Commit | Line | Data |
---|---|---|
c906108c | 1 | /* Find a variable's value in memory, for GDB, the GNU debugger. |
1bac305b | 2 | |
6aba47ca | 3 | Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, |
9b254dd1 | 4 | 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2007, 2008 |
6aba47ca | 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 | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
c5aa993b | 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 | 19 | You should have received a copy of the GNU General Public License |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
c906108c SS |
21 | |
22 | #include "defs.h" | |
23 | #include "symtab.h" | |
24 | #include "gdbtypes.h" | |
25 | #include "frame.h" | |
26 | #include "value.h" | |
27 | #include "gdbcore.h" | |
28 | #include "inferior.h" | |
29 | #include "target.h" | |
30 | #include "gdb_string.h" | |
14e534aa | 31 | #include "gdb_assert.h" |
c906108c | 32 | #include "floatformat.h" |
c5aa993b | 33 | #include "symfile.h" /* for overlay functions */ |
4e052eda | 34 | #include "regcache.h" |
eb8bc282 | 35 | #include "user-regs.h" |
fe898f56 | 36 | #include "block.h" |
c906108c | 37 | |
c906108c SS |
38 | /* Basic byte-swapping routines. GDB has needed these for a long time... |
39 | All extract a target-format integer at ADDR which is LEN bytes long. */ | |
40 | ||
41 | #if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8 | |
42 | /* 8 bit characters are a pretty safe assumption these days, so we | |
43 | assume it throughout all these swapping routines. If we had to deal with | |
44 | 9 bit characters, we would need to make len be in bits and would have | |
45 | to re-write these routines... */ | |
c5aa993b | 46 | you lose |
c906108c SS |
47 | #endif |
48 | ||
a9ac8f51 | 49 | LONGEST |
0d509538 | 50 | extract_signed_integer (const gdb_byte *addr, int len) |
c906108c SS |
51 | { |
52 | LONGEST retval; | |
37611a2b AC |
53 | const unsigned char *p; |
54 | const unsigned char *startaddr = addr; | |
55 | const unsigned char *endaddr = startaddr + len; | |
c906108c SS |
56 | |
57 | if (len > (int) sizeof (LONGEST)) | |
8a3fe4f8 AC |
58 | error (_("\ |
59 | That operation is not available on integers of more than %d bytes."), | |
baa6f10b | 60 | (int) sizeof (LONGEST)); |
c906108c SS |
61 | |
62 | /* Start at the most significant end of the integer, and work towards | |
63 | the least significant. */ | |
0d20ae72 | 64 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG) |
c906108c SS |
65 | { |
66 | p = startaddr; | |
67 | /* Do the sign extension once at the start. */ | |
c5aa993b | 68 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
c906108c SS |
69 | for (++p; p < endaddr; ++p) |
70 | retval = (retval << 8) | *p; | |
71 | } | |
72 | else | |
73 | { | |
74 | p = endaddr - 1; | |
75 | /* Do the sign extension once at the start. */ | |
c5aa993b | 76 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
c906108c SS |
77 | for (--p; p >= startaddr; --p) |
78 | retval = (retval << 8) | *p; | |
79 | } | |
80 | return retval; | |
81 | } | |
82 | ||
83 | ULONGEST | |
0d509538 | 84 | extract_unsigned_integer (const gdb_byte *addr, int len) |
c906108c SS |
85 | { |
86 | ULONGEST retval; | |
37611a2b AC |
87 | const unsigned char *p; |
88 | const unsigned char *startaddr = addr; | |
89 | const unsigned char *endaddr = startaddr + len; | |
c906108c SS |
90 | |
91 | if (len > (int) sizeof (ULONGEST)) | |
8a3fe4f8 AC |
92 | error (_("\ |
93 | That operation is not available on integers of more than %d bytes."), | |
