;
446
447 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
448 error ("Attempt to dereference a generic pointer.");
449
450 val = allocate_value (type);
451
452 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), TYPE_LENGTH (type));
453
454 VALUE_LVAL (val) = lval_memory;
455 VALUE_ADDRESS (val) = addr;
456 VALUE_BFD_SECTION (val) = sect;
457
458 return val;
459 }
460
461 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
462
463 struct value *
464 value_at_lazy (struct type *type, CORE_ADDR addr, asection *sect)
465 {
466 struct value *val;
467
468 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
469 error ("Attempt to dereference a generic pointer.");
470
471 val = allocate_value (type);
472
473 VALUE_LVAL (val) = lval_memory;
474 VALUE_ADDRESS (val) = addr;
475 VALUE_LAZY (val) = 1;
476 VALUE_BFD_SECTION (val) = sect;
477
478 return val;
479 }
480
481 /* Called only from the VALUE_CONTENTS and VALUE_CONTENTS_ALL macros,
482 if the current data for a variable needs to be loaded into
483 VALUE_CONTENTS(VAL). Fetches the data from the user's process, and
484 clears the lazy flag to indicate that the data in the buffer is valid.
485
486 If the value is zero-length, we avoid calling read_memory, which would
487 abort. We mark the value as fetched anyway -- all 0 bytes of it.
488
489 This function returns a value because it is used in the VALUE_CONTENTS
490 macro as part of an expression, where a void would not work. The
491 value is ignored. */
492
493 int
494 value_fetch_lazy (struct value *val)
495 {
496 CORE_ADDR addr = VALUE_ADDRESS (val) + VALUE_OFFSET (val);
497 int length = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val));
498
499 struct type *type = VALUE_TYPE (val);
500 if (length)
501 read_memory (addr, VALUE_CONTENTS_ALL_RAW (val), length);
502
503 VALUE_LAZY (val) = 0;
504 return 0;
505 }
506
507
508 /* Store the contents of FROMVAL into the location of TOVAL.
509 Return a new value with the location of TOVAL and contents of FROMVAL. */
510
511 struct value *
512 value_assign (struct value *toval, struct value *fromval)
513 {
514 register struct type *type;
515 struct value *val;
516 char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE);
517 int use_buffer = 0;
518
519 if (!toval->modifiable)
520 error ("Left operand of assignment is not a modifiable lvalue.");
521
522 COERCE_REF (toval);
523
524 type = VALUE_TYPE (toval);
525 if (VALUE_LVAL (toval) != lval_internalvar)
526 fromval = value_cast (type, fromval);
527 else
528 COERCE_ARRAY (fromval);
529 CHECK_TYPEDEF (type);
530
531 /* If TOVAL is a special machine register requiring conversion
532 of program values to a special raw format,
533 convert FROMVAL's contents now, with result in `raw_buffer',
534 and set USE_BUFFER to the number of bytes to write. */
535
536 if (VALUE_REGNO (toval) >= 0)
537 {
538 int regno = VALUE_REGNO (toval);
539 if (CONVERT_REGISTER_P (regno))
540 {
541 struct type *fromtype = check_typedef (VALUE_TYPE (fromval));
542 VALUE_TO_REGISTER (fromtype, regno, VALUE_CONTENTS (fromval), raw_buffer);
543 use_buffer = REGISTER_RAW_SIZE (regno);
544 }
545 }
546
547 switch (VALUE_LVAL (toval))
548 {
549 case lval_internalvar:
550 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
551 val = value_copy (VALUE_INTERNALVAR (toval)->value);
552 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
553 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
554 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
555 return val;
556
557 case lval_internalvar_component:
558 set_internalvar_component (VALUE_INTERNALVAR (toval),
559 VALUE_OFFSET (toval),
560 VALUE_BITPOS (toval),
561 VALUE_BITSIZE (toval),
562 fromval);
563 break;
564
565 case lval_memory:
566 {
567 char *dest_buffer;
568 CORE_ADDR changed_addr;
569 int changed_len;
570
571 if (VALUE_BITSIZE (toval))
572 {
573 char buffer[sizeof (LONGEST)];
574 /* We assume that the argument to read_memory is in units of
575 host chars. FIXME: Is that correct? */
576 changed_len = (VALUE_BITPOS (toval)
577 + VALUE_BITSIZE (toval)
578 + HOST_CHAR_BIT - 1)
579 / HOST_CHAR_BIT;
580
581 if (changed_len > (int) sizeof (LONGEST))
582 error ("Can't handle bitfields which don't fit in a %d bit word.",
583 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
584
585 read_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
586 buffer, changed_len);
587 modify_field (buffer, value_as_long (fromval),
588 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
589 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
590 dest_buffer = buffer;
591 }
592 else if (use_buffer)
593 {
594 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
595 changed_len = use_buffer;
596 dest_buffer = raw_buffer;
597 }
598 else
599 {
600 changed_addr = VALUE_ADDRESS (toval) + VALUE_OFFSET (toval);
601 changed_len = TYPE_LENGTH (type);
602 dest_buffer = VALUE_CONTENTS (fromval);
603 }
604
605 write_memory (changed_addr, dest_buffer, changed_len);
606 if (memory_changed_hook)
607 memory_changed_hook (changed_addr, changed_len);
608 target_changed_event ();
609 }
610 break;
611
612 case lval_reg_frame_relative:
613 case lval_register:
614 {
615 struct frame_id old_frame;
616 /* value is stored in a series of registers in the frame
617 specified by the structure. Copy that value out, modify
618 it, and copy it back in. */
619 int amount_copied;
620 int amount_to_copy;
621 char *buffer;
622 int value_reg;
623 int reg_offset;
624 int byte_offset;
625 int regno;
626 struct frame_info *frame;
627
628 /* Since modifying a register can trash the frame chain, we
629 save the old frame and then restore the new frame
630 afterwards. */
631 old_frame = get_frame_id (deprecated_selected_frame);
632
633 /* Figure out which frame this is in currently. */
634 if (VALUE_LVAL (toval) == lval_register)
635 {
636 frame = get_current_frame ();
637 value_reg = VALUE_REGNO (toval);
638 }
639 else
640 {
641 for (frame = get_current_frame ();
642 frame && get_frame_base (frame) != VALUE_FRAME (toval);
643 frame = get_prev_frame (frame))
644 ;
645 value_reg = VALUE_FRAME_REGNUM (toval);
646 }
647
648 if (!frame)
649 error ("Value being assigned to is no longer active.");
650
651 /* Locate the first register that falls in the value that
652 needs to be transfered. Compute the offset of the value in
653 that register. */
654 {
655 int offset;
656 for (reg_offset = value_reg, offset = 0;
657 offset + REGISTER_RAW_SIZE (reg_offset) <= VALUE_OFFSET (toval);
658 reg_offset++);
659 byte_offset = VALUE_OFFSET (toval) - offset;
660 }
661
662 /* Compute the number of register aligned values that need to
663 be copied. */
664 if (VALUE_BITSIZE (toval))
665 amount_to_copy = byte_offset + 1;
666 else
667 amount_to_copy = byte_offset + TYPE_LENGTH (type);
668
669 /* And a bounce buffer. Be slightly over generous. */
670 buffer = (char *) alloca (amount_to_copy
671 + MAX_REGISTER_RAW_SIZE);
672
673 /* Copy it in. */
674 for (regno = reg_offset, amount_copied = 0;
675 amount_copied < amount_to_copy;
676 amount_copied += REGISTER_RAW_SIZE (regno), regno++)
677 {
678 frame_register_read (frame, regno, buffer + amount_copied);
679 }
680
681 /* Modify what needs to be modified. */
682 if (VALUE_BITSIZE (toval))
683 {
684 modify_field (buffer + byte_offset,
685 value_as_long (fromval),
686 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
687 }
688 else if (use_buffer)
689 {
690 memcpy (buffer + VALUE_OFFSET (toval), raw_buffer, use_buffer);
691 }
692 else
693 {
694 memcpy (buffer + byte_offset, VALUE_CONTENTS (fromval),
695 TYPE_LENGTH (type));
696 /* Do any conversion necessary when storing this type to
697 more than one register. */
698 #ifdef REGISTER_CONVERT_FROM_TYPE
699 REGISTER_CONVERT_FROM_TYPE (value_reg, type,
700 (buffer + byte_offset));
701 #endif
702 }
703
704 /* Copy it out. */
705 for (regno = reg_offset, amount_copied = 0;
706 amount_copied < amount_to_copy;
707 amount_copied += REGISTER_RAW_SIZE (regno), regno++)
708 {
709 enum lval_type lval;
710 CORE_ADDR addr;
711 int optim;
712 int realnum;
713
714 /* Just find out where to put it. */
715 frame_register (frame, regno, &optim, &lval, &addr, &realnum,
716 NULL);
717
718 if (optim)
719 error ("Attempt to assign to a value that was optimized out.");
720 if (lval == lval_memory)
721 write_memory (addr, buffer + amount_copied,
722 REGISTER_RAW_SIZE (regno));
723 else if (lval == lval_register)
724 regcache_cooked_write (current_regcache, realnum,
725 (buffer + amount_copied));
726 else
727 error ("Attempt to assign to an unmodifiable value.");
728 }
729
730 if (register_changed_hook)
731 register_changed_hook (-1);
732 target_changed_event ();
733
734 /* Assigning to the stack pointer, frame pointer, and other
735 (architecture and calling convention specific) registers
736 may cause the frame cache to be out of date. We just do
737 this on all assignments to registers for simplicity; I
738 doubt the slowdown matters. */
739 reinit_frame_cache ();
740
741 /* Having destoroyed the frame cache, restore the selected
742 frame. */
743 /* FIXME: cagney/2002-11-02: There has to be a better way of
744 doing this. Instead of constantly saving/restoring the
745 frame. Why not create a get_selected_frame() function
746 that, having saved the selected frame's ID can
747 automatically re-find the previously selected frame
748 automatically. */
749 {
750 struct frame_info *fi = frame_find_by_id (old_frame);
751 if (fi != NULL)
752 select_frame (fi);
753 }
754 }
755 break;
756
757
758 default:
759 error ("Left operand of assignment is not an lvalue.");
760 }
761
762 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
763 If the field is signed, and is negative, then sign extend. */
764 if ((VALUE_BITSIZE (toval) > 0)
765 && (VALUE_BITSIZE (toval) < 8 * (int) sizeof (LONGEST)))
766 {
767 LONGEST fieldval = value_as_long (fromval);
768 LONGEST valmask = (((ULONGEST) 1) << VALUE_BITSIZE (toval)) - 1;
769
770 fieldval &= valmask;
771 if (!TYPE_UNSIGNED (type) && (fieldval & (valmask ^ (valmask >> 1))))
772 fieldval |= ~valmask;
773
774 fromval = value_from_longest (type, fieldval);
775 }
776
777 val = value_copy (toval);
778 memcpy (VALUE_CONTENTS_RAW (val), VALUE_CONTENTS (fromval),
779 TYPE_LENGTH (type));
780 VALUE_TYPE (val) = type;
781 val = value_change_enclosing_type (val, VALUE_ENCLOSING_TYPE (fromval));
782 VALUE_EMBEDDED_OFFSET (val) = VALUE_EMBEDDED_OFFSET (fromval);
783 VALUE_POINTED_TO_OFFSET (val) = VALUE_POINTED_TO_OFFSET (fromval);
784
785 return val;
786 }
787
788 /* Extend a value VAL to COUNT repetitions of its type. */
789
790 struct value *
791 value_repeat (struct value *arg1, int count)
792 {
793 struct value *val;
794
795 if (VALUE_LVAL (arg1) != lval_memory)
796 error ("Only values in memory can be extended with '@'.");
797 if (count < 1)
798 error ("Invalid number %d of repetitions.", count);
799
800 val = allocate_repeat_value (VALUE_ENCLOSING_TYPE (arg1), count);
801
802 read_memory (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1),
803 VALUE_CONTENTS_ALL_RAW (val),
804 TYPE_LENGTH (VALUE_ENCLOSING_TYPE (val)));
805 VALUE_LVAL (val) = lval_memory;
806 VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1);
807
808 return val;
809 }
810
811 struct value *
812 value_of_variable (struct symbol *var, struct block *b)
813 {
814 struct value *val;
815 struct frame_info *frame = NULL;
816
817 if (!b)
818 frame = NULL; /* Use selected frame. */
819 else if (symbol_read_needs_frame (var))
820 {
821 frame = block_innermost_frame (b);
822 if (!frame)
823 {
824 if (BLOCK_FUNCTION (b)
825 && SYMBOL_SOURCE_NAME (BLOCK_FUNCTION (b)))
826 error ("No frame is currently executing in block %s.",
827 SYMBOL_SOURCE_NAME (BLOCK_FUNCTION (b)));
828 else
829 error ("No frame is currently executing in specified block");
830 }
831 }
832
833 val = read_var_value (var, frame);
834 if (!val)
835 error ("Address of symbol \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var));
836
837 return val;
838 }
839
840 /* Given a value which is an array, return a value which is a pointer to its
841 first element, regardless of whether or not the array has a nonzero lower
842 bound.
843
844 FIXME: A previous comment here indicated that this routine should be
845 substracting the array's lower bound. It's not clear to me that this
846 is correct. Given an array subscripting operation, it would certainly
847 work to do the adjustment here, essentially computing:
848
849 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
850
851 However I believe a more appropriate and logical place to account for
852 the lower bound is to do so in value_subscript, essentially computing:
853
854 (&array[0] + ((index - lowerbound) * sizeof array[0]))
855
856 As further evidence consider what would happen with operations other
857 than array subscripting, where the caller would get back a value that
858 had an address somewhere before the actual first element of the array,
859 and the information about the lower bound would be lost because of
860 the coercion to pointer type.
