Commit | Line | Data |
---|---|---|
c906108c | 1 | /* Find a variable's value in memory, for GDB, the GNU debugger. |
1bac305b | 2 | |
6aba47ca DJ |
3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
4 | 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2007 | |
5 | Free Software 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 | |
197e01b6 EZ |
21 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
22 | Boston, MA 02110-1301, 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 |
0d509538 | 52 | extract_signed_integer (const gdb_byte *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)) | |
8a3fe4f8 AC |
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. */ | |
0d20ae72 | 66 | if (gdbarch_byte_order (current_gdbarch) == 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 | |
0d509538 | 86 | extract_unsigned_integer (const gdb_byte *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)) | |
8a3fe4f8 AC |
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; | |
0d20ae72 | 101 | if (gdbarch_byte_order (current_gdbarch) == 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 | |
0d509538 AC |
120 | extract_long_unsigned_integer (const gdb_byte *addr, int orig_len, |
121 | LONGEST *pval) | |
c906108c | 122 | { |
0d509538 AC |
123 | const gdb_byte *p; |
124 | const gdb_byte *first_addr; | |
c906108c SS |
125 | int len; |
126 | ||
127 | len = orig_len; | |
0d20ae72 | 128 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG) |
c906108c | 129 | { |
0d509538 AC |
130 | for (p = addr; |
131 | len > (int) sizeof (LONGEST) && p < addr + orig_len; | |
c906108c SS |
132 | p++) |
133 | { | |
134 | if (*p == 0) | |
135 | len--; | |
136 | else | |
137 | break; | |
138 | } | |
139 | first_addr = p; | |
140 | } | |
141 | else | |
142 | { | |
0d509538 AC |
143 | first_addr = addr; |
144 | for (p = addr + orig_len - 1; | |
145 | len > (int) sizeof (LONGEST) && p >= addr; | |
c906108c SS |
146 | p--) |
147 | { | |
148 | if (*p == 0) | |
149 | len--; | |
150 | else | |
151 | break; | |
152 | } | |
153 | } | |
154 | ||
155 | if (len <= (int) sizeof (LONGEST)) | |
156 | { | |
157 | *pval = (LONGEST) extract_unsigned_integer (first_addr, | |
158 | sizeof (LONGEST)); | |
159 | return 1; | |
160 | } | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
4478b372 | 165 | |
4478b372 JB |
166 | /* Treat the bytes at BUF as a pointer of type TYPE, and return the |
167 | address it represents. */ | |
168 | CORE_ADDR | |
0d509538 | 169 | extract_typed_address (const gdb_byte *buf, struct type *type) |
4478b372 JB |
170 | { |
171 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
172 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 | 173 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 AC |
174 | _("extract_typed_address: " |
175 | "type is not a pointer or reference")); | |
4478b372 JB |
176 | |
177 | return POINTER_TO_ADDRESS (type, buf); | |
178 | } | |
179 | ||
180 | ||
c906108c | 181 | void |
0d509538 | 182 | store_signed_integer (gdb_byte *addr, int len, LONGEST val) |
c906108c | 183 | { |
0d509538 AC |
184 | gdb_byte *p; |
185 | gdb_byte *startaddr = addr; | |
186 | gdb_byte *endaddr = startaddr + len; | |
c906108c SS |
187 | |
188 | /* Start at the least significant end of the integer, and work towards | |
189 | the most significant. */ | |
0d20ae72 | 190 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG) |