baa6f10b | 94 | (int) sizeof (ULONGEST)); |
c906108c SS |
95 | |
96 | /* Start at the most significant end of the integer, and work towards | |
97 | the least significant. */ | |
98 | retval = 0; | |
0d20ae72 | 99 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG) |
c906108c SS |
100 | { |
101 | for (p = startaddr; p < endaddr; ++p) | |
102 | retval = (retval << 8) | *p; | |
103 | } | |
104 | else | |
105 | { | |
106 | for (p = endaddr - 1; p >= startaddr; --p) | |
107 | retval = (retval << 8) | *p; | |
108 | } | |
109 | return retval; | |
110 | } | |
111 | ||
112 | /* Sometimes a long long unsigned integer can be extracted as a | |
113 | LONGEST value. This is done so that we can print these values | |
114 | better. If this integer can be converted to a LONGEST, this | |
115 | function returns 1 and sets *PVAL. Otherwise it returns 0. */ | |
116 | ||
117 | int | |
0d509538 AC |
118 | extract_long_unsigned_integer (const gdb_byte *addr, int orig_len, |
119 | LONGEST *pval) | |
c906108c | 120 | { |
0d509538 AC |
121 | const gdb_byte *p; |
122 | const gdb_byte *first_addr; | |
c906108c SS |
123 | int len; |
124 | ||
125 | len = orig_len; | |
0d20ae72 | 126 | if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG) |
c906108c | 127 | { |
0d509538 AC |
128 | for (p = addr; |
129 | len > (int) sizeof (LONGEST) && p < addr + orig_len; | |
c906108c SS |
130 | p++) |
131 | { | |
132 | if (*p == 0) | |
133 | len--; | |
134 | else | |
135 | break; | |
136 | } | |
137 | first_addr = p; | |
138 | } | |
139 | else | |
140 | { | |
0d509538 AC |
141 | first_addr = addr; |
142 | for (p = addr + orig_len - 1; | |
143 | len > (int) sizeof (LONGEST) && p >= addr; | |
c906108c SS |
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 | |
0d509538 | 167 | extract_typed_address (const gdb_byte *buf, struct type *type) |
4478b372 JB |
168 | { |
169 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
170 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 | 171 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 AC |
172 | _("extract_typed_address: " |
173 | "type is not a pointer or reference")); | |
4478b372 | 174 | |
76e71323 | 175 | return gdbarch_pointer_to_address (current_gdbarch, type, buf); |
4478b372 JB |
176 | } |
177 | ||
178 | ||
c906108c | 179 | void |
0d509538 | 180 | store_signed_integer (gdb_byte *addr, int len, LONGEST val) |
c906108c | 181 | { |
0d509538 AC |
182 | gdb_byte *p; |
183 | gdb_byte *startaddr = addr; | |
184 | gdb_byte *endaddr = startaddr + len; | |
c906108c SS |
185 | |
186 | /* Start at the least significant end of the integer, and work towards | |
187 | the most significant. */ | |
0d20ae72 | 188 | if (gdbarch_byte_order (current_gdbarch) == 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 | |
0d509538 | 207 | store_unsigned_integer (gdb_byte *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. */ | |
0d20ae72 | 215 | if (gdbarch_byte_order (current_gdbarch) == 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 | |
0d509538 | 236 | store_typed_address (gdb_byte *buf, struct type *type, CORE_ADDR addr) |
4478b372 JB |
237 | { |
238 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
239 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 | 240 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 AC |
241 | _("store_typed_address: " |
242 | "type is not a pointer or reference")); | |
4478b372 | 243 | |
76e71323 | 244 | gdbarch_address_to_pointer (current_gdbarch, type, buf, addr); |
