* elf32-s390.c (elf_howto_table): Change R_390_GOT12 to
[deliverable/binutils-gdb.git] / gdb / findvar.c
CommitLineData
c906108c 1/* Find a variable's value in memory, for GDB, the GNU debugger.
1bac305b
AC
2
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2003 Free Software
5 Foundation, Inc.
c906108c 6
c5aa993b 7 This file is part of GDB.
c906108c 8
c5aa993b
JM
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
c906108c 13
c5aa993b
JM
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
c906108c 18
c5aa993b
JM
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
c906108c
SS
23
24#include "defs.h"
25#include "symtab.h"
26#include "gdbtypes.h"
27#include "frame.h"
28#include "value.h"
29#include "gdbcore.h"
30#include "inferior.h"
31#include "target.h"
32#include "gdb_string.h"
14e534aa 33#include "gdb_assert.h"
c906108c 34#include "floatformat.h"
c5aa993b 35#include "symfile.h" /* for overlay functions */
4e052eda 36#include "regcache.h"
0406ec40 37#include "builtin-regs.h"
fe898f56 38#include "block.h"
c906108c 39
c906108c
SS
40/* Basic byte-swapping routines. GDB has needed these for a long time...
41 All extract a target-format integer at ADDR which is LEN bytes long. */
42
43#if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8
44 /* 8 bit characters are a pretty safe assumption these days, so we
45 assume it throughout all these swapping routines. If we had to deal with
46 9 bit characters, we would need to make len be in bits and would have
47 to re-write these routines... */
c5aa993b 48you lose
c906108c
SS
49#endif
50
a9ac8f51 51LONGEST
37611a2b 52extract_signed_integer (const void *addr, int len)
c906108c
SS
53{
54 LONGEST retval;
37611a2b
AC
55 const unsigned char *p;
56 const unsigned char *startaddr = addr;
57 const unsigned char *endaddr = startaddr + len;
c906108c
SS
58
59 if (len > (int) sizeof (LONGEST))
60 error ("\
61That operation is not available on integers of more than %d bytes.",
baa6f10b 62 (int) sizeof (LONGEST));
c906108c
SS
63
64 /* Start at the most significant end of the integer, and work towards
65 the least significant. */
d7449b42 66 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
c906108c
SS
67 {
68 p = startaddr;
69 /* Do the sign extension once at the start. */
c5aa993b 70 retval = ((LONGEST) * p ^ 0x80) - 0x80;
c906108c
SS
71 for (++p; p < endaddr; ++p)
72 retval = (retval << 8) | *p;
73 }
74 else
75 {
76 p = endaddr - 1;
77 /* Do the sign extension once at the start. */
c5aa993b 78 retval = ((LONGEST) * p ^ 0x80) - 0x80;
c906108c
SS
79 for (--p; p >= startaddr; --p)
80 retval = (retval << 8) | *p;
81 }
82 return retval;
83}
84
85ULONGEST
37611a2b 86extract_unsigned_integer (const void *addr, int len)
c906108c
SS
87{
88 ULONGEST retval;
37611a2b
AC
89 const unsigned char *p;
90 const unsigned char *startaddr = addr;
91 const unsigned char *endaddr = startaddr + len;
c906108c
SS
92
93 if (len > (int) sizeof (ULONGEST))
94 error ("\
95That operation is not available on integers of more than %d bytes.",
baa6f10b 96 (int) sizeof (ULONGEST));
c906108c
SS
97
98 /* Start at the most significant end of the integer, and work towards
99 the least significant. */
100 retval = 0;
d7449b42 101 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
c906108c
SS
102 {
103 for (p = startaddr; p < endaddr; ++p)
104 retval = (retval << 8) | *p;
105 }
106 else
107 {
108 for (p = endaddr - 1; p >= startaddr; --p)
109 retval = (retval << 8) | *p;
110 }
111 return retval;
112}
113
114/* Sometimes a long long unsigned integer can be extracted as a