c906108c SS |
191 | { |
192 | for (p = endaddr - 1; p >= startaddr; --p) | |
193 | { | |
194 | *p = val & 0xff; | |
195 | val >>= 8; | |
196 | } | |
197 | } | |
198 | else | |
199 | { | |
200 | for (p = startaddr; p < endaddr; ++p) | |
201 | { | |
202 | *p = val & 0xff; | |
203 | val >>= 8; | |
204 | } | |
205 | } | |
206 | } | |
207 | ||
208 | void | |
0d509538 | 209 | store_unsigned_integer (gdb_byte *addr, int len, ULONGEST val) |
c906108c SS |
210 | { |
211 | unsigned char *p; | |
c5aa993b | 212 | unsigned char *startaddr = (unsigned char *) addr; |
c906108c SS |
213 | unsigned char *endaddr = startaddr + len; |
214 | ||
215 | /* Start at the least significant end of the integer, and work towards | |
216 | the most significant. */ | |
0d20ae72 | 217 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG) |
c906108c SS |
218 | { |
219 | for (p = endaddr - 1; p >= startaddr; --p) | |
220 | { | |
221 | *p = val & 0xff; | |
222 | val >>= 8; | |
223 | } | |
224 | } | |
225 | else | |
226 | { | |
227 | for (p = startaddr; p < endaddr; ++p) | |
228 | { | |
229 | *p = val & 0xff; | |
230 | val >>= 8; | |
231 | } | |
232 | } | |
233 | } | |
234 | ||
4478b372 JB |
235 | /* Store the address ADDR as a pointer of type TYPE at BUF, in target |
236 | form. */ | |
237 | void | |
0d509538 | 238 | store_typed_address (gdb_byte *buf, struct type *type, CORE_ADDR addr) |
4478b372 JB |
239 | { |
240 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
241 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 | 242 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 AC |
243 | _("store_typed_address: " |
244 | "type is not a pointer or reference")); | |
4478b372 JB |
245 | |
246 | ADDRESS_TO_POINTER (type, buf, addr); | |
247 | } | |
248 | ||
249 | ||
250 | ||
376c9600 AC |
251 | /* Return a `value' with the contents of (virtual or cooked) register |
252 | REGNUM as found in the specified FRAME. The register's type is | |
9c5ea4d9 | 253 | determined by register_type(). */ |
c906108c | 254 | |
3d6d86c6 | 255 | struct value * |
376c9600 | 256 | value_of_register (int regnum, struct frame_info *frame) |
c906108c SS |
257 | { |
258 | CORE_ADDR addr; | |
259 | int optim; | |
3d6d86c6 | 260 | struct value *reg_val; |
ac2adee5 | 261 | int realnum; |
10c42a71 | 262 | gdb_byte raw_buffer[MAX_REGISTER_SIZE]; |
c906108c SS |
263 | enum lval_type lval; |
264 | ||
9564ee9f | 265 | /* User registers lie completely outside of the range of normal |
0406ec40 | 266 | registers. Catch them early so that the target never sees them. */ |
f57d151a UW |
267 | if (regnum >= gdbarch_num_regs (current_gdbarch) |
268 | + gdbarch_num_pseudo_regs (current_gdbarch)) | |
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 | |
7b83296f | 273 | reg_val = allocate_value (register_type (current_gdbarch, regnum)); |
c906108c | 274 | |
990a07ab | 275 | memcpy (value_contents_raw (reg_val), raw_buffer, |
01e1877c | 276 | register_size (current_gdbarch, regnum)); |
c906108c SS |
277 | VALUE_LVAL (reg_val) = lval; |
278 | VALUE_ADDRESS (reg_val) = addr; | |
9ee8fc9d | 279 | VALUE_REGNUM (reg_val) = regnum; |
feb13ab0 | 280 | set_value_optimized_out (reg_val, optim); |
0c16dd26 | 281 | VALUE_FRAME_ID (reg_val) = get_frame_id (frame); |
c906108c SS |
282 | return reg_val; |
283 | } | |
4478b372 JB |
284 | |
285 | /* Given a pointer of type TYPE in target form in BUF, return the | |