861 */
862
863 struct value *
864 value_coerce_array (struct value *arg1)
865 {
866 register struct type *type = check_typedef (VALUE_TYPE (arg1));
867
868 if (VALUE_LVAL (arg1) != lval_memory)
869 error ("Attempt to take address of value not located in memory.");
870
871 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
872 (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
873 }
874
875 /* Given a value which is a function, return a value which is a pointer
876 to it. */
877
878 struct value *
879 value_coerce_function (struct value *arg1)
880 {
881 struct value *retval;
882
883 if (VALUE_LVAL (arg1) != lval_memory)
884 error ("Attempt to take address of value not located in memory.");
885
886 retval = value_from_pointer (lookup_pointer_type (VALUE_TYPE (arg1)),
887 (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
888 VALUE_BFD_SECTION (retval) = VALUE_BFD_SECTION (arg1);
889 return retval;
890 }
891
892 /* Return a pointer value for the object for which ARG1 is the contents. */
893
894 struct value *
895 value_addr (struct value *arg1)
896 {
897 struct value *arg2;
898
899 struct type *type = check_typedef (VALUE_TYPE (arg1));
900 if (TYPE_CODE (type) == TYPE_CODE_REF)
901 {
902 /* Copy the value, but change the type from (T&) to (T*).
903 We keep the same location information, which is efficient,
904 and allows &(&X) to get the location containing the reference. */
905 arg2 = value_copy (arg1);
906 VALUE_TYPE (arg2) = lookup_pointer_type (TYPE_TARGET_TYPE (type));
907 return arg2;
908 }
909 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
910 return value_coerce_function (arg1);
911
912 if (VALUE_LVAL (arg1) != lval_memory)
913 error ("Attempt to take address of value not located in memory.");
914
915 /* Get target memory address */
916 arg2 = value_from_pointer (lookup_pointer_type (VALUE_TYPE (arg1)),
917 (VALUE_ADDRESS (arg1)
918 + VALUE_OFFSET (arg1)
919 + VALUE_EMBEDDED_OFFSET (arg1)));
920
921 /* This may be a pointer to a base subobject; so remember the
922 full derived object's type ... */
923 arg2 = value_change_enclosing_type (arg2, lookup_pointer_type (VALUE_ENCLOSING_TYPE (arg1)));
924 /* ... and also the relative position of the subobject in the full object */
925 VALUE_POINTED_TO_OFFSET (arg2) = VALUE_EMBEDDED_OFFSET (arg1);
926 VALUE_BFD_SECTION (arg2) = VALUE_BFD_SECTION (arg1);
927 return arg2;
928 }
929
930 /* Given a value of a pointer type, apply the C unary * operator to it. */
931
932 struct value *
933 value_ind (struct value *arg1)
934 {
935 struct type *base_type;
936 struct value *arg2;
937
938 COERCE_ARRAY (arg1);
939
940 base_type = check_typedef (VALUE_TYPE (arg1));
941
942 if (TYPE_CODE (base_type) == TYPE_CODE_MEMBER)
943 error ("not implemented: member types in value_ind");
944
945 /* Allow * on an integer so we can cast it to whatever we want.
946 This returns an int, which seems like the most C-like thing
947 to do. "long long" variables are rare enough that
948 BUILTIN_TYPE_LONGEST would seem to be a mistake. */
949 if (TYPE_CODE (base_type) == TYPE_CODE_INT)
950 return value_at_lazy (builtin_type_int,
951 (CORE_ADDR) value_as_long (arg1),
952 VALUE_BFD_SECTION (arg1));
953 else if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
954 {
955 struct type *enc_type;
956 /* We may be pointing to something embedded in a larger object */
957 /* Get the real type of the enclosing object */
958 enc_type = check_typedef (VALUE_ENCLOSING_TYPE (arg1));
959 enc_type = TYPE_TARGET_TYPE (enc_type);
960 /* Retrieve the enclosing object pointed to */
961 arg2 = value_at_lazy (enc_type,
962 value_as_address (arg1) - VALUE_POINTED_TO_OFFSET (arg1),
963 VALUE_BFD_SECTION (arg1));
964 /* Re-adjust type */
965 VALUE_TYPE (arg2) = TYPE_TARGET_TYPE (base_type);
966 /* Add embedding info */
967 arg2 = value_change_enclosing_type (arg2, enc_type);
968 VALUE_EMBEDDED_OFFSET (arg2) = VALUE_POINTED_TO_OFFSET (arg1);
969
970 /* We may be pointing to an object of some derived type */
971 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
972 return arg2;
973 }
974
975 error ("Attempt to take contents of a non-pointer value.");
976 return 0; /* For lint -- never reached */
977 }
978 \f
979 /* Pushing small parts of stack frames. */
980
981 /* Push one word (the size of object that a register holds). */
982
983 CORE_ADDR
984 push_word (CORE_ADDR sp, ULONGEST word)
985 {
986 register int len = REGISTER_SIZE;
987 char *buffer = alloca (MAX_REGISTER_RAW_SIZE);
988
989 store_unsigned_integer (buffer, len, word);
990 if (INNER_THAN (1, 2))
991 {
992 /* stack grows downward */
993 sp -= len;
994 write_memory (sp, buffer, len);
995 }
996 else
997 {
998 /* stack grows upward */
999 write_memory (sp, buffer, len);
1000 sp += len;
1001 }
1002
1003 return sp;
1004 }
1005
1006 /* Push LEN bytes with data at BUFFER. */
1007
1008 CORE_ADDR
1009 push_bytes (CORE_ADDR sp, char *buffer, int len)
1010 {
1011 if (INNER_THAN (1, 2))
1012 {
1013 /* stack grows downward */
1014 sp -= len;
1015 write_memory (sp, buffer, len);
1016 }
1017 else
1018 {
1019 /* stack grows upward */
1020 write_memory (sp, buffer, len);
1021 sp += len;
1022 }
1023
1024 return sp;
1025 }
1026
1027 #ifndef PARM_BOUNDARY
1028 #define PARM_BOUNDARY (0)
1029 #endif
1030
1031 /* Push onto the stack the specified value VALUE. Pad it correctly for
1032 it to be an argument to a function. */
1033
1034 static CORE_ADDR
1035 value_push (register CORE_ADDR sp, struct value *arg)
1036 {
1037 register int len = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (arg));
1038 register int container_len = len;
1039 register int offset;
1040
1041 /* How big is the container we're going to put this value in? */
1042 if (PARM_BOUNDARY)
1043 container_len = ((len + PARM_BOUNDARY / TARGET_CHAR_BIT - 1)
1044 & ~(PARM_BOUNDARY / TARGET_CHAR_BIT - 1));
1045
1046 /* Are we going to put it at the high or low end of the container? */
1047 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
1048 offset = container_len - len;
1049 else
1050 offset = 0;
1051
1052 if (INNER_THAN (1, 2))
1053 {
1054 /* stack grows downward */
1055 sp -= container_len;
1056 write_memory (sp + offset, VALUE_CONTENTS_ALL (arg), len);
1057 }
1058 else
1059 {
1060 /* stack grows upward */
1061 write_memory (sp + offset, VALUE_CONTENTS_ALL (arg), len);
1062 sp += container_len;
1063 }
1064
1065 return sp;
1066 }
1067
1068 CORE_ADDR
1069 default_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
1070 int struct_return, CORE_ADDR struct_addr)
1071 {
1072 /* ASSERT ( !struct_return); */
1073 int i;
1074 for (i = nargs - 1; i >= 0; i--)
1075 sp = value_push (sp, args[i]);
1076 return sp;
1077 }
1078
1079 /* Perform the standard coercions that are specified
1080 for arguments to be passed to C functions.
1081
1082 If PARAM_TYPE is non-NULL, it is the expected parameter type.
1083 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
1084
1085 static struct value *
1086 value_arg_coerce (struct value *arg, struct type *param_type,
1087 int is_prototyped)
1088 {
1089 register struct type *arg_type = check_typedef (VALUE_TYPE (arg));
1090 register struct type *type
1091 = param_type ? check_typedef (param_type) : arg_type;
1092
1093 switch (TYPE_CODE (type))
1094 {
1095 case TYPE_CODE_REF:
1096 if (TYPE_CODE (arg_type) != TYPE_CODE_REF
1097 && TYPE_CODE (arg_type) != TYPE_CODE_PTR)
1098 {
1099 arg = value_addr (arg);
1100 VALUE_TYPE (arg) = param_type;
1101 return arg;
1102 }
1103 break;
1104 case TYPE_CODE_INT:
1105 case TYPE_CODE_CHAR:
1106 case TYPE_CODE_BOOL:
1107 case TYPE_CODE_ENUM:
1108 /* If we don't have a prototype, coerce to integer type if necessary. */
1109 if (!is_prototyped)
1110 {
1111 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
1112 type = builtin_type_int;
1113 }
1114 /* Currently all target ABIs require at least the width of an integer
1115 type for an argument. We may have to conditionalize the following
1116 type coercion for future targets. */
1117 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
1118 type = builtin_type_int;
1119 break;
1120 case TYPE_CODE_FLT:
1121 if (!is_prototyped && coerce_float_to_double)
1122 {
1123 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
1124 type = builtin_type_double;
1125 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double))
1126 type = builtin_type_long_double;
1127 }
1128 break;
1129 case TYPE_CODE_FUNC:
1130 type = lookup_pointer_type (type);
1131 break;
1132 case TYPE_CODE_ARRAY:
1133 /* Arrays are coerced to pointers to their first element, unless
1134 they are vectors, in which case we want to leave them alone,
1135 because they are passed by value. */
1136 if (current_language->c_style_arrays)
1137 if (!TYPE_VECTOR (type))
1138 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
1139 break;
1140 case TYPE_CODE_UNDEF:
1141 case TYPE_CODE_PTR:
1142 case TYPE_CODE_STRUCT:
1143 case TYPE_CODE_UNION:
1144 case TYPE_CODE_VOID:
1145 case TYPE_CODE_SET:
1146 case TYPE_CODE_RANGE:
1147 case TYPE_CODE_STRING:
1148 case TYPE_CODE_BITSTRING:
1149 case TYPE_CODE_ERROR:
1150 case TYPE_CODE_MEMBER:
1151 case TYPE_CODE_METHOD:
1152 case TYPE_CODE_COMPLEX:
1153 default:
1154 break;
1155 }
1156
1157 return value_cast (type, arg);
1158 }
1159
1160 /* Determine a function's address and its return type from its value.
1161 Calls error() if the function is not valid for calling. */
1162
1163 static CORE_ADDR
1164 find_function_addr (struct value *function, struct type **retval_type)
1165 {
1166 register struct type *ftype = check_typedef (VALUE_TYPE (function));
1167 register enum type_code code = TYPE_CODE (ftype);
1168 struct type *value_type;
1169 CORE_ADDR funaddr;
1170
1171 /* If it's a member function, just look at the function
1172 part of it. */
1173
1174 /* Determine address to call. */
1175 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
1176 {
1177 funaddr = VALUE_ADDRESS (function);
1178 value_type = TYPE_TARGET_TYPE (ftype);
1179 }
1180 else if (code == TYPE_CODE_PTR)
1181 {
1182 funaddr = value_as_address (function);
1183 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
1184 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
1185 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1186 {
1187 funaddr = CONVERT_FROM_FUNC_PTR_ADDR (funaddr);
1188 value_type = TYPE_TARGET_TYPE (ftype);
1189 }
1190 else
1191 value_type = builtin_type_int;
1192 }
1193 else if (code == TYPE_CODE_INT)
1194 {
1195 /* Handle the case of functions lacking debugging info.
1196 Their values are characters since their addresses are char */
1197 if (TYPE_LENGTH (ftype) == 1)
1198 funaddr = value_as_address (value_addr (function));
1199 else
1200 /* Handle integer used as address of a function. */
1201 funaddr = (CORE_ADDR) value_as_long (function);
1202
1203 value_type = builtin_type_int;
1204 }
1205 else
1206 error ("Invalid data type for function to be called.");
1207
1208 *retval_type = value_type;
1209 return funaddr;
1210 }
1211
1212 /* All this stuff with a dummy frame may seem unnecessarily complicated
1213 (why not just save registers in GDB?). The purpose of pushing a dummy
1214 frame which looks just like a real frame is so that if you call a
1215 function and then hit a breakpoint (get a signal, etc), "backtrace"
1216 will look right. Whether the backtrace needs to actually show the
1217 stack at the time the inferior function was called is debatable, but
1218 it certainly needs to not display garbage. So if you are contemplating
1219 making dummy frames be different from normal frames, consider that. */
1220
1221 /* Perform a function call in the inferior.
1222 ARGS is a vector of values of arguments (NARGS of them).
1223 FUNCTION is a value, the function to be called.
1224 Returns a value representing what the function returned.
1225 May fail to return, if a breakpoint or signal is hit
1226 during the execution of the function.
1227
1228 ARGS is modified to contain coerced values. */
1229
1230 static struct value *
1231 hand_function_call (struct value *function, int nargs, struct value **args)
1232 {
1233 register CORE_ADDR sp;
1234 register int i;
1235 int rc;
1236 CORE_ADDR start_sp;
1237 /* CALL_DUMMY is an array of words (REGISTER_SIZE), but each word
1238 is in host byte order. Before calling FIX_CALL_DUMMY, we byteswap it
1239 and remove any extra bytes which might exist because ULONGEST is
1240 bigger than REGISTER_SIZE.
