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, |
4c38e0a4 | 4 | 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2007, 2008, 2009, |
7b6bb8da | 5 | 2010, 2011 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" |
e0740f77 | 37 | #include "objfiles.h" |
c906108c | 38 | |
9659616a MS |
39 | /* Basic byte-swapping routines. All 'extract' functions return a |
40 | host-format integer from a target-format integer at ADDR which is | |
41 | LEN bytes long. */ | |
c906108c SS |
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 |
e17a4113 UW |
52 | extract_signed_integer (const gdb_byte *addr, int len, |
53 | enum bfd_endian byte_order) | |
c906108c SS |
54 | { |
55 | LONGEST retval; | |
37611a2b AC |
56 | const unsigned char *p; |
57 | const unsigned char *startaddr = addr; | |
58 | const unsigned char *endaddr = startaddr + len; | |
c906108c SS |
59 | |
60 | if (len > (int) sizeof (LONGEST)) | |
8a3fe4f8 AC |
61 | error (_("\ |
62 | That operation is not available on integers of more than %d bytes."), | |
baa6f10b | 63 | (int) sizeof (LONGEST)); |
c906108c SS |
64 | |
65 | /* Start at the most significant end of the integer, and work towards | |
66 | the least significant. */ | |
e17a4113 | 67 | if (byte_order == BFD_ENDIAN_BIG) |
c906108c SS |
68 | { |
69 | p = startaddr; | |
70 | /* Do the sign extension once at the start. */ | |
c5aa993b | 71 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
c906108c SS |
72 | for (++p; p < endaddr; ++p) |
73 | retval = (retval << 8) | *p; | |
74 | } | |
75 | else | |
76 | { | |
77 | p = endaddr - 1; | |
78 | /* Do the sign extension once at the start. */ | |
c5aa993b | 79 | retval = ((LONGEST) * p ^ 0x80) - 0x80; |
c906108c SS |
80 | for (--p; p >= startaddr; --p) |
81 | retval = (retval << 8) | *p; | |
82 | } | |
83 | return retval; | |
84 | } | |
85 | ||
86 | ULONGEST | |
e17a4113 UW |
87 | extract_unsigned_integer (const gdb_byte *addr, int len, |
88 | enum bfd_endian byte_order) | |
c906108c SS |
89 | { |
90 | ULONGEST retval; | |
37611a2b AC |
91 | const unsigned char *p; |
92 | const unsigned char *startaddr = addr; | |
93 | const unsigned char *endaddr = startaddr + len; | |
c906108c SS |
94 | |
95 | if (len > (int) sizeof (ULONGEST)) | |
8a3fe4f8 AC |
96 | error (_("\ |
97 | That operation is not available on integers of more than %d bytes."), | |
baa6f10b | 98 | (int) sizeof (ULONGEST)); |
c906108c SS |
99 | |
100 | /* Start at the most significant end of the integer, and work towards | |
101 | the least significant. */ | |
102 | retval = 0; | |
e17a4113 | 103 | if (byte_order == BFD_ENDIAN_BIG) |
c906108c SS |
104 | { |
105 | for (p = startaddr; p < endaddr; ++p) | |
106 | retval = (retval << 8) | *p; | |
107 | } | |
108 | else | |
109 | { | |
110 | for (p = endaddr - 1; p >= startaddr; --p) | |
111 | retval = (retval << 8) | *p; | |
112 | } | |
113 | return retval; | |
114 | } | |
115 | ||
116 | /* Sometimes a long long unsigned integer can be extracted as a | |
117 | LONGEST value. This is done so that we can print these values | |
118 | better. If this integer can be converted to a LONGEST, this | |
119 | function returns 1 and sets *PVAL. Otherwise it returns 0. */ | |
120 | ||
121 | int | |
0d509538 | 122 | extract_long_unsigned_integer (const gdb_byte *addr, int orig_len, |
e17a4113 | 123 | enum bfd_endian byte_order, LONGEST *pval) |
c906108c | 124 | { |
0d509538 AC |
125 | const gdb_byte *p; |
126 | const gdb_byte *first_addr; | |
c906108c SS |
127 | int len; |
128 | ||
129 | len = orig_len; | |