286 | address it represents. */ | |
287 | CORE_ADDR | |
b60c417a | 288 | unsigned_pointer_to_address (struct type *type, const gdb_byte *buf) |
4478b372 | 289 | { |
af1342ab | 290 | return extract_unsigned_integer (buf, TYPE_LENGTH (type)); |
4478b372 JB |
291 | } |
292 | ||
ac2e2ef7 | 293 | CORE_ADDR |
b60c417a | 294 | signed_pointer_to_address (struct type *type, const gdb_byte *buf) |
ac2e2ef7 AC |
295 | { |
296 | return extract_signed_integer (buf, TYPE_LENGTH (type)); | |
297 | } | |
4478b372 JB |
298 | |
299 | /* Given an address, store it as a pointer of type TYPE in target | |
300 | format in BUF. */ | |
301 | void | |
b60c417a AC |
302 | unsigned_address_to_pointer (struct type *type, gdb_byte *buf, |
303 | CORE_ADDR addr) | |
4478b372 | 304 | { |
fbd9dcd3 | 305 | store_unsigned_integer (buf, TYPE_LENGTH (type), addr); |
4478b372 JB |
306 | } |
307 | ||
ac2e2ef7 | 308 | void |
b60c417a | 309 | address_to_signed_pointer (struct type *type, gdb_byte *buf, CORE_ADDR addr) |
ac2e2ef7 AC |
310 | { |
311 | store_signed_integer (buf, TYPE_LENGTH (type), addr); | |
312 | } | |
c906108c SS |
313 | \f |
314 | /* Will calling read_var_value or locate_var_value on SYM end | |
315 | up caring what frame it is being evaluated relative to? SYM must | |
316 | be non-NULL. */ | |
317 | int | |
fba45db2 | 318 | symbol_read_needs_frame (struct symbol *sym) |
c906108c SS |
319 | { |
320 | switch (SYMBOL_CLASS (sym)) | |
321 | { | |
322 | /* All cases listed explicitly so that gcc -Wall will detect it if | |
c5aa993b | 323 | we failed to consider one. */ |
4c2df51b DJ |
324 | case LOC_COMPUTED: |
325 | case LOC_COMPUTED_ARG: | |
a67af2b9 AC |
326 | /* FIXME: cagney/2004-01-26: It should be possible to |
327 | unconditionally call the SYMBOL_OPS method when available. | |
d3efc286 | 328 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
329 | function) location in a function's symbol. Oops! For the |
330 | moment enable this when/where applicable. */ | |
331 | return SYMBOL_OPS (sym)->read_needs_frame (sym); | |
4c2df51b | 332 | |
c906108c SS |
333 | case LOC_REGISTER: |
334 | case LOC_ARG: | |
335 | case LOC_REF_ARG: | |
336 | case LOC_REGPARM: | |
337 | case LOC_REGPARM_ADDR: | |
338 | case LOC_LOCAL: | |
339 | case LOC_LOCAL_ARG: | |
340 | case LOC_BASEREG: | |
341 | case LOC_BASEREG_ARG: | |
407caf07 | 342 | case LOC_HP_THREAD_LOCAL_STATIC: |
c906108c SS |
343 | return 1; |
344 | ||
345 | case LOC_UNDEF: | |
346 | case LOC_CONST: | |
347 | case LOC_STATIC: | |
348 | case LOC_INDIRECT: | |
349 | case LOC_TYPEDEF: | |
350 | ||
351 | case LOC_LABEL: | |
352 | /* Getting the address of a label can be done independently of the block, | |
c5aa993b JM |
353 | even if some *uses* of that address wouldn't work so well without |
354 | the right frame. */ | |
c906108c SS |
355 | |
356 | case LOC_BLOCK: | |
357 | case LOC_CONST_BYTES: | |
358 | case LOC_UNRESOLVED: | |
359 | case LOC_OPTIMIZED_OUT: | |
360 | return 0; | |
361 | } | |
362 | return 1; | |
363 | } | |
364 | ||
365 | /* Given a struct symbol for a variable, | |
366 | and a stack frame id, read the value of the variable | |
367 | and return a (pointer to a) struct value containing the value. | |
368 | If the variable cannot be found, return a zero pointer. | |
206415a3 | 369 | If FRAME is NULL, use the selected frame. */ |
c906108c | 370 | |
