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c906108c | 1 | /* Find a variable's value in memory, for GDB, the GNU debugger. |
b6ba6518 KB |
2 | Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
3 | 1996, 1997, 1998, 1999, 2000, 2001 | |
c906108c SS |
4 | Free Software Foundation, Inc. |
5 | ||
c5aa993b | 6 | This file is part of GDB. |
c906108c | 7 | |
c5aa993b JM |
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. | |
c906108c | 12 | |
c5aa993b JM |
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. | |
c906108c | 17 | |
c5aa993b JM |
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. */ | |
c906108c SS |
22 | |
23 | #include "defs.h" | |
24 | #include "symtab.h" | |
25 | #include "gdbtypes.h" | |
26 | #include "frame.h" | |
27 | #include "value.h" | |
28 | #include "gdbcore.h" | |
29 | #include "inferior.h" | |
30 | #include "target.h" | |
31 | #include "gdb_string.h" | |
14e534aa | 32 | #include "gdb_assert.h" |
c906108c | 33 | #include "floatformat.h" |
c5aa993b | 34 | #include "symfile.h" /* for overlay functions */ |
4e052eda | 35 | #include "regcache.h" |
c906108c | 36 | |
c906108c SS |
37 | /* Basic byte-swapping routines. GDB has needed these for a long time... |
38 | All extract a target-format integer at ADDR which is LEN bytes long. */ | |
39 | ||
40 | #if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8 | |
41 | /* 8 bit characters are a pretty safe assumption these days, so we | |
42 | assume it throughout all these swapping routines. If we had to deal with | |
43 | 9 bit characters, we would need to make len be in bits and would have | |
44 | to re-write these routines... */ | |
c5aa993b | 45 | you lose |
c906108c SS |
46 | #endif |
47 | ||
a9ac8f51 AC |
48 | LONGEST |
49 | extract_signed_integer (void *addr, int len) | |
c906108c SS |
50 | { |
51 | LONGEST retval; | |
52 | unsigned char *p; | |
c5aa993b | 53 | unsigned char *startaddr = (unsigned char *) addr; |
c906108c SS |
54 | unsigned char *endaddr = startaddr + len; |
55 | ||
56 | if (len > (int) sizeof (LONGEST)) | |
57 | error ("\ | |
58 | That operation is not available on integers of more than %d bytes.", | |
59 | sizeof (LONGEST)); | |
60 | ||
61 | /* Start at the most significant end of the integer, and work towards | |
62 | the least significant. */ | |
d7449b42 | 63 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
c906108c SS |
64 | { |
65 | p = startaddr; | |
66 | /* Do the sign extension once at the start. */ | |
c5aa993b | 67 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
c906108c SS |
68 | for (++p; p < endaddr; ++p) |
69 | retval = (retval << 8) | *p; | |
70 | } | |
71 | else | |
72 | { | |
73 | p = endaddr - 1; | |
74 | /* Do the sign extension once at the start. */ | |
c5aa993b | 75 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
c906108c SS |
76 | for (--p; p >= startaddr; --p) |
77 | retval = (retval << 8) | *p; | |
78 | } | |
79 | return retval; | |
80 | } | |
81 | ||
82 | ULONGEST | |
a9ac8f51 | 83 | extract_unsigned_integer (void *addr, int len) |
c906108c SS |
84 | { |
85 | ULONGEST retval; | |
86 | unsigned char *p; | |
c5aa993b | 87 | unsigned char *startaddr = (unsigned char *) addr; |
c906108c SS |
88 | unsigned char *endaddr = startaddr + len; |
89 | ||
90 | if (len > (int) sizeof (ULONGEST)) | |
91 | error ("\ | |
92 | That operation is not available on integers of more than %d bytes.", | |
93 | sizeof (ULONGEST)); | |
94 | ||
95 | /* Start at the most significant end of the integer, and work towards | |
96 | the least significant. */ | |
97 | retval = 0; | |
d7449b42 | 98 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
c906108c SS |
99 | { |
100 | for (p = startaddr; p < endaddr; ++p) | |
101 | retval = (retval << 8) | *p; | |
102 | } | |
103 | else | |
104 | { | |
105 | for (p = endaddr - 1; p >= startaddr; --p) | |
106 | retval = (retval << 8) | *p; | |
107 | } | |
108 | return retval; | |
109 | } | |
110 | ||