e17a4113 | 130 | if (byte_order == BFD_ENDIAN_BIG) |
c906108c | 131 | { |
0d509538 AC |
132 | for (p = addr; |
133 | len > (int) sizeof (LONGEST) && p < addr + orig_len; | |
c906108c SS |
134 | p++) |
135 | { | |
136 | if (*p == 0) | |
137 | len--; | |
138 | else | |
139 | break; | |
140 | } | |
141 | first_addr = p; | |
142 | } | |
143 | else | |
144 | { | |
0d509538 AC |
145 | first_addr = addr; |
146 | for (p = addr + orig_len - 1; | |
147 | len > (int) sizeof (LONGEST) && p >= addr; | |
c906108c SS |
148 | p--) |
149 | { | |
150 | if (*p == 0) | |
151 | len--; | |
152 | else | |
153 | break; | |
154 | } | |
155 | } | |
156 | ||
157 | if (len <= (int) sizeof (LONGEST)) | |
158 | { | |
159 | *pval = (LONGEST) extract_unsigned_integer (first_addr, | |
e17a4113 UW |
160 | sizeof (LONGEST), |
161 | byte_order); | |
c906108c SS |
162 | return 1; |
163 | } | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
4478b372 | 168 | |
4478b372 JB |
169 | /* Treat the bytes at BUF as a pointer of type TYPE, and return the |
170 | address it represents. */ | |
171 | CORE_ADDR | |
0d509538 | 172 | extract_typed_address (const gdb_byte *buf, struct type *type) |
4478b372 JB |
173 | { |
174 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
175 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 | 176 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 AC |
177 | _("extract_typed_address: " |
178 | "type is not a pointer or reference")); | |
4478b372 | 179 | |
50810684 | 180 | return gdbarch_pointer_to_address (get_type_arch (type), type, buf); |
4478b372 JB |
181 | } |
182 | ||
9659616a MS |
183 | /* All 'store' functions accept a host-format integer and store a |
184 | target-format integer at ADDR which is LEN bytes long. */ | |
4478b372 | 185 | |
c906108c | 186 | void |
e17a4113 UW |
187 | store_signed_integer (gdb_byte *addr, int len, |
188 | enum bfd_endian byte_order, LONGEST val) | |
c906108c | 189 | { |
0d509538 AC |
190 | gdb_byte *p; |
191 | gdb_byte *startaddr = addr; | |
192 | gdb_byte *endaddr = startaddr + len; | |
c906108c SS |
193 | |
194 | /* Start at the least significant end of the integer, and work towards | |
195 | the most significant. */ | |
e17a4113 | 196 | if (byte_order == BFD_ENDIAN_BIG) |
c906108c SS |
197 | { |
198 | for (p = endaddr - 1; p >= startaddr; --p) | |
199 | { | |
200 | *p = val & 0xff; | |
201 | val >>= 8; | |
202 | } | |
203 | } | |
204 | else | |
205 | { | |
206 | for (p = startaddr; p < endaddr; ++p) | |
207 | { | |
208 | *p = val & 0xff; | |
209 | val >>= 8; | |
210 | } | |
211 | } | |
212 | } | |
213 | ||
214 | void | |
e17a4113 UW |
215 | store_unsigned_integer (gdb_byte *addr, int len, |
216 | enum bfd_endian byte_order, ULONGEST val) | |
c906108c SS |
217 | { |
218 | unsigned char *p; | |
c5aa993b | 219 | unsigned char *startaddr = (unsigned char *) addr; |
c906108c SS |
220 | unsigned char *endaddr = startaddr + len; |
221 | ||
222 | /* Start at the least significant end of the integer, and work towards | |
223 | the most significant. */ | |
e17a4113 | 224 | if (byte_order == BFD_ENDIAN_BIG) |
c906108c SS |
225 | { |
226 | for (p = endaddr - 1; p >= startaddr; --p) | |
227 | { | |
228 | *p = val & 0xff; | |
229 | val >>= 8; | |
230 | } | |
231 | } | |
232 | else | |
233 | { | |
234 | for (p = startaddr; p < endaddr; ++p) | |
235 | { | |
236 | *p = val & 0xff; | |
237 | val >>= 8; | |
238 | } | |
239 | } | |
240 | } | |
241 | ||
4478b372 JB |
242 | /* Store the address ADDR as a pointer of type TYPE at BUF, in target |