3d6d86c6 | 371 | struct value * |
aa1ee363 | 372 | read_var_value (struct symbol *var, struct frame_info *frame) |
c906108c | 373 | { |
52f0bd74 | 374 | struct value *v; |
c906108c SS |
375 | struct type *type = SYMBOL_TYPE (var); |
376 | CORE_ADDR addr; | |
52f0bd74 | 377 | int len; |
c906108c | 378 | |
bb044262 DJ |
379 | if (SYMBOL_CLASS (var) == LOC_COMPUTED |
380 | || SYMBOL_CLASS (var) == LOC_COMPUTED_ARG | |
381 | || SYMBOL_CLASS (var) == LOC_REGISTER | |
382 | || SYMBOL_CLASS (var) == LOC_REGPARM) | |
383 | /* These cases do not use V. */ | |
384 | v = NULL; | |
385 | else | |
386 | { | |
387 | v = allocate_value (type); | |
388 | VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */ | |
389 | } | |
c906108c SS |
390 | |
391 | len = TYPE_LENGTH (type); | |
392 | ||
7dd88986 DJ |
393 | /* FIXME drow/2003-09-06: this call to the selected frame should be |
394 | pushed upwards to the callers. */ | |
c5aa993b | 395 | if (frame == NULL) |
7dd88986 | 396 | frame = deprecated_safe_get_selected_frame (); |
c906108c SS |
397 | |
398 | switch (SYMBOL_CLASS (var)) | |
399 | { | |
400 | case LOC_CONST: | |
401 | /* Put the constant back in target format. */ | |
990a07ab | 402 | store_signed_integer (value_contents_raw (v), len, |
c906108c SS |
403 | (LONGEST) SYMBOL_VALUE (var)); |
404 | VALUE_LVAL (v) = not_lval; | |
405 | return v; | |
406 | ||
407 | case LOC_LABEL: | |
408 | /* Put the constant back in target format. */ | |
409 | if (overlay_debugging) | |
4478b372 JB |
410 | { |
411 | CORE_ADDR addr | |
412 | = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
413 | SYMBOL_BFD_SECTION (var)); | |
990a07ab | 414 | store_typed_address (value_contents_raw (v), type, addr); |
4478b372 | 415 | } |
c906108c | 416 | else |
990a07ab | 417 | store_typed_address (value_contents_raw (v), type, |
4478b372 | 418 | SYMBOL_VALUE_ADDRESS (var)); |
c906108c SS |
419 | VALUE_LVAL (v) = not_lval; |
420 | return v; | |
421 | ||
422 | case LOC_CONST_BYTES: | |
423 | { | |
4e38b386 | 424 | memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), len); |
c906108c SS |
425 | VALUE_LVAL (v) = not_lval; |
426 | return v; | |
427 | } | |
428 | ||
429 | case LOC_STATIC: | |
430 | if (overlay_debugging) | |
431 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
432 | SYMBOL_BFD_SECTION (var)); | |
433 | else | |
434 | addr = SYMBOL_VALUE_ADDRESS (var); | |
435 | break; | |
436 | ||
437 | case LOC_INDIRECT: | |
f76febae AC |
438 | { |
439 | /* The import slot does not have a real address in it from the | |
440 | dynamic loader (dld.sl on HP-UX), if the target hasn't | |
441 | begun execution yet, so check for that. */ | |
442 | CORE_ADDR locaddr; | |
443 | struct value *loc; | |
444 | if (!target_has_execution) | |
8a3fe4f8 | 445 | error (_("\ |
c906108c | 446 | Attempt to access variable defined in different shared object or load module when\n\ |
8a3fe4f8 | 447 | addresses have not been bound by the dynamic loader. Try again when executable is running.")); |
c5aa993b | 448 | |
f76febae | 449 | locaddr = SYMBOL_VALUE_ADDRESS (var); |
00a4c844 | 450 | loc = value_at (lookup_pointer_type (type), locaddr); |
1aa20aa8 | 451 | addr = value_as_address (loc); |
bb044262 | 452 | break; |
f76febae | 453 | } |
c906108c SS |
454 | |
455 | case LOC_ARG: | |
456 | if (frame == NULL) | |
457 | return 0; | |
da62e633 | 458 | addr = get_frame_args_address (frame); |