1241
1242 NOTE: This is pretty wierd, as the call dummy is actually a
1243 sequence of instructions. But CISC machines will have
1244 to pack the instructions into REGISTER_SIZE units (and
1245 so will RISC machines for which INSTRUCTION_SIZE is not
1246 REGISTER_SIZE).
1247
1248 NOTE: This is pretty stupid. CALL_DUMMY should be in strict
1249 target byte order. */
1250
1251 static ULONGEST *dummy;
1252 int sizeof_dummy1;
1253 char *dummy1;
1254 CORE_ADDR old_sp;
1255 struct type *value_type;
1256 unsigned char struct_return;
1257 CORE_ADDR struct_addr = 0;
1258 struct regcache *retbuf;
1259 struct cleanup *retbuf_cleanup;
1260 struct inferior_status *inf_status;
1261 struct cleanup *inf_status_cleanup;
1262 CORE_ADDR funaddr;
1263 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
1264 CORE_ADDR real_pc;
1265 struct type *param_type = NULL;
1266 struct type *ftype = check_typedef (SYMBOL_TYPE (function));
1267 int n_method_args = 0;
1268
1269 dummy = alloca (SIZEOF_CALL_DUMMY_WORDS);
1270 sizeof_dummy1 = REGISTER_SIZE * SIZEOF_CALL_DUMMY_WORDS / sizeof (ULONGEST);
1271 dummy1 = alloca (sizeof_dummy1);
1272 memcpy (dummy, CALL_DUMMY_WORDS, SIZEOF_CALL_DUMMY_WORDS);
1273
1274 if (!target_has_execution)
1275 noprocess ();
1276
1277 /* Create a cleanup chain that contains the retbuf (buffer
1278 containing the register values). This chain is create BEFORE the
1279 inf_status chain so that the inferior status can cleaned up
1280 (restored or discarded) without having the retbuf freed. */
1281 retbuf = regcache_xmalloc (current_gdbarch);
1282 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
1283
1284 /* A cleanup for the inferior status. Create this AFTER the retbuf
1285 so that this can be discarded or applied without interfering with
1286 the regbuf. */
1287 inf_status = save_inferior_status (1);
1288 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
1289
1290 /* PUSH_DUMMY_FRAME is responsible for saving the inferior registers
1291 (and POP_FRAME for restoring them). (At least on most machines)
1292 they are saved on the stack in the inferior. */
1293 PUSH_DUMMY_FRAME;
1294
1295 old_sp = read_sp ();
1296
1297 /* Ensure that the initial SP is correctly aligned. */
1298 if (gdbarch_frame_align_p (current_gdbarch))
1299 {
1300 /* NOTE: cagney/2002-09-18:
1301
1302 On a RISC architecture, a void parameterless generic dummy
1303 frame (i.e., no parameters, no result) typically does not
1304 need to push anything the stack and hence can leave SP and
1305 FP. Similarly, a framelss (possibly leaf) function does not
1306 push anything on the stack and, hence, that too can leave FP
1307 and SP unchanged. As a consequence, a sequence of void
1308 parameterless generic dummy frame calls to frameless
1309 functions will create a sequence of effectively identical
1310 frames (SP, FP and TOS and PC the same). This, not
1311 suprisingly, results in what appears to be a stack in an
1312 infinite loop --- when GDB tries to find a generic dummy
1313 frame on the internal dummy frame stack, it will always find
1314 the first one.
1315
1316 To avoid this problem, the code below always grows the stack.
1317 That way, two dummy frames can never be identical. It does
1318 burn a few bytes of stack but that is a small price to pay
1319 :-). */
1320 sp = gdbarch_frame_align (current_gdbarch, old_sp);
1321 if (sp == old_sp)
1322 {
1323 if (INNER_THAN (1, 2))
1324 /* Stack grows down. */
1325 sp = gdbarch_frame_align (current_gdbarch, old_sp - 1);
1326 else
1327 /* Stack grows up. */
1328 sp = gdbarch_frame_align (current_gdbarch, old_sp + 1);
1329 }
1330 gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp)
1331 || (INNER_THAN (2, 1) && sp >= old_sp));
1332 }
1333 else
1334 /* FIXME: cagney/2002-09-18: Hey, you loose! Who knows how badly
1335 aligned the SP is! Further, per comment above, if the generic
1336 dummy frame ends up empty (because nothing is pushed) GDB won't
1337 be able to correctly perform back traces. If a target is
1338 having trouble with backtraces, first thing to do is add
1339 FRAME_ALIGN() to its architecture vector. After that, try
1340 adding SAVE_DUMMY_FRAME_TOS() and modifying FRAME_CHAIN so that
1341 when the next outer frame is a generic dummy, it returns the
1342 current frame's base. */
1343 sp = old_sp;
1344
1345 if (INNER_THAN (1, 2))
1346 {
1347 /* Stack grows down */
1348 sp -= sizeof_dummy1;
1349 start_sp = sp;
1350 }
1351 else
1352 {
1353 /* Stack grows up */
1354 start_sp = sp;
1355 sp += sizeof_dummy1;
1356 }
1357
1358 /* NOTE: cagney/2002-09-10: Don't bother re-adjusting the stack
1359 after allocating space for the call dummy. A target can specify
1360 a SIZEOF_DUMMY1 (via SIZEOF_CALL_DUMMY_WORDS) such that all local
1361 alignment requirements are met. */
1362
1363 funaddr = find_function_addr (function, &value_type);
1364 CHECK_TYPEDEF (value_type);
1365
1366 {
1367 struct block *b = block_for_pc (funaddr);
1368 /* If compiled without -g, assume GCC 2. */
1369 using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
1370 }
1371
1372 /* Are we returning a value using a structure return or a normal
1373 value return? */
1374
1375 struct_return = using_struct_return (function, funaddr, value_type,
1376 using_gcc);
1377
1378 /* Create a call sequence customized for this function
1379 and the number of arguments for it. */
1380 for (i = 0; i < (int) (SIZEOF_CALL_DUMMY_WORDS / sizeof (dummy[0])); i++)
1381 store_unsigned_integer (&dummy1[i * REGISTER_SIZE],
1382 REGISTER_SIZE,
1383 (ULONGEST) dummy[i]);
1384
1385 #ifdef GDB_TARGET_IS_HPPA
1386 real_pc = FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
1387 value_type, using_gcc);
1388 #else
1389 FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
1390 value_type, using_gcc);
1391 real_pc = start_sp;
1392 #endif
1393
1394 if (CALL_DUMMY_LOCATION == ON_STACK)
1395 {
1396 write_memory (start_sp, (char *) dummy1, sizeof_dummy1);
1397 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
1398 generic_save_call_dummy_addr (start_sp, start_sp + sizeof_dummy1);
1399 }
1400
1401 if (CALL_DUMMY_LOCATION == BEFORE_TEXT_END)
1402 {
1403 /* Convex Unix prohibits executing in the stack segment. */
1404 /* Hope there is empty room at the top of the text segment. */
1405 extern CORE_ADDR text_end;
1406 static int checked = 0;
1407 if (!checked)
1408 for (start_sp = text_end - sizeof_dummy1; start_sp < text_end; ++start_sp)
1409 if (read_memory_integer (start_sp, 1) != 0)
1410 error ("text segment full -- no place to put call");
1411 checked = 1;
1412 sp = old_sp;
1413 real_pc = text_end - sizeof_dummy1;
1414 write_memory (real_pc, (char *) dummy1, sizeof_dummy1);
1415 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
1416 generic_save_call_dummy_addr (real_pc, real_pc + sizeof_dummy1);
1417 }
1418
1419 if (CALL_DUMMY_LOCATION == AFTER_TEXT_END)
1420 {
1421 extern CORE_ADDR text_end;
1422 int errcode;
1423 sp = old_sp;
1424 real_pc = text_end;
1425 errcode = target_write_memory (real_pc, (char *) dummy1, sizeof_dummy1);
1426 if (errcode != 0)
1427 error ("Cannot write text segment -- call_function failed");
1428 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
1429 generic_save_call_dummy_addr (real_pc, real_pc + sizeof_dummy1);
1430 }
1431
1432 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
1433 {
1434 real_pc = funaddr;
1435 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
1436 /* NOTE: cagney/2002-04-13: The entry point is going to be
1437 modified with a single breakpoint. */
1438 generic_save_call_dummy_addr (CALL_DUMMY_ADDRESS (),
1439 CALL_DUMMY_ADDRESS () + 1);
1440 }
1441
1442 #ifdef lint
1443 sp = old_sp; /* It really is used, for some ifdef's... */
1444 #endif
1445
1446 if (nargs < TYPE_NFIELDS (ftype))
1447 error ("too few arguments in function call");
1448
1449 for (i = nargs - 1; i >= 0; i--)
1450 {
1451 int prototyped;
1452
1453 /* FIXME drow/2002-05-31: Should just always mark methods as
1454 prototyped. Can we respect TYPE_VARARGS? Probably not. */
1455 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
1456 prototyped = 1;
1457 else
1458 prototyped = TYPE_PROTOTYPED (ftype);
1459
1460 if (i < TYPE_NFIELDS (ftype))
1461 args[i] = value_arg_coerce (args[i], TYPE_FIELD_TYPE (ftype, i),
1462 prototyped);
1463 else
1464 args[i] = value_arg_coerce (args[i], NULL, 0);
1465
1466 /*elz: this code is to handle the case in which the function to be called
1467 has a pointer to function as parameter and the corresponding actual argument
1468 is the address of a function and not a pointer to function variable.
1469 In aCC compiled code, the calls through pointers to functions (in the body
1470 of the function called by hand) are made via $$dyncall_external which
1471 requires some registers setting, this is taken care of if we call
1472 via a function pointer variable, but not via a function address.
1473 In cc this is not a problem. */
1474
1475 if (using_gcc == 0)
1476 if (param_type && TYPE_CODE (ftype) != TYPE_CODE_METHOD)
1477 /* if this parameter is a pointer to function */
1478 if (TYPE_CODE (param_type) == TYPE_CODE_PTR)
1479 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type)) == TYPE_CODE_FUNC)
1480 /* elz: FIXME here should go the test about the compiler used
1481 to compile the target. We want to issue the error
1482 message only if the compiler used was HP's aCC.