111 | /* Sometimes a long long unsigned integer can be extracted as a | |
112 | LONGEST value. This is done so that we can print these values | |
113 | better. If this integer can be converted to a LONGEST, this | |
114 | function returns 1 and sets *PVAL. Otherwise it returns 0. */ | |
115 | ||
116 | int | |
a9ac8f51 | 117 | extract_long_unsigned_integer (void *addr, int orig_len, LONGEST *pval) |
c906108c SS |
118 | { |
119 | char *p, *first_addr; | |
120 | int len; | |
121 | ||
122 | len = orig_len; | |
d7449b42 | 123 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
c906108c SS |
124 | { |
125 | for (p = (char *) addr; | |
126 | len > (int) sizeof (LONGEST) && p < (char *) addr + orig_len; | |
127 | p++) | |
128 | { | |
129 | if (*p == 0) | |
130 | len--; | |
131 | else | |
132 | break; | |
133 | } | |
134 | first_addr = p; | |
135 | } | |
136 | else | |
137 | { | |
138 | first_addr = (char *) addr; | |
139 | for (p = (char *) addr + orig_len - 1; | |
140 | len > (int) sizeof (LONGEST) && p >= (char *) addr; | |
141 | p--) | |
142 | { | |
143 | if (*p == 0) | |
144 | len--; | |
145 | else | |
146 | break; | |
147 | } | |
148 | } | |
149 | ||
150 | if (len <= (int) sizeof (LONGEST)) | |
151 | { | |
152 | *pval = (LONGEST) extract_unsigned_integer (first_addr, | |
153 | sizeof (LONGEST)); | |
154 | return 1; | |
155 | } | |
156 | ||
157 | return 0; | |
158 | } | |
159 | ||
4478b372 JB |
160 | |
161 | /* Treat the LEN bytes at ADDR as a target-format address, and return | |
162 | that address. ADDR is a buffer in the GDB process, not in the | |
163 | inferior. | |
164 | ||
165 | This function should only be used by target-specific code. It | |
166 | assumes that a pointer has the same representation as that thing's | |
167 | address represented as an integer. Some machines use word | |
168 | addresses, or similarly munged things, for certain types of | |
169 | pointers, so that assumption doesn't hold everywhere. | |
170 | ||
171 | Common code should use extract_typed_address instead, or something | |
172 | else based on POINTER_TO_ADDRESS. */ | |
173 | ||
c906108c | 174 | CORE_ADDR |
a9ac8f51 | 175 | extract_address (void *addr, int len) |
c906108c SS |
176 | { |
177 | /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure | |
178 | whether we want this to be true eventually. */ | |
c5aa993b | 179 | return (CORE_ADDR) extract_unsigned_integer (addr, len); |
c906108c SS |
180 | } |
181 | ||
4478b372 | 182 | |
4478b372 JB |
183 | /* Treat the bytes at BUF as a pointer of type TYPE, and return the |
184 | address it represents. */ | |
185 | CORE_ADDR | |
186 | extract_typed_address (void *buf, struct type *type) | |
187 | { | |
188 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
189 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 AC |
190 | internal_error (__FILE__, __LINE__, |
191 | "extract_typed_address: " | |
4478b372 JB |
192 | "type is not a pointer or reference"); |
193 | ||
194 | return POINTER_TO_ADDRESS (type, buf); | |
195 | } | |
196 | ||
197 | ||
c906108c | 198 | void |
a9ac8f51 | 199 | store_signed_integer (void *addr, int len, LONGEST val) |
c906108c SS |
200 | { |
201 | unsigned char *p; | |
c5aa993b | 202 | unsigned char *startaddr = (unsigned char *) addr; |
c906108c SS |
203 | unsigned char *endaddr = startaddr + len; |
204 | ||
205 | /* Start at the least significant end of the integer, and work towards | |
206 | the most significant. */ | |
d7449b42 | 207 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
c906108c SS |
208 | { |
209 | for (p = endaddr - 1; p >= startaddr; --p) | |
210 | { | |
211 | *p = val & 0xff; | |
212 | val >>= 8; | |
213 | } | |
214 | } | |
215 | else | |
216 | { | |
217 | for (p = startaddr; p < endaddr; ++p) | |
218 | { | |
219 | *p = val & 0xff; | |
220 | val >>= 8; | |
221 | } | |
222 | } | |
223 | } | |
224 | ||
225 | void | |
a9ac8f51 | 226 | store_unsigned_integer (void *addr, int len, ULONGEST val) |
c906108c SS |
227 | { |