c906108c SS |
459 | if (!addr) |
460 | return 0; | |
461 | addr += SYMBOL_VALUE (var); | |
462 | break; | |
463 | ||
464 | case LOC_REF_ARG: | |
f76febae AC |
465 | { |
466 | struct value *ref; | |
467 | CORE_ADDR argref; | |
468 | if (frame == NULL) | |
469 | return 0; | |
da62e633 | 470 | argref = get_frame_args_address (frame); |
f76febae AC |
471 | if (!argref) |
472 | return 0; | |
473 | argref += SYMBOL_VALUE (var); | |
00a4c844 | 474 | ref = value_at (lookup_pointer_type (type), argref); |
1aa20aa8 | 475 | addr = value_as_address (ref); |
f76febae AC |
476 | break; |
477 | } | |
c906108c SS |
478 | |
479 | case LOC_LOCAL: | |
480 | case LOC_LOCAL_ARG: | |
481 | if (frame == NULL) | |
482 | return 0; | |
da62e633 | 483 | addr = get_frame_locals_address (frame); |
c906108c SS |
484 | addr += SYMBOL_VALUE (var); |
485 | break; | |
486 | ||
487 | case LOC_BASEREG: | |
488 | case LOC_BASEREG_ARG: | |
407caf07 | 489 | case LOC_HP_THREAD_LOCAL_STATIC: |
c906108c | 490 | { |
3d6d86c6 | 491 | struct value *regval; |
c5aa993b | 492 | |
9ed10b08 ND |
493 | regval = value_from_register (lookup_pointer_type (type), |
494 | SYMBOL_BASEREG (var), frame); | |
495 | if (regval == NULL) | |
8a3fe4f8 | 496 | error (_("Value of base register not available.")); |
1aa20aa8 | 497 | addr = value_as_address (regval); |
c5aa993b JM |
498 | addr += SYMBOL_VALUE (var); |
499 | break; | |
c906108c | 500 | } |
c5aa993b | 501 | |
c906108c | 502 | case LOC_TYPEDEF: |
8a3fe4f8 | 503 | error (_("Cannot look up value of a typedef")); |
c906108c SS |
504 | break; |
505 | ||
506 | case LOC_BLOCK: | |
507 | if (overlay_debugging) | |
c5aa993b | 508 | VALUE_ADDRESS (v) = symbol_overlayed_address |
c906108c SS |
509 | (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_BFD_SECTION (var)); |
510 | else | |
511 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); | |
512 | return v; | |
513 | ||
514 | case LOC_REGISTER: | |
515 | case LOC_REGPARM: | |
516 | case LOC_REGPARM_ADDR: | |
517 | { | |
518 | struct block *b; | |
519 | int regno = SYMBOL_VALUE (var); | |
3d6d86c6 | 520 | struct value *regval; |
c906108c SS |
521 | |
522 | if (frame == NULL) | |
523 | return 0; | |
ae767bfb | 524 | b = get_frame_block (frame, 0); |
c906108c SS |
525 | |
526 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) | |
527 | { | |
528 | regval = value_from_register (lookup_pointer_type (type), | |
c5aa993b | 529 | regno, |
c906108c SS |
530 | frame); |
531 | ||
532 | if (regval == NULL) | |
8a3fe4f8 | 533 | error (_("Value of register variable not available.")); |
c906108c | 534 | |
1aa20aa8 | 535 | addr = value_as_address (regval); |
c906108c SS |
536 | VALUE_LVAL (v) = lval_memory; |
537 | } | |
538 | else | |
539 | { | |
540 | regval = value_from_register (type, regno, frame); | |
541 | ||
542 | if (regval == NULL) | |
8a3fe4f8 | 543 | error (_("Value of register variable not available.")); |
c906108c SS |
544 | return regval; |
545 | } | |
546 | } | |
547 | break; | |
548 | ||
4c2df51b DJ |
549 | case LOC_COMPUTED: |
550 | case LOC_COMPUTED_ARG: | |
a67af2b9 AC |
551 | /* FIXME: cagney/2004-01-26: It should be possible to |
552 | unconditionally call the SYMBOL_OPS method when available. | |
d3efc286 | 553 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
554 | function) location in a function's symbol. Oops! For the |
555 | moment enable this when/where applicable. */ | |