1483 If we used HP's cc, then there is no problem and no need
1484 to return at this point */
1485 if (using_gcc == 0) /* && compiler == aCC */
1486 /* go see if the actual parameter is a variable of type
1487 pointer to function or just a function */
1488 if (args[i]->lval == not_lval)
1489 {
1490 char *arg_name;
1491 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL))
1492 error ("\
1493 You cannot use function <%s> as argument. \n\
1494 You must use a pointer to function type variable. Command ignored.", arg_name);
1495 }
1496 }
1497
1498 if (REG_STRUCT_HAS_ADDR_P ())
1499 {
1500 /* This is a machine like the sparc, where we may need to pass a
1501 pointer to the structure, not the structure itself. */
1502 for (i = nargs - 1; i >= 0; i--)
1503 {
1504 struct type *arg_type = check_typedef (VALUE_TYPE (args[i]));
1505 if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT
1506 || TYPE_CODE (arg_type) == TYPE_CODE_UNION
1507 || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
1508 || TYPE_CODE (arg_type) == TYPE_CODE_STRING
1509 || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING
1510 || TYPE_CODE (arg_type) == TYPE_CODE_SET
1511 || (TYPE_CODE (arg_type) == TYPE_CODE_FLT
1512 && TYPE_LENGTH (arg_type) > 8)
1513 )
1514 && REG_STRUCT_HAS_ADDR (using_gcc, arg_type))
1515 {
1516 CORE_ADDR addr;
1517 int len; /* = TYPE_LENGTH (arg_type); */
1518 int aligned_len;
1519 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i]));
1520 len = TYPE_LENGTH (arg_type);
1521
1522 if (STACK_ALIGN_P ())
1523 /* MVS 11/22/96: I think at least some of this
1524 stack_align code is really broken. Better to let
1525 PUSH_ARGUMENTS adjust the stack in a target-defined
1526 manner. */
1527 aligned_len = STACK_ALIGN (len);
1528 else
1529 aligned_len = len;
1530 if (INNER_THAN (1, 2))
1531 {
1532 /* stack grows downward */
1533 sp -= aligned_len;
1534 /* ... so the address of the thing we push is the
1535 stack pointer after we push it. */
1536 addr = sp;
1537 }
1538 else
1539 {
1540 /* The stack grows up, so the address of the thing
1541 we push is the stack pointer before we push it. */
1542 addr = sp;
1543 sp += aligned_len;
1544 }
1545 /* Push the structure. */
1546 write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len);
1547 /* The value we're going to pass is the address of the
1548 thing we just pushed. */
1549 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
1550 (LONGEST) addr); */
1551 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
1552 addr);
1553 }
1554 }
1555 }
1556
1557
1558 /* Reserve space for the return structure to be written on the
1559 stack, if necessary. Make certain that the value is correctly
1560 aligned. */
1561
1562 if (struct_return)
1563 {
1564 int len = TYPE_LENGTH (value_type);
1565 if (STACK_ALIGN_P ())
1566 /* MVS 11/22/96: I think at least some of this stack_align
1567 code is really broken. Better to let PUSH_ARGUMENTS adjust
1568 the stack in a target-defined manner. */
1569 len = STACK_ALIGN (len);
1570 if (INNER_THAN (1, 2))
1571 {
1572 /* Stack grows downward. Align STRUCT_ADDR and SP after
1573 making space for the return value. */
1574 sp -= len;
1575 if (gdbarch_frame_align_p (current_gdbarch))
1576 sp = gdbarch_frame_align (current_gdbarch, sp);
1577 struct_addr = sp;
1578 }
1579 else
1580 {
1581 /* Stack grows upward. Align the frame, allocate space, and
1582 then again, re-align the frame??? */
1583 if (gdbarch_frame_align_p (current_gdbarch))
1584 sp = gdbarch_frame_align (current_gdbarch, sp);
1585 struct_addr = sp;
1586 sp += len;
1587 if (gdbarch_frame_align_p (current_gdbarch))
1588 sp = gdbarch_frame_align (current_gdbarch, sp);
1589 }
1590 }
1591
1592 /* elz: on HPPA no need for this extra alignment, maybe it is needed
1593 on other architectures. This is because all the alignment is
1594 taken care of in the above code (ifdef REG_STRUCT_HAS_ADDR) and
1595 in hppa_push_arguments */
1596 if (EXTRA_STACK_ALIGNMENT_NEEDED)
1597 {
1598 /* MVS 11/22/96: I think at least some of this stack_align code
1599 is really broken. Better to let PUSH_ARGUMENTS adjust the
1600 stack in a target-defined manner. */
1601 if (STACK_ALIGN_P () && INNER_THAN (1, 2))
1602 {
1603 /* If stack grows down, we must leave a hole at the top. */
1604 int len = 0;
1605
1606 for (i = nargs - 1; i >= 0; i--)
1607 len += TYPE_LENGTH (VALUE_ENCLOSING_TYPE (args[i]));
1608 if (CALL_DUMMY_STACK_ADJUST_P)
1609 len += CALL_DUMMY_STACK_ADJUST;
1610 sp -= STACK_ALIGN (len) - len;
1611 }
1612 }
1613
1614 sp = PUSH_ARGUMENTS (nargs, args, sp, struct_return, struct_addr);
1615
1616 if (PUSH_RETURN_ADDRESS_P ())
1617 /* for targets that use no CALL_DUMMY */
1618 /* There are a number of targets now which actually don't write
1619 any CALL_DUMMY instructions into the target, but instead just
1620 save the machine state, push the arguments, and jump directly
1621 to the callee function. Since this doesn't actually involve
1622 executing a JSR/BSR instruction, the return address must be set
1623 up by hand, either by pushing onto the stack or copying into a
1624 return-address register as appropriate. Formerly this has been
1625 done in PUSH_ARGUMENTS, but that's overloading its
1626 functionality a bit, so I'm making it explicit to do it here. */
1627 sp = PUSH_RETURN_ADDRESS (real_pc, sp);
1628
1629 if (STACK_ALIGN_P () && !INNER_THAN (1, 2))
1630 {
1631 /* If stack grows up, we must leave a hole at the bottom, note
1632 that sp already has been advanced for the arguments! */
1633 if (CALL_DUMMY_STACK_ADJUST_P)
1634 sp += CALL_DUMMY_STACK_ADJUST;
1635 sp = STACK_ALIGN (sp);
1636 }
1637
1638 /* XXX This seems wrong. For stacks that grow down we shouldn't do
1639 anything here! */
1640 /* MVS 11/22/96: I think at least some of this stack_align code is
1641 really broken. Better to let PUSH_ARGUMENTS adjust the stack in
1642 a target-defined manner. */
1643 if (CALL_DUMMY_STACK_ADJUST_P)
1644 if (INNER_THAN (1, 2))
1645 {
1646 /* stack grows downward */
1647 sp -= CALL_DUMMY_STACK_ADJUST;
1648 }
1649
1650 /* Store the address at which the structure is supposed to be
1651 written. Note that this (and the code which reserved the space
1652 above) assumes that gcc was used to compile this function. Since
1653 it doesn't cost us anything but space and if the function is pcc
1654 it will ignore this value, we will make that assumption.
1655
1656 Also note that on some machines (like the sparc) pcc uses a
1657 convention like gcc's. */
1658
1659 if (struct_return)
1660 STORE_STRUCT_RETURN (struct_addr, sp);
1661
1662 /* Write the stack pointer. This is here because the statements above
1663 might fool with it. On SPARC, this write also stores the register
1664 window into the right place in the new stack frame, which otherwise
1665 wouldn't happen. (See store_inferior_registers in sparc-nat.c.) */
1666 write_sp (sp);
1667
1668 if (SAVE_DUMMY_FRAME_TOS_P ())
1669 SAVE_DUMMY_FRAME_TOS (sp);
1670
1671 {
1672 char *name;
1673 struct symbol *symbol;
1674
1675 name = NULL;
1676 symbol = find_pc_function (funaddr);
1677 if (symbol)
1678 {
1679 name = SYMBOL_SOURCE_NAME (symbol);
1680 }
1681 else
1682 {
1683 /* Try the minimal symbols. */
1684 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
1685
1686 if (msymbol)
1687 {
1688 name = SYMBOL_SOURCE_NAME (msymbol);
1689 }
1690 }
1691 if (name == NULL)
1692 {
1693 char format[80];
1694 sprintf (format, "at %s", local_hex_format ());
1695 name = alloca (80);
1696 /* FIXME-32x64: assumes funaddr fits in a long. */
1697 sprintf (name, format, (unsigned long) funaddr);
1698 }
1699
1700 /* Execute the stack dummy routine, calling FUNCTION.
1701 When it is done, discard the empty frame
1702 after storing the contents of all regs into retbuf. */
1703 rc = run_stack_dummy (real_pc + CALL_DUMMY_START_OFFSET, retbuf);
1704
1705 if (rc == 1)
1706 {
1707 /* We stopped inside the FUNCTION because of a random signal.
1708 Further execution of the FUNCTION is not allowed. */
1709
1710 if (unwind_on_signal_p)
1711 {
1712 /* The user wants the context restored. */
1713
1714 /* We must get back to the frame we were before the dummy call. */
1715 POP_FRAME;
1716
1717 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1718 a C++ name with arguments and stuff. */
1719 error ("\
1720 The program being debugged was signaled while in a function called from GDB.\n\
1721 GDB has restored the context to what it was before the call.\n\
1722 To change this behavior use \"set unwindonsignal off\"\n\
1723 Evaluation of the expression containing the function (%s) will be abandoned.",
1724 name);
1725 }
1726 else
1727 {
1728 /* The user wants to stay in the frame where we stopped (default).*/
1729
1730 /* If we restored the inferior status (via the cleanup),
1731 we would print a spurious error message (Unable to
1732 restore previously selected frame), would write the
1733 registers from the inf_status (which is wrong), and
1734 would do other wrong things. */
1735 discard_cleanups (inf_status_cleanup);
1736 discard_inferior_status (inf_status);
1737
1738 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1739 a C++ name with arguments and stuff. */
1740 error ("\
1741 The program being debugged was signaled while in a function called from GDB.\n\
1742 GDB remains in the frame where the signal was received.\n\
1743 To change this behavior use \"set unwindonsignal on\"\n\
1744 Evaluation of the expression containing the function (%s) will be abandoned.",
1745 name);
1746 }
1747 }
1748
1749 if (rc == 2)
1750 {
1751 /* We hit a breakpoint inside the FUNCTION. */
1752
1753 /* If we restored the inferior status (via the cleanup), we
1754 would print a spurious error message (Unable to restore
1755 previously selected frame), would write the registers from
1756 the inf_status (which is wrong), and would do other wrong
1757 things. */
1758 discard_cleanups (inf_status_cleanup);
1759 discard_inferior_status (inf_status);
1760
1761 /* The following error message used to say "The expression
1762 which contained the function call has been discarded." It
1763 is a hard concept to explain in a few words. Ideally, GDB
1764 would be able to resume evaluation of the expression when
1765 the function finally is done executing. Perhaps someday
1766 this will be implemented (it would not be easy). */
1767
1768 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1769 a C++ name with arguments and stuff. */
1770 error ("\
1771 The program being debugged stopped while in a function called from GDB.\n\
1772 When the function (%s) is done executing, GDB will silently\n\
1773 stop (instead of continuing to evaluate the expression containing\n\
1774 the function call).", name);
1775 }
1776
1777 /* If we get here the called FUNCTION run to completion. */
1778
1779 /* Restore the inferior status, via its cleanup. At this stage,
1780 leave the RETBUF alone. */
1781 do_cleanups (inf_status_cleanup);
1782
1783 /* Figure out the value returned by the function. */
1784 /* elz: I defined this new macro for the hppa architecture only.
1785 this gives us a way to get the value returned by the function
1786 from the stack, at the same address we told the function to put
1787 it. We cannot assume on the pa that r28 still contains the
1788 address of the returned structure. Usually this will be
1789 overwritten by the callee. I don't know about other
1790 architectures, so I defined this macro */
1791 #ifdef VALUE_RETURNED_FROM_STACK
1792 if (struct_return)
1793 {
1794 do_cleanups (retbuf_cleanup);
1795 return VALUE_RETURNED_FROM_STACK (value_type, struct_addr);
1796 }
1797 #endif
1798 /* NOTE: cagney/2002-09-10: Only when the stack has been correctly
1799 aligned (using frame_align()) do we can trust STRUCT_ADDR and
1800 fetch the return value direct from the stack. This lack of
1801 trust comes about because legacy targets have a nasty habit of
1802 silently, and local to PUSH_ARGUMENTS(), moving STRUCT_ADDR.
1803 For such targets, just hope that value_being_returned() can
1804 find the adjusted value. */
1805 if (struct_return && gdbarch_frame_align_p (current_gdbarch))
1806 {
1807 struct value *retval = value_at (value_type, struct_addr, NULL);
1808 do_cleanups (retbuf_cleanup);
1809 return retval;
1810 }
1811 else
1812 {
1813 struct value *retval = value_being_returned (value_type, retbuf,
1814 struct_return);
1815 do_cleanups (retbuf_cleanup);
1816 return retval;
1817 }
1818 }
1819 }
1820
1821 struct value *
1822 call_function_by_hand (struct value *function, int nargs, struct value **args)
1823 {
1824 if (CALL_DUMMY_P)
1825 {
1826 return hand_function_call (function, nargs, args);
1827 }
1828 else
1829 {
1830 error ("Cannot invoke functions on this machine.");
1831 }
1832 }
1833 \f
1834
1835
1836 /* Create a value for an array by allocating space in the inferior, copying
1837 the data into that space, and then setting up an array value.
1838
1839 The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
1840 populated from the values passed in ELEMVEC.
1841
1842 The element type of the array is inherited from the type of the
1843 first element, and all elements must have the same size (though we
1844 don't currently enforce any restriction on their types). */
1845
1846 struct value *
1847 value_array (int lowbound, int highbound, struct value **elemvec)
1848 {
1849 int nelem;
1850 int idx;
1851 unsigned int typelength;
1852 struct value *val;
1853 struct type *rangetype;
1854 struct type *arraytype;
1855 CORE_ADDR addr;
1856
1857 /* Validate that the bounds are reasonable and that each of the elements
1858 have the same size. */
1859
1860 nelem = highbound - lowbound + 1;
1861 if (nelem <= 0)
1862 {
1863 error ("bad array bounds (%d, %d)", lowbound, highbound);
1864 }
1865 typelength = TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[0]));
1866 for (idx = 1; idx < nelem; idx++)
1867 {
1868 if (TYPE_LENGTH (VALUE_ENCLOSING_TYPE (elemvec[idx])) != typelength)
1869 {
1870 error ("array elements must all be the same size");
1871 }
1872 }
1873
1874 rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
1875 lowbound, highbound);
1876 arraytype = create_array_type ((struct type *) NULL,
1877 VALUE_ENCLOSING_TYPE (elemvec[0]), rangetype);
1878
1879 if (!current_language->c_style_arrays)
1880 {
1881 val = allocate_value (arraytype);
1882 for (idx = 0; idx < nelem; idx++)
1883 {
1884 memcpy (VALUE_CONTENTS_ALL_RAW (val) + (idx * typelength),
1885 VALUE_CONTENTS_ALL (elemvec[idx]),
1886 typelength);
1887 }
1888 VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (elemvec[0]);
1889 return val;
1890 }
1891
1892 /* Allocate space to store the array in the inferior, and then initialize
1893 it by copying in each element. FIXME: Is it worth it to create a
1894 local buffer in which to collect each value and then write all the
1895 bytes in one operation? */
1896
1897 addr = allocate_space_in_inferior (nelem * typelength);
1898 for (idx = 0; idx < nelem; idx++)
1899 {
1900 write_memory (addr + (idx * typelength), VALUE_CONTENTS_ALL (elemvec[idx]),
1901 typelength);
1902 }
1903
1904 /* Create the array type and set up an array value to be evaluated lazily. */
1905
1906 val = value_at_lazy (arraytype, addr, VALUE_BFD_SECTION (elemvec[0]));
1907 return (val);
1908 }
1909
1910 /* Create a value for a string constant by allocating space in the inferior,
1911 copying the data into that space, and returning the address with type
1912 TYPE_CODE_STRING. PTR points to the string constant data; LEN is number
1913 of characters.