228 | unsigned char *p; | |
c5aa993b | 229 | unsigned char *startaddr = (unsigned char *) addr; |
c906108c SS |
230 | unsigned char *endaddr = startaddr + len; |
231 | ||
232 | /* Start at the least significant end of the integer, and work towards | |
233 | the most significant. */ | |
d7449b42 | 234 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
c906108c SS |
235 | { |
236 | for (p = endaddr - 1; p >= startaddr; --p) | |
237 | { | |
238 | *p = val & 0xff; | |
239 | val >>= 8; | |
240 | } | |
241 | } | |
242 | else | |
243 | { | |
244 | for (p = startaddr; p < endaddr; ++p) | |
245 | { | |
246 | *p = val & 0xff; | |
247 | val >>= 8; | |
248 | } | |
249 | } | |
250 | } | |
251 | ||
4478b372 JB |
252 | /* Store the address VAL as a LEN-byte value in target byte order at |
253 | ADDR. ADDR is a buffer in the GDB process, not in the inferior. | |
254 | ||
255 | This function should only be used by target-specific code. It | |
256 | assumes that a pointer has the same representation as that thing's | |
257 | address represented as an integer. Some machines use word | |
258 | addresses, or similarly munged things, for certain types of | |
259 | pointers, so that assumption doesn't hold everywhere. | |
260 | ||
261 | Common code should use store_typed_address instead, or something else | |
262 | based on ADDRESS_TO_POINTER. */ | |
c906108c | 263 | void |
a9ac8f51 | 264 | store_address (void *addr, int len, LONGEST val) |
c906108c | 265 | { |
c906108c SS |
266 | store_unsigned_integer (addr, len, val); |
267 | } | |
4478b372 JB |
268 | |
269 | ||
4478b372 JB |
270 | /* Store the address ADDR as a pointer of type TYPE at BUF, in target |
271 | form. */ | |
272 | void | |
273 | store_typed_address (void *buf, struct type *type, CORE_ADDR addr) | |
274 | { | |
275 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
276 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 AC |
277 | internal_error (__FILE__, __LINE__, |
278 | "store_typed_address: " | |
4478b372 JB |
279 | "type is not a pointer or reference"); |
280 | ||
281 | ADDRESS_TO_POINTER (type, buf, addr); | |
282 | } | |
283 | ||
284 | ||
285 | ||
376c9600 AC |
286 | /* Return a `value' with the contents of (virtual or cooked) register |
287 | REGNUM as found in the specified FRAME. The register's type is | |
288 | determined by REGISTER_VIRTUAL_TYPE. | |
c906108c | 289 | |
376c9600 AC |
290 | NOTE: returns NULL if register value is not available. Caller will |
291 | check return value or die! */ | |
c906108c | 292 | |
3d6d86c6 | 293 | struct value * |
376c9600 | 294 | value_of_register (int regnum, struct frame_info *frame) |
c906108c SS |
295 | { |
296 | CORE_ADDR addr; | |
297 | int optim; | |
3d6d86c6 | 298 | struct value *reg_val; |
e6cbd02a | 299 | char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE); |
c906108c SS |
300 | enum lval_type lval; |
301 | ||
302 | get_saved_register (raw_buffer, &optim, &addr, | |
376c9600 | 303 | frame, regnum, &lval); |
c906108c | 304 | |
32178cab | 305 | if (register_cached (regnum) < 0) |
c5aa993b | 306 | return NULL; /* register value not available */ |
c906108c SS |
307 | |
308 | reg_val = allocate_value (REGISTER_VIRTUAL_TYPE (regnum)); | |
309 | ||
310 | /* Convert raw data to virtual format if necessary. */ | |
311 | ||
c906108c SS |
312 | if (REGISTER_CONVERTIBLE (regnum)) |
313 | { | |
314 | REGISTER_CONVERT_TO_VIRTUAL (regnum, REGISTER_VIRTUAL_TYPE (regnum), | |
315 | raw_buffer, VALUE_CONTENTS_RAW (reg_val)); | |
316 | } | |
392a587b JM |
317 | else if (REGISTER_RAW_SIZE (regnum) == REGISTER_VIRTUAL_SIZE (regnum)) |
318 | memcpy (VALUE_CONTENTS_RAW (reg_val), raw_buffer, | |
319 | REGISTER_RAW_SIZE (regnum)); | |
c906108c | 320 | else |
8e65ff28 AC |
321 | internal_error (__FILE__, __LINE__, |
322 | "Register \"%s\" (%d) has conflicting raw (%d) and virtual (%d) size", | |
96baa820 JM |
323 | REGISTER_NAME (regnum), |
324 | regnum, | |
325 | REGISTER_RAW_SIZE (regnum), | |
