Commit | Line | Data |
---|---|---|
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" |
eb8bc282 | 37 | #include "user-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 | 48 | you lose |
c906108c SS |
49 | #endif |
50 | ||
a9ac8f51 | 51 | LONGEST |
37611a2b | 52 | extract_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 ("\ | |
61 | That 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 | ||
85 | ULONGEST | |
37611a2b | 86 | extract_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 ("\ | |
95 | That 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 | ||
119 | int | |
66140c26 | 120 | extract_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. */ | |
166 | CORE_ADDR | |
66140c26 | 167 | extract_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 | 179 | void |
a9ac8f51 | 180 | store_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 | ||
206 | void | |
a9ac8f51 | 207 | store_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. */ | |
235 | void | |
236 | store_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 | 256 | struct value * |
376c9600 | 257 | value_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 | ||
eb8bc282 | 266 | /* User registers lie completly outside of the range of normal |
0406ec40 AC |
267 | registers. Catch them early so that the target never sees them. */ |
268 | if (regnum >= NUM_REGS + NUM_PSEUDO_REGS) | |
eb8bc282 | 269 | return value_of_user_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 | } |
12c266ea | 292 | else if (DEPRECATED_REGISTER_RAW_SIZE (regnum) == DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum)) |
392a587b | 293 | memcpy (VALUE_CONTENTS_RAW (reg_val), raw_buffer, |
12c266ea | 294 | DEPRECATED_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, | |
12c266ea | 300 | DEPRECATED_REGISTER_RAW_SIZE (regnum), |
f30992d4 | 301 | DEPRECATED_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. */ | |
311 | CORE_ADDR | |
66140c26 | 312 | unsigned_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 | 317 | CORE_ADDR |
66140c26 | 318 | signed_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. */ | |
325 | void | |
ac2e2ef7 | 326 | unsigned_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 |
331 | void |
332 | address_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. */ | |
340 | int | |
fba45db2 | 341 | symbol_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: | |
a67af2b9 AC |
349 | /* FIXME: cagney/2004-01-26: It should be possible to |
350 | unconditionally call the SYMBOL_OPS method when available. | |
351 | Unfortunatly DWARF 2 stores the frame-base (instead of the | |
352 | function) location in a function's symbol. Oops! For the | |
353 | moment enable this when/where applicable. */ | |
354 | return SYMBOL_OPS (sym)->read_needs_frame (sym); | |
4c2df51b | 355 | |
c906108c SS |
356 | case LOC_REGISTER: |
357 | case LOC_ARG: | |
358 | case LOC_REF_ARG: | |
359 | case LOC_REGPARM: | |
360 | case LOC_REGPARM_ADDR: | |
361 | case LOC_LOCAL: | |
362 | case LOC_LOCAL_ARG: | |
363 | case LOC_BASEREG: | |
364 | case LOC_BASEREG_ARG: | |
407caf07 | 365 | case LOC_HP_THREAD_LOCAL_STATIC: |
c906108c SS |
366 | return 1; |
367 | ||
368 | case LOC_UNDEF: | |
369 | case LOC_CONST: | |
370 | case LOC_STATIC: | |
371 | case LOC_INDIRECT: | |
372 | case LOC_TYPEDEF: | |
373 | ||
374 | case LOC_LABEL: | |
375 | /* Getting the address of a label can be done independently of the block, | |
c5aa993b JM |
376 | even if some *uses* of that address wouldn't work so well without |
377 | the right frame. */ | |
c906108c SS |
378 | |
379 | case LOC_BLOCK: | |
380 | case LOC_CONST_BYTES: | |
381 | case LOC_UNRESOLVED: | |
382 | case LOC_OPTIMIZED_OUT: | |
383 | return 0; | |
384 | } | |
385 | return 1; | |
386 | } | |
387 | ||