1914 Note that string types are like array of char types with a lower bound of
1915 zero and an upper bound of LEN - 1. Also note that the string may contain
1916 embedded null bytes. */
1917
1918 struct value *
1919 value_string (char *ptr, int len)
1920 {
1921 struct value *val;
1922 int lowbound = current_language->string_lower_bound;
1923 struct type *rangetype = create_range_type ((struct type *) NULL,
1924 builtin_type_int,
1925 lowbound, len + lowbound - 1);
1926 struct type *stringtype
1927 = create_string_type ((struct type *) NULL, rangetype);
1928 CORE_ADDR addr;
1929
1930 if (current_language->c_style_arrays == 0)
1931 {
1932 val = allocate_value (stringtype);
1933 memcpy (VALUE_CONTENTS_RAW (val), ptr, len);
1934 return val;
1935 }
1936
1937
1938 /* Allocate space to store the string in the inferior, and then
1939 copy LEN bytes from PTR in gdb to that address in the inferior. */
1940
1941 addr = allocate_space_in_inferior (len);
1942 write_memory (addr, ptr, len);
1943
1944 val = value_at_lazy (stringtype, addr, NULL);
1945 return (val);
1946 }
1947
1948 struct value *
1949 value_bitstring (char *ptr, int len)
1950 {
1951 struct value *val;
1952 struct type *domain_type = create_range_type (NULL, builtin_type_int,
1953 0, len - 1);
1954 struct type *type = create_set_type ((struct type *) NULL, domain_type);
1955 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1956 val = allocate_value (type);
1957 memcpy (VALUE_CONTENTS_RAW (val), ptr, TYPE_LENGTH (type));
1958 return val;
1959 }
1960 \f
1961 /* See if we can pass arguments in T2 to a function which takes arguments
1962 of types T1. T1 is a list of NARGS arguments, and T2 is a NULL-terminated
1963 vector. If some arguments need coercion of some sort, then the coerced
1964 values are written into T2. Return value is 0 if the arguments could be
1965 matched, or the position at which they differ if not.
1966
1967 STATICP is nonzero if the T1 argument list came from a
1968 static member function. T2 will still include the ``this'' pointer,
1969 but it will be skipped.
1970
1971 For non-static member functions, we ignore the first argument,
1972 which is the type of the instance variable. This is because we want
1973 to handle calls with objects from derived classes. This is not
1974 entirely correct: we should actually check to make sure that a
1975 requested operation is type secure, shouldn't we? FIXME. */
1976
1977 static int
1978 typecmp (int staticp, int varargs, int nargs,
1979 struct field t1[], struct value *t2[])
1980 {
1981 int i;
1982
1983 if (t2 == 0)
1984 internal_error (__FILE__, __LINE__, "typecmp: no argument list");
1985
1986 /* Skip ``this'' argument if applicable. T2 will always include THIS. */
1987 if (staticp)
1988 t2 ++;
1989
1990 for (i = 0;
1991 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1992 i++)
1993 {
1994 struct type *tt1, *tt2;
1995
1996 if (!t2[i])
1997 return i + 1;
1998
1999 tt1 = check_typedef (t1[i].type);
2000 tt2 = check_typedef (VALUE_TYPE (t2[i]));
2001
2002 if (TYPE_CODE (tt1) == TYPE_CODE_REF
2003 /* We should be doing hairy argument matching, as below. */
2004 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
2005 {
2006 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
2007 t2[i] = value_coerce_array (t2[i]);
2008 else
2009 t2[i] = value_addr (t2[i]);
2010 continue;
2011 }
2012
2013 /* djb - 20000715 - Until the new type structure is in the
2014 place, and we can attempt things like implicit conversions,
2015 we need to do this so you can take something like a map<const
2016 char *>, and properly access map["hello"], because the
2017 argument to [] will be a reference to a pointer to a char,
2018 and the argument will be a pointer to a char. */
2019 while ( TYPE_CODE(tt1) == TYPE_CODE_REF ||
2020 TYPE_CODE (tt1) == TYPE_CODE_PTR)
2021 {
2022 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
2023 }
2024 while ( TYPE_CODE(tt2) == TYPE_CODE_ARRAY ||
2025 TYPE_CODE(tt2) == TYPE_CODE_PTR ||
2026 TYPE_CODE(tt2) == TYPE_CODE_REF)
2027 {
2028 tt2 = check_typedef( TYPE_TARGET_TYPE(tt2) );
2029 }
2030 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
2031 continue;
2032 /* Array to pointer is a `trivial conversion' according to the ARM. */
2033
2034 /* We should be doing much hairier argument matching (see section 13.2
2035 of the ARM), but as a quick kludge, just check for the same type
2036 code. */
2037 if (TYPE_CODE (t1[i].type) != TYPE_CODE (VALUE_TYPE (t2[i])))
2038 return i + 1;
2039 }
2040 if (varargs || t2[i] == NULL)
2041 return 0;
2042 return i + 1;
2043 }
2044
2045 /* Helper function used by value_struct_elt to recurse through baseclasses.
2046 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
2047 and search in it assuming it has (class) type TYPE.
2048 If found, return value, else return NULL.
2049
2050 If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
2051 look for a baseclass named NAME. */
2052
2053 static struct value *
2054 search_struct_field (char *name, struct value *arg1, int offset,
2055 register struct type *type, int looking_for_baseclass)
2056 {
2057 int i;
2058 int nbases = TYPE_N_BASECLASSES (type);
2059
2060 CHECK_TYPEDEF (type);
2061
2062 if (!looking_for_baseclass)
2063 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
2064 {
2065 char *t_field_name = TYPE_FIELD_NAME (type, i);
2066
2067 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2068 {
2069 struct value *v;
2070 if (TYPE_FIELD_STATIC (type, i))
2071 {
2072 v = value_static_field (type, i);
2073 if (v == 0)
2074 error ("field %s is nonexistent or has been optimised out",
2075 name);
2076 }
2077 else
2078 {
2079 v = value_primitive_field (arg1, offset, i, type);
2080 if (v == 0)
2081 error ("there is no field named %s", name);
2082 }
2083 return v;
2084 }
2085
2086 if (t_field_name
2087 && (t_field_name[0] == '\0'
2088 || (TYPE_CODE (type) == TYPE_CODE_UNION
2089 && (strcmp_iw (t_field_name, "else") == 0))))
2090 {
2091 struct type *field_type = TYPE_FIELD_TYPE (type, i);
2092 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
2093 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
2094 {
2095 /* Look for a match through the fields of an anonymous union,
2096 or anonymous struct. C++ provides anonymous unions.
2097
2098 In the GNU Chill (now deleted from GDB)
2099 implementation of variant record types, each
2100 <alternative field> has an (anonymous) union type,
2101 each member of the union represents a <variant
2102 alternative>. Each <variant alternative> is
2103 represented as a struct, with a member for each
2104 <variant field>. */
2105
2106 struct value *v;
2107 int new_offset = offset;
2108
2109 /* This is pretty gross. In G++, the offset in an
2110 anonymous union is relative to the beginning of the
2111 enclosing struct. In the GNU Chill (now deleted
2112 from GDB) implementation of variant records, the
2113 bitpos is zero in an anonymous union field, so we
2114 have to add the offset of the union here. */
2115 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
2116 || (TYPE_NFIELDS (field_type) > 0
2117 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
2118 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
2119
2120 v = search_struct_field (name, arg1, new_offset, field_type,
2121 looking_for_baseclass);
2122 if (v)
2123 return v;
2124 }
2125 }
2126 }
2127
2128 for (i = 0; i < nbases; i++)
2129 {
2130 struct value *v;
2131 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
2132 /* If we are looking for baseclasses, this is what we get when we
2133 hit them. But it could happen that the base part's member name
2134 is not yet filled in. */
2135 int found_baseclass = (looking_for_baseclass
2136 && TYPE_BASECLASS_NAME (type, i) != NULL
2137 && (strcmp_iw (name, TYPE_BASECLASS_NAME (type, i)) == 0));
2138
2139 if (BASETYPE_VIA_VIRTUAL (type, i))
2140 {
2141 int boffset;
2142 struct value *v2 = allocate_value (basetype);
2143
2144 boffset = baseclass_offset (type, i,
2145 VALUE_CONTENTS (arg1) + offset,
2146 VALUE_ADDRESS (arg1)
2147 + VALUE_OFFSET (arg1) + offset);
2148 if (boffset == -1)
2149 error ("virtual baseclass botch");
2150
2151 /* The virtual base class pointer might have been clobbered by the
2152 user program. Make sure that it still points to a valid memory
2153 location. */
2154
2155 boffset += offset;
2156 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
2157 {
2158 CORE_ADDR base_addr;
2159
2160 base_addr = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1) + boffset;
2161 if (target_read_memory (base_addr, VALUE_CONTENTS_RAW (v2),
2162 TYPE_LENGTH (basetype)) != 0)
2163 error ("virtual baseclass botch");
2164 VALUE_LVAL (v2) = lval_memory;
2165 VALUE_ADDRESS (v2) = base_addr;
2166 }
2167 else
2168 {
2169 VALUE_LVAL (v2) = VALUE_LVAL (arg1);
2170 VALUE_ADDRESS (v2) = VALUE_ADDRESS (arg1);
2171 VALUE_OFFSET (v2) = VALUE_OFFSET (arg1) + boffset;
2172 if (VALUE_LAZY (arg1))
2173 VALUE_LAZY (v2) = 1;
2174 else
2175 memcpy (VALUE_CONTENTS_RAW (v2),
2176 VALUE_CONTENTS_RAW (arg1) + boffset,
2177 TYPE_LENGTH (basetype));
2178 }
2179
2180 if (found_baseclass)
2181 return v2;
2182 v = search_struct_field (name, v2, 0, TYPE_BASECLASS (type, i),
2183 looking_for_baseclass);
2184 }
2185 else if (found_baseclass)
2186 v = value_primitive_field (arg1, offset, i, type);
2187 else
2188 v = search_struct_field (name, arg1,
2189 offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
2190 basetype, looking_for_baseclass);
2191 if (v)
2192 return v;
2193 }
2194 return NULL;
2195 }
2196
2197
2198 /* Return the offset (in bytes) of the virtual base of type BASETYPE
2199 * in an object pointed to by VALADDR (on the host), assumed to be of
2200 * type TYPE. OFFSET is number of bytes beyond start of ARG to start
2201 * looking (in case VALADDR is the contents of an enclosing object).
2202 *
2203 * This routine recurses on the primary base of the derived class because
2204 * the virtual base entries of the primary base appear before the other
2205 * virtual base entries.
2206 *
2207 * If the virtual base is not found, a negative integer is returned.
2208 * The magnitude of the negative integer is the number of entries in
2209 * the virtual table to skip over (entries corresponding to various
2210 * ancestral classes in the chain of primary bases).
2211 *
2212 * Important: This assumes the HP / Taligent C++ runtime
2213 * conventions. Use baseclass_offset() instead to deal with g++
2214 * conventions. */
2215
2216 void
2217 find_rt_vbase_offset (struct type *type, struct type *basetype, char *valaddr,
2218 int offset, int *boffset_p, int *skip_p)
2219 {
2220 int boffset; /* offset of virtual base */
2221 int index; /* displacement to use in virtual table */
2222 int skip;
2223
2224 struct value *vp;
2225 CORE_ADDR vtbl; /* the virtual table pointer */
2226 struct type *pbc; /* the primary base class */
2227
2228 /* Look for the virtual base recursively in the primary base, first.
2229 * This is because the derived class object and its primary base
2230 * subobject share the primary virtual table. */
2231
2232 boffset = 0;
2233 pbc = TYPE_PRIMARY_BASE (type);
2234 if (pbc)
2235 {
2236 find_rt_vbase_offset (pbc, basetype, valaddr, offset, &boffset, &skip);
2237 if (skip < 0)
2238 {
2239 *boffset_p = boffset;
2240 *skip_p = -1;
2241 return;
2242 }
2243 }
2244 else
2245 skip = 0;
2246
2247
2248 /* Find the index of the virtual base according to HP/Taligent
2249 runtime spec. (Depth-first, left-to-right.) */
2250 index = virtual_base_index_skip_primaries (basetype, type);
2251
2252 if (index < 0)
2253 {
2254 *skip_p = skip + virtual_base_list_length_skip_primaries (type);
2255 *boffset_p = 0;
2256 return;
2257 }
2258
2259 /* pai: FIXME -- 32x64 possible problem */
2260 /* First word (4 bytes) in object layout is the vtable pointer */
2261 vtbl = *(CORE_ADDR *) (valaddr + offset);
2262
2263 /* Before the constructor is invoked, things are usually zero'd out. */
2264 if (vtbl == 0)
2265 error ("Couldn't find virtual table -- object may not be constructed yet.");
2266
2267
2268 /* Find virtual base's offset -- jump over entries for primary base
2269 * ancestors, then use the index computed above. But also adjust by
2270 * HP_ACC_VBASE_START for the vtable slots before the start of the
2271 * virtual base entries. Offset is negative -- virtual base entries
2272 * appear _before_ the address point of the virtual table. */
2273
2274 /* pai: FIXME -- 32x64 problem, if word = 8 bytes, change multiplier
2275 & use long type */
2276
2277 /* epstein : FIXME -- added param for overlay section. May not be correct */
2278 vp = value_at (builtin_type_int, vtbl + 4 * (-skip - index - HP_ACC_VBASE_START), NULL);
2279 boffset = value_as_long (vp);
2280 *skip_p = -1;
2281 *boffset_p = boffset;
2282 return;
2283 }
2284
2285
2286 /* Helper function used by value_struct_elt to recurse through baseclasses.
2287 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
2288 and search in it assuming it has (class) type TYPE.