326 | REGISTER_VIRTUAL_SIZE (regnum)); | |
c906108c SS |
327 | VALUE_LVAL (reg_val) = lval; |
328 | VALUE_ADDRESS (reg_val) = addr; | |
329 | VALUE_REGNO (reg_val) = regnum; | |
330 | VALUE_OPTIMIZED_OUT (reg_val) = optim; | |
331 | return reg_val; | |
332 | } | |
4478b372 JB |
333 | |
334 | /* Given a pointer of type TYPE in target form in BUF, return the | |
335 | address it represents. */ | |
336 | CORE_ADDR | |
ac2e2ef7 | 337 | unsigned_pointer_to_address (struct type *type, void *buf) |
4478b372 JB |
338 | { |
339 | return extract_address (buf, TYPE_LENGTH (type)); | |
340 | } | |
341 | ||
ac2e2ef7 AC |
342 | CORE_ADDR |
343 | signed_pointer_to_address (struct type *type, void *buf) | |
344 | { | |
345 | return extract_signed_integer (buf, TYPE_LENGTH (type)); | |
346 | } | |
4478b372 JB |
347 | |
348 | /* Given an address, store it as a pointer of type TYPE in target | |
349 | format in BUF. */ | |
350 | void | |
ac2e2ef7 | 351 | unsigned_address_to_pointer (struct type *type, void *buf, CORE_ADDR addr) |
4478b372 JB |
352 | { |
353 | store_address (buf, TYPE_LENGTH (type), addr); | |
354 | } | |
355 | ||
ac2e2ef7 AC |
356 | void |
357 | address_to_signed_pointer (struct type *type, void *buf, CORE_ADDR addr) | |
358 | { | |
359 | store_signed_integer (buf, TYPE_LENGTH (type), addr); | |
360 | } | |
c906108c SS |
361 | \f |
362 | /* Will calling read_var_value or locate_var_value on SYM end | |
363 | up caring what frame it is being evaluated relative to? SYM must | |
364 | be non-NULL. */ | |
365 | int | |
fba45db2 | 366 | symbol_read_needs_frame (struct symbol *sym) |
c906108c SS |
367 | { |
368 | switch (SYMBOL_CLASS (sym)) | |
369 | { | |
370 | /* All cases listed explicitly so that gcc -Wall will detect it if | |
c5aa993b | 371 | we failed to consider one. */ |
c906108c SS |
372 | case LOC_REGISTER: |
373 | case LOC_ARG: | |
374 | case LOC_REF_ARG: | |
375 | case LOC_REGPARM: | |
376 | case LOC_REGPARM_ADDR: | |
377 | case LOC_LOCAL: | |
378 | case LOC_LOCAL_ARG: | |
379 | case LOC_BASEREG: | |
380 | case LOC_BASEREG_ARG: | |
381 | case LOC_THREAD_LOCAL_STATIC: | |
382 | return 1; | |
383 | ||
384 | case LOC_UNDEF: | |
385 | case LOC_CONST: | |
386 | case LOC_STATIC: | |
387 | case LOC_INDIRECT: | |
388 | case LOC_TYPEDEF: | |
389 | ||
390 | case LOC_LABEL: | |
391 | /* Getting the address of a label can be done independently of the block, | |
c5aa993b JM |
392 | even if some *uses* of that address wouldn't work so well without |
393 | the right frame. */ | |
c906108c SS |
394 | |
395 | case LOC_BLOCK: | |
396 | case LOC_CONST_BYTES: | |
397 | case LOC_UNRESOLVED: | |
398 | case LOC_OPTIMIZED_OUT: | |
399 | return 0; | |
400 | } | |
401 | return 1; | |
402 | } | |
403 | ||
404 | /* Given a struct symbol for a variable, | |
405 | and a stack frame id, read the value of the variable | |
406 | and return a (pointer to a) struct value containing the value. | |
407 | If the variable cannot be found, return a zero pointer. | |
408 | If FRAME is NULL, use the selected_frame. */ | |
409 | ||
3d6d86c6 | 410 | struct value * |
fba45db2 | 411 | read_var_value (register struct symbol *var, struct frame_info *frame) |
c906108c | 412 | { |
3d6d86c6 | 413 | register struct value *v; |
c906108c SS |
414 | struct type *type = SYMBOL_TYPE (var); |
415 | CORE_ADDR addr; | |
416 | register int len; | |
417 | ||
418 | v = allocate_value (type); | |
419 | VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */ | |
420 | VALUE_BFD_SECTION (v) = SYMBOL_BFD_SECTION (var); | |
421 | ||
422 | len = TYPE_LENGTH (type); | |
423 | ||
c5aa993b JM |
424 | if (frame == NULL) |
425 | frame = selected_frame; | |
c906108c SS |
426 | |
427 | switch (SYMBOL_CLASS (var)) | |
428 | { | |
429 | case LOC_CONST: | |
430 | /* Put the constant back in target format. */ | |
431 | store_signed_integer (VALUE_CONTENTS_RAW (v), len, | |
432 | (LONGEST) SYMBOL_VALUE (var)); | |
433 | VALUE_LVAL (v) = not_lval; | |