4478b372 JB |
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 | |
9c5ea4d9 | 251 | determined by register_type(). */ |
c906108c | 252 | |
3d6d86c6 | 253 | struct value * |
376c9600 | 254 | value_of_register (int regnum, struct frame_info *frame) |
c906108c | 255 | { |
e9e45075 | 256 | struct gdbarch *gdbarch = get_frame_arch (frame); |
c906108c SS |
257 | CORE_ADDR addr; |
258 | int optim; | |
3d6d86c6 | 259 | struct value *reg_val; |
ac2adee5 | 260 | int realnum; |
10c42a71 | 261 | gdb_byte raw_buffer[MAX_REGISTER_SIZE]; |
c906108c SS |
262 | enum lval_type lval; |
263 | ||
9564ee9f | 264 | /* User registers lie completely outside of the range of normal |
0406ec40 | 265 | registers. Catch them early so that the target never sees them. */ |
e9e45075 UW |
266 | if (regnum >= gdbarch_num_regs (gdbarch) |
267 | + gdbarch_num_pseudo_regs (gdbarch)) | |
eb8bc282 | 268 | return value_of_user_reg (regnum, frame); |
0406ec40 | 269 | |
ac2adee5 | 270 | frame_register (frame, regnum, &optim, &lval, &addr, &realnum, raw_buffer); |
c906108c | 271 | |
e9e45075 | 272 | reg_val = allocate_value (register_type (gdbarch, regnum)); |
c906108c | 273 | |
990a07ab | 274 | memcpy (value_contents_raw (reg_val), raw_buffer, |
e9e45075 | 275 | register_size (gdbarch, regnum)); |
c906108c SS |
276 | VALUE_LVAL (reg_val) = lval; |
277 | VALUE_ADDRESS (reg_val) = addr; | |
9ee8fc9d | 278 | VALUE_REGNUM (reg_val) = regnum; |
feb13ab0 | 279 | set_value_optimized_out (reg_val, optim); |
0c16dd26 | 280 | VALUE_FRAME_ID (reg_val) = get_frame_id (frame); |
c906108c SS |
281 | return reg_val; |
282 | } | |
4478b372 | 283 | |
9214ee5f DJ |
284 | /* Return a `value' with the contents of (virtual or cooked) register |
285 | REGNUM as found in the specified FRAME. The register's type is | |
286 | determined by register_type(). The value is not fetched. */ | |
287 | ||
288 | struct value * | |
289 | value_of_register_lazy (struct frame_info *frame, int regnum) | |
290 | { | |
291 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
292 | struct value *reg_val; | |
293 | ||
294 | gdb_assert (regnum < (gdbarch_num_regs (gdbarch) | |
295 | + gdbarch_num_pseudo_regs (gdbarch))); | |
296 | ||
297 | /* We should have a valid (i.e. non-sentinel) frame. */ | |
298 | gdb_assert (frame_id_p (get_frame_id (frame))); | |
299 | ||
300 | reg_val = allocate_value (register_type (gdbarch, regnum)); | |
301 | VALUE_LVAL (reg_val) = lval_register; | |
302 | VALUE_REGNUM (reg_val) = regnum; | |
303 | VALUE_FRAME_ID (reg_val) = get_frame_id (frame); | |
304 | set_value_lazy (reg_val, 1); | |
305 | return reg_val; | |
306 | } | |
307 | ||
4478b372 JB |
308 | /* Given a pointer of type TYPE in target form in BUF, return the |
309 | address it represents. */ | |
310 | CORE_ADDR | |
b60c417a | 311 | unsigned_pointer_to_address (struct type *type, const gdb_byte *buf) |
4478b372 | 312 | { |
af1342ab | 313 | return extract_unsigned_integer (buf, TYPE_LENGTH (type)); |
4478b372 JB |
314 | } |
315 | ||
ac2e2ef7 | 316 | CORE_ADDR |
b60c417a | 317 | signed_pointer_to_address (struct type *type, const gdb_byte *buf) |
ac2e2ef7 AC |
318 | { |
319 | return extract_signed_integer (buf, TYPE_LENGTH (type)); | |
320 | } | |
4478b372 JB |
321 | |
322 | /* Given an address, store it as a pointer of type TYPE in target | |
323 | format in BUF. */ | |
324 | void | |
b60c417a AC |
325 | unsigned_address_to_pointer (struct type *type, gdb_byte *buf, |
326 | CORE_ADDR addr) | |
4478b372 | 327 | { |