2289 If found, return value, else if name matched and args not return (value)-1,
2290 else return NULL. */
2291
2292 static struct value *
2293 search_struct_method (char *name, struct value **arg1p,
2294 struct value **args, int offset,
2295 int *static_memfuncp, register struct type *type)
2296 {
2297 int i;
2298 struct value *v;
2299 int name_matched = 0;
2300 char dem_opname[64];
2301
2302 CHECK_TYPEDEF (type);
2303 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2304 {
2305 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2306 /* FIXME! May need to check for ARM demangling here */
2307 if (strncmp (t_field_name, "__", 2) == 0 ||
2308 strncmp (t_field_name, "op", 2) == 0 ||
2309 strncmp (t_field_name, "type", 4) == 0)
2310 {
2311 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2312 t_field_name = dem_opname;
2313 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2314 t_field_name = dem_opname;
2315 }
2316 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2317 {
2318 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2319 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2320 name_matched = 1;
2321
2322 check_stub_method_group (type, i);
2323 if (j > 0 && args == 0)
2324 error ("cannot resolve overloaded method `%s': no arguments supplied", name);
2325 else if (j == 0 && args == 0)
2326 {
2327 v = value_fn_field (arg1p, f, j, type, offset);
2328 if (v != NULL)
2329 return v;
2330 }
2331 else
2332 while (j >= 0)
2333 {
2334 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2335 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2336 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2337 TYPE_FN_FIELD_ARGS (f, j), args))
2338 {
2339 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2340 return value_virtual_fn_field (arg1p, f, j, type, offset);
2341 if (TYPE_FN_FIELD_STATIC_P (f, j) && static_memfuncp)
2342 *static_memfuncp = 1;
2343 v = value_fn_field (arg1p, f, j, type, offset);
2344 if (v != NULL)
2345 return v;
2346 }
2347 j--;
2348 }
2349 }
2350 }
2351
2352 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2353 {
2354 int base_offset;
2355
2356 if (BASETYPE_VIA_VIRTUAL (type, i))
2357 {
2358 if (TYPE_HAS_VTABLE (type))
2359 {
2360 /* HP aCC compiled type, search for virtual base offset
2361 according to HP/Taligent runtime spec. */
2362 int skip;
2363 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
2364 VALUE_CONTENTS_ALL (*arg1p),
2365 offset + VALUE_EMBEDDED_OFFSET (*arg1p),
2366 &base_offset, &skip);
2367 if (skip >= 0)
2368 error ("Virtual base class offset not found in vtable");
2369 }
2370 else
2371 {
2372 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2373 char *base_valaddr;
2374
2375 /* The virtual base class pointer might have been clobbered by the
2376 user program. Make sure that it still points to a valid memory
2377 location. */
2378
2379 if (offset < 0 || offset >= TYPE_LENGTH (type))
2380 {
2381 base_valaddr = (char *) alloca (TYPE_LENGTH (baseclass));
2382 if (target_read_memory (VALUE_ADDRESS (*arg1p)
2383 + VALUE_OFFSET (*arg1p) + offset,
2384 base_valaddr,
2385 TYPE_LENGTH (baseclass)) != 0)
2386 error ("virtual baseclass botch");
2387 }
2388 else
2389 base_valaddr = VALUE_CONTENTS (*arg1p) + offset;
2390
2391 base_offset =
2392 baseclass_offset (type, i, base_valaddr,
2393 VALUE_ADDRESS (*arg1p)
2394 + VALUE_OFFSET (*arg1p) + offset);
2395 if (base_offset == -1)
2396 error ("virtual baseclass botch");
2397 }
2398 }
2399 else
2400 {
2401 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2402 }
2403 v = search_struct_method (name, arg1p, args, base_offset + offset,
2404 static_memfuncp, TYPE_BASECLASS (type, i));
2405 if (v == (struct value *) - 1)
2406 {
2407 name_matched = 1;
2408 }
2409 else if (v)
2410 {
2411 /* FIXME-bothner: Why is this commented out? Why is it here? */
2412 /* *arg1p = arg1_tmp; */
2413 return v;
2414 }
2415 }
2416 if (name_matched)
2417 return (struct value *) - 1;
2418 else
2419 return NULL;
2420 }
2421
2422 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2423 extract the component named NAME from the ultimate target structure/union
2424 and return it as a value with its appropriate type.
2425 ERR is used in the error message if *ARGP's type is wrong.
2426
2427 C++: ARGS is a list of argument types to aid in the selection of
2428 an appropriate method. Also, handle derived types.
2429
2430 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2431 where the truthvalue of whether the function that was resolved was
2432 a static member function or not is stored.
2433
2434 ERR is an error message to be printed in case the field is not found. */
2435
2436 struct value *
2437 value_struct_elt (struct value **argp, struct value **args,
2438 char *name, int *static_memfuncp, char *err)
2439 {
2440 register struct type *t;
2441 struct value *v;
2442
2443 COERCE_ARRAY (*argp);
2444
2445 t = check_typedef (VALUE_TYPE (*argp));
2446
2447 /* Follow pointers until we get to a non-pointer. */
2448
2449 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2450 {
2451 *argp = value_ind (*argp);
2452 /* Don't coerce fn pointer to fn and then back again! */
2453 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
2454 COERCE_ARRAY (*argp);
2455 t = check_typedef (VALUE_TYPE (*argp));
2456 }
2457
2458 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2459 error ("not implemented: member type in value_struct_elt");
2460
2461 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2462 && TYPE_CODE (t) != TYPE_CODE_UNION)
2463 error ("Attempt to extract a component of a value that is not a %s.", err);
2464
2465 /* Assume it's not, unless we see that it is. */
2466 if (static_memfuncp)
2467 *static_memfuncp = 0;
2468
2469 if (!args)
2470 {
2471 /* if there are no arguments ...do this... */
2472
2473 /* Try as a field first, because if we succeed, there
2474 is less work to be done. */
2475 v = search_struct_field (name, *argp, 0, t, 0);
2476 if (v)
2477 return v;
2478
2479 /* C++: If it was not found as a data field, then try to
2480 return it as a pointer to a method. */
2481
2482 if (destructor_name_p (name, t))
2483 error ("Cannot get value of destructor");
2484
2485 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
2486
2487 if (v == (struct value *) - 1)
2488 error ("Cannot take address of a method");
2489 else if (v == 0)
2490 {
2491 if (TYPE_NFN_FIELDS (t))
2492 error ("There is no member or method named %s.", name);
2493 else
2494 error ("There is no member named %s.", name);
2495 }
2496 return v;
2497 }
2498
2499 if (destructor_name_p (name, t))
2500 {
2501 if (!args[1])
2502 {
2503 /* Destructors are a special case. */
2504 int m_index, f_index;
2505
2506 v = NULL;
2507 if (get_destructor_fn_field (t, &m_index, &f_index))
2508 {
2509 v = value_fn_field (NULL, TYPE_FN_FIELDLIST1 (t, m_index),
2510 f_index, NULL, 0);
2511 }
2512 if (v == NULL)
2513 error ("could not find destructor function named %s.", name);
2514 else
2515 return v;
2516 }
2517 else
2518 {
2519 error ("destructor should not have any argument");
2520 }
2521 }
2522 else
2523 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
2524
2525 if (v == (struct value *) - 1)
2526 {
2527 error ("One of the arguments you tried to pass to %s could not be converted to what the function wants.", name);
2528 }
2529 else if (v == 0)
2530 {
2531 /* See if user tried to invoke data as function. If so,
2532 hand it back. If it's not callable (i.e., a pointer to function),
2533 gdb should give an error. */
2534 v = search_struct_field (name, *argp, 0, t, 0);
2535 }
2536
2537 if (!v)
2538 error ("Structure has no component named %s.", name);
2539 return v;
2540 }
2541
2542 /* Search through the methods of an object (and its bases)
2543 * to find a specified method. Return the pointer to the
2544 * fn_field list of overloaded instances.
2545 * Helper function for value_find_oload_list.
2546 * ARGP is a pointer to a pointer to a value (the object)
2547 * METHOD is a string containing the method name
2548 * OFFSET is the offset within the value
2549 * TYPE is the assumed type of the object
2550 * NUM_FNS is the number of overloaded instances
2551 * BASETYPE is set to the actual type of the subobject where the method is found
2552 * BOFFSET is the offset of the base subobject where the method is found */
2553
2554 static struct fn_field *
2555 find_method_list (struct value **argp, char *method, int offset,
2556 struct type *type, int *num_fns,
2557 struct type **basetype, int *boffset)
2558 {
2559 int i;
2560 struct fn_field *f;
2561 CHECK_TYPEDEF (type);
2562
2563 *num_fns = 0;
2564
2565 /* First check in object itself */
2566 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2567 {
2568 /* pai: FIXME What about operators and type conversions? */
2569 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2570 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2571 {
2572 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2573 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2574
2575 *num_fns = len;
2576 *basetype = type;
2577 *boffset = offset;
2578
2579 /* Resolve any stub methods. */
2580 check_stub_method_group (type, i);
2581
2582 return f;
2583 }
2584 }
2585
2586 /* Not found in object, check in base subobjects */
2587 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2588 {
2589 int base_offset;
2590 if (BASETYPE_VIA_VIRTUAL (type, i))
2591 {
2592 if (TYPE_HAS_VTABLE (type))
2593 {
2594 /* HP aCC compiled type, search for virtual base offset
2595 * according to HP/Taligent runtime spec. */
2596 int skip;
2597 find_rt_vbase_offset (type, TYPE_BASECLASS (type, i),
2598 VALUE_CONTENTS_ALL (*argp),
2599 offset + VALUE_EMBEDDED_OFFSET (*argp),
2600 &base_offset, &skip);
2601 if (skip >= 0)
2602 error ("Virtual base class offset not found in vtable");
2603 }
2604 else
2605 {
2606 /* probably g++ runtime model */
2607 base_offset = VALUE_OFFSET (*argp) + offset;
2608 base_offset =
2609 baseclass_offset (type, i,
2610 VALUE_CONTENTS (*argp) + base_offset,
2611 VALUE_ADDRESS (*argp) + base_offset);
2612 if (base_offset == -1)
2613 error ("virtual baseclass botch");
2614 }
2615 }
2616 else
2617 /* non-virtual base, simply use bit position from debug info */
2618 {
2619 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2620 }
2621 f = find_method_list (argp, method, base_offset + offset,
2622 TYPE_BASECLASS (type, i), num_fns, basetype,
2623 boffset);
2624 if (f)
2625 return f;
2626 }
2627 return NULL;
2628 }
2629
2630 /* Return the list of overloaded methods of a specified name.
2631 * ARGP is a pointer to a pointer to a value (the object)
2632 * METHOD is the method name
2633 * OFFSET is the offset within the value contents
2634 * NUM_FNS is the number of overloaded instances
2635 * BASETYPE is set to the type of the base subobject that defines the method
2636 * BOFFSET is the offset of the base subobject which defines the method */
2637
2638 struct fn_field *
2639 value_find_oload_method_list (struct value **argp, char *method, int offset,
2640 int *num_fns, struct type **basetype,
2641 int *boffset)
2642 {
2643 struct type *t;
2644
2645 t = check_typedef (VALUE_TYPE (*argp));
2646
2647 /* code snarfed from value_struct_elt */
2648 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2649 {
2650 *argp = value_ind (*argp);
2651 /* Don't coerce fn pointer to fn and then back again! */
2652 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
2653 COERCE_ARRAY (*argp);
2654 t = check_typedef (VALUE_TYPE (*argp));
2655 }
2656
2657 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
2658 error ("Not implemented: member type in value_find_oload_lis");
2659
2660 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2661 && TYPE_CODE (t) != TYPE_CODE_UNION)
2662 error ("Attempt to extract a component of a value that is not a struct or union");
2663
2664 return find_method_list (argp, method, 0, t, num_fns, basetype, boffset);
2665 }
2666
2667 /* Given an array of argument types (ARGTYPES) (which includes an
2668 entry for "this" in the case of C++ methods), the number of
2669 arguments NARGS, the NAME of a function whether it's a method or
2670 not (METHOD), and the degree of laxness (LAX) in conforming to
2671 overload resolution rules in ANSI C++, find the best function that
2672 matches on the argument types according to the overload resolution
2673 rules.
2674
2675 In the case of class methods, the parameter OBJ is an object value
2676 in which to search for overloaded methods.
2677
2678 In the case of non-method functions, the parameter FSYM is a symbol
2679 corresponding to one of the overloaded functions.
2680
2681 Return value is an integer: 0 -> good match, 10 -> debugger applied
2682 non-standard coercions, 100 -> incompatible.
2683
2684 If a method is being searched for, VALP will hold the value.
2685 If a non-method is being searched for, SYMP will hold the symbol for it.
2686
2687 If a method is being searched for, and it is a static method,
2688 then STATICP will point to a non-zero value.
2689
2690 Note: This function does *not* check the value of
2691 overload_resolution. Caller must check it to see whether overload
2692 resolution is permitted.
2693 */
2694
2695 int
2696 find_overload_match (struct type **arg_types, int nargs, char *name, int method,
2697 int lax, struct value **objp, struct symbol *fsym,
2698 struct value **valp, struct symbol **symp, int *staticp)
2699 {
2700 int nparms;
2701 struct type **parm_types;
2702 int champ_nparms = 0;
2703 struct value *obj = (objp ? *objp : NULL);
2704
2705 short oload_champ = -1; /* Index of best overloaded function */
2706 short oload_ambiguous = 0; /* Current ambiguity state for overload resolution */
2707 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs */
2708 short oload_ambig_champ = -1; /* 2nd contender for best match */
2709 short oload_non_standard = 0; /* did we have to use non-standard conversions? */
2710 short oload_incompatible = 0; /* are args supplied incompatible with any function? */
2711
2712 struct badness_vector *bv; /* A measure of how good an overloaded instance is */
2713 struct badness_vector *oload_champ_bv = NULL; /* The measure for the current best match */
2714
2715 struct value *temp = obj;
2716 struct fn_field *fns_ptr = NULL; /* For methods, the list of overloaded methods */
2717 struct symbol **oload_syms = NULL; /* For non-methods, the list of overloaded function symbols */
2718 int num_fns = 0; /* Number of overloaded instances being considered */
2719 struct type *basetype = NULL;
2720 int boffset;
2721 register int jj;
2722 register int ix;
2723 int static_offset;
2724 struct cleanup *cleanups = NULL;
2725
2726 char *obj_type_name = NULL;
2727 char *func_name = NULL;
2728
2729 /* Get the list of overloaded methods or functions */
2730 if (method)
2731 {
2732 obj_type_name = TYPE_NAME (VALUE_TYPE (obj));
2733 /* Hack: evaluate_subexp_standard often passes in a pointer
2734 value rather than the object itself, so try again */
2735 if ((!obj_type_name || !*obj_type_name) &&
2736 (TYPE_CODE (VALUE_TYPE (obj)) == TYPE_CODE_PTR))
2737 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (VALUE_TYPE (obj)));
2738
2739 fns_ptr = value_find_oload_method_list (&temp, name, 0,
2740 &num_fns,
2741 &basetype, &boffset);
2742 if (!fns_ptr || !num_fns)
2743 error ("Couldn't find method %s%s%s",
2744 obj_type_name,
2745 (obj_type_name && *obj_type_name) ? "::" : "",
2746 name);
2747 /* If we are dealing with stub method types, they should have
2748 been resolved by find_method_list via value_find_oload_method_list
2749 above. */
2750 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2751 }
2752 else
2753 {
2754 int i = -1;
2755 func_name = cplus_demangle (SYMBOL_NAME (fsym), DMGL_NO_OPTS);
2756
2757 /* If the name is NULL this must be a C-style function.
2758 Just return the same symbol. */
2759 if (!func_name)
2760 {
2761 *symp = fsym;
2762 return 0;
2763 }
2764
2765 oload_syms = make_symbol_overload_list (fsym);
2766 cleanups = make_cleanup (xfree, oload_syms);
2767 while (oload_syms[++i])
2768 num_fns++;
2769 if (!num_fns)
2770 error ("Couldn't find function %s", func_name);
2771 }
2772
2773 oload_champ_bv = NULL;
2774
2775 /* Consider each candidate in turn */
2776 for (ix = 0; ix < num_fns; ix++)
2777 {
2778 static_offset = 0;
2779 if (method)
2780 {
2781 if (TYPE_FN_FIELD_STATIC_P (fns_ptr, ix))
2782 static_offset = 1;
2783 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2784 }
2785 else
2786 {
2787 /* If it's not a method, this is the proper place */
2788 nparms=TYPE_NFIELDS(SYMBOL_TYPE(oload_syms[ix]));
2789 }
2790
2791 /* Prepare array of parameter types */
2792 parm_types = (struct type **) xmalloc (nparms * (sizeof (struct type *)));
2793 for (jj = 0; jj < nparms; jj++)
2794 parm_types[jj] = (method
2795 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2796 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]), jj));
2797
2798 /* Compare parameter types to supplied argument types. Skip THIS for
2799 static methods. */
2800 bv = rank_function (parm_types, nparms, arg_types + static_offset,
2801 nargs - static_offset);
2802
2803 if (!oload_champ_bv)
2804 {
2805 oload_champ_bv = bv;
2806 oload_champ = 0;
2807 champ_nparms = nparms;
2808 }
2809 else
2810 /* See whether current candidate is better or worse than previous best */
2811 switch (compare_badness (bv, oload_champ_bv))
2812 {
2813 case 0:
2814 oload_ambiguous = 1; /* top two contenders are equally good */
2815 oload_ambig_champ = ix;
2816 break;
2817 case 1:
2818 oload_ambiguous = 2; /* incomparable top contenders */
2819 oload_ambig_champ = ix;
2820 break;
2821 case 2:
2822 oload_champ_bv = bv; /* new champion, record details */
2823 oload_ambiguous = 0;
2824 oload_champ = ix;
2825 oload_ambig_champ = -1;
2826 champ_nparms = nparms;
2827 break;
2828 case 3:
2829 default:
2830 break;
2831 }
2832 xfree (parm_types);
2833 if (overload_debug)
2834 {
2835 if (method)
2836 fprintf_filtered (gdb_stderr,"Overloaded method instance %s, # of parms %d\n", fns_ptr[ix].physname, nparms);
2837 else
2838 fprintf_filtered (gdb_stderr,"Overloaded function instance %s # of parms %d\n", SYMBOL_DEMANGLED_NAME (oload_syms[ix]), nparms);
2839 for (jj = 0; jj < nargs - static_offset; jj++)
2840 fprintf_filtered (gdb_stderr,"...Badness @ %d : %d\n", jj, bv->rank[jj]);
2841 fprintf_filtered (gdb_stderr,"Overload resolution champion is %d, ambiguous? %d\n", oload_champ, oload_ambiguous);
2842 }
2843 } /* end loop over all candidates */
2844 /* NOTE: dan/2000-03-10: Seems to be a better idea to just pick one
2845 if they have the exact same goodness. This is because there is no
2846 way to differentiate based on return type, which we need to in
2847 cases like overloads of .begin() <It's both const and non-const> */
2848 #if 0
2849 if (oload_ambiguous)
2850 {
2851 if (method)
2852 error ("Cannot resolve overloaded method %s%s%s to unique instance; disambiguate by specifying function signature",
2853 obj_type_name,
2854 (obj_type_name && *obj_type_name) ? "::" : "",
2855 name);
2856 else
2857 error ("Cannot resolve overloaded function %s to unique instance; disambiguate by specifying function signature",
2858 func_name);
2859 }
2860 #endif
2861
2862 /* Check how bad the best match is. */
2863 static_offset = 0;
2864 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
2865 static_offset = 1;
2866 for (ix = 1; ix <= nargs - static_offset; ix++)
2867 {
2868 if (oload_champ_bv->rank[ix] >= 100)
2869 oload_incompatible = 1; /* truly mismatched types */
2870
2871 else if (oload_champ_bv->rank[ix] >= 10)
2872 oload_non_standard = 1; /* non-standard type conversions needed */
2873 }
2874 if (oload_incompatible)
2875 {
2876 if (method)
2877 error ("Cannot resolve method %s%s%s to any overloaded instance",
2878 obj_type_name,
2879 (obj_type_name && *obj_type_name) ? "::" : "",
2880 name);
2881 else
2882 error ("Cannot resolve function %s to any overloaded instance",
2883 func_name);
2884 }
2885 else if (oload_non_standard)
2886 {
2887 if (method)
2888 warning ("Using non-standard conversion to match method %s%s%s to supplied arguments",
2889 obj_type_name,
2890 (obj_type_name && *obj_type_name) ? "::" : "",
2891 name);
2892 else
2893 warning ("Using non-standard conversion to match function %s to supplied arguments",
2894 func_name);
2895 }
2896
2897 if (method)
2898 {
2899 if (staticp && TYPE_FN_FIELD_STATIC_P (fns_ptr, oload_champ))
2900 *staticp = 1;
2901 else if (staticp)
2902 *staticp = 0;
2903 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
2904 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
2905 else
2906 *valp = value_fn_field (&temp, fns_ptr, oload_champ, basetype, boffset);
2907 }
2908 else
2909 {
2910 *symp = oload_syms[oload_champ];
2911 xfree (func_name);
2912 }
2913
2914 if (objp)
2915 {
2916 if (TYPE_CODE (VALUE_TYPE (temp)) != TYPE_CODE_PTR
2917 && TYPE_CODE (VALUE_TYPE (*objp)) == TYPE_CODE_PTR)
2918 {
2919 temp = value_addr (temp);
2920 }
2921 *objp = temp;
2922 }
2923 if (cleanups != NULL)
2924 do_cleanups (cleanups);
2925
2926 return oload_incompatible ? 100 : (oload_non_standard ? 10 : 0);
2927 }
2928
2929 /* C++: return 1 is NAME is a legitimate name for the destructor
2930 of type TYPE. If TYPE does not have a destructor, or
2931 if NAME is inappropriate for TYPE, an error is signaled. */
2932 int
2933 destructor_name_p (const char *name, const struct type *type)
2934 {
2935 /* destructors are a special case. */
2936
2937 if (name[0] == '~')
2938 {
2939 char *dname = type_name_no_tag (type);
2940 char *cp = strchr (dname, '<');
2941 unsigned int len;
2942
2943 /* Do not compare the template part for template classes. */
2944 if (cp == NULL)
2945 len = strlen (dname);
2946 else
2947 len = cp - dname;
2948 if (strlen (name + 1) != len || !STREQN (dname, name + 1, len))
2949 error ("name of destructor must equal name of class");
2950 else
2951 return 1;
2952 }
2953 return 0;
2954 }
2955
2956 /* Helper function for check_field: Given TYPE, a structure/union,
2957 return 1 if the component named NAME from the ultimate
2958 target structure/union is defined, otherwise, return 0. */
2959
2960 static int
2961 check_field_in (register struct type *type, const char *name)
2962 {
2963 register int i;
2964
2965 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2966 {
2967 char *t_field_name = TYPE_FIELD_NAME (type, i);
2968 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2969 return 1;
2970 }
2971
2972 /* C++: If it was not found as a data field, then try to
2973 return it as a pointer to a method. */
2974
2975 /* Destructors are a special case. */
2976 if (destructor_name_p (name, type))
2977 {
2978 int m_index, f_index;
2979
2980 return get_destructor_fn_field (type, &m_index, &f_index);
2981 }
2982
2983 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2984 {
2985 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2986 return 1;
2987 }
2988
2989 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2990 if (check_field_in (TYPE_BASECLASS (type, i), name))
2991 return 1;
2992
2993 return 0;
2994 }
2995
2996
2997 /* C++: Given ARG1, a value of type (pointer to a)* structure/union,
2998 return 1 if the component named NAME from the ultimate
2999 target structure/union is defined, otherwise, return 0. */
3000
3001 int
3002 check_field (struct value *arg1, const char *name)
3003 {
3004 register struct type *t;
3005
3006 COERCE_ARRAY (arg1);
3007
3008 t = VALUE_TYPE (arg1);
3009
3010 /* Follow pointers until we get to a non-pointer. */
3011
3012 for (;;)
3013 {
3014 CHECK_TYPEDEF (t);
3015 if (TYPE_CODE (t) != TYPE_CODE_PTR && TYPE_CODE (t) != TYPE_CODE_REF)
3016 break;
3017 t = TYPE_TARGET_TYPE (t);
3018 }
3019
3020 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
3021 error ("not implemented: member type in check_field");
3022
3023 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3024 && TYPE_CODE (t) != TYPE_CODE_UNION)
3025 error ("Internal error: `this' is not an aggregate");
3026
3027 return check_field_in (t, name);
3028 }
3029
3030 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3031 return the address of this member as a "pointer to member"
3032 type. If INTYPE is non-null, then it will be the type
3033 of the member we are looking for. This will help us resolve
3034 "pointers to member functions". This function is used
3035 to resolve user expressions of the form "DOMAIN::NAME". */
3036
3037 struct value *
3038 value_struct_elt_for_reference (struct type *domain, int offset,
3039 struct type *curtype, char *name,
3040 struct type *intype)
3041 {
3042 register struct type *t = curtype;
3043 register int i;
3044 struct value *v;
3045
3046 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3047 && TYPE_CODE (t) != TYPE_CODE_UNION)
3048 error ("Internal error: non-aggregate type to value_struct_elt_for_reference");
3049
3050 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3051 {
3052 char *t_field_name = TYPE_FIELD_NAME (t, i);
3053
3054 if (t_field_name && STREQ (t_field_name, name))
3055 {
3056 if (TYPE_FIELD_STATIC (t, i))
3057 {
3058 v = value_static_field (t, i);
3059 if (v == NULL)
3060 error ("static field %s has been optimized out",
3061 name);
3062 return v;
3063 }
3064 if (TYPE_FIELD_PACKED (t, i))
3065 error ("pointers to bitfield members not allowed");
3066
3067 return value_from_longest
3068 (lookup_reference_type (lookup_member_type (TYPE_FIELD_TYPE (t, i),
3069 domain)),
3070 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3071 }
3072 }
3073
3074 /* C++: If it was not found as a data field, then try to
3075 return it as a pointer to a method. */
3076
3077 /* Destructors are a special case. */
3078 if (destructor_name_p (name, t))
3079 {
3080 error ("member pointers to destructors not implemented yet");
3081 }
3082
3083 /* Perform all necessary dereferencing. */
3084 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3085 intype = TYPE_TARGET_TYPE (intype);
3086
3087 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3088 {
3089 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3090 char dem_opname[64];
3091
3092 if (strncmp (t_field_name, "__", 2) == 0 ||
3093 strncmp (t_field_name, "op", 2) == 0 ||
3094 strncmp (t_field_name, "type", 4) == 0)
3095 {
3096 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
3097 t_field_name = dem_opname;
3098 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
3099 t_field_name = dem_opname;
3100 }
3101 if (t_field_name && STREQ (t_field_name, name))
3102 {
3103 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
3104 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3105
3106 check_stub_method_group (t, i);
3107
3108 if (intype == 0 && j > 1)
3109 error ("non-unique member `%s' requires type instantiation", name);
3110 if (intype)
3111 {
3112 while (j--)
3113 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
3114 break;
3115 if (j < 0)
3116 error ("no member function matches that type instantiation");
3117 }
3118 else
3119 j = 0;
3120
3121 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3122 {
3123 return value_from_longest
3124 (lookup_reference_type
3125 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
3126 domain)),
3127 (LONGEST) METHOD_PTR_FROM_VOFFSET (TYPE_FN_FIELD_VOFFSET (f, j)));
3128 }
3129 else
3130 {
3131 struct symbol *s = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3132 0, VAR_NAMESPACE, 0, NULL);
3133 if (s == NULL)
3134 {
3135 v = 0;
3136 }
3137 else
3138 {
3139 v = read_var_value (s, 0);
3140 #if 0
3141 VALUE_TYPE (v) = lookup_reference_type
3142 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
3143 domain));
3144 #endif
3145 }
3146 return v;
3147 }
3148 }
3149 }
3150 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3151 {
3152 struct value *v;
3153 int base_offset;
3154
3155 if (BASETYPE_VIA_VIRTUAL (t, i))
3156 base_offset = 0;
3157 else
3158 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3159 v = value_struct_elt_for_reference (domain,
3160 offset + base_offset,
3161 TYPE_BASECLASS (t, i),
3162 name,
3163 intype);
3164 if (v)
3165 return v;
3166 }
3167 return 0;
3168 }
3169
3170
3171 /* Given a pointer value V, find the real (RTTI) type
3172 of the object it points to.
3173 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3174 and refer to the values computed for the object pointed to. */
3175
3176 struct type *
3177 value_rtti_target_type (struct value *v, int *full, int *top, int *using_enc)
3178 {
3179 struct value *target;
3180
3181 target = value_ind (v);
3182
3183 return value_rtti_type (target, full, top, using_enc);
3184 }
3185
3186 /* Given a value pointed to by ARGP, check its real run-time type, and
3187 if that is different from the enclosing type, create a new value
3188 using the real run-time type as the enclosing type (and of the same
3189 type as ARGP) and return it, with the embedded offset adjusted to
3190 be the correct offset to the enclosed object
3191 RTYPE is the type, and XFULL, XTOP, and XUSING_ENC are the other
3192 parameters, computed by value_rtti_type(). If these are available,
3193 they can be supplied and a second call to value_rtti_type() is avoided.
3194 (Pass RTYPE == NULL if they're not available */
3195
3196 struct value *
3197 value_full_object (struct value *argp, struct type *rtype, int xfull, int xtop,
3198 int xusing_enc)
3199 {
3200 struct type *real_type;
3201 int full = 0;
3202 int top = -1;
3203 int using_enc = 0;
3204 struct value *new_val;
3205
3206 if (rtype)
3207 {
3208 real_type = rtype;
3209 full = xfull;
3210 top = xtop;
3211 using_enc = xusing_enc;
3212 }
3213 else
3214 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3215
3216 /* If no RTTI data, or if object is already complete, do nothing */
3217 if (!real_type || real_type == VALUE_ENCLOSING_TYPE (argp))
3218 return argp;
3219
3220 /* If we have the full object, but for some reason the enclosing
3221 type is wrong, set it *//* pai: FIXME -- sounds iffy */
3222 if (full)
3223 {
3224 argp = value_change_enclosing_type (argp, real_type);
3225 return argp;
3226 }
3227
3228 /* Check if object is in memory */
3229 if (VALUE_LVAL (argp) != lval_memory)
3230 {
3231 warning ("Couldn't retrieve complete object of RTTI type %s; object may be in register(s).", TYPE_NAME (real_type));
3232
3233 return argp;
3234 }
3235
3236 /* All other cases -- retrieve the complete object */
3237 /* Go back by the computed top_offset from the beginning of the object,
3238 adjusting for the embedded offset of argp if that's what value_rtti_type
3239 used for its computation. */
3240 new_val = value_at_lazy (real_type, VALUE_ADDRESS (argp) - top +
3241 (using_enc ? 0 : VALUE_EMBEDDED_OFFSET (argp)),
3242 VALUE_BFD_SECTION (argp));
3243 VALUE_TYPE (new_val) = VALUE_TYPE (argp);
3244 VALUE_EMBEDDED_OFFSET (new_val) = using_enc ? top + VALUE_EMBEDDED_OFFSET (argp) : top;
3245 return new_val;
3246 }
3247
3248
3249
3250
3251 /* Return the value of the local variable, if one exists.
3252 Flag COMPLAIN signals an error if the request is made in an
3253 inappropriate context. */
3254
3255 struct value *
3256 value_of_local (const char *name, int complain)
3257 {
3258 struct symbol *func, *sym;
3259 struct block *b;
3260 int i;
3261 struct value * ret;
3262
3263 if (deprecated_selected_frame == 0)
3264 {
3265 if (complain)
3266 error ("no frame selected");
3267 else
3268 return 0;
3269 }
3270
3271 func = get_frame_function (deprecated_selected_frame);
3272 if (!func)
3273 {
3274 if (complain)
3275 error ("no `%s' in nameless context", name);
3276 else
3277 return 0;
3278 }
3279
3280 b = SYMBOL_BLOCK_VALUE (func);
3281 i = BLOCK_NSYMS (b);
3282 if (i <= 0)
3283 {
3284 if (complain)
3285 error ("no args, no `%s'", name);
3286 else
3287 return 0;
3288 }
3289
3290 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
3291 symbol instead of the LOC_ARG one (if both exist). */
3292 sym = lookup_block_symbol (b, name, NULL, VAR_NAMESPACE);
3293 if (sym == NULL)
3294 {
3295 if (complain)
3296 error ("current stack frame does not contain a variable named `%s'", name);
3297 else
3298 return NULL;
3299 }
3300
3301 ret = read_var_value (sym, deprecated_selected_frame);
3302 if (ret == 0 && complain)
3303 error ("`%s' argument unreadable", name);
3304 return ret;
3305 }
3306
3307 /* C++/Objective-C: return the value of the class instance variable,
3308 if one exists. Flag COMPLAIN signals an error if the request is
3309 made in an inappropriate context. */
3310
3311 struct value *
3312 value_of_this (int complain)
3313 {
3314 if (current_language->la_language == language_objc)
3315 return value_of_local ("self", complain);
3316 else
3317 return value_of_local ("this", complain);
3318 }
3319
3320 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH elements
3321 long, starting at LOWBOUND. The result has the same lower bound as
3322 the original ARRAY. */
3323
3324 struct value *
3325 value_slice (struct value *array, int lowbound, int length)
3326 {
3327 struct type *slice_range_type, *slice_type, *range_type;
3328 LONGEST lowerbound, upperbound;
3329 struct value *slice;
3330 struct type *array_type;
3331 array_type = check_typedef (VALUE_TYPE (array));
3332 COERCE_VARYING_ARRAY (array, array_type);
3333 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3334 && TYPE_CODE (array_type) != TYPE_CODE_STRING
3335 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
3336 error ("cannot take slice of non-array");
3337 range_type = TYPE_INDEX_TYPE (array_type);
3338 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3339 error ("slice from bad array or bitstring");
3340 if (lowbound < lowerbound || length < 0
3341 || lowbound + length - 1 > upperbound)
3342 error ("slice out of range");
3343 /* FIXME-type-allocation: need a way to free this type when we are
3344 done with it. */
3345 slice_range_type = create_range_type ((struct type *) NULL,
3346 TYPE_TARGET_TYPE (range_type),
3347 lowbound, lowbound + length - 1);
3348 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
3349 {
3350 int i;
3351 slice_type = create_set_type ((struct type *) NULL, slice_range_type);
3352 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
3353 slice = value_zero (slice_type, not_lval);
3354 for (i = 0; i < length; i++)
3355 {
3356 int element = value_bit_index (array_type,
3357 VALUE_CONTENTS (array),
3358 lowbound + i);
3359 if (element < 0)
3360 error ("internal error accessing bitstring");
3361 else if (element > 0)
3362 {
3363 int j = i % TARGET_CHAR_BIT;
3364 if (BITS_BIG_ENDIAN)
3365 j = TARGET_CHAR_BIT - 1 - j;
3366 VALUE_CONTENTS_RAW (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3367 }
3368 }
3369 /* We should set the address, bitssize, and bitspos, so the clice
3370 can be used on the LHS, but that may require extensions to
3371 value_assign. For now, just leave as a non_lval. FIXME. */
3372 }
3373 else
3374 {
3375 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3376 LONGEST offset
3377 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3378 slice_type = create_array_type ((struct type *) NULL, element_type,
3379 slice_range_type);
3380 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3381 slice = allocate_value (slice_type);
3382 if (VALUE_LAZY (array))
3383 VALUE_LAZY (slice) = 1;
3384 else
3385 memcpy (VALUE_CONTENTS (slice), VALUE_CONTENTS (array) + offset,
3386 TYPE_LENGTH (slice_type));
3387 if (VALUE_LVAL (array) == lval_internalvar)
3388 VALUE_LVAL (slice) = lval_internalvar_component;
3389 else
3390 VALUE_LVAL (slice) = VALUE_LVAL (array);
3391 VALUE_ADDRESS (slice) = VALUE_ADDRESS (array);
3392 VALUE_OFFSET (slice) = VALUE_OFFSET (array) + offset;
3393 }
3394 return slice;
3395 }
3396
3397 /* Create a value for a FORTRAN complex number. Currently most of
3398 the time values are coerced to COMPLEX*16 (i.e. a complex number
3399 composed of 2 doubles. This really should be a smarter routine
3400 that figures out precision inteligently as opposed to assuming
3401 doubles. FIXME: fmb */
3402
3403 struct value *
3404 value_literal_complex (struct value *arg1, struct value *arg2, struct type *type)
3405 {
3406 struct value *val;
3407 struct type *real_type = TYPE_TARGET_TYPE (type);
3408
3409 val = allocate_value (type);
3410 arg1 = value_cast (real_type, arg1);
3411 arg2 = value_cast (real_type, arg2);
3412
3413 memcpy (VALUE_CONTENTS_RAW (val),
3414 VALUE_CONTENTS (arg1), TYPE_LENGTH (real_type));
3415 memcpy (VALUE_CONTENTS_RAW (val) + TYPE_LENGTH (real_type),
3416 VALUE_CONTENTS (arg2), TYPE_LENGTH (real_type));
3417 return val;
3418 }
3419
3420 /* Cast a value into the appropriate complex data type. */
3421
3422 static struct value *
3423 cast_into_complex (struct type *type, struct value *val)
3424 {
3425 struct type *real_type = TYPE_TARGET_TYPE (type);
3426 if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_COMPLEX)
3427 {
3428 struct type *val_real_type = TYPE_TARGET_TYPE (VALUE_TYPE (val));
3429 struct value *re_val = allocate_value (val_real_type);
3430 struct value *im_val = allocate_value (val_real_type);
3431
3432 memcpy (VALUE_CONTENTS_RAW (re_val),
3433 VALUE_CONTENTS (val), TYPE_LENGTH (val_real_type));
3434 memcpy (VALUE_CONTENTS_RAW (im_val),
3435 VALUE_CONTENTS (val) + TYPE_LENGTH (val_real_type),
3436 TYPE_LENGTH (val_real_type));
3437
3438 return value_literal_complex (re_val, im_val, type);
3439 }
3440 else if (TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FLT
3441 || TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_INT)
3442 return value_literal_complex (val, value_zero (real_type, not_lval), type);
3443 else
3444 error ("cannot cast non-number to complex");
3445 }
3446
3447 void
3448 _initialize_valops (void)
3449 {
3450 #if 0
3451 add_show_from_set
3452 (add_set_cmd ("abandon", class_support, var_boolean, (char *) &auto_abandon,
3453 "Set automatic abandonment of expressions upon failure.",
3454 &setlist),
3455 &showlist);
3456 #endif
3457
3458 add_show_from_set
3459 (add_set_cmd ("overload-resolution", class_support, var_boolean, (char *) &overload_resolution,
3460 "Set overload resolution in evaluating C++ functions.",
3461 &setlist),
3462 &showlist);
3463 overload_resolution = 1;
3464
3465 add_show_from_set (
3466 add_set_cmd ("unwindonsignal", no_class, var_boolean,
3467 (char *) &unwind_on_signal_p,
3468 "Set unwinding of stack if a signal is received while in a call dummy.\n\
3469 The unwindonsignal lets the user determine what gdb should do if a signal\n\
3470 is received while in a function called from gdb (call dummy). If set, gdb\n\
3471 unwinds the stack and restore the context to what as it was before the call.\n\
3472 The default is to stop in the frame where the signal was received.", &setlist),
3473 &showlist);
3474
3475 add_show_from_set
3476 (add_set_cmd ("coerce-float-to-double", class_obscure, var_boolean,
3477 (char *) &coerce_float_to_double,
3478 "Set coercion of floats to doubles when calling functions\n"
3479 "Variables of type float should generally be converted to doubles before\n"
3480 "calling an unprototyped function, and left alone when calling a prototyped\n"
3481 "function. However, some older debug info formats do not provide enough\n"
3482 "information to determine that a function is prototyped. If this flag is\n"
3483 "set, GDB will perform the conversion for a function it considers\n"
3484 "unprototyped.\n"
3485 "The default is to perform the conversion.\n",
3486 &setlist),
3487 &showlist);
3488 coerce_float_to_double = 1;
3489 }
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