243 | form. */ | |
244 | void | |
0d509538 | 245 | store_typed_address (gdb_byte *buf, struct type *type, CORE_ADDR addr) |
4478b372 JB |
246 | { |
247 | if (TYPE_CODE (type) != TYPE_CODE_PTR | |
248 | && TYPE_CODE (type) != TYPE_CODE_REF) | |
8e65ff28 | 249 | internal_error (__FILE__, __LINE__, |
e2e0b3e5 AC |
250 | _("store_typed_address: " |
251 | "type is not a pointer or reference")); | |
4478b372 | 252 | |
50810684 | 253 | gdbarch_address_to_pointer (get_type_arch (type), type, buf, addr); |
4478b372 JB |
254 | } |
255 | ||
256 | ||
257 | ||
376c9600 AC |
258 | /* Return a `value' with the contents of (virtual or cooked) register |
259 | REGNUM as found in the specified FRAME. The register's type is | |
9c5ea4d9 | 260 | determined by register_type(). */ |
c906108c | 261 | |
3d6d86c6 | 262 | struct value * |
376c9600 | 263 | value_of_register (int regnum, struct frame_info *frame) |
c906108c | 264 | { |
e9e45075 | 265 | struct gdbarch *gdbarch = get_frame_arch (frame); |
c906108c SS |
266 | CORE_ADDR addr; |
267 | int optim; | |
3d6d86c6 | 268 | struct value *reg_val; |
ac2adee5 | 269 | int realnum; |
10c42a71 | 270 | gdb_byte raw_buffer[MAX_REGISTER_SIZE]; |
c906108c SS |
271 | enum lval_type lval; |
272 | ||
9564ee9f | 273 | /* User registers lie completely outside of the range of normal |
0406ec40 | 274 | registers. Catch them early so that the target never sees them. */ |
e9e45075 UW |
275 | if (regnum >= gdbarch_num_regs (gdbarch) |
276 | + gdbarch_num_pseudo_regs (gdbarch)) | |
eb8bc282 | 277 | return value_of_user_reg (regnum, frame); |
0406ec40 | 278 | |
ac2adee5 | 279 | frame_register (frame, regnum, &optim, &lval, &addr, &realnum, raw_buffer); |
c906108c | 280 | |
e9e45075 | 281 | reg_val = allocate_value (register_type (gdbarch, regnum)); |
c906108c | 282 | |
990a07ab | 283 | memcpy (value_contents_raw (reg_val), raw_buffer, |
e9e45075 | 284 | register_size (gdbarch, regnum)); |
c906108c | 285 | VALUE_LVAL (reg_val) = lval; |
42ae5230 | 286 | set_value_address (reg_val, addr); |
9ee8fc9d | 287 | VALUE_REGNUM (reg_val) = regnum; |
feb13ab0 | 288 | set_value_optimized_out (reg_val, optim); |
0c16dd26 | 289 | VALUE_FRAME_ID (reg_val) = get_frame_id (frame); |
c906108c SS |
290 | return reg_val; |
291 | } | |
4478b372 | 292 | |
9214ee5f DJ |
293 | /* Return a `value' with the contents of (virtual or cooked) register |
294 | REGNUM as found in the specified FRAME. The register's type is | |
295 | determined by register_type(). The value is not fetched. */ | |
296 | ||
297 | struct value * | |
298 | value_of_register_lazy (struct frame_info *frame, int regnum) | |
299 | { | |
300 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
301 | struct value *reg_val; | |
302 | ||
303 | gdb_assert (regnum < (gdbarch_num_regs (gdbarch) | |
304 | + gdbarch_num_pseudo_regs (gdbarch))); | |
305 | ||
306 | /* We should have a valid (i.e. non-sentinel) frame. */ | |
307 | gdb_assert (frame_id_p (get_frame_id (frame))); | |
308 | ||
41e8491f | 309 | reg_val = allocate_value_lazy (register_type (gdbarch, regnum)); |
9214ee5f DJ |
310 | VALUE_LVAL (reg_val) = lval_register; |
311 | VALUE_REGNUM (reg_val) = regnum; | |
312 | VALUE_FRAME_ID (reg_val) = get_frame_id (frame); | |
9214ee5f DJ |
313 | return reg_val; |
314 | } | |
315 | ||
4478b372 JB |
316 | /* Given a pointer of type TYPE in target form in BUF, return the |
317 | address it represents. */ | |
318 | CORE_ADDR | |
9898f801 UW |
319 | unsigned_pointer_to_address (struct gdbarch *gdbarch, |
320 | struct type *type, const gdb_byte *buf) | |