fbd9dcd3 | 328 | store_unsigned_integer (buf, TYPE_LENGTH (type), addr); |
4478b372 JB |
329 | } |
330 | ||
ac2e2ef7 | 331 | void |
b60c417a | 332 | address_to_signed_pointer (struct type *type, gdb_byte *buf, CORE_ADDR addr) |
ac2e2ef7 AC |
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 | 347 | case LOC_COMPUTED: |
a67af2b9 AC |
348 | /* FIXME: cagney/2004-01-26: It should be possible to |
349 | unconditionally call the SYMBOL_OPS method when available. | |
d3efc286 | 350 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
351 | function) location in a function's symbol. Oops! For the |
352 | moment enable this when/where applicable. */ | |
353 | return SYMBOL_OPS (sym)->read_needs_frame (sym); | |
4c2df51b | 354 | |
c906108c SS |
355 | case LOC_REGISTER: |
356 | case LOC_ARG: | |
357 | case LOC_REF_ARG: | |
c906108c SS |
358 | case LOC_REGPARM_ADDR: |
359 | case LOC_LOCAL: | |
c906108c SS |
360 | return 1; |
361 | ||
362 | case LOC_UNDEF: | |
363 | case LOC_CONST: | |
364 | case LOC_STATIC: | |
c906108c SS |
365 | case LOC_TYPEDEF: |
366 | ||
367 | case LOC_LABEL: | |
368 | /* Getting the address of a label can be done independently of the block, | |
c5aa993b JM |
369 | even if some *uses* of that address wouldn't work so well without |
370 | the right frame. */ | |
c906108c SS |
371 | |
372 | case LOC_BLOCK: | |
373 | case LOC_CONST_BYTES: | |
374 | case LOC_UNRESOLVED: | |
375 | case LOC_OPTIMIZED_OUT: | |
376 | return 0; | |
377 | } | |
378 | return 1; | |
379 | } | |
380 | ||
381 | /* Given a struct symbol for a variable, | |
382 | and a stack frame id, read the value of the variable | |
383 | and return a (pointer to a) struct value containing the value. | |
384 | If the variable cannot be found, return a zero pointer. | |
206415a3 | 385 | If FRAME is NULL, use the selected frame. */ |
c906108c | 386 | |
3d6d86c6 | 387 | struct value * |
aa1ee363 | 388 | read_var_value (struct symbol *var, struct frame_info *frame) |
c906108c | 389 | { |
52f0bd74 | 390 | struct value *v; |
c906108c SS |
391 | struct type *type = SYMBOL_TYPE (var); |
392 | CORE_ADDR addr; | |
52f0bd74 | 393 | int len; |
c906108c | 394 | |
bb044262 | 395 | if (SYMBOL_CLASS (var) == LOC_COMPUTED |
2a2d4dc3 | 396 | || SYMBOL_CLASS (var) == LOC_REGISTER) |
bb044262 DJ |
397 | /* These cases do not use V. */ |
398 | v = NULL; | |
399 | else | |
400 | { | |
401 | v = allocate_value (type); | |
402 | VALUE_LVAL (v) = lval_memory; /* The most likely possibility. */ | |
403 | } | |
c906108c SS |
404 | |
405 | len = TYPE_LENGTH (type); | |
406 | ||
7dd88986 DJ |
407 | /* FIXME drow/2003-09-06: this call to the selected frame should be |
408 | pushed upwards to the callers. */ | |
c5aa993b | 409 | if (frame == NULL) |
7dd88986 | 410 | frame = deprecated_safe_get_selected_frame (); |
c906108c SS |
411 | |
412 | switch (SYMBOL_CLASS (var)) | |
413 | { | |
414 | case LOC_CONST: | |
415 | /* Put the constant back in target format. */ | |
990a07ab | 416 | store_signed_integer (value_contents_raw (v), len, |
c906108c SS |
417 | (LONGEST) SYMBOL_VALUE (var)); |
418 | VALUE_LVAL (v) = not_lval; | |
419 | return v; | |
420 | ||
421 | case LOC_LABEL: | |
422 | /* Put the constant back in target format. */ | |
423 | if (overlay_debugging) | |
4478b372 JB |
424 | { |
425 | CORE_ADDR addr | |
426 | = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
714835d5 | 427 | SYMBOL_OBJ_SECTION (var)); |
990a07ab | 428 | store_typed_address (value_contents_raw (v), type, addr); |
4478b372 | 429 | } |