434 | return v; | |
435 | ||
436 | case LOC_LABEL: | |
437 | /* Put the constant back in target format. */ | |
438 | if (overlay_debugging) | |
4478b372 JB |
439 | { |
440 | CORE_ADDR addr | |
441 | = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
442 | SYMBOL_BFD_SECTION (var)); | |
443 | store_typed_address (VALUE_CONTENTS_RAW (v), type, addr); | |
444 | } | |
c906108c | 445 | else |
4478b372 JB |
446 | store_typed_address (VALUE_CONTENTS_RAW (v), type, |
447 | SYMBOL_VALUE_ADDRESS (var)); | |
c906108c SS |
448 | VALUE_LVAL (v) = not_lval; |
449 | return v; | |
450 | ||
451 | case LOC_CONST_BYTES: | |
452 | { | |
453 | char *bytes_addr; | |
454 | bytes_addr = SYMBOL_VALUE_BYTES (var); | |
455 | memcpy (VALUE_CONTENTS_RAW (v), bytes_addr, len); | |
456 | VALUE_LVAL (v) = not_lval; | |
457 | return v; | |
458 | } | |
459 | ||
460 | case LOC_STATIC: | |
461 | if (overlay_debugging) | |
462 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
463 | SYMBOL_BFD_SECTION (var)); | |
464 | else | |
465 | addr = SYMBOL_VALUE_ADDRESS (var); | |
466 | break; | |
467 | ||
468 | case LOC_INDIRECT: | |
f76febae AC |
469 | { |
470 | /* The import slot does not have a real address in it from the | |
471 | dynamic loader (dld.sl on HP-UX), if the target hasn't | |
472 | begun execution yet, so check for that. */ | |
473 | CORE_ADDR locaddr; | |
474 | struct value *loc; | |
475 | if (!target_has_execution) | |
476 | error ("\ | |
c906108c SS |
477 | Attempt to access variable defined in different shared object or load module when\n\ |
478 | addresses have not been bound by the dynamic loader. Try again when executable is running."); | |
c5aa993b | 479 | |
f76febae AC |
480 | locaddr = SYMBOL_VALUE_ADDRESS (var); |
481 | loc = value_at (lookup_pointer_type (type), locaddr, NULL); | |
1aa20aa8 | 482 | addr = value_as_address (loc); |
f76febae | 483 | } |
c906108c SS |
484 | |
485 | case LOC_ARG: | |
486 | if (frame == NULL) | |
487 | return 0; | |
488 | addr = FRAME_ARGS_ADDRESS (frame); | |
489 | if (!addr) | |
490 | return 0; | |
491 | addr += SYMBOL_VALUE (var); | |
492 | break; | |
493 | ||
494 | case LOC_REF_ARG: | |
f76febae AC |
495 | { |
496 | struct value *ref; | |
497 | CORE_ADDR argref; | |
498 | if (frame == NULL) | |
499 | return 0; | |
500 | argref = FRAME_ARGS_ADDRESS (frame); | |
501 | if (!argref) | |
502 | return 0; | |
503 | argref += SYMBOL_VALUE (var); | |
504 | ref = value_at (lookup_pointer_type (type), argref, NULL); | |
1aa20aa8 | 505 | addr = value_as_address (ref); |
f76febae AC |
506 | break; |
507 | } | |
c906108c SS |
508 | |
509 | case LOC_LOCAL: | |
510 | case LOC_LOCAL_ARG: | |
511 | if (frame == NULL) | |
512 | return 0; | |
513 | addr = FRAME_LOCALS_ADDRESS (frame); | |
514 | addr += SYMBOL_VALUE (var); | |
515 | break; | |
516 | ||
517 | case LOC_BASEREG: | |
518 | case LOC_BASEREG_ARG: | |
c906108c SS |
519 | case LOC_THREAD_LOCAL_STATIC: |
520 | { | |
3d6d86c6 | 521 | struct value *regval; |
c5aa993b | 522 | |
9ed10b08 ND |
523 | regval = value_from_register (lookup_pointer_type (type), |
524 | SYMBOL_BASEREG (var), frame); | |
525 | if (regval == NULL) | |
526 | error ("Value of base register not available."); | |
1aa20aa8 | 527 | addr = value_as_address (regval); |
c5aa993b JM |
528 | addr += SYMBOL_VALUE (var); |
529 | break; | |
c906108c | 530 | } |
c5aa993b | 531 | |
c906108c SS |
532 | case LOC_TYPEDEF: |
533 | error ("Cannot look up value of a typedef"); | |
534 | break; | |
535 | ||
536 | case LOC_BLOCK: | |
537 | if (overlay_debugging) | |
c5aa993b | 538 | VALUE_ADDRESS (v) = symbol_overlayed_address |
c906108c SS |
539 | (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var)); |
540 | else | |
541 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); | |
542 | return v; | |
543 | ||
544 | case LOC_REGISTER: | |
545 | case LOC_REGPARM: | |
546 | case LOC_REGPARM_ADDR: | |
547 | { | |
548 | struct block *b; | |
549 | int regno = SYMBOL_VALUE (var); | |