4478b372 | 321 | { |
e17a4113 | 322 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
bb9bcb69 | 323 | |
e17a4113 | 324 | return extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order); |
4478b372 JB |
325 | } |
326 | ||
ac2e2ef7 | 327 | CORE_ADDR |
9898f801 UW |
328 | signed_pointer_to_address (struct gdbarch *gdbarch, |
329 | struct type *type, const gdb_byte *buf) | |
ac2e2ef7 | 330 | { |
e17a4113 | 331 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
bb9bcb69 | 332 | |
e17a4113 | 333 | return extract_signed_integer (buf, TYPE_LENGTH (type), byte_order); |
ac2e2ef7 | 334 | } |
4478b372 JB |
335 | |
336 | /* Given an address, store it as a pointer of type TYPE in target | |
337 | format in BUF. */ | |
338 | void | |
9898f801 UW |
339 | unsigned_address_to_pointer (struct gdbarch *gdbarch, struct type *type, |
340 | gdb_byte *buf, CORE_ADDR addr) | |
4478b372 | 341 | { |
e17a4113 | 342 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
bb9bcb69 | 343 | |
e17a4113 | 344 | store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order, addr); |
4478b372 JB |
345 | } |
346 | ||
ac2e2ef7 | 347 | void |
9898f801 UW |
348 | address_to_signed_pointer (struct gdbarch *gdbarch, struct type *type, |
349 | gdb_byte *buf, CORE_ADDR addr) | |
ac2e2ef7 | 350 | { |
e17a4113 | 351 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
bb9bcb69 | 352 | |
e17a4113 | 353 | store_signed_integer (buf, TYPE_LENGTH (type), byte_order, addr); |
ac2e2ef7 | 354 | } |
c906108c SS |
355 | \f |
356 | /* Will calling read_var_value or locate_var_value on SYM end | |
357 | up caring what frame it is being evaluated relative to? SYM must | |
358 | be non-NULL. */ | |
359 | int | |
fba45db2 | 360 | symbol_read_needs_frame (struct symbol *sym) |
c906108c SS |
361 | { |
362 | switch (SYMBOL_CLASS (sym)) | |
363 | { | |
364 | /* All cases listed explicitly so that gcc -Wall will detect it if | |
c5aa993b | 365 | we failed to consider one. */ |
4c2df51b | 366 | case LOC_COMPUTED: |
a67af2b9 | 367 | /* FIXME: cagney/2004-01-26: It should be possible to |
768a979c | 368 | unconditionally call the SYMBOL_COMPUTED_OPS method when available. |
d3efc286 | 369 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
370 | function) location in a function's symbol. Oops! For the |
371 | moment enable this when/where applicable. */ | |
768a979c | 372 | return SYMBOL_COMPUTED_OPS (sym)->read_needs_frame (sym); |
4c2df51b | 373 | |
c906108c SS |
374 | case LOC_REGISTER: |
375 | case LOC_ARG: | |
376 | case LOC_REF_ARG: | |
c906108c SS |
377 | case LOC_REGPARM_ADDR: |
378 | case LOC_LOCAL: | |
c906108c SS |
379 | return 1; |
380 | ||
381 | case LOC_UNDEF: | |
382 | case LOC_CONST: | |
383 | case LOC_STATIC: | |
c906108c SS |
384 | case LOC_TYPEDEF: |
385 | ||
386 | case LOC_LABEL: | |
387 | /* Getting the address of a label can be done independently of the block, | |
c5aa993b JM |
388 | even if some *uses* of that address wouldn't work so well without |
389 | the right frame. */ | |
c906108c SS |
390 | |
391 | case LOC_BLOCK: | |
392 | case LOC_CONST_BYTES: | |
393 | case LOC_UNRESOLVED: | |
394 | case LOC_OPTIMIZED_OUT: | |
395 | return 0; | |
396 | } | |
397 | return 1; | |
398 | } | |
399 | ||
400 | /* Given a struct symbol for a variable, | |
401 | and a stack frame id, read the value of the variable | |
0963b4bd | 402 | and return a (pointer to a) struct value containing the value. |
61212c0f | 403 | If the variable cannot be found, return a zero pointer. */ |
c906108c | 404 | |