c906108c | 430 | else |
990a07ab | 431 | store_typed_address (value_contents_raw (v), type, |
4478b372 | 432 | SYMBOL_VALUE_ADDRESS (var)); |
c906108c SS |
433 | VALUE_LVAL (v) = not_lval; |
434 | return v; | |
435 | ||
436 | case LOC_CONST_BYTES: | |
437 | { | |
4e38b386 | 438 | memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), len); |
c906108c SS |
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), | |
714835d5 | 446 | SYMBOL_OBJ_SECTION (var)); |
c906108c SS |
447 | else |
448 | addr = SYMBOL_VALUE_ADDRESS (var); | |
449 | break; | |
450 | ||
c906108c SS |
451 | case LOC_ARG: |
452 | if (frame == NULL) | |
453 | return 0; | |
da62e633 | 454 | addr = get_frame_args_address (frame); |
c906108c SS |
455 | if (!addr) |
456 | return 0; | |
457 | addr += SYMBOL_VALUE (var); | |
458 | break; | |
459 | ||
460 | case LOC_REF_ARG: | |
f76febae AC |
461 | { |
462 | struct value *ref; | |
463 | CORE_ADDR argref; | |
464 | if (frame == NULL) | |
465 | return 0; | |
da62e633 | 466 | argref = get_frame_args_address (frame); |
f76febae AC |
467 | if (!argref) |
468 | return 0; | |
469 | argref += SYMBOL_VALUE (var); | |
00a4c844 | 470 | ref = value_at (lookup_pointer_type (type), argref); |
1aa20aa8 | 471 | addr = value_as_address (ref); |
f76febae AC |
472 | break; |
473 | } | |
c906108c SS |
474 | |
475 | case LOC_LOCAL: | |
c906108c SS |
476 | if (frame == NULL) |
477 | return 0; | |
da62e633 | 478 | addr = get_frame_locals_address (frame); |
c906108c SS |
479 | addr += SYMBOL_VALUE (var); |
480 | break; | |
481 | ||
c906108c | 482 | case LOC_TYPEDEF: |
8a3fe4f8 | 483 | error (_("Cannot look up value of a typedef")); |
c906108c SS |
484 | break; |
485 | ||
486 | case LOC_BLOCK: | |
487 | if (overlay_debugging) | |
c5aa993b | 488 | VALUE_ADDRESS (v) = symbol_overlayed_address |
714835d5 | 489 | (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (var)); |
c906108c SS |
490 | else |
491 | VALUE_ADDRESS (v) = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); | |
492 | return v; | |
493 | ||
494 | case LOC_REGISTER: | |
c906108c SS |
495 | case LOC_REGPARM_ADDR: |
496 | { | |
c906108c | 497 | int regno = SYMBOL_VALUE (var); |
3d6d86c6 | 498 | struct value *regval; |
c906108c SS |
499 | |
500 | if (frame == NULL) | |
501 | return 0; | |
c906108c SS |
502 | |
503 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) | |
504 | { | |
505 | regval = value_from_register (lookup_pointer_type (type), | |
c5aa993b | 506 | regno, |
c906108c SS |
507 | frame); |
508 | ||
509 | if (regval == NULL) | |
8a3fe4f8 | 510 | error (_("Value of register variable not available.")); |
c906108c | 511 | |
1aa20aa8 | 512 | addr = value_as_address (regval); |
c906108c SS |
513 | VALUE_LVAL (v) = lval_memory; |
514 | } | |
515 | else | |
516 | { | |
517 | regval = value_from_register (type, regno, frame); | |
518 | ||
519 | if (regval == NULL) | |
8a3fe4f8 | 520 | error (_("Value of register variable not available.")); |
c906108c SS |
521 | return regval; |
522 | } | |
523 | } | |
524 | break; | |
525 | ||
4c2df51b | 526 | case LOC_COMPUTED: |
a67af2b9 AC |
527 | /* FIXME: cagney/2004-01-26: It should be possible to |
528 | unconditionally call the SYMBOL_OPS method when available. | |
d3efc286 | 529 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
530 | function) location in a function's symbol. Oops! For the |
531 | moment enable this when/where applicable. */ | |
532 | if (frame == 0 && SYMBOL_OPS (var)->read_needs_frame (var)) | |
533 | return 0; | |