388 | /* Given a struct symbol for a variable, | |
389 | and a stack frame id, read the value of the variable | |
390 | and return a (pointer to a) struct value containing the value. | |
391 | If the variable cannot be found, return a zero pointer. | |
6e7f8b9c | 392 | If FRAME is NULL, use the deprecated_selected_frame. */ |
c906108c | 393 | |
3d6d86c6 | 394 | struct value * |
aa1ee363 | 395 | read_var_value (struct symbol *var, struct frame_info *frame) |
c906108c | 396 | { |
52f0bd74 | 397 | struct value *v; |
c906108c SS |
398 | struct type *type = SYMBOL_TYPE (var); |
399 | CORE_ADDR addr; | |
52f0bd74 | 400 | int len; |
c906108c SS |
401 | |
402 | v = allocate_value (type); | |
403 | VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */ | |
404 | VALUE_BFD_SECTION (v) = SYMBOL_BFD_SECTION (var); | |
405 | ||
406 | len = TYPE_LENGTH (type); | |
407 | ||
7dd88986 DJ |
408 | |
409 | /* FIXME drow/2003-09-06: this call to the selected frame should be | |
410 | pushed upwards to the callers. */ | |
c5aa993b | 411 | if (frame == NULL) |
7dd88986 | 412 | frame = deprecated_safe_get_selected_frame (); |
c906108c SS |
413 | |
414 | switch (SYMBOL_CLASS (var)) | |
415 | { | |
416 | case LOC_CONST: | |
417 | /* Put the constant back in target format. */ | |
418 | store_signed_integer (VALUE_CONTENTS_RAW (v), len, | |
419 | (LONGEST) SYMBOL_VALUE (var)); | |
420 | VALUE_LVAL (v) = not_lval; | |
421 | return v; | |
422 | ||
423 | case LOC_LABEL: | |
424 | /* Put the constant back in target format. */ | |
425 | if (overlay_debugging) | |
4478b372 JB |
426 | { |
427 | CORE_ADDR addr | |
428 | = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
429 | SYMBOL_BFD_SECTION (var)); | |
430 | store_typed_address (VALUE_CONTENTS_RAW (v), type, addr); | |
431 | } | |
c906108c | 432 | else |
4478b372 JB |
433 | store_typed_address (VALUE_CONTENTS_RAW (v), type, |
434 | SYMBOL_VALUE_ADDRESS (var)); | |
c906108c SS |
435 | VALUE_LVAL (v) = not_lval; |
436 | return v; | |
437 | ||
438 | case LOC_CONST_BYTES: | |
439 | { | |
440 | char *bytes_addr; | |
441 | bytes_addr = SYMBOL_VALUE_BYTES (var); | |
442 | memcpy (VALUE_CONTENTS_RAW (v), bytes_addr, len); | |
443 | VALUE_LVAL (v) = not_lval; | |
444 | return v; | |
445 | } | |
446 | ||
447 | case LOC_STATIC: | |
448 | if (overlay_debugging) | |
449 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
450 | SYMBOL_BFD_SECTION (var)); | |
451 | else | |
452 | addr = SYMBOL_VALUE_ADDRESS (var); | |
453 | break; | |
454 | ||
455 | case LOC_INDIRECT: | |
f76febae AC |
456 | { |
457 | /* The import slot does not have a real address in it from the | |
458 | dynamic loader (dld.sl on HP-UX), if the target hasn't | |
459 | begun execution yet, so check for that. */ | |
460 | CORE_ADDR locaddr; | |
461 | struct value *loc; | |
462 | if (!target_has_execution) | |
463 | error ("\ | |
c906108c SS |
464 | Attempt to access variable defined in different shared object or load module when\n\ |
465 | addresses have not been bound by the dynamic loader. Try again when executable is running."); | |
c5aa993b | 466 | |
f76febae AC |
467 | locaddr = SYMBOL_VALUE_ADDRESS (var); |
468 | loc = value_at (lookup_pointer_type (type), locaddr, NULL); | |
1aa20aa8 | 469 | addr = value_as_address (loc); |
f76febae | 470 | } |
c906108c SS |
471 | |
472 | case LOC_ARG: | |
473 | if (frame == NULL) | |
474 | return 0; | |
da62e633 | 475 | addr = get_frame_args_address (frame); |
c906108c SS |
476 | if (!addr) |
477 | return 0; | |
478 | addr += SYMBOL_VALUE (var); | |
479 | break; | |
480 | ||
481 | case LOC_REF_ARG: | |
f76febae AC |
482 | { |
483 | struct value *ref; | |
484 | CORE_ADDR argref; | |
485 | if (frame == NULL) | |
486 | return 0; | |
da62e633 | 487 | argref = get_frame_args_address (frame); |
f76febae AC |
488 | if (!argref) |
489 | return 0; | |