3d6d86c6 | 405 | struct value * |
aa1ee363 | 406 | read_var_value (struct symbol *var, struct frame_info *frame) |
c906108c | 407 | { |
52f0bd74 | 408 | struct value *v; |
c906108c SS |
409 | struct type *type = SYMBOL_TYPE (var); |
410 | CORE_ADDR addr; | |
52f0bd74 | 411 | int len; |
c906108c | 412 | |
41e8491f JK |
413 | /* Call check_typedef on our type to make sure that, if TYPE is |
414 | a TYPE_CODE_TYPEDEF, its length is set to the length of the target type | |
415 | instead of zero. However, we do not replace the typedef type by the | |
416 | target type, because we want to keep the typedef in order to be able to | |
417 | set the returned value type description correctly. */ | |
418 | check_typedef (type); | |
c906108c SS |
419 | |
420 | len = TYPE_LENGTH (type); | |
421 | ||
61212c0f UW |
422 | if (symbol_read_needs_frame (var)) |
423 | gdb_assert (frame); | |
c906108c SS |
424 | |
425 | switch (SYMBOL_CLASS (var)) | |
426 | { | |
427 | case LOC_CONST: | |
428 | /* Put the constant back in target format. */ | |
41e8491f | 429 | v = allocate_value (type); |
990a07ab | 430 | store_signed_integer (value_contents_raw (v), len, |
e17a4113 | 431 | gdbarch_byte_order (get_type_arch (type)), |
c906108c SS |
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. */ | |
41e8491f | 438 | v = allocate_value (type); |
c906108c | 439 | if (overlay_debugging) |
4478b372 JB |
440 | { |
441 | CORE_ADDR addr | |
442 | = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
714835d5 | 443 | SYMBOL_OBJ_SECTION (var)); |
bb9bcb69 | 444 | |
990a07ab | 445 | store_typed_address (value_contents_raw (v), type, addr); |
4478b372 | 446 | } |
c906108c | 447 | else |
990a07ab | 448 | store_typed_address (value_contents_raw (v), type, |
4478b372 | 449 | SYMBOL_VALUE_ADDRESS (var)); |
c906108c SS |
450 | VALUE_LVAL (v) = not_lval; |
451 | return v; | |
452 | ||
453 | case LOC_CONST_BYTES: | |
41e8491f | 454 | v = allocate_value (type); |
bb9bcb69 MS |
455 | memcpy (value_contents_raw (v), SYMBOL_VALUE_BYTES (var), len); |
456 | VALUE_LVAL (v) = not_lval; | |
457 | return v; | |
c906108c SS |
458 | |
459 | case LOC_STATIC: | |
41e8491f | 460 | v = allocate_value_lazy (type); |
c906108c SS |
461 | if (overlay_debugging) |
462 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (var), | |
714835d5 | 463 | SYMBOL_OBJ_SECTION (var)); |
c906108c SS |
464 | else |
465 | addr = SYMBOL_VALUE_ADDRESS (var); | |
466 | break; | |
467 | ||
c906108c | 468 | case LOC_ARG: |
da62e633 | 469 | addr = get_frame_args_address (frame); |
c906108c SS |
470 | if (!addr) |
471 | return 0; | |
472 | addr += SYMBOL_VALUE (var); | |
41e8491f | 473 | v = allocate_value_lazy (type); |
c906108c SS |
474 | break; |
475 | ||
476 | case LOC_REF_ARG: | |
f76febae AC |
477 | { |
478 | struct value *ref; | |
479 | CORE_ADDR argref; | |
bb9bcb69 | 480 | |
da62e633 | 481 | argref = get_frame_args_address (frame); |
f76febae AC |
482 | if (!argref) |
483 | return 0; | |
484 | argref += SYMBOL_VALUE (var); | |
00a4c844 | 485 | ref = value_at (lookup_pointer_type (type), argref); |
1aa20aa8 | 486 | addr = value_as_address (ref); |
41e8491f | 487 | v = allocate_value_lazy (type); |
f76febae AC |
488 | break; |
489 | } | |
c906108c SS |
490 | |
491 | case LOC_LOCAL: | |
da62e633 | 492 | addr = get_frame_locals_address (frame); |
c906108c | 493 | addr += SYMBOL_VALUE (var); |
41e8491f | 494 | v = allocate_value_lazy (type); |
c906108c SS |
495 | break; |
496 | ||
c906108c | 497 | case LOC_TYPEDEF: |