534 | return SYMBOL_OPS (var)->read_variable (var, frame); | |
4c2df51b | 535 | |
c906108c SS |
536 | case LOC_UNRESOLVED: |
537 | { | |
538 | struct minimal_symbol *msym; | |
539 | ||
3567439c | 540 | msym = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL); |
c906108c SS |
541 | if (msym == NULL) |
542 | return 0; | |
543 | if (overlay_debugging) | |
544 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), | |
714835d5 | 545 | SYMBOL_OBJ_SECTION (msym)); |
c906108c SS |
546 | else |
547 | addr = SYMBOL_VALUE_ADDRESS (msym); | |
548 | } | |
549 | break; | |
550 | ||
551 | case LOC_OPTIMIZED_OUT: | |
552 | VALUE_LVAL (v) = not_lval; | |
feb13ab0 | 553 | set_value_optimized_out (v, 1); |
c906108c SS |
554 | return v; |
555 | ||
556 | default: | |
8a3fe4f8 | 557 | error (_("Cannot look up value of a botched symbol.")); |
c906108c SS |
558 | break; |
559 | } | |
560 | ||
561 | VALUE_ADDRESS (v) = addr; | |
dfa52d88 | 562 | set_value_lazy (v, 1); |
c906108c SS |
563 | return v; |
564 | } | |
565 | ||
9acbedc0 UW |
566 | /* Install default attributes for register values. */ |
567 | ||
568 | struct value * | |
569 | default_value_from_register (struct type *type, int regnum, | |
570 | struct frame_info *frame) | |
571 | { | |
572 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
573 | int len = TYPE_LENGTH (type); | |
574 | struct value *value = allocate_value (type); | |
575 | ||
576 | VALUE_LVAL (value) = lval_register; | |
577 | VALUE_FRAME_ID (value) = get_frame_id (frame); | |
578 | VALUE_REGNUM (value) = regnum; | |
579 | ||
580 | /* Any structure stored in more than one register will always be | |
581 | an integral number of registers. Otherwise, you need to do | |
582 | some fiddling with the last register copied here for little | |
583 | endian machines. */ | |
e9e45075 | 584 | if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG |
9acbedc0 UW |
585 | && len < register_size (gdbarch, regnum)) |
586 | /* Big-endian, and we want less than full size. */ | |
587 | set_value_offset (value, register_size (gdbarch, regnum) - len); | |
588 | else | |
589 | set_value_offset (value, 0); | |
590 | ||
591 | return value; | |
592 | } | |
593 | ||
00fa51f6 | 594 | /* Return a value of type TYPE, stored in register REGNUM, in frame FRAME. */ |
c906108c | 595 | |
3d6d86c6 | 596 | struct value * |
fba45db2 | 597 | value_from_register (struct type *type, int regnum, struct frame_info *frame) |
c906108c | 598 | { |
ff2e87ac | 599 | struct gdbarch *gdbarch = get_frame_arch (frame); |
9acbedc0 UW |
600 | struct type *type1 = check_typedef (type); |
601 | struct value *v; | |
602 | ||
e9e45075 | 603 | if (gdbarch_convert_register_p (gdbarch, regnum, type1)) |
ff2e87ac AC |
604 | { |
605 | /* The ISA/ABI need to something weird when obtaining the | |
606 | specified value from this register. It might need to | |
607 | re-order non-adjacent, starting with REGNUM (see MIPS and | |
608 | i386). It might need to convert the [float] register into | |
609 | the corresponding [integer] type (see Alpha). The assumption | |
c1afe53d | 610 | is that gdbarch_register_to_value populates the entire value |
ff2e87ac | 611 | including the location. */ |
9acbedc0 UW |
612 | v = allocate_value (type); |
613 | VALUE_LVAL (v) = lval_register; | |
614 | VALUE_FRAME_ID (v) = get_frame_id (frame); | |
615 | VALUE_REGNUM (v) = regnum; | |
e9e45075 | 616 | gdbarch_register_to_value (gdbarch, |
c1afe53d | 617 | frame, regnum, type1, value_contents_raw (v)); |
ff2e87ac AC |
618 | } |