490 | argref += SYMBOL_VALUE (var); | |
491 | ref = value_at (lookup_pointer_type (type), argref, NULL); | |
1aa20aa8 | 492 | addr = value_as_address (ref); |
f76febae AC |
493 | break; |
494 | } | |
c906108c SS |
495 | |
496 | case LOC_LOCAL: | |
497 | case LOC_LOCAL_ARG: | |
498 | if (frame == NULL) | |
499 | return 0; | |
da62e633 | 500 | addr = get_frame_locals_address (frame); |
c906108c SS |
501 | addr += SYMBOL_VALUE (var); |
502 | break; | |
503 | ||
504 | case LOC_BASEREG: | |
505 | case LOC_BASEREG_ARG: | |
407caf07 | 506 | case LOC_HP_THREAD_LOCAL_STATIC: |
c906108c | 507 | { |
3d6d86c6 | 508 | struct value *regval; |
c5aa993b | 509 | |
9ed10b08 ND |
510 | regval = value_from_register (lookup_pointer_type (type), |
511 | SYMBOL_BASEREG (var), frame); | |
512 | if (regval == NULL) | |
513 | error ("Value of base register not available."); | |
1aa20aa8 | 514 | addr = value_as_address (regval); |
c5aa993b JM |
515 | addr += SYMBOL_VALUE (var); |
516 | break; | |
c906108c | 517 | } |
c5aa993b | 518 | |
c906108c SS |
519 | case LOC_TYPEDEF: |
520 | error ("Cannot look up value of a typedef"); | |
521 | break; | |
522 | ||
523 | case LOC_BLOCK: | |
524 | if (overlay_debugging) | |
c5aa993b | 525 | VALUE_ADDRESS (v) = symbol_overlayed_address |
c906108c SS |
526 | (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var)); |
527 | else | |
528 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); | |
529 | return v; | |
530 | ||
531 | case LOC_REGISTER: | |
532 | case LOC_REGPARM: | |
533 | case LOC_REGPARM_ADDR: | |
534 | { | |
535 | struct block *b; | |
536 | int regno = SYMBOL_VALUE (var); | |
3d6d86c6 | 537 | struct value *regval; |
c906108c SS |
538 | |
539 | if (frame == NULL) | |
540 | return 0; | |
ae767bfb | 541 | b = get_frame_block (frame, 0); |
c906108c SS |
542 | |
543 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) | |
544 | { | |
545 | regval = value_from_register (lookup_pointer_type (type), | |
c5aa993b | 546 | regno, |
c906108c SS |
547 | frame); |
548 | ||
549 | if (regval == NULL) | |
550 | error ("Value of register variable not available."); | |
551 | ||
1aa20aa8 | 552 | addr = value_as_address (regval); |
c906108c SS |
553 | VALUE_LVAL (v) = lval_memory; |
554 | } | |
555 | else | |
556 | { | |
557 | regval = value_from_register (type, regno, frame); | |
558 | ||
559 | if (regval == NULL) | |
560 | error ("Value of register variable not available."); | |
561 | return regval; | |
562 | } | |
563 | } | |
564 | break; | |
565 | ||
4c2df51b DJ |
566 | case LOC_COMPUTED: |
567 | case LOC_COMPUTED_ARG: | |
a67af2b9 AC |
568 | /* FIXME: cagney/2004-01-26: It should be possible to |
569 | unconditionally call the SYMBOL_OPS method when available. | |
570 | Unfortunatly DWARF 2 stores the frame-base (instead of the | |
571 | function) location in a function's symbol. Oops! For the | |
572 | moment enable this when/where applicable. */ | |
573 | if (frame == 0 && SYMBOL_OPS (var)->read_needs_frame (var)) | |
574 | return 0; | |
575 | return SYMBOL_OPS (var)->read_variable (var, frame); | |
4c2df51b | 576 | |
c906108c SS |
577 | case LOC_UNRESOLVED: |
578 | { | |
579 | struct minimal_symbol *msym; | |
580 | ||
22abf04a | 581 | msym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (var), NULL, NULL); |
c906108c SS |
582 | if (msym == NULL) |
583 | return 0; | |
584 | if (overlay_debugging) | |
585 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), | |
586 | SYMBOL_BFD_SECTION (msym)); | |
587 | else | |
588 | addr = SYMBOL_VALUE_ADDRESS (msym); | |
589 | } | |
590 | break; | |
591 | ||
592 | case LOC_OPTIMIZED_OUT: | |
593 | VALUE_LVAL (v) = not_lval; | |
594 | VALUE_OPTIMIZED_OUT (v) = 1; | |
595 | return v; | |
596 | ||
597 | default: | |
598 | error ("Cannot look up value of a botched symbol."); | |