3d6d86c6 | 550 | struct value *regval; |
c906108c SS |
551 | |
552 | if (frame == NULL) | |
553 | return 0; | |
ae767bfb | 554 | b = get_frame_block (frame, 0); |
c906108c SS |
555 | |
556 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) | |
557 | { | |
558 | regval = value_from_register (lookup_pointer_type (type), | |
c5aa993b | 559 | regno, |
c906108c SS |
560 | frame); |
561 | ||
562 | if (regval == NULL) | |
563 | error ("Value of register variable not available."); | |
564 | ||
1aa20aa8 | 565 | addr = value_as_address (regval); |
c906108c SS |
566 | VALUE_LVAL (v) = lval_memory; |
567 | } | |
568 | else | |
569 | { | |
570 | regval = value_from_register (type, regno, frame); | |
571 | ||
572 | if (regval == NULL) | |
573 | error ("Value of register variable not available."); | |
574 | return regval; | |
575 | } | |
576 | } | |
577 | break; | |
578 | ||
579 | case LOC_UNRESOLVED: | |
580 | { | |
581 | struct minimal_symbol *msym; | |
582 | ||
583 | msym = lookup_minimal_symbol (SYMBOL_NAME (var), NULL, NULL); | |
584 | if (msym == NULL) | |
585 | return 0; | |
586 | if (overlay_debugging) | |
587 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), | |
588 | SYMBOL_BFD_SECTION (msym)); | |
589 | else | |
590 | addr = SYMBOL_VALUE_ADDRESS (msym); | |
591 | } | |
592 | break; | |
593 | ||
594 | case LOC_OPTIMIZED_OUT: | |
595 | VALUE_LVAL (v) = not_lval; | |
596 | VALUE_OPTIMIZED_OUT (v) = 1; | |
597 | return v; | |
598 | ||
599 | default: | |
600 | error ("Cannot look up value of a botched symbol."); | |
601 | break; | |
602 | } | |
603 | ||
604 | VALUE_ADDRESS (v) = addr; | |
605 | VALUE_LAZY (v) = 1; | |
606 | return v; | |
607 | } | |
608 | ||
609 | /* Return a value of type TYPE, stored in register REGNUM, in frame | |
0f2c5ba5 | 610 | FRAME. |
c906108c SS |
611 | |
612 | NOTE: returns NULL if register value is not available. | |
613 | Caller will check return value or die! */ | |
614 | ||
3d6d86c6 | 615 | struct value * |
fba45db2 | 616 | value_from_register (struct type *type, int regnum, struct frame_info *frame) |
c906108c | 617 | { |
e6cbd02a | 618 | char *raw_buffer = (char*) alloca (MAX_REGISTER_RAW_SIZE); |
c906108c SS |
619 | CORE_ADDR addr; |
620 | int optim; | |
3d6d86c6 | 621 | struct value *v = allocate_value (type); |
c906108c SS |
622 | char *value_bytes = 0; |
623 | int value_bytes_copied = 0; | |
624 | int num_storage_locs; | |
625 | enum lval_type lval; | |
626 | int len; | |
627 | ||
628 | CHECK_TYPEDEF (type); | |
629 | len = TYPE_LENGTH (type); | |
630 | ||
631 | VALUE_REGNO (v) = regnum; | |
632 | ||
633 | num_storage_locs = (len > REGISTER_VIRTUAL_SIZE (regnum) ? | |
634 | ((len - 1) / REGISTER_RAW_SIZE (regnum)) + 1 : | |
635 | 1); | |
636 | ||
637 | if (num_storage_locs > 1 | |
638 | #ifdef GDB_TARGET_IS_H8500 | |
639 | || TYPE_CODE (type) == TYPE_CODE_PTR | |
640 | #endif | |
c5aa993b | 641 | ) |
c906108c SS |
642 | { |
643 | /* Value spread across multiple storage locations. */ | |
c5aa993b | 644 | |
c906108c SS |
645 | int local_regnum; |
646 | int mem_stor = 0, reg_stor = 0; | |
647 | int mem_tracking = 1; | |
648 | CORE_ADDR last_addr = 0; | |
649 | CORE_ADDR first_addr = 0; | |
650 | ||
651 | value_bytes = (char *) alloca (len + MAX_REGISTER_RAW_SIZE); | |
652 | ||
653 | /* Copy all of the data out, whereever it may be. */ | |
654 | ||
655 | #ifdef GDB_TARGET_IS_H8500 | |
656 | /* This piece of hideosity is required because the H8500 treats registers | |
657 | differently depending upon whether they are used as pointers or not. As a | |
658 | pointer, a register needs to have a page register tacked onto the front. | |
659 | An alternate way to do this would be to have gcc output different register | |
660 | numbers for the pointer & non-pointer form of the register. But, it | |
661 | doesn't, so we're stuck with this. */ | |
662 | ||
663 | if (TYPE_CODE (type) == TYPE_CODE_PTR | |
664 | && len > 2) | |
665 | { | |
666 | int page_regnum; | |
667 | ||
668 | switch (regnum) | |
669 | { | |
c5aa993b JM |
670 | case R0_REGNUM: |
671 | case R1_REGNUM: | |
672 | case R2_REGNUM: | |
673 | case R3_REGNUM: | |
c906108c SS |
674 | page_regnum = SEG_D_REGNUM; |
675 | break; | |
c5aa993b JM |
676 | case R4_REGNUM: |
677 | case R5_REGNUM: | |
c906108c SS |
678 | page_regnum = SEG_E_REGNUM; |
679 | break; | |
c5aa993b JM |
680 | case R6_REGNUM: |
681 | case R7_REGNUM: | |
c906108c SS |
682 | page_regnum = SEG_T_REGNUM; |
683 | break; | |
684 | } | |
685 | ||
686 | value_bytes[0] = 0; | |
687 | get_saved_register (value_bytes + 1, | |
688 | &optim, | |
689 | &addr, | |
690 | frame, | |
691 | page_regnum, | |
692 | &lval); | |
693 | ||
32178cab | 694 | if (register_cached (page_regnum) == -1) |
c906108c SS |
695 | return NULL; /* register value not available */ |
696 | ||
697 | if (lval == lval_register) | |
698 | reg_stor++; | |
699 | else | |
700 | mem_stor++; | |
701 | first_addr = addr; | |
702 | last_addr = addr; | |
703 | ||
704 | get_saved_register (value_bytes + 2, | |
705 | &optim, | |
706 | &addr, | |
707 | frame, | |
708 | regnum, | |
709 | &lval); | |
710 | ||
32178cab | 711 | if (register_cached (regnum) == -1) |
c906108c SS |
712 | return NULL; /* register value not available */ |
713 | ||
714 | if (lval == lval_register) | |
715 | reg_stor++; | |
716 | else | |
717 | { | |
718 | mem_stor++; | |
719 | mem_tracking = mem_tracking && (addr == last_addr); | |
720 | } | |
721 | last_addr = addr; | |
722 | } | |
723 | else | |
c5aa993b | 724 | #endif /* GDB_TARGET_IS_H8500 */ |
c906108c SS |
725 | for (local_regnum = regnum; |
726 | value_bytes_copied < len; | |
727 | (value_bytes_copied += REGISTER_RAW_SIZE (local_regnum), | |
728 | ++local_regnum)) | |
729 | { | |
730 | get_saved_register (value_bytes + value_bytes_copied, | |
731 | &optim, | |
732 | &addr, | |
733 | frame, | |
734 | local_regnum, | |
735 | &lval); | |
736 | ||
32178cab | 737 | if (register_cached (local_regnum) == -1) |
c5aa993b | 738 | return NULL; /* register value not available */ |
c906108c SS |
739 | |
740 | if (regnum == local_regnum) | |
741 | first_addr = addr; | |
742 | if (lval == lval_register) | |
743 | reg_stor++; | |
744 | else | |
745 | { | |
746 | mem_stor++; | |
c5aa993b | 747 | |
c906108c SS |
748 | mem_tracking = |
749 | (mem_tracking | |
750 | && (regnum == local_regnum | |
751 | || addr == last_addr)); | |
752 | } | |
753 | last_addr = addr; | |
754 | } | |
755 | ||
756 | if ((reg_stor && mem_stor) | |
757 | || (mem_stor && !mem_tracking)) | |
758 | /* Mixed storage; all of the hassle we just went through was | |
759 | for some good purpose. */ | |
760 | { | |
761 | VALUE_LVAL (v) = lval_reg_frame_relative; | |
762 | VALUE_FRAME (v) = FRAME_FP (frame); | |
763 | VALUE_FRAME_REGNUM (v) = regnum; | |
764 | } | |
765 | else if (mem_stor) | |
766 | { | |
767 | VALUE_LVAL (v) = lval_memory; | |
768 | VALUE_ADDRESS (v) = first_addr; | |
769 | } | |
770 | else if (reg_stor) | |
771 | { | |
772 | VALUE_LVAL (v) = lval_register; | |
773 | VALUE_ADDRESS (v) = first_addr; | |
774 | } | |
775 | else | |
8e65ff28 AC |
776 | internal_error (__FILE__, __LINE__, |
777 | "value_from_register: Value not stored anywhere!"); | |
c906108c SS |
778 | |
779 | VALUE_OPTIMIZED_OUT (v) = optim; | |
780 | ||
781 | /* Any structure stored in more than one register will always be | |
c5aa993b JM |
782 | an integral number of registers. Otherwise, you'd need to do |
783 | some fiddling with the last register copied here for little | |
784 | endian machines. */ | |
c906108c SS |
785 | |
786 | /* Copy into the contents section of the value. */ | |
787 | memcpy (VALUE_CONTENTS_RAW (v), value_bytes, len); | |
788 | ||
789 | /* Finally do any conversion necessary when extracting this | |
790 | type from more than one register. */ | |
791 | #ifdef REGISTER_CONVERT_TO_TYPE | |
c5aa993b | 792 | REGISTER_CONVERT_TO_TYPE (regnum, type, VALUE_CONTENTS_RAW (v)); |