619 | else | |
c906108c | 620 | { |
ff2e87ac | 621 | int len = TYPE_LENGTH (type); |
00fa51f6 | 622 | |
9acbedc0 UW |
623 | /* Construct the value. */ |
624 | v = gdbarch_value_from_register (gdbarch, type, regnum, frame); | |
00fa51f6 UW |
625 | |
626 | /* Get the data. */ | |
627 | if (!get_frame_register_bytes (frame, regnum, value_offset (v), len, | |
628 | value_contents_raw (v))) | |
629 | set_value_optimized_out (v, 1); | |
c906108c | 630 | } |
c906108c SS |
631 | return v; |
632 | } | |
ff2e87ac | 633 | |
0b2b0195 UW |
634 | /* Return contents of register REGNUM in frame FRAME as address, |
635 | interpreted as value of type TYPE. Will abort if register | |
636 | value is not available. */ | |
637 | ||
638 | CORE_ADDR | |
639 | address_from_register (struct type *type, int regnum, struct frame_info *frame) | |
640 | { | |
641 | struct value *value; | |
642 | CORE_ADDR result; | |
643 | ||
644 | value = value_from_register (type, regnum, frame); | |
645 | gdb_assert (value); | |
646 | ||
647 | result = value_as_address (value); | |
648 | release_value (value); | |
649 | value_free (value); | |
650 | ||
651 | return result; | |
652 | } | |
653 | ||
c906108c SS |
654 | \f |
655 | /* Given a struct symbol for a variable or function, | |
656 | and a stack frame id, | |
657 | return a (pointer to a) struct value containing the properly typed | |
658 | address. */ | |
659 | ||
3d6d86c6 | 660 | struct value * |
aa1ee363 | 661 | locate_var_value (struct symbol *var, struct frame_info *frame) |
c906108c | 662 | { |
5045add0 | 663 | struct gdbarch *gdbarch; |
c906108c SS |
664 | CORE_ADDR addr = 0; |
665 | struct type *type = SYMBOL_TYPE (var); | |
3d6d86c6 | 666 | struct value *lazy_value; |
c906108c SS |
667 | |
668 | /* Evaluate it first; if the result is a memory address, we're fine. | |
669 | Lazy evaluation pays off here. */ | |
670 | ||
671 | lazy_value = read_var_value (var, frame); | |
672 | if (lazy_value == 0) | |
8a3fe4f8 | 673 | error (_("Address of \"%s\" is unknown."), SYMBOL_PRINT_NAME (var)); |
c906108c | 674 | |
9214ee5f | 675 | if ((VALUE_LVAL (lazy_value) == lval_memory && value_lazy (lazy_value)) |
c906108c SS |
676 | || TYPE_CODE (type) == TYPE_CODE_FUNC) |
677 | { | |
3d6d86c6 | 678 | struct value *val; |
c906108c SS |
679 | |
680 | addr = VALUE_ADDRESS (lazy_value); | |
4478b372 | 681 | val = value_from_pointer (lookup_pointer_type (type), addr); |
c906108c SS |
682 | return val; |
683 | } | |
684 | ||
685 | /* Not a memory address; check what the problem was. */ | |
c5aa993b | 686 | switch (VALUE_LVAL (lazy_value)) |
c906108c SS |
687 | { |
688 | case lval_register: | |
5045add0 UW |
689 | gdb_assert (frame); |
690 | gdbarch = get_frame_arch (frame); | |
c9f4d572 | 691 | gdb_assert (gdbarch_register_name |
e9e45075 | 692 | (gdbarch, VALUE_REGNUM (lazy_value)) != NULL |
c9f4d572 | 693 | && *gdbarch_register_name |
e9e45075 | 694 | (gdbarch, VALUE_REGNUM (lazy_value)) != '\0'); |
8a3fe4f8 AC |
695 | error (_("Address requested for identifier " |
696 | "\"%s\" which is in register $%s"), | |
de5ad195 | 697 | SYMBOL_PRINT_NAME (var), |
e9e45075 | 698 | gdbarch_register_name (gdbarch, VALUE_REGNUM (lazy_value))); |
14e534aa PM |
699 | break; |
700 | ||
c906108c | 701 | default: |
8a3fe4f8 | 702 | error (_("Can't take address of \"%s\" which isn't an lvalue."), |
de5ad195 | 703 | SYMBOL_PRINT_NAME (var)); |
c906108c SS |
704 | break; |
705 | } | |
c5aa993b | 706 | return 0; /* For lint -- never reached */ |
c906108c | 707 | } |