599 | break; | |
600 | } | |
601 | ||
602 | VALUE_ADDRESS (v) = addr; | |
603 | VALUE_LAZY (v) = 1; | |
604 | return v; | |
605 | } | |
606 | ||
607 | /* Return a value of type TYPE, stored in register REGNUM, in frame | |
0f2c5ba5 | 608 | FRAME. |
c906108c SS |
609 | |
610 | NOTE: returns NULL if register value is not available. | |
611 | Caller will check return value or die! */ | |
612 | ||
3d6d86c6 | 613 | struct value * |
fba45db2 | 614 | value_from_register (struct type *type, int regnum, struct frame_info *frame) |
c906108c | 615 | { |
ff2e87ac | 616 | struct gdbarch *gdbarch = get_frame_arch (frame); |
3d6d86c6 | 617 | struct value *v = allocate_value (type); |
c906108c | 618 | CHECK_TYPEDEF (type); |
c906108c | 619 | |
ff2e87ac AC |
620 | if (CONVERT_REGISTER_P (regnum, type)) |
621 | { | |
622 | /* The ISA/ABI need to something weird when obtaining the | |
623 | specified value from this register. It might need to | |
624 | re-order non-adjacent, starting with REGNUM (see MIPS and | |
625 | i386). It might need to convert the [float] register into | |
626 | the corresponding [integer] type (see Alpha). The assumption | |
627 | is that REGISTER_TO_VALUE populates the entire value | |
628 | including the location. */ | |
629 | REGISTER_TO_VALUE (frame, regnum, type, VALUE_CONTENTS_RAW (v)); | |
630 | VALUE_LVAL (v) = lval_reg_frame_relative; | |
631 | VALUE_FRAME_ID (v) = get_frame_id (frame); | |
632 | VALUE_FRAME_REGNUM (v) = regnum; | |
633 | } | |
634 | else | |
c906108c | 635 | { |
c906108c SS |
636 | int local_regnum; |
637 | int mem_stor = 0, reg_stor = 0; | |
638 | int mem_tracking = 1; | |
639 | CORE_ADDR last_addr = 0; | |
640 | CORE_ADDR first_addr = 0; | |
ff2e87ac AC |
641 | int first_realnum = regnum; |
642 | int len = TYPE_LENGTH (type); | |
643 | int value_bytes_copied; | |
644 | int optimized = 0; | |
645 | char *value_bytes = (char *) alloca (len + MAX_REGISTER_SIZE); | |
c906108c SS |
646 | |
647 | /* Copy all of the data out, whereever it may be. */ | |
ff2e87ac AC |
648 | for (local_regnum = regnum, value_bytes_copied = 0; |
649 | value_bytes_copied < len; | |
12c266ea | 650 | (value_bytes_copied += DEPRECATED_REGISTER_RAW_SIZE (local_regnum), |
ff2e87ac AC |
651 | ++local_regnum)) |
652 | { | |
653 | int realnum; | |
654 | int optim; | |
655 | enum lval_type lval; | |
656 | CORE_ADDR addr; | |
657 | frame_register (frame, local_regnum, &optim, &lval, &addr, | |
658 | &realnum, value_bytes + value_bytes_copied); | |
659 | optimized += optim; | |
660 | if (register_cached (local_regnum) == -1) | |
661 | return NULL; /* register value not available */ | |
662 | ||
663 | if (regnum == local_regnum) | |
664 | { | |
c906108c | 665 | first_addr = addr; |
ff2e87ac AC |
666 | first_realnum = realnum; |
667 | } | |
668 | if (lval == lval_register) | |
669 | reg_stor++; | |
670 | else | |
671 | { | |
672 | mem_stor++; | |
673 | ||
674 | mem_tracking = (mem_tracking | |
675 | && (regnum == local_regnum | |
676 | || addr == last_addr)); | |
677 | } | |
678 | last_addr = addr; | |
679 | } | |
680 | ||
681 | /* FIXME: cagney/2003-06-04: Shouldn't this always use | |
682 | lval_reg_frame_relative? If it doesn't and the register's | |
683 | location changes (say after a resume) then this value is | |
684 | going to have wrong information. */ | |
c906108c SS |
685 | if ((reg_stor && mem_stor) |
686 | || (mem_stor && !mem_tracking)) | |
687 | /* Mixed storage; all of the hassle we just went through was | |
688 | for some good purpose. */ | |
689 | { | |
690 | VALUE_LVAL (v) = lval_reg_frame_relative; | |
1df6926e | 691 | VALUE_FRAME_ID (v) = get_frame_id (frame); |
c906108c SS |
692 | VALUE_FRAME_REGNUM (v) = regnum; |
693 | } | |
694 | else if (mem_stor) | |
695 | { | |
696 | VALUE_LVAL (v) = lval_memory; | |