556 | if (frame == 0 && SYMBOL_OPS (var)->read_needs_frame (var)) | |
557 | return 0; | |
558 | return SYMBOL_OPS (var)->read_variable (var, frame); | |
4c2df51b | 559 | |
c906108c SS |
560 | case LOC_UNRESOLVED: |
561 | { | |
562 | struct minimal_symbol *msym; | |
563 | ||
22abf04a | 564 | msym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (var), NULL, NULL); |
c906108c SS |
565 | if (msym == NULL) |
566 | return 0; | |
567 | if (overlay_debugging) | |
568 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), | |
569 | SYMBOL_BFD_SECTION (msym)); | |
570 | else | |
571 | addr = SYMBOL_VALUE_ADDRESS (msym); | |
572 | } | |
573 | break; | |
574 | ||
575 | case LOC_OPTIMIZED_OUT: | |
576 | VALUE_LVAL (v) = not_lval; | |
feb13ab0 | 577 | set_value_optimized_out (v, 1); |
c906108c SS |
578 | return v; |
579 | ||
580 | default: | |
8a3fe4f8 | 581 | error (_("Cannot look up value of a botched symbol.")); |
c906108c SS |
582 | break; |
583 | } | |
584 | ||
585 | VALUE_ADDRESS (v) = addr; | |
dfa52d88 | 586 | set_value_lazy (v, 1); |
c906108c SS |
587 | return v; |
588 | } | |
589 | ||
9acbedc0 UW |
590 | /* Install default attributes for register values. */ |
591 | ||
592 | struct value * | |
593 | default_value_from_register (struct type *type, int regnum, | |
594 | struct frame_info *frame) | |
595 | { | |
596 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
597 | int len = TYPE_LENGTH (type); | |
598 | struct value *value = allocate_value (type); | |
599 | ||
600 | VALUE_LVAL (value) = lval_register; | |
601 | VALUE_FRAME_ID (value) = get_frame_id (frame); | |
602 | VALUE_REGNUM (value) = regnum; | |
603 | ||
604 | /* Any structure stored in more than one register will always be | |
605 | an integral number of registers. Otherwise, you need to do | |
606 | some fiddling with the last register copied here for little | |
607 | endian machines. */ | |
0d20ae72 | 608 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG |
9acbedc0 UW |
609 | && len < register_size (gdbarch, regnum)) |
610 | /* Big-endian, and we want less than full size. */ | |
611 | set_value_offset (value, register_size (gdbarch, regnum) - len); | |
612 | else | |
613 | set_value_offset (value, 0); | |
614 | ||
615 | return value; | |
616 | } | |
617 | ||
00fa51f6 | 618 | /* Return a value of type TYPE, stored in register REGNUM, in frame FRAME. */ |
c906108c | 619 | |
3d6d86c6 | 620 | struct value * |
fba45db2 | 621 | value_from_register (struct type *type, int regnum, struct frame_info *frame) |
c906108c | 622 | { |
ff2e87ac | 623 | struct gdbarch *gdbarch = get_frame_arch (frame); |
9acbedc0 UW |
624 | struct type *type1 = check_typedef (type); |
625 | struct value *v; | |
626 | ||
627 | if (CONVERT_REGISTER_P (regnum, type1)) | |
ff2e87ac AC |
628 | { |
629 | /* The ISA/ABI need to something weird when obtaining the | |
630 | specified value from this register. It might need to | |
631 | re-order non-adjacent, starting with REGNUM (see MIPS and | |
632 | i386). It might need to convert the [float] register into | |
633 | the corresponding [integer] type (see Alpha). The assumption | |
634 | is that REGISTER_TO_VALUE populates the entire value | |
635 | including the location. */ | |
9acbedc0 UW |
636 | v = allocate_value (type); |
637 | VALUE_LVAL (v) = lval_register; | |
638 | VALUE_FRAME_ID (v) = get_frame_id (frame); | |