8a3fe4f8 | 498 | error (_("Cannot look up value of a typedef")); |
c906108c SS |
499 | break; |
500 | ||
501 | case LOC_BLOCK: | |
41e8491f | 502 | v = allocate_value_lazy (type); |
c906108c | 503 | if (overlay_debugging) |
41e8491f JK |
504 | addr = symbol_overlayed_address |
505 | (BLOCK_START (SYMBOL_BLOCK_VALUE (var)), SYMBOL_OBJ_SECTION (var)); | |
c906108c | 506 | else |
41e8491f JK |
507 | addr = BLOCK_START (SYMBOL_BLOCK_VALUE (var)); |
508 | break; | |
c906108c SS |
509 | |
510 | case LOC_REGISTER: | |
c906108c SS |
511 | case LOC_REGPARM_ADDR: |
512 | { | |
768a979c UW |
513 | int regno = SYMBOL_REGISTER_OPS (var) |
514 | ->register_number (var, get_frame_arch (frame)); | |
3d6d86c6 | 515 | struct value *regval; |
c906108c | 516 | |
c906108c SS |
517 | if (SYMBOL_CLASS (var) == LOC_REGPARM_ADDR) |
518 | { | |
519 | regval = value_from_register (lookup_pointer_type (type), | |
c5aa993b | 520 | regno, |
c906108c SS |
521 | frame); |
522 | ||
523 | if (regval == NULL) | |
8a3fe4f8 | 524 | error (_("Value of register variable not available.")); |
c906108c | 525 | |
1aa20aa8 | 526 | addr = value_as_address (regval); |
41e8491f | 527 | v = allocate_value_lazy (type); |
c906108c SS |
528 | } |
529 | else | |
530 | { | |
531 | regval = value_from_register (type, regno, frame); | |
532 | ||
533 | if (regval == NULL) | |
8a3fe4f8 | 534 | error (_("Value of register variable not available.")); |
c906108c SS |
535 | return regval; |
536 | } | |
537 | } | |
538 | break; | |
539 | ||
4c2df51b | 540 | case LOC_COMPUTED: |
a67af2b9 | 541 | /* FIXME: cagney/2004-01-26: It should be possible to |
768a979c | 542 | unconditionally call the SYMBOL_COMPUTED_OPS method when available. |
d3efc286 | 543 | Unfortunately DWARF 2 stores the frame-base (instead of the |
a67af2b9 AC |
544 | function) location in a function's symbol. Oops! For the |
545 | moment enable this when/where applicable. */ | |
768a979c | 546 | return SYMBOL_COMPUTED_OPS (var)->read_variable (var, frame); |
4c2df51b | 547 | |
c906108c SS |
548 | case LOC_UNRESOLVED: |
549 | { | |
550 | struct minimal_symbol *msym; | |
e0740f77 | 551 | struct obj_section *obj_section; |
c906108c | 552 | |
3567439c | 553 | msym = lookup_minimal_symbol (SYMBOL_LINKAGE_NAME (var), NULL, NULL); |
c906108c SS |
554 | if (msym == NULL) |
555 | return 0; | |
556 | if (overlay_debugging) | |
557 | addr = symbol_overlayed_address (SYMBOL_VALUE_ADDRESS (msym), | |
714835d5 | 558 | SYMBOL_OBJ_SECTION (msym)); |
c906108c SS |
559 | else |
560 | addr = SYMBOL_VALUE_ADDRESS (msym); | |
e0740f77 JK |
561 | |
562 | obj_section = SYMBOL_OBJ_SECTION (msym); | |
563 | if (obj_section | |
564 | && (obj_section->the_bfd_section->flags & SEC_THREAD_LOCAL) != 0) | |
565 | addr = target_translate_tls_address (obj_section->objfile, addr); | |
41e8491f | 566 | v = allocate_value_lazy (type); |
c906108c SS |
567 | } |
568 | break; | |
569 | ||
570 | case LOC_OPTIMIZED_OUT: | |
41e8491f | 571 | v = allocate_value_lazy (type); |
c906108c | 572 | VALUE_LVAL (v) = not_lval; |
feb13ab0 | 573 | set_value_optimized_out (v, 1); |
c906108c SS |
574 | return v; |
575 | ||
576 | default: | |
8a3fe4f8 | 577 | error (_("Cannot look up value of a botched symbol.")); |
c906108c SS |
578 | break; |
579 | } | |
580 | ||
41e8491f | 581 | VALUE_LVAL (v) = lval_memory; |
42ae5230 | 582 | set_value_address (v, addr); |
c906108c SS |
583 | return v; |
584 | } | |
585 | ||
9acbedc0 UW |
586 | /* Install default attributes for register values. */ |
587 | ||
588 | struct value * | |