697 | VALUE_ADDRESS (v) = first_addr; | |
698 | } | |
699 | else if (reg_stor) | |
700 | { | |
701 | VALUE_LVAL (v) = lval_register; | |
702 | VALUE_ADDRESS (v) = first_addr; | |
ff2e87ac | 703 | VALUE_REGNO (v) = first_realnum; |
c906108c SS |
704 | } |
705 | else | |
8e65ff28 AC |
706 | internal_error (__FILE__, __LINE__, |
707 | "value_from_register: Value not stored anywhere!"); | |
ff2e87ac AC |
708 | |
709 | VALUE_OPTIMIZED_OUT (v) = optimized; | |
710 | ||
c906108c | 711 | /* Any structure stored in more than one register will always be |
ff2e87ac | 712 | an integral number of registers. Otherwise, you need to do |
c5aa993b JM |
713 | some fiddling with the last register copied here for little |
714 | endian machines. */ | |
ff2e87ac | 715 | if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG |
12c266ea | 716 | && len < DEPRECATED_REGISTER_RAW_SIZE (regnum)) |
ff2e87ac | 717 | /* Big-endian, and we want less than full size. */ |
12c266ea | 718 | VALUE_OFFSET (v) = DEPRECATED_REGISTER_RAW_SIZE (regnum) - len; |
ff2e87ac AC |
719 | else |
720 | VALUE_OFFSET (v) = 0; | |
721 | memcpy (VALUE_CONTENTS_RAW (v), value_bytes + VALUE_OFFSET (v), len); | |
c906108c | 722 | } |
c906108c SS |
723 | return v; |
724 | } | |
ff2e87ac | 725 | |
c906108c SS |
726 | \f |
727 | /* Given a struct symbol for a variable or function, | |
728 | and a stack frame id, | |
729 | return a (pointer to a) struct value containing the properly typed | |
730 | address. */ | |
731 | ||
3d6d86c6 | 732 | struct value * |
aa1ee363 | 733 | locate_var_value (struct symbol *var, struct frame_info *frame) |
c906108c SS |
734 | { |
735 | CORE_ADDR addr = 0; | |
736 | struct type *type = SYMBOL_TYPE (var); | |
3d6d86c6 | 737 | struct value *lazy_value; |
c906108c SS |
738 | |
739 | /* Evaluate it first; if the result is a memory address, we're fine. | |
740 | Lazy evaluation pays off here. */ | |
741 | ||
742 | lazy_value = read_var_value (var, frame); | |
743 | if (lazy_value == 0) | |
de5ad195 | 744 | error ("Address of \"%s\" is unknown.", SYMBOL_PRINT_NAME (var)); |
c906108c SS |
745 | |
746 | if (VALUE_LAZY (lazy_value) | |
747 | || TYPE_CODE (type) == TYPE_CODE_FUNC) | |
748 | { | |
3d6d86c6 | 749 | struct value *val; |
c906108c SS |
750 | |
751 | addr = VALUE_ADDRESS (lazy_value); | |
4478b372 | 752 | val = value_from_pointer (lookup_pointer_type (type), addr); |
c906108c SS |
753 | VALUE_BFD_SECTION (val) = VALUE_BFD_SECTION (lazy_value); |
754 | return val; | |
755 | } | |
756 | ||
757 | /* Not a memory address; check what the problem was. */ | |
c5aa993b | 758 | switch (VALUE_LVAL (lazy_value)) |
c906108c SS |
759 | { |
760 | case lval_register: | |
14e534aa PM |
761 | gdb_assert (REGISTER_NAME (VALUE_REGNO (lazy_value)) != NULL |
762 | && *REGISTER_NAME (VALUE_REGNO (lazy_value)) != '\0'); | |
763 | error("Address requested for identifier " | |
764 | "\"%s\" which is in register $%s", | |
de5ad195 | 765 | SYMBOL_PRINT_NAME (var), |
14e534aa PM |
766 | REGISTER_NAME (VALUE_REGNO (lazy_value))); |
767 | break; | |
768 | ||
c906108c | 769 | case lval_reg_frame_relative: |
14e534aa PM |
770 | gdb_assert (REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != NULL |
771 | && *REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value)) != '\0'); | |
772 | error("Address requested for identifier " | |
773 | "\"%s\" which is in frame register $%s", | |
de5ad195 | 774 | SYMBOL_PRINT_NAME (var), |
14e534aa | 775 | REGISTER_NAME (VALUE_FRAME_REGNUM (lazy_value))); |
c906108c SS |
776 | break; |
777 | ||
778 | default: | |
779 | error ("Can't take address of \"%s\" which isn't an lvalue.", | |
de5ad195 | 780 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
781 | break; |
782 | } | |
c5aa993b | 783 | return 0; /* For lint -- never reached */ |
c906108c | 784 | } |