639 | VALUE_REGNUM (v) = regnum; | |
640 | REGISTER_TO_VALUE (frame, regnum, type1, value_contents_raw (v)); | |
ff2e87ac AC |
641 | } |
642 | else | |
c906108c | 643 | { |
ff2e87ac | 644 | int len = TYPE_LENGTH (type); |
00fa51f6 | 645 | |
9acbedc0 UW |
646 | /* Construct the value. */ |
647 | v = gdbarch_value_from_register (gdbarch, type, regnum, frame); | |
00fa51f6 UW |
648 | |
649 | /* Get the data. */ | |
650 | if (!get_frame_register_bytes (frame, regnum, value_offset (v), len, | |
651 | value_contents_raw (v))) | |
652 | set_value_optimized_out (v, 1); | |
c906108c | 653 | } |
c906108c SS |
654 | return v; |
655 | } | |
ff2e87ac | 656 | |
0b2b0195 UW |
657 | /* Return contents of register REGNUM in frame FRAME as address, |
658 | interpreted as value of type TYPE. Will abort if register | |
659 | value is not available. */ | |
660 | ||
661 | CORE_ADDR | |
662 | address_from_register (struct type *type, int regnum, struct frame_info *frame) | |
663 | { | |
664 | struct value *value; | |
665 | CORE_ADDR result; | |
666 | ||
667 | value = value_from_register (type, regnum, frame); | |
668 | gdb_assert (value); | |
669 | ||
670 | result = value_as_address (value); | |
671 | release_value (value); | |
672 | value_free (value); | |
673 | ||
674 | return result; | |
675 | } | |
676 | ||
c906108c SS |
677 | \f |
678 | /* Given a struct symbol for a variable or function, | |
679 | and a stack frame id, | |
680 | return a (pointer to a) struct value containing the properly typed | |
681 | address. */ | |
682 | ||
3d6d86c6 | 683 | struct value * |
aa1ee363 | 684 | locate_var_value (struct symbol *var, struct frame_info *frame) |
c906108c SS |
685 | { |
686 | CORE_ADDR addr = 0; | |
687 | struct type *type = SYMBOL_TYPE (var); | |
3d6d86c6 | 688 | struct value *lazy_value; |
c906108c SS |
689 | |
690 | /* Evaluate it first; if the result is a memory address, we're fine. | |
691 | Lazy evaluation pays off here. */ | |
692 | ||
693 | lazy_value = read_var_value (var, frame); | |
694 | if (lazy_value == 0) | |
8a3fe4f8 | 695 | error (_("Address of \"%s\" is unknown."), SYMBOL_PRINT_NAME (var)); |
c906108c | 696 | |
d69fe07e | 697 | if (value_lazy (lazy_value) |
c906108c SS |
698 | || TYPE_CODE (type) == TYPE_CODE_FUNC) |
699 | { | |
3d6d86c6 | 700 | struct value *val; |
c906108c SS |
701 | |
702 | addr = VALUE_ADDRESS (lazy_value); | |
4478b372 | 703 | val = value_from_pointer (lookup_pointer_type (type), addr); |
c906108c SS |
704 | return val; |
705 | } | |
706 | ||
707 | /* Not a memory address; check what the problem was. */ | |
c5aa993b | 708 | switch (VALUE_LVAL (lazy_value)) |
c906108c SS |
709 | { |
710 | case lval_register: | |
9ee8fc9d AC |
711 | gdb_assert (REGISTER_NAME (VALUE_REGNUM (lazy_value)) != NULL |
712 | && *REGISTER_NAME (VALUE_REGNUM (lazy_value)) != '\0'); | |
8a3fe4f8 AC |
713 | error (_("Address requested for identifier " |
714 | "\"%s\" which is in register $%s"), | |
de5ad195 | 715 | SYMBOL_PRINT_NAME (var), |
9ee8fc9d | 716 | REGISTER_NAME (VALUE_REGNUM (lazy_value))); |
14e534aa PM |
717 | break; |
718 | ||
c906108c | 719 | default: |
8a3fe4f8 | 720 | error (_("Can't take address of \"%s\" which isn't an lvalue."), |
de5ad195 | 721 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
722 | break; |
723 | } | |
c5aa993b | 724 | return 0; /* For lint -- never reached */ |
c906108c | 725 | } |