115 LONGEST value. This is done so that we can print these values
116 better. If this integer can be converted to a LONGEST, this
117 function returns 1 and sets *PVAL. Otherwise it returns 0. */
118
119int
66140c26 120extract_long_unsigned_integer (const void *addr, int orig_len, LONGEST *pval)
c906108c
SS
121{
122 char *p, *first_addr;
123 int len;
124
125 len = orig_len;
d7449b42 126 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
c906108c
SS
127 {
128 for (p = (char *) addr;
129 len > (int) sizeof (LONGEST) && p < (char *) addr + orig_len;
130 p++)
131 {
132 if (*p == 0)
133 len--;
134 else
135 break;
136 }
137 first_addr = p;
138 }
139 else
140 {
141 first_addr = (char *) addr;
142 for (p = (char *) addr + orig_len - 1;
143 len > (int) sizeof (LONGEST) && p >= (char *) addr;
144 p--)
145 {
146 if (*p == 0)
147 len--;
148 else
149 break;
150 }
151 }
152
153 if (len <= (int) sizeof (LONGEST))
154 {
155 *pval = (LONGEST) extract_unsigned_integer (first_addr,
156 sizeof (LONGEST));
157 return 1;
158 }
159
160 return 0;
161}
162
4478b372 163
4478b372
JB
164/* Treat the bytes at BUF as a pointer of type TYPE, and return the
165 address it represents. */
166CORE_ADDR
66140c26 167extract_typed_address (const void *buf, struct type *type)
4478b372
JB
168{
169 if (TYPE_CODE (type) != TYPE_CODE_PTR
170 && TYPE_CODE (type) != TYPE_CODE_REF)
8e65ff28
AC
171 internal_error (__FILE__, __LINE__,
172 "extract_typed_address: "
4478b372
JB
173 "type is not a pointer or reference");
174
175 return POINTER_TO_ADDRESS (type, buf);
176}
177
178
c906108c 179void
a9ac8f51 180store_signed_integer (void *addr, int len, LONGEST val)
c906108c
SS
181{
182 unsigned char *p;
c5aa993b 183 unsigned char *startaddr = (unsigned char *) addr;
c906108c
SS
184 unsigned char *endaddr = startaddr + len;
185
186 /* Start at the least significant end of the integer, and work towards
187 the most significant. */
d7449b42 188 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
c906108c
SS
189 {
190 for (p = endaddr - 1; p >= startaddr; --p)
191 {
192 *p = val & 0xff;
193 val >>= 8;
194 }
195 }
196 else
197 {
198 for (p = startaddr; p < endaddr; ++p)
199 {
200 *p = val & 0xff;
201 val >>= 8;
202 }
203 }
204}
205
206void
a9ac8f51 207store_unsigned_integer (void *addr, int len, ULONGEST val)
c906108c
SS
208{
209 unsigned char *p;
c5aa993b 210 unsigned char *startaddr = (unsigned char *) addr;
c906108c
SS
211 unsigned char *endaddr = startaddr + len;
212
213 /* Start at the least significant end of the integer, and work towards
214 the most significant. */
d7449b42 215 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
c906108c
SS
216 {
217 for (p = endaddr - 1; p >= startaddr; --p)
218 {
219 *p = val & 0xff;
220 val >>= 8;
221 }
222 }
223 else
224 {
225 for (p = startaddr; p < endaddr; ++p)
226 {
227 *p = val & 0xff;
228 val >>= 8;
229 }
230 }
231}
232
4478b372
JB
233/* Store the address ADDR as a pointer of type TYPE at BUF, in target
234 form. */
235void
236store_typed_address (void *buf, struct type *type, CORE_ADDR addr)
237{
238 if (TYPE_CODE (type) != TYPE_CODE_PTR
239 && TYPE_CODE (type) != TYPE_CODE_REF)
8e65ff28
AC
240 internal_error (__FILE__, __LINE__,
241 "store_typed_address: "
4478b372
JB
242 "type is not a pointer or reference");
243
244 ADDRESS_TO_POINTER (type, buf, addr);
245}
246
247
248
376c9600
AC
249/* Return a `value' with the contents of (virtual or cooked) register
250 REGNUM as found in the specified FRAME. The register's type is
7b83296f 251 determined by register_type().
c906108c 252
376c9600
AC
253 NOTE: returns NULL if register value is not available. Caller will
254 check return value or die! */
c906108c 255
3d6d86c6 256struct value *
376c9600 257value_of_register (int regnum, struct frame_info *frame)
c906108c
SS
258{
259 CORE_ADDR addr;
260 int optim;
3d6d86c6 261 struct value *reg_val;
ac2adee5 262 int realnum;
d9d9c31f 263 char raw_buffer[MAX_REGISTER_SIZE];
c906108c
SS
264 enum lval_type lval;
265
0406ec40
AC
266 /* Builtin registers lie completly outside of the range of normal
267 registers. Catch them early so that the target never sees them. */
268 if (regnum >= NUM_REGS + NUM_PSEUDO_REGS)
0a1e1ca1 269 return value_of_builtin_reg (regnum, frame);
0406ec40 270
ac2adee5 271 frame_register (frame, regnum, &optim, &lval, &addr, &realnum, raw_buffer);
c906108c 272
c97dcfc7
AC
273 /* FIXME: cagney/2002-05-15: This test is just bogus.
274
275 It indicates that the target failed to supply a value for a
276 register because it was "not available" at this time. Problem
277 is, the target still has the register and so get saved_register()
278 may be returning a value saved on the stack. */
279
32178cab 280 if (register_cached (regnum) < 0)
c5aa993b 281 return NULL; /* register value not available */
c906108c 282
7b83296f 283 reg_val = allocate_value (register_type (current_gdbarch, regnum));
c906108c
SS
284
285 /* Convert raw data to virtual format if necessary. */
286
781a750d 287 if (DEPRECATED_REGISTER_CONVERTIBLE (regnum))
c906108c 288 {
781a750d
AC
289 DEPRECATED_REGISTER_CONVERT_TO_VIRTUAL (regnum, register_type (current_gdbarch, regnum),
290 raw_buffer, VALUE_CONTENTS_RAW (reg_val));
c906108c 291 }
392a587b
JM
292 else if (REGISTER_RAW_SIZE (regnum) == REGISTER_VIRTUAL_SIZE (regnum))
293 memcpy (VALUE_CONTENTS_RAW (reg_val), raw_buffer,
294 REGISTER_RAW_SIZE (regnum));
c906108c 295 else
8e65ff28
AC
296 internal_error (__FILE__, __LINE__,
297 "Register \"%s\" (%d) has conflicting raw (%d) and virtual (%d) size",
96baa820
JM
298 REGISTER_NAME (regnum),
299 regnum,
300 REGISTER_RAW_SIZE (regnum),
301 REGISTER_VIRTUAL_SIZE (regnum));
c906108c
SS
302 VALUE_LVAL (reg_val) = lval;
303 VALUE_ADDRESS (reg_val) = addr;
304 VALUE_REGNO (reg_val) = regnum;
305 VALUE_OPTIMIZED_OUT (reg_val) = optim;
306 return reg_val;
307}
4478b372
JB
308
309/* Given a pointer of type TYPE in target form in BUF, return the
310 address it represents. */
311CORE_ADDR
66140c26 312unsigned_pointer_to_address (struct type *type, const void *buf)
4478b372 313{
af1342ab 314 return extract_unsigned_integer (buf, TYPE_LENGTH (type));
4478b372
JB
315}
316
ac2e2ef7 317CORE_ADDR
66140c26 318signed_pointer_to_address (struct type *type, const void *buf)
ac2e2ef7
AC
319{
320 return extract_signed_integer (buf, TYPE_LENGTH (type));
321}
4478b372
JB
322
323/* Given an address, store it as a pointer of type TYPE in target
324 format in BUF. */
325void
ac2e2ef7 326unsigned_address_to_pointer (struct type *type, void *buf, CORE_ADDR addr)
4478b372 327{
fbd9dcd3 328 store_unsigned_integer (buf, TYPE_LENGTH (type), addr);
4478b372
JB
329}
330
ac2e2ef7
AC
331void
332address_to_signed_pointer (struct type *type, void *buf, CORE_ADDR addr)
333{
334 store_signed_integer (buf, TYPE_LENGTH (type), addr);
335}
c906108c
SS
336\f
337/* Will calling read_var_value or locate_var_value on SYM end
338 up caring what frame it is being evaluated relative to? SYM must
339 be non-NULL. */
340int
fba45db2 341symbol_read_needs_frame (struct symbol *sym)
c906108c
SS
342{
343 switch (SYMBOL_CLASS (sym))
344 {
345 /* All cases listed explicitly so that gcc -Wall will detect it if
c5aa993b 346 we failed to consider one. */
4c2df51b
DJ
347 case LOC_COMPUTED:
348 case LOC_COMPUTED_ARG:
349 {
350 struct location_funcs *symfuncs = SYMBOL_LOCATION_FUNCS (sym);