589 | default_value_from_register (struct type *type, int regnum, | |
590 | struct frame_info *frame) | |
591 | { | |
592 | struct gdbarch *gdbarch = get_frame_arch (frame); | |
593 | int len = TYPE_LENGTH (type); | |
594 | struct value *value = allocate_value (type); | |
595 | ||
596 | VALUE_LVAL (value) = lval_register; | |
597 | VALUE_FRAME_ID (value) = get_frame_id (frame); | |
598 | VALUE_REGNUM (value) = regnum; | |
599 | ||
600 | /* Any structure stored in more than one register will always be | |
601 | an integral number of registers. Otherwise, you need to do | |
602 | some fiddling with the last register copied here for little | |
603 | endian machines. */ | |
e9e45075 | 604 | if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG |
9acbedc0 UW |
605 | && len < register_size (gdbarch, regnum)) |
606 | /* Big-endian, and we want less than full size. */ | |
607 | set_value_offset (value, register_size (gdbarch, regnum) - len); | |
608 | else | |
609 | set_value_offset (value, 0); | |
610 | ||
611 | return value; | |
612 | } | |
613 | ||
00fa51f6 | 614 | /* Return a value of type TYPE, stored in register REGNUM, in frame FRAME. */ |
c906108c | 615 | |
3d6d86c6 | 616 | struct value * |
fba45db2 | 617 | value_from_register (struct type *type, int regnum, struct frame_info *frame) |
c906108c | 618 | { |
ff2e87ac | 619 | struct gdbarch *gdbarch = get_frame_arch (frame); |
9acbedc0 UW |
620 | struct type *type1 = check_typedef (type); |
621 | struct value *v; | |
622 | ||
e9e45075 | 623 | if (gdbarch_convert_register_p (gdbarch, regnum, type1)) |
ff2e87ac AC |
624 | { |
625 | /* The ISA/ABI need to something weird when obtaining the | |
626 | specified value from this register. It might need to | |
627 | re-order non-adjacent, starting with REGNUM (see MIPS and | |
628 | i386). It might need to convert the [float] register into | |
629 | the corresponding [integer] type (see Alpha). The assumption | |
c1afe53d | 630 | is that gdbarch_register_to_value populates the entire value |
ff2e87ac | 631 | including the location. */ |
9acbedc0 UW |
632 | v = allocate_value (type); |
633 | VALUE_LVAL (v) = lval_register; | |
634 | VALUE_FRAME_ID (v) = get_frame_id (frame); | |
635 | VALUE_REGNUM (v) = regnum; | |
e9e45075 | 636 | gdbarch_register_to_value (gdbarch, |
c1afe53d | 637 | frame, regnum, type1, value_contents_raw (v)); |
ff2e87ac AC |
638 | } |
639 | else | |
c906108c | 640 | { |
ff2e87ac | 641 | int len = TYPE_LENGTH (type); |
00fa51f6 | 642 | |
9acbedc0 UW |
643 | /* Construct the value. */ |
644 | v = gdbarch_value_from_register (gdbarch, type, regnum, frame); | |
00fa51f6 UW |
645 | |
646 | /* Get the data. */ | |
647 | if (!get_frame_register_bytes (frame, regnum, value_offset (v), len, | |
648 | value_contents_raw (v))) | |
649 | set_value_optimized_out (v, 1); | |
c906108c | 650 | } |
c906108c SS |
651 | return v; |
652 | } | |
ff2e87ac | 653 | |
0b2b0195 UW |
654 | /* Return contents of register REGNUM in frame FRAME as address, |
655 | interpreted as value of type TYPE. Will abort if register | |
656 | value is not available. */ | |
657 | ||
658 | CORE_ADDR | |
659 | address_from_register (struct type *type, int regnum, struct frame_info *frame) | |
660 | { | |
661 | struct value *value; | |
662 | CORE_ADDR result; | |
663 | ||
664 | value = value_from_register (type, regnum, frame); | |
665 | gdb_assert (value); | |
666 | ||
667 | result = value_as_address (value); | |
668 | release_value (value); | |
669 | value_free (value); | |
670 | ||
671 | return result; | |
672 | } |