c906108c SS |
793 | #endif |
794 | return v; | |
795 | } | |
796 | ||
797 | /* Data is completely contained within a single register. Locate the | |
798 | register's contents in a real register or in core; | |
799 | read the data in raw format. */ | |
800 | ||
801 | get_saved_register (raw_buffer, &optim, &addr, frame, regnum, &lval); | |
802 | ||
32178cab | 803 | if (register_cached (regnum) == -1) |
c5aa993b | 804 | return NULL; /* register value not available */ |
c906108c SS |
805 | |
806 | VALUE_OPTIMIZED_OUT (v) = optim; | |
807 | VALUE_LVAL (v) = lval; | |
808 | VALUE_ADDRESS (v) = addr; | |
809 | ||
810 | /* Convert raw data to virtual format if necessary. */ | |
c5aa993b | 811 | |
c906108c SS |
812 | if (REGISTER_CONVERTIBLE (regnum)) |
813 | { | |
814 | REGISTER_CONVERT_TO_VIRTUAL (regnum, type, | |
815 | raw_buffer, VALUE_CONTENTS_RAW (v)); | |
816 | } | |
817 | else | |
c906108c SS |
818 | { |
819 | /* Raw and virtual formats are the same for this register. */ | |
820 | ||
d7449b42 | 821 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG && len < REGISTER_RAW_SIZE (regnum)) |
c906108c | 822 | { |
c5aa993b | 823 | /* Big-endian, and we want less than full size. */ |
c906108c SS |
824 | VALUE_OFFSET (v) = REGISTER_RAW_SIZE (regnum) - len; |
825 | } | |
826 | ||
827 | memcpy (VALUE_CONTENTS_RAW (v), raw_buffer + VALUE_OFFSET (v), len); | |
828 | } | |
c5aa993b | 829 | |
c906108c SS |
830 | return v; |
831 | } | |
832 | \f | |
833 | /* Given a struct symbol for a variable or function, | |
834 | and a stack frame id, | |
835 | return a (pointer to a) struct value containing the properly typed | |
836 | address. */ | |
837 | ||
3d6d86c6 | 838 | struct value * |
fba45db2 | 839 | locate_var_value (register struct symbol *var, struct frame_info *frame) |
c906108c SS |
840 | { |
841 | CORE_ADDR addr = 0; | |
842 | struct type *type = SYMBOL_TYPE (var); | |
3d6d86c6 | 843 | struct value *lazy_value; |
c906108c SS |
844 | |
845 | /* Evaluate it first; if the result is a memory address, we're fine. | |
846 | Lazy evaluation pays off here. */ | |
847 | ||
848 | lazy_value = read_var_value (var, frame); | |
849 | if (lazy_value == 0) | |
850 | error ("Address of \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var)); | |
851 | ||
852 | if (VALUE_LAZY (lazy_value) | |
853 | || TYPE_CODE (type) == TYPE_CODE_FUNC) | |
854 | { | |
3d6d86c6 | 855 | struct value *val; |
c906108c SS |
856 | |
857 | addr = VALUE_ADDRESS (lazy_value); | |
4478b372 | 858 | val = value_from_pointer (lookup_pointer_type (type), addr); |
c906108c SS |
859 | VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (lazy_value); |
860 | return val; | |
861 | } | |
862 | ||
863 | /* Not a memory address; check what the problem was. */ | |
c5aa993b | 864 | switch (VALUE_LVAL (lazy_value)) |
c906108c SS |
865 | { |
866 | case lval_register: | |
14e534aa PM |
867 | gdb_assert (REGISTER_NAME (VALUE_REGNO (lazy_value)) != NULL |
868 | && *REGISTER_NAME (VALUE_REGNO (lazy_value)) != '\0'); | |
869 | error("Address requested for identifier " | |
870 | "\"%s\" which is in register $%s", | |
871 | SYMBOL_SOURCE_NAME (var), | |
872 | REGISTER_NAME (VALUE_REGNO (lazy_value))); | |
873 | break; | |
874 | ||
c906108c | 875 | case lval_reg_frame_relative: |
14e534aa PM |
876 | gdb_assert (REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != NULL |
877 | && *REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != '\0'); | |
878 | error("Address requested for identifier " | |
879 | "\"%s\" which is in frame register $%s", | |
880 | SYMBOL_SOURCE_NAME (var), | |
881 | REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value))); | |
c906108c SS |
882 | break; |
883 | ||
884 | default: | |
885 | error ("Can't take address of \"%s\" which isn't an lvalue.", | |
886 | SYMBOL_SOURCE_NAME (var)); | |
887 | break; | |
888 | } | |
c5aa993b | 889 | return 0; /* For lint -- never reached */ |
c906108c | 890 | } |