351 return (symfuncs->read_needs_frame) (sym);
352 }
353 break;
354
c906108c
SS
355 case LOC_REGISTER:
356 case LOC_ARG:
357 case LOC_REF_ARG:
358 case LOC_REGPARM:
359 case LOC_REGPARM_ADDR:
360 case LOC_LOCAL:
361 case LOC_LOCAL_ARG:
362 case LOC_BASEREG:
363 case LOC_BASEREG_ARG:
407caf07 364 case LOC_HP_THREAD_LOCAL_STATIC:
c906108c
SS
365 return 1;
366
367 case LOC_UNDEF:
368 case LOC_CONST:
369 case LOC_STATIC:
370 case LOC_INDIRECT:
371 case LOC_TYPEDEF:
372
373 case LOC_LABEL:
374 /* Getting the address of a label can be done independently of the block,
c5aa993b
JM
375 even if some *uses* of that address wouldn't work so well without
376 the right frame. */
c906108c
SS
377
378 case LOC_BLOCK:
379 case LOC_CONST_BYTES:
380 case LOC_UNRESOLVED:
381 case LOC_OPTIMIZED_OUT:
382 return 0;
383 }
384 return 1;
385}
386
387/* Given a struct symbol for a variable,
388 and a stack frame id, read the value of the variable
389 and return a (pointer to a) struct value containing the value.
390 If the variable cannot be found, return a zero pointer.
6e7f8b9c 391 If FRAME is NULL, use the deprecated_selected_frame. */
c906108c 392
3d6d86c6 393struct value *
fba45db2 394read_var_value (register struct symbol *var, struct frame_info *frame)
c906108c 395{
3d6d86c6 396 register struct value *v;
c906108c
SS
397 struct type *type = SYMBOL_TYPE (var);
398 CORE_ADDR addr;
399 register int len;
400
401 v = allocate_value (type);
402 VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */
403 VALUE_BFD_SECTION (v) = SYMBOL_BFD_SECTION (var);
404
405 len = TYPE_LENGTH (type);
406
c5aa993b 407 if (frame == NULL)
6e7f8b9c 408 frame = deprecated_selected_frame;
c906108c
SS
409
410 switch (SYMBOL_CLASS (var))
411 {
412 case LOC_CONST:
413 /* Put the constant back in target format. */
414 store_signed_integer (VALUE_CONTENTS_RAW (v), len,
415 (LONGEST) SYMBOL_VALUE (var));
416 VALUE_LVAL (v) = not_lval;
417 return v;
418
419 case LOC_LABEL:
420 /* Put the constant back in target format. */
421 if (overlay_debugging)
4478b372
JB
422 {
423 CORE_ADDR addr
424 = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
425 SYMBOL_BFD_SECTION (var));
426 store_typed_address (VALUE_CONTENTS_RAW (v), type, addr);
427 }
c906108c 428 else
4478b372
JB
429 store_typed_address (VALUE_CONTENTS_RAW (v), type,
430 SYMBOL_VALUE_ADDRESS (var));
c906108c
SS
431 VALUE_LVAL (v) = not_lval;
432 return v;
433
434 case LOC_CONST_BYTES:
435 {
436 char *bytes_addr;
437 bytes_addr = SYMBOL_VALUE_BYTES (var);
438 memcpy (VALUE_CONTENTS_RAW (v), bytes_addr, len);
439 VALUE_LVAL (v) = not_lval;
440 return v;
441 }
442
443 case LOC_STATIC:
444 if (overlay_debugging)
445 addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var),
446 SYMBOL_BFD_SECTION (var));
447 else
448 addr = SYMBOL_VALUE_ADDRESS (var);
449 break;
450
451 case LOC_INDIRECT:
f76febae
AC
452 {
453 /* The import slot does not have a real address in it from the
454 dynamic loader (dld.sl on HP-UX), if the target hasn't
455 begun execution yet, so check for that. */
456 CORE_ADDR locaddr;
457 struct value *loc;
458 if (!target_has_execution)
459 error ("\
c906108c
SS
460Attempt to access variable defined in different shared object or load module when\n\
461addresses have not been bound by the dynamic loader. Try again when executable is running.");
c5aa993b 462
f76febae
AC
463 locaddr = SYMBOL_VALUE_ADDRESS (var);
464 loc = value_at (lookup_pointer_type (type), locaddr, NULL);
1aa20aa8 465 addr = value_as_address (loc);
f76febae 466 }
c906108c
SS
467
468 case LOC_ARG:
469 if (frame == NULL)
470 return 0;
da62e633 471 addr = get_frame_args_address (frame);
c906108c
SS
472 if (!addr)
473 return 0;
474 addr += SYMBOL_VALUE (var);
475 break;
476
477 case LOC_REF_ARG:
f76febae
AC
478 {
479 struct value *ref;
480 CORE_ADDR argref;
481 if (frame == NULL)
482 return 0;
da62e633 483 argref = get_frame_args_address (frame);
f76febae
AC
484 if (!argref)
485 return 0;
486 argref += SYMBOL_VALUE (var);
487 ref = value_at (lookup_pointer_type (type), argref, NULL);
1aa20aa8 488 addr = value_as_address (ref);
f76febae
AC
489 break;
490 }
c906108c
SS
491
492 case LOC_LOCAL:
493 case LOC_LOCAL_ARG:
494 if (frame == NULL)
495 return 0;
da62e633 496 addr = get_frame_locals_address (frame);
c906108c
SS
497 addr += SYMBOL_VALUE (var);
498 break;
499
500 case LOC_BASEREG:
501 case LOC_BASEREG_ARG:
407caf07 502 case LOC_HP_THREAD_LOCAL_STATIC:
c906108c 503 {
3d6d86c6 504 struct value *regval;
c5aa993b 505
9ed10b08
ND
506 regval = value_from_register (lookup_pointer_type (type),
507 SYMBOL_BASEREG (var), frame);
508 if (regval == NULL)
509 error ("Value of base register not available.");
1aa20aa8 510 addr = value_as_address (regval);
c5aa993b
JM
511 addr += SYMBOL_VALUE (var);
512 break;
c906108c 513 }
c5aa993b 514
9d774e44
EZ
515 case LOC_THREAD_LOCAL_STATIC:
516 {
9d774e44
EZ
517 if (target_get_thread_local_address_p ())
518 addr = target_get_thread_local_address (inferior_ptid,
519 SYMBOL_OBJFILE (var),
520 SYMBOL_VALUE_ADDRESS (var));
521 /* It wouldn't be wrong here to try a gdbarch method, too;
522 finding TLS is an ABI-specific thing. But we don't do that
523 yet. */
524 else
525 error ("Cannot find thread-local variables on this target");
526 break;
527 }
528
c906108c
SS
529 case LOC_TYPEDEF:
530 error ("Cannot look up value of a typedef");
531 break;
532
533 case LOC_BLOCK:
534 if (overlay_debugging)
c5aa993b 535 VALUE_ADDRESS (v) = symbol_overlayed_address
c906108c
SS
536 (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var));
537 else
538 VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var));
539 return v;
540
541 case LOC_REGISTER:
542 case LOC_REGPARM:
543 case LOC_REGPARM_ADDR:
544 {
545 struct block *b;
546 int regno = SYMBOL_VALUE (var);
3d6d86c6 547 struct value *regval;
c906108c
SS
548
549 if (frame == NULL)
550 return 0;
ae767bfb 551 b = get_frame_block (frame, 0);
c906108c
SS
552
553 if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR)
554 {
555 regval = value_from_register (lookup_pointer_type (type),
c5aa993b 556 regno,
c906108c
SS
557 frame);
558
559 if (regval == NULL)
560 error ("Value of register variable not available.");
561
1aa20aa8 562 addr = value_as_address (regval);
c906108c
SS
563 VALUE_LVAL (v) = lval_memory;
564 }
565 else
566 {
567 regval = value_from_register (type, regno, frame);
568
569 if (regval == NULL)
570 error ("Value of register variable not available.");
571 return regval;
572 }
573 }
574 break;
575
4c2df51b
DJ
576 case LOC_COMPUTED:
577 case LOC_COMPUTED_ARG:
578 {
579 struct location_funcs *funcs = SYMBOL_LOCATION_FUNCS (var);
580
581 if (frame == 0 && (funcs->read_needs_frame) (var))
582 return 0;
583 return (funcs->read_variable) (var, frame);
584
585 }
586 break;
587
c906108c
SS
588 case LOC_UNRESOLVED:
589 {
590 struct minimal_symbol *msym;
591
22abf04a 592 msym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (var), NULL, NULL);
c906108c
SS
593 if (msym == NULL)
594 return 0;
595 if (overlay_debugging)
596 addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym),
597 SYMBOL_BFD_SECTION (msym));
598 else
599 addr = SYMBOL_VALUE_ADDRESS (msym);
600 }
601 break;
602
603 case LOC_OPTIMIZED_OUT:
604 VALUE_LVAL (v) = not_lval;
605 VALUE_OPTIMIZED_OUT (v) = 1;
606 return v;
607
608 default:
609 error ("Cannot look up value of a botched symbol.");
610 break;
611 }
612
613 VALUE_ADDRESS (v) = addr;
614 VALUE_LAZY (v) = 1;
615 return v;
616}
617
618/* Return a value of type TYPE, stored in register REGNUM, in frame
0f2c5ba5 619 FRAME.
c906108c
SS
620
621 NOTE: returns NULL if register value is not available.
622 Caller will check return value or die! */
623
3d6d86c6 624struct value *
fba45db2 625value_from_register (struct type *type, int regnum, struct frame_info *frame)
c906108c 626{
ff2e87ac 627 struct gdbarch *gdbarch = get_frame_arch (frame);
3d6d86c6 628 struct value *v = allocate_value (type);
c906108c 629 CHECK_TYPEDEF (type);
c906108c 630
ff2e87ac
AC
631 if (CONVERT_REGISTER_P (regnum, type))
632 {
633 /* The ISA/ABI need to something weird when obtaining the
634 specified value from this register. It might need to
635 re-order non-adjacent, starting with REGNUM (see MIPS and
636 i386). It might need to convert the [float] register into
637 the corresponding [integer] type (see Alpha). The assumption
638 is that REGISTER_TO_VALUE populates the entire value
639 including the location. */
640 REGISTER_TO_VALUE (frame, regnum, type, VALUE_CONTENTS_RAW (v));
641 VALUE_LVAL (v) = lval_reg_frame_relative;
642 VALUE_FRAME_ID (v) = get_frame_id (frame);
643 VALUE_FRAME_REGNUM (v) = regnum;
644 }
645 else
c906108c 646 {
c906108c
SS
647 int local_regnum;
648 int mem_stor = 0, reg_stor = 0;
649 int mem_tracking = 1;
650 CORE_ADDR last_addr = 0;
651 CORE_ADDR first_addr = 0;
ff2e87ac
AC
652 int first_realnum = regnum;
653 int len = TYPE_LENGTH (type);
654 int value_bytes_copied;
655 int optimized = 0;
656 char *value_bytes = (char *) alloca (len + MAX_REGISTER_SIZE);
c906108c
SS
657
658 /* Copy all of the data out, whereever it may be. */
ff2e87ac
AC
659 for (local_regnum = regnum, value_bytes_copied = 0;
660 value_bytes_copied < len;
661 (value_bytes_copied += REGISTER_RAW_SIZE (local_regnum),
662 ++local_regnum))
663 {
664 int realnum;
665 int optim;
666 enum lval_type lval;
667 CORE_ADDR addr;
668 frame_register (frame, local_regnum, &optim, &lval, &addr,
669 &realnum, value_bytes + value_bytes_copied);
670 optimized += optim;
671 if (register_cached (local_regnum) == -1)
672 return NULL; /* register value not available */
673
674 if (regnum == local_regnum)
675 {
c906108c 676 first_addr = addr;
ff2e87ac
AC
677 first_realnum = realnum;
678 }
679 if (lval == lval_register)
680 reg_stor++;
681 else
682 {
683 mem_stor++;
684
685 mem_tracking = (mem_tracking
686 && (regnum == local_regnum
687 || addr == last_addr));
688 }
689 last_addr = addr;
690 }
691
692 /* FIXME: cagney/2003-06-04: Shouldn't this always use
693 lval_reg_frame_relative? If it doesn't and the register's
694 location changes (say after a resume) then this value is
695 going to have wrong information. */
c906108c
SS
696 if ((reg_stor && mem_stor)
697 || (mem_stor && !mem_tracking))
698 /* Mixed storage; all of the hassle we just went through was
699 for some good purpose. */
700 {
701 VALUE_LVAL (v) = lval_reg_frame_relative;
1df6926e 702 VALUE_FRAME_ID (v) = get_frame_id (frame);
c906108c
SS
703 VALUE_FRAME_REGNUM (v) = regnum;
704 }
705 else if (mem_stor)
706 {
707 VALUE_LVAL (v) = lval_memory;
708 VALUE_ADDRESS (v) = first_addr;
709 }
710 else if (reg_stor)
711 {
712 VALUE_LVAL (v) = lval_register;
713 VALUE_ADDRESS (v) = first_addr;
ff2e87ac 714 VALUE_REGNO (v) = first_realnum;
c906108c
SS
715 }
716 else
8e65ff28
AC
717 internal_error (__FILE__, __LINE__,
718 "value_from_register: Value not stored anywhere!");
ff2e87ac
AC
719
720 VALUE_OPTIMIZED_OUT (v) = optimized;
721
c906108c 722 /* Any structure stored in more than one register will always be
ff2e87ac 723 an integral number of registers. Otherwise, you need to do
c5aa993b
JM
724 some fiddling with the last register copied here for little
725 endian machines. */
ff2e87ac
AC
726 if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG
727 && len < REGISTER_RAW_SIZE (regnum))
728 /* Big-endian, and we want less than full size. */
729 VALUE_OFFSET (v) = REGISTER_RAW_SIZE (regnum) - len;
730 else
731 VALUE_OFFSET (v) = 0;
732 memcpy (VALUE_CONTENTS_RAW (v), value_bytes + VALUE_OFFSET (v), len);
c906108c 733 }
c906108c
SS
734 return v;
735}
ff2e87ac 736
c906108c
SS
737\f
738/* Given a struct symbol for a variable or function,
739 and a stack frame id,
740 return a (pointer to a) struct value containing the properly typed
741 address. */
742
3d6d86c6 743struct value *
fba45db2 744locate_var_value (register struct symbol *var, struct frame_info *frame)
c906108c
SS
745{
746 CORE_ADDR addr = 0;
747 struct type *type = SYMBOL_TYPE (var);
3d6d86c6 748 struct value *lazy_value;
c906108c
SS
749
750 /* Evaluate it first; if the result is a memory address, we're fine.
751 Lazy evaluation pays off here. */
752
753 lazy_value = read_var_value (var, frame);
754 if (lazy_value == 0)
de5ad195 755 error ("Address of \"%s\" is unknown.", SYMBOL_PRINT_NAME (var));
c906108c
SS
756
757 if (VALUE_LAZY (lazy_value)
758 || TYPE_CODE (type) == TYPE_CODE_FUNC)
759 {
3d6d86c6 760 struct value *val;
c906108c
SS
761
762 addr = VALUE_ADDRESS (lazy_value);
4478b372 763 val = value_from_pointer (lookup_pointer_type (type), addr);
c906108c
SS
764 VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (lazy_value);
765 return val;
766 }
767
768 /* Not a memory address; check what the problem was. */
c5aa993b 769 switch (VALUE_LVAL (lazy_value))
c906108c
SS
770 {
771 case lval_register:
14e534aa
PM
772 gdb_assert (REGISTER_NAME (VALUE_REGNO (lazy_value)) != NULL
773 && *REGISTER_NAME (VALUE_REGNO (lazy_value)) != '\0');
774 error("Address requested for identifier "
775 "\"%s\" which is in register $%s",
de5ad195 776 SYMBOL_PRINT_NAME (var),
14e534aa
PM
777 REGISTER_NAME (VALUE_REGNO (lazy_value)));
778 break;
779
c906108c 780 case lval_reg_frame_relative:
14e534aa
PM
781 gdb_assert (REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != NULL
782 && *REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != '\0');
783 error("Address requested for identifier "
784 "\"%s\" which is in frame register $%s",
de5ad195 785 SYMBOL_PRINT_NAME (var),
14e534aa 786 REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)));
c906108c
SS
787 break;
788
789 default:
790 error ("Can't take address of \"%s\" which isn't an lvalue.",
de5ad195 791 SYMBOL_PRINT_NAME (var));
c906108c
SS
792 break;
793 }
c5aa993b 794 return 0; /* For lint -- never reached */
c906108c 795}
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