Commit | Line | Data |
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4c2df51b | 1 | /* DWARF 2 location expression support for GDB. |
feb13ab0 | 2 | |
4c38e0a4 JB |
3 | Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010 |
4 | Free Software Foundation, Inc. | |
feb13ab0 | 5 | |
4c2df51b DJ |
6 | Contributed by Daniel Jacobowitz, MontaVista Software, Inc. |
7 | ||
8 | This file is part of GDB. | |
9 | ||
10 | This program is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
a9762ec7 JB |
12 | the Free Software Foundation; either version 3 of the License, or |
13 | (at your option) any later version. | |
4c2df51b | 14 | |
a9762ec7 JB |
15 | This program is distributed in the hope that it will be useful, |
16 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | GNU General Public License for more details. | |
4c2df51b DJ |
19 | |
20 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
4c2df51b DJ |
22 | |
23 | #include "defs.h" | |
24 | #include "ui-out.h" | |
25 | #include "value.h" | |
26 | #include "frame.h" | |
27 | #include "gdbcore.h" | |
28 | #include "target.h" | |
29 | #include "inferior.h" | |
a55cc764 DJ |
30 | #include "ax.h" |
31 | #include "ax-gdb.h" | |
e4adbba9 | 32 | #include "regcache.h" |
c3228f12 | 33 | #include "objfiles.h" |
93ad78a7 | 34 | #include "exceptions.h" |
edb3359d | 35 | #include "block.h" |
4c2df51b | 36 | |
fa8f86ff | 37 | #include "dwarf2.h" |
4c2df51b DJ |
38 | #include "dwarf2expr.h" |
39 | #include "dwarf2loc.h" | |
e7802207 | 40 | #include "dwarf2-frame.h" |
4c2df51b DJ |
41 | |
42 | #include "gdb_string.h" | |
eff4f95e | 43 | #include "gdb_assert.h" |
4c2df51b | 44 | |
0936ad1d SS |
45 | static void |
46 | dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, | |
0d45f56e | 47 | const gdb_byte **start, size_t *length); |
0936ad1d | 48 | |
0d53c4c4 DJ |
49 | /* A helper function for dealing with location lists. Given a |
50 | symbol baton (BATON) and a pc value (PC), find the appropriate | |
51 | location expression, set *LOCEXPR_LENGTH, and return a pointer | |
52 | to the beginning of the expression. Returns NULL on failure. | |
53 | ||
54 | For now, only return the first matching location expression; there | |
55 | can be more than one in the list. */ | |
56 | ||
947bb88f | 57 | static const gdb_byte * |
0d53c4c4 | 58 | find_location_expression (struct dwarf2_loclist_baton *baton, |
b6b08ebf | 59 | size_t *locexpr_length, CORE_ADDR pc) |
0d53c4c4 | 60 | { |
0d53c4c4 | 61 | CORE_ADDR low, high; |
947bb88f | 62 | const gdb_byte *loc_ptr, *buf_end; |
852483bc | 63 | int length; |
ae0d2f24 | 64 | struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu); |
f7fd4728 | 65 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
e17a4113 | 66 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
ae0d2f24 | 67 | unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu); |
0d53c4c4 | 68 | CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); |
8edfa926 | 69 | /* Adjust base_address for relocatable objects. */ |
ae0d2f24 UW |
70 | CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets, |
71 | SECT_OFF_TEXT (objfile)); | |
8edfa926 | 72 | CORE_ADDR base_address = baton->base_address + base_offset; |
0d53c4c4 DJ |
73 | |
74 | loc_ptr = baton->data; | |
75 | buf_end = baton->data + baton->size; | |
76 | ||
77 | while (1) | |
78 | { | |
b5758fe4 UW |
79 | if (buf_end - loc_ptr < 2 * addr_size) |
80 | error (_("find_location_expression: Corrupted DWARF expression.")); | |
0d53c4c4 | 81 | |
b5758fe4 UW |
82 | low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
83 | loc_ptr += addr_size; | |
0d53c4c4 DJ |
84 | |
85 | /* A base-address-selection entry. */ | |
b5758fe4 | 86 | if (low == base_mask) |
0d53c4c4 | 87 | { |
b5758fe4 UW |
88 | base_address = dwarf2_read_address (gdbarch, |
89 | loc_ptr, buf_end, addr_size); | |
90 | loc_ptr += addr_size; | |
0d53c4c4 DJ |
91 | continue; |
92 | } | |
93 | ||
b5758fe4 UW |
94 | high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); |
95 | loc_ptr += addr_size; | |
96 | ||
97 | /* An end-of-list entry. */ | |
98 | if (low == 0 && high == 0) | |
99 | return NULL; | |
100 | ||
0d53c4c4 DJ |
101 | /* Otherwise, a location expression entry. */ |
102 | low += base_address; | |
103 | high += base_address; | |
104 | ||
e17a4113 | 105 | length = extract_unsigned_integer (loc_ptr, 2, byte_order); |
0d53c4c4 DJ |
106 | loc_ptr += 2; |
107 | ||
108 | if (pc >= low && pc < high) | |
109 | { | |
110 | *locexpr_length = length; | |
111 | return loc_ptr; | |
112 | } | |
113 | ||
114 | loc_ptr += length; | |
115 | } | |
116 | } | |
117 | ||
4c2df51b DJ |
118 | /* This is the baton used when performing dwarf2 expression |
119 | evaluation. */ | |
120 | struct dwarf_expr_baton | |
121 | { | |
122 | struct frame_info *frame; | |
123 | struct objfile *objfile; | |
124 | }; | |
125 | ||
126 | /* Helper functions for dwarf2_evaluate_loc_desc. */ | |
127 | ||
4bc9efe1 | 128 | /* Using the frame specified in BATON, return the value of register |
0b2b0195 | 129 | REGNUM, treated as a pointer. */ |
4c2df51b | 130 | static CORE_ADDR |
61fbb938 | 131 | dwarf_expr_read_reg (void *baton, int dwarf_regnum) |
4c2df51b | 132 | { |
4c2df51b | 133 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
5e2b427d | 134 | struct gdbarch *gdbarch = get_frame_arch (debaton->frame); |
e5192dd8 | 135 | CORE_ADDR result; |
0b2b0195 | 136 | int regnum; |
e4adbba9 | 137 | |
5e2b427d UW |
138 | regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum); |
139 | result = address_from_register (builtin_type (gdbarch)->builtin_data_ptr, | |
0b2b0195 | 140 | regnum, debaton->frame); |
4c2df51b DJ |
141 | return result; |
142 | } | |
143 | ||
144 | /* Read memory at ADDR (length LEN) into BUF. */ | |
145 | ||
146 | static void | |
852483bc | 147 | dwarf_expr_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
4c2df51b DJ |
148 | { |
149 | read_memory (addr, buf, len); | |
150 | } | |
151 | ||
152 | /* Using the frame specified in BATON, find the location expression | |
153 | describing the frame base. Return a pointer to it in START and | |
154 | its length in LENGTH. */ | |
155 | static void | |
0d45f56e | 156 | dwarf_expr_frame_base (void *baton, const gdb_byte **start, size_t * length) |
4c2df51b | 157 | { |
da62e633 AC |
158 | /* FIXME: cagney/2003-03-26: This code should be using |
159 | get_frame_base_address(), and then implement a dwarf2 specific | |
160 | this_base method. */ | |
4c2df51b | 161 | struct symbol *framefunc; |
4c2df51b | 162 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
0d53c4c4 | 163 | |
edb3359d DJ |
164 | /* Use block_linkage_function, which returns a real (not inlined) |
165 | function, instead of get_frame_function, which may return an | |
166 | inlined function. */ | |
167 | framefunc = block_linkage_function (get_frame_block (debaton->frame, NULL)); | |
0d53c4c4 | 168 | |
eff4f95e JG |
169 | /* If we found a frame-relative symbol then it was certainly within |
170 | some function associated with a frame. If we can't find the frame, | |
171 | something has gone wrong. */ | |
172 | gdb_assert (framefunc != NULL); | |
173 | ||
0936ad1d SS |
174 | dwarf_expr_frame_base_1 (framefunc, |
175 | get_frame_address_in_block (debaton->frame), | |
176 | start, length); | |
177 | } | |
178 | ||
179 | static void | |
180 | dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc, | |
0d45f56e | 181 | const gdb_byte **start, size_t *length) |
0936ad1d | 182 | { |
edb3359d DJ |
183 | if (SYMBOL_LOCATION_BATON (framefunc) == NULL) |
184 | *start = NULL; | |
185 | else if (SYMBOL_COMPUTED_OPS (framefunc) == &dwarf2_loclist_funcs) | |
0d53c4c4 DJ |
186 | { |
187 | struct dwarf2_loclist_baton *symbaton; | |
22c6caba | 188 | |
0d53c4c4 | 189 | symbaton = SYMBOL_LOCATION_BATON (framefunc); |
0936ad1d | 190 | *start = find_location_expression (symbaton, length, pc); |
0d53c4c4 DJ |
191 | } |
192 | else | |
193 | { | |
194 | struct dwarf2_locexpr_baton *symbaton; | |
9a619af0 | 195 | |
0d53c4c4 | 196 | symbaton = SYMBOL_LOCATION_BATON (framefunc); |
ebd3bcc1 JK |
197 | if (symbaton != NULL) |
198 | { | |
199 | *length = symbaton->size; | |
200 | *start = symbaton->data; | |
201 | } | |
202 | else | |
203 | *start = NULL; | |
0d53c4c4 DJ |
204 | } |
205 | ||
206 | if (*start == NULL) | |
8a3fe4f8 | 207 | error (_("Could not find the frame base for \"%s\"."), |
0d53c4c4 | 208 | SYMBOL_NATURAL_NAME (framefunc)); |
4c2df51b DJ |
209 | } |
210 | ||
e7802207 TT |
211 | /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for |
212 | the frame in BATON. */ | |
213 | ||
214 | static CORE_ADDR | |
215 | dwarf_expr_frame_cfa (void *baton) | |
216 | { | |
217 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; | |
9a619af0 | 218 | |
e7802207 TT |
219 | return dwarf2_frame_cfa (debaton->frame); |
220 | } | |
221 | ||
4c2df51b DJ |
222 | /* Using the objfile specified in BATON, find the address for the |
223 | current thread's thread-local storage with offset OFFSET. */ | |
224 | static CORE_ADDR | |
225 | dwarf_expr_tls_address (void *baton, CORE_ADDR offset) | |
226 | { | |
227 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; | |
4c2df51b | 228 | |
9e35dae4 | 229 | return target_translate_tls_address (debaton->objfile, offset); |
4c2df51b DJ |
230 | } |
231 | ||
052b9502 NF |
232 | struct piece_closure |
233 | { | |
88bfdde4 TT |
234 | /* Reference count. */ |
235 | int refc; | |
236 | ||
052b9502 NF |
237 | /* The number of pieces used to describe this variable. */ |
238 | int n_pieces; | |
239 | ||
6063c216 UW |
240 | /* The target address size, used only for DWARF_VALUE_STACK. */ |
241 | int addr_size; | |
cec03d70 | 242 | |
052b9502 NF |
243 | /* The pieces themselves. */ |
244 | struct dwarf_expr_piece *pieces; | |
245 | }; | |
246 | ||
247 | /* Allocate a closure for a value formed from separately-described | |
248 | PIECES. */ | |
249 | ||
250 | static struct piece_closure * | |
cec03d70 | 251 | allocate_piece_closure (int n_pieces, struct dwarf_expr_piece *pieces, |
6063c216 | 252 | int addr_size) |
052b9502 NF |
253 | { |
254 | struct piece_closure *c = XZALLOC (struct piece_closure); | |
255 | ||
88bfdde4 | 256 | c->refc = 1; |
052b9502 | 257 | c->n_pieces = n_pieces; |
6063c216 | 258 | c->addr_size = addr_size; |
052b9502 NF |
259 | c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece); |
260 | ||
261 | memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece)); | |
262 | ||
263 | return c; | |
264 | } | |
265 | ||
d3b1e874 TT |
266 | /* The lowest-level function to extract bits from a byte buffer. |
267 | SOURCE is the buffer. It is updated if we read to the end of a | |
268 | byte. | |
269 | SOURCE_OFFSET_BITS is the offset of the first bit to read. It is | |
270 | updated to reflect the number of bits actually read. | |
271 | NBITS is the number of bits we want to read. It is updated to | |
272 | reflect the number of bits actually read. This function may read | |
273 | fewer bits. | |
274 | BITS_BIG_ENDIAN is taken directly from gdbarch. | |
275 | This function returns the extracted bits. */ | |
276 | ||
277 | static unsigned int | |
278 | extract_bits_primitive (const gdb_byte **source, | |
279 | unsigned int *source_offset_bits, | |
280 | int *nbits, int bits_big_endian) | |
281 | { | |
282 | unsigned int avail, mask, datum; | |
283 | ||
284 | gdb_assert (*source_offset_bits < 8); | |
285 | ||
286 | avail = 8 - *source_offset_bits; | |
287 | if (avail > *nbits) | |
288 | avail = *nbits; | |
289 | ||
290 | mask = (1 << avail) - 1; | |
291 | datum = **source; | |
292 | if (bits_big_endian) | |
293 | datum >>= 8 - (*source_offset_bits + *nbits); | |
294 | else | |
295 | datum >>= *source_offset_bits; | |
296 | datum &= mask; | |
297 | ||
298 | *nbits -= avail; | |
299 | *source_offset_bits += avail; | |
300 | if (*source_offset_bits >= 8) | |
301 | { | |
302 | *source_offset_bits -= 8; | |
303 | ++*source; | |
304 | } | |
305 | ||
306 | return datum; | |
307 | } | |
308 | ||
309 | /* Extract some bits from a source buffer and move forward in the | |
310 | buffer. | |
311 | ||
312 | SOURCE is the source buffer. It is updated as bytes are read. | |
313 | SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as | |
314 | bits are read. | |
315 | NBITS is the number of bits to read. | |
316 | BITS_BIG_ENDIAN is taken directly from gdbarch. | |
317 | ||
318 | This function returns the bits that were read. */ | |
319 | ||
320 | static unsigned int | |
321 | extract_bits (const gdb_byte **source, unsigned int *source_offset_bits, | |
322 | int nbits, int bits_big_endian) | |
323 | { | |
324 | unsigned int datum; | |
325 | ||
326 | gdb_assert (nbits > 0 && nbits <= 8); | |
327 | ||
328 | datum = extract_bits_primitive (source, source_offset_bits, &nbits, | |
329 | bits_big_endian); | |
330 | if (nbits > 0) | |
331 | { | |
332 | unsigned int more; | |
333 | ||
334 | more = extract_bits_primitive (source, source_offset_bits, &nbits, | |
335 | bits_big_endian); | |
336 | if (bits_big_endian) | |
337 | datum <<= nbits; | |
338 | else | |
339 | more <<= nbits; | |
340 | datum |= more; | |
341 | } | |
342 | ||
343 | return datum; | |
344 | } | |
345 | ||
346 | /* Write some bits into a buffer and move forward in the buffer. | |
347 | ||
348 | DATUM is the bits to write. The low-order bits of DATUM are used. | |
349 | DEST is the destination buffer. It is updated as bytes are | |
350 | written. | |
351 | DEST_OFFSET_BITS is the bit offset in DEST at which writing is | |
352 | done. | |
353 | NBITS is the number of valid bits in DATUM. | |
354 | BITS_BIG_ENDIAN is taken directly from gdbarch. */ | |
355 | ||
356 | static void | |
357 | insert_bits (unsigned int datum, | |
358 | gdb_byte *dest, unsigned int dest_offset_bits, | |
359 | int nbits, int bits_big_endian) | |
360 | { | |
361 | unsigned int mask; | |
362 | ||
363 | gdb_assert (dest_offset_bits >= 0 && dest_offset_bits + nbits <= 8); | |
364 | ||
365 | mask = (1 << nbits) - 1; | |
366 | if (bits_big_endian) | |
367 | { | |
368 | datum <<= 8 - (dest_offset_bits + nbits); | |
369 | mask <<= 8 - (dest_offset_bits + nbits); | |
370 | } | |
371 | else | |
372 | { | |
373 | datum <<= dest_offset_bits; | |
374 | mask <<= dest_offset_bits; | |
375 | } | |
376 | ||
377 | gdb_assert ((datum & ~mask) == 0); | |
378 | ||
379 | *dest = (*dest & ~mask) | datum; | |
380 | } | |
381 | ||
382 | /* Copy bits from a source to a destination. | |
383 | ||
384 | DEST is where the bits should be written. | |
385 | DEST_OFFSET_BITS is the bit offset into DEST. | |
386 | SOURCE is the source of bits. | |
387 | SOURCE_OFFSET_BITS is the bit offset into SOURCE. | |
388 | BIT_COUNT is the number of bits to copy. | |
389 | BITS_BIG_ENDIAN is taken directly from gdbarch. */ | |
390 | ||
391 | static void | |
392 | copy_bitwise (gdb_byte *dest, unsigned int dest_offset_bits, | |
393 | const gdb_byte *source, unsigned int source_offset_bits, | |
394 | unsigned int bit_count, | |
395 | int bits_big_endian) | |
396 | { | |
397 | unsigned int dest_avail; | |
398 | int datum; | |
399 | ||
400 | /* Reduce everything to byte-size pieces. */ | |
401 | dest += dest_offset_bits / 8; | |
402 | dest_offset_bits %= 8; | |
403 | source += source_offset_bits / 8; | |
404 | source_offset_bits %= 8; | |
405 | ||
406 | dest_avail = 8 - dest_offset_bits % 8; | |
407 | ||
408 | /* See if we can fill the first destination byte. */ | |
409 | if (dest_avail < bit_count) | |
410 | { | |
411 | datum = extract_bits (&source, &source_offset_bits, dest_avail, | |
412 | bits_big_endian); | |
413 | insert_bits (datum, dest, dest_offset_bits, dest_avail, bits_big_endian); | |
414 | ++dest; | |
415 | dest_offset_bits = 0; | |
416 | bit_count -= dest_avail; | |
417 | } | |
418 | ||
419 | /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer | |
420 | than 8 bits remaining. */ | |
421 | gdb_assert (dest_offset_bits % 8 == 0 || bit_count < 8); | |
422 | for (; bit_count >= 8; bit_count -= 8) | |
423 | { | |
424 | datum = extract_bits (&source, &source_offset_bits, 8, bits_big_endian); | |
425 | *dest++ = (gdb_byte) datum; | |
426 | } | |
427 | ||
428 | /* Finally, we may have a few leftover bits. */ | |
429 | gdb_assert (bit_count <= 8 - dest_offset_bits % 8); | |
430 | if (bit_count > 0) | |
431 | { | |
432 | datum = extract_bits (&source, &source_offset_bits, bit_count, | |
433 | bits_big_endian); | |
434 | insert_bits (datum, dest, dest_offset_bits, bit_count, bits_big_endian); | |
435 | } | |
436 | } | |
437 | ||
052b9502 NF |
438 | static void |
439 | read_pieced_value (struct value *v) | |
440 | { | |
441 | int i; | |
442 | long offset = 0; | |
d3b1e874 | 443 | ULONGEST bits_to_skip; |
052b9502 NF |
444 | gdb_byte *contents; |
445 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); | |
446 | struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v)); | |
afd74c5f | 447 | size_t type_len; |
d3b1e874 TT |
448 | size_t buffer_size = 0; |
449 | char *buffer = NULL; | |
450 | struct cleanup *cleanup; | |
451 | int bits_big_endian | |
452 | = gdbarch_bits_big_endian (get_type_arch (value_type (v))); | |
afd74c5f TT |
453 | |
454 | if (value_type (v) != value_enclosing_type (v)) | |
455 | internal_error (__FILE__, __LINE__, | |
456 | _("Should not be able to create a lazy value with " | |
457 | "an enclosing type")); | |
052b9502 | 458 | |
d3b1e874 TT |
459 | cleanup = make_cleanup (free_current_contents, &buffer); |
460 | ||
052b9502 | 461 | contents = value_contents_raw (v); |
d3b1e874 TT |
462 | bits_to_skip = 8 * value_offset (v); |
463 | type_len = 8 * TYPE_LENGTH (value_type (v)); | |
464 | ||
afd74c5f | 465 | for (i = 0; i < c->n_pieces && offset < type_len; i++) |
052b9502 NF |
466 | { |
467 | struct dwarf_expr_piece *p = &c->pieces[i]; | |
d3b1e874 TT |
468 | size_t this_size, this_size_bits; |
469 | long dest_offset_bits, source_offset_bits, source_offset; | |
0d45f56e | 470 | const gdb_byte *intermediate_buffer; |
d3b1e874 TT |
471 | |
472 | /* Compute size, source, and destination offsets for copying, in | |
473 | bits. */ | |
474 | this_size_bits = p->size; | |
475 | if (bits_to_skip > 0 && bits_to_skip >= this_size_bits) | |
afd74c5f | 476 | { |
d3b1e874 | 477 | bits_to_skip -= this_size_bits; |
afd74c5f TT |
478 | continue; |
479 | } | |
d3b1e874 TT |
480 | if (this_size_bits > type_len - offset) |
481 | this_size_bits = type_len - offset; | |
482 | if (bits_to_skip > 0) | |
afd74c5f | 483 | { |
d3b1e874 TT |
484 | dest_offset_bits = 0; |
485 | source_offset_bits = bits_to_skip; | |
486 | this_size_bits -= bits_to_skip; | |
487 | bits_to_skip = 0; | |
afd74c5f TT |
488 | } |
489 | else | |
490 | { | |
d3b1e874 TT |
491 | dest_offset_bits = offset; |
492 | source_offset_bits = 0; | |
afd74c5f | 493 | } |
9a619af0 | 494 | |
d3b1e874 TT |
495 | this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; |
496 | source_offset = source_offset_bits / 8; | |
497 | if (buffer_size < this_size) | |
498 | { | |
499 | buffer_size = this_size; | |
500 | buffer = xrealloc (buffer, buffer_size); | |
501 | } | |
502 | intermediate_buffer = buffer; | |
503 | ||
504 | /* Copy from the source to DEST_BUFFER. */ | |
cec03d70 | 505 | switch (p->location) |
052b9502 | 506 | { |
cec03d70 TT |
507 | case DWARF_VALUE_REGISTER: |
508 | { | |
509 | struct gdbarch *arch = get_frame_arch (frame); | |
cec03d70 | 510 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, |
44353522 | 511 | p->v.expr.value); |
afd74c5f | 512 | int reg_offset = source_offset; |
dcbf108f UW |
513 | |
514 | if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG | |
afd74c5f | 515 | && this_size < register_size (arch, gdb_regnum)) |
d3b1e874 TT |
516 | { |
517 | /* Big-endian, and we want less than full size. */ | |
518 | reg_offset = register_size (arch, gdb_regnum) - this_size; | |
519 | /* We want the lower-order THIS_SIZE_BITS of the bytes | |
520 | we extract from the register. */ | |
521 | source_offset_bits += 8 * this_size - this_size_bits; | |
522 | } | |
dcbf108f | 523 | |
63b4f126 MGD |
524 | if (gdb_regnum != -1) |
525 | { | |
526 | get_frame_register_bytes (frame, gdb_regnum, reg_offset, | |
d3b1e874 | 527 | this_size, buffer); |
63b4f126 MGD |
528 | } |
529 | else | |
530 | { | |
531 | error (_("Unable to access DWARF register number %s"), | |
532 | paddress (arch, p->v.expr.value)); | |
533 | } | |
cec03d70 TT |
534 | } |
535 | break; | |
536 | ||
537 | case DWARF_VALUE_MEMORY: | |
44353522 | 538 | if (p->v.expr.in_stack_memory) |
d3b1e874 | 539 | read_stack (p->v.expr.value + source_offset, buffer, this_size); |
44353522 | 540 | else |
d3b1e874 | 541 | read_memory (p->v.expr.value + source_offset, buffer, this_size); |
cec03d70 TT |
542 | break; |
543 | ||
544 | case DWARF_VALUE_STACK: | |
545 | { | |
6063c216 | 546 | struct gdbarch *gdbarch = get_type_arch (value_type (v)); |
afd74c5f | 547 | size_t n = this_size; |
9a619af0 | 548 | |
afd74c5f TT |
549 | if (n > c->addr_size - source_offset) |
550 | n = (c->addr_size >= source_offset | |
551 | ? c->addr_size - source_offset | |
552 | : 0); | |
553 | if (n == 0) | |
554 | { | |
555 | /* Nothing. */ | |
556 | } | |
557 | else if (source_offset == 0) | |
d3b1e874 | 558 | store_unsigned_integer (buffer, n, |
afd74c5f TT |
559 | gdbarch_byte_order (gdbarch), |
560 | p->v.expr.value); | |
561 | else | |
562 | { | |
563 | gdb_byte bytes[sizeof (ULONGEST)]; | |
564 | ||
565 | store_unsigned_integer (bytes, n + source_offset, | |
566 | gdbarch_byte_order (gdbarch), | |
567 | p->v.expr.value); | |
d3b1e874 | 568 | memcpy (buffer, bytes + source_offset, n); |
afd74c5f | 569 | } |
cec03d70 TT |
570 | } |
571 | break; | |
572 | ||
573 | case DWARF_VALUE_LITERAL: | |
574 | { | |
afd74c5f TT |
575 | size_t n = this_size; |
576 | ||
577 | if (n > p->v.literal.length - source_offset) | |
578 | n = (p->v.literal.length >= source_offset | |
579 | ? p->v.literal.length - source_offset | |
580 | : 0); | |
581 | if (n != 0) | |
d3b1e874 | 582 | intermediate_buffer = p->v.literal.data + source_offset; |
cec03d70 TT |
583 | } |
584 | break; | |
585 | ||
cb826367 TT |
586 | case DWARF_VALUE_OPTIMIZED_OUT: |
587 | /* We just leave the bits empty for now. This is not ideal | |
588 | but gdb currently does not have a nice way to represent | |
589 | optimized-out pieces. */ | |
d3b1e874 | 590 | warning (_("bits %ld-%ld in computed object were optimized out; " |
cb826367 TT |
591 | "replacing with zeroes"), |
592 | offset, | |
d3b1e874 | 593 | offset + (long) this_size_bits); |
cb826367 TT |
594 | break; |
595 | ||
cec03d70 TT |
596 | default: |
597 | internal_error (__FILE__, __LINE__, _("invalid location type")); | |
052b9502 | 598 | } |
d3b1e874 TT |
599 | |
600 | if (p->location != DWARF_VALUE_OPTIMIZED_OUT) | |
601 | copy_bitwise (contents, dest_offset_bits, | |
602 | intermediate_buffer, source_offset_bits % 8, | |
603 | this_size_bits, bits_big_endian); | |
604 | ||
605 | offset += this_size_bits; | |
052b9502 | 606 | } |
d3b1e874 TT |
607 | |
608 | do_cleanups (cleanup); | |
052b9502 NF |
609 | } |
610 | ||
611 | static void | |
612 | write_pieced_value (struct value *to, struct value *from) | |
613 | { | |
614 | int i; | |
615 | long offset = 0; | |
d3b1e874 | 616 | ULONGEST bits_to_skip; |
afd74c5f | 617 | const gdb_byte *contents; |
052b9502 NF |
618 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (to); |
619 | struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to)); | |
afd74c5f | 620 | size_t type_len; |
d3b1e874 TT |
621 | size_t buffer_size = 0; |
622 | char *buffer = NULL; | |
623 | struct cleanup *cleanup; | |
624 | int bits_big_endian | |
625 | = gdbarch_bits_big_endian (get_type_arch (value_type (to))); | |
052b9502 NF |
626 | |
627 | if (frame == NULL) | |
628 | { | |
629 | set_value_optimized_out (to, 1); | |
630 | return; | |
631 | } | |
632 | ||
d3b1e874 TT |
633 | cleanup = make_cleanup (free_current_contents, &buffer); |
634 | ||
afd74c5f | 635 | contents = value_contents (from); |
d3b1e874 TT |
636 | bits_to_skip = 8 * value_offset (to); |
637 | type_len = 8 * TYPE_LENGTH (value_type (to)); | |
afd74c5f | 638 | for (i = 0; i < c->n_pieces && offset < type_len; i++) |
052b9502 NF |
639 | { |
640 | struct dwarf_expr_piece *p = &c->pieces[i]; | |
d3b1e874 TT |
641 | size_t this_size_bits, this_size; |
642 | long dest_offset_bits, source_offset_bits, dest_offset, source_offset; | |
643 | int need_bitwise; | |
644 | const gdb_byte *source_buffer; | |
afd74c5f | 645 | |
d3b1e874 TT |
646 | this_size_bits = p->size; |
647 | if (bits_to_skip > 0 && bits_to_skip >= this_size_bits) | |
afd74c5f | 648 | { |
d3b1e874 | 649 | bits_to_skip -= this_size_bits; |
afd74c5f TT |
650 | continue; |
651 | } | |
d3b1e874 TT |
652 | if (this_size_bits > type_len - offset) |
653 | this_size_bits = type_len - offset; | |
654 | if (bits_to_skip > 0) | |
afd74c5f | 655 | { |
d3b1e874 TT |
656 | dest_offset_bits = bits_to_skip; |
657 | source_offset_bits = 0; | |
658 | this_size_bits -= bits_to_skip; | |
659 | bits_to_skip = 0; | |
afd74c5f TT |
660 | } |
661 | else | |
662 | { | |
d3b1e874 TT |
663 | dest_offset_bits = 0; |
664 | source_offset_bits = offset; | |
665 | } | |
666 | ||
667 | this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; | |
668 | source_offset = source_offset_bits / 8; | |
669 | dest_offset = dest_offset_bits / 8; | |
670 | if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0) | |
671 | { | |
672 | source_buffer = contents + source_offset; | |
673 | need_bitwise = 0; | |
674 | } | |
675 | else | |
676 | { | |
677 | if (buffer_size < this_size) | |
678 | { | |
679 | buffer_size = this_size; | |
680 | buffer = xrealloc (buffer, buffer_size); | |
681 | } | |
682 | source_buffer = buffer; | |
683 | need_bitwise = 1; | |
afd74c5f | 684 | } |
9a619af0 | 685 | |
cec03d70 | 686 | switch (p->location) |
052b9502 | 687 | { |
cec03d70 TT |
688 | case DWARF_VALUE_REGISTER: |
689 | { | |
690 | struct gdbarch *arch = get_frame_arch (frame); | |
44353522 | 691 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.expr.value); |
afd74c5f | 692 | int reg_offset = dest_offset; |
dcbf108f UW |
693 | |
694 | if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG | |
afd74c5f | 695 | && this_size <= register_size (arch, gdb_regnum)) |
dcbf108f | 696 | /* Big-endian, and we want less than full size. */ |
afd74c5f | 697 | reg_offset = register_size (arch, gdb_regnum) - this_size; |
dcbf108f | 698 | |
63b4f126 MGD |
699 | if (gdb_regnum != -1) |
700 | { | |
d3b1e874 TT |
701 | if (need_bitwise) |
702 | { | |
703 | get_frame_register_bytes (frame, gdb_regnum, reg_offset, | |
704 | this_size, buffer); | |
705 | copy_bitwise (buffer, dest_offset_bits, | |
706 | contents, source_offset_bits, | |
707 | this_size_bits, | |
708 | bits_big_endian); | |
709 | } | |
710 | ||
63b4f126 | 711 | put_frame_register_bytes (frame, gdb_regnum, reg_offset, |
d3b1e874 | 712 | this_size, source_buffer); |
63b4f126 MGD |
713 | } |
714 | else | |
715 | { | |
716 | error (_("Unable to write to DWARF register number %s"), | |
717 | paddress (arch, p->v.expr.value)); | |
718 | } | |
cec03d70 TT |
719 | } |
720 | break; | |
721 | case DWARF_VALUE_MEMORY: | |
d3b1e874 TT |
722 | if (need_bitwise) |
723 | { | |
724 | /* Only the first and last bytes can possibly have any | |
725 | bits reused. */ | |
726 | read_memory (p->v.expr.value + dest_offset, buffer, 1); | |
727 | read_memory (p->v.expr.value + dest_offset + this_size - 1, | |
728 | buffer + this_size - 1, 1); | |
729 | copy_bitwise (buffer, dest_offset_bits, | |
730 | contents, source_offset_bits, | |
731 | this_size_bits, | |
732 | bits_big_endian); | |
733 | } | |
734 | ||
afd74c5f | 735 | write_memory (p->v.expr.value + dest_offset, |
d3b1e874 | 736 | source_buffer, this_size); |
cec03d70 TT |
737 | break; |
738 | default: | |
739 | set_value_optimized_out (to, 1); | |
d3b1e874 | 740 | goto done; |
052b9502 | 741 | } |
d3b1e874 | 742 | offset += this_size_bits; |
052b9502 | 743 | } |
d3b1e874 TT |
744 | |
745 | done: | |
746 | do_cleanups (cleanup); | |
052b9502 NF |
747 | } |
748 | ||
749 | static void * | |
750 | copy_pieced_value_closure (struct value *v) | |
751 | { | |
752 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); | |
753 | ||
88bfdde4 TT |
754 | ++c->refc; |
755 | return c; | |
052b9502 NF |
756 | } |
757 | ||
758 | static void | |
759 | free_pieced_value_closure (struct value *v) | |
760 | { | |
761 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); | |
762 | ||
88bfdde4 TT |
763 | --c->refc; |
764 | if (c->refc == 0) | |
765 | { | |
766 | xfree (c->pieces); | |
767 | xfree (c); | |
768 | } | |
052b9502 NF |
769 | } |
770 | ||
771 | /* Functions for accessing a variable described by DW_OP_piece. */ | |
772 | static struct lval_funcs pieced_value_funcs = { | |
773 | read_pieced_value, | |
774 | write_pieced_value, | |
775 | copy_pieced_value_closure, | |
776 | free_pieced_value_closure | |
777 | }; | |
778 | ||
4c2df51b | 779 | /* Evaluate a location description, starting at DATA and with length |
a2d33775 | 780 | SIZE, to find the current location of variable of TYPE in the context |
4c2df51b | 781 | of FRAME. */ |
a2d33775 | 782 | |
4c2df51b | 783 | static struct value * |
a2d33775 | 784 | dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame, |
947bb88f | 785 | const gdb_byte *data, unsigned short size, |
ae0d2f24 | 786 | struct dwarf2_per_cu_data *per_cu) |
4c2df51b | 787 | { |
4c2df51b DJ |
788 | struct value *retval; |
789 | struct dwarf_expr_baton baton; | |
790 | struct dwarf_expr_context *ctx; | |
4a227398 | 791 | struct cleanup *old_chain; |
4c2df51b | 792 | |
0d53c4c4 DJ |
793 | if (size == 0) |
794 | { | |
a2d33775 | 795 | retval = allocate_value (type); |
0d53c4c4 | 796 | VALUE_LVAL (retval) = not_lval; |
feb13ab0 | 797 | set_value_optimized_out (retval, 1); |
10fb19b6 | 798 | return retval; |
0d53c4c4 DJ |
799 | } |
800 | ||
4c2df51b | 801 | baton.frame = frame; |
ae0d2f24 | 802 | baton.objfile = dwarf2_per_cu_objfile (per_cu); |
4c2df51b DJ |
803 | |
804 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
805 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
806 | ||
f7fd4728 | 807 | ctx->gdbarch = get_objfile_arch (baton.objfile); |
ae0d2f24 | 808 | ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); |
4c2df51b DJ |
809 | ctx->baton = &baton; |
810 | ctx->read_reg = dwarf_expr_read_reg; | |
811 | ctx->read_mem = dwarf_expr_read_mem; | |
812 | ctx->get_frame_base = dwarf_expr_frame_base; | |
e7802207 | 813 | ctx->get_frame_cfa = dwarf_expr_frame_cfa; |
4c2df51b DJ |
814 | ctx->get_tls_address = dwarf_expr_tls_address; |
815 | ||
816 | dwarf_expr_eval (ctx, data, size); | |
87808bd6 JB |
817 | if (ctx->num_pieces > 0) |
818 | { | |
052b9502 NF |
819 | struct piece_closure *c; |
820 | struct frame_id frame_id = get_frame_id (frame); | |
821 | ||
6063c216 UW |
822 | c = allocate_piece_closure (ctx->num_pieces, ctx->pieces, |
823 | ctx->addr_size); | |
a2d33775 | 824 | retval = allocate_computed_value (type, &pieced_value_funcs, c); |
052b9502 | 825 | VALUE_FRAME_ID (retval) = frame_id; |
87808bd6 | 826 | } |
4c2df51b DJ |
827 | else |
828 | { | |
cec03d70 TT |
829 | switch (ctx->location) |
830 | { | |
831 | case DWARF_VALUE_REGISTER: | |
832 | { | |
833 | struct gdbarch *arch = get_frame_arch (frame); | |
834 | CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0); | |
835 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum); | |
9a619af0 | 836 | |
63b4f126 | 837 | if (gdb_regnum != -1) |
a2d33775 | 838 | retval = value_from_register (type, gdb_regnum, frame); |
63b4f126 | 839 | else |
a2d33775 JK |
840 | error (_("Unable to access DWARF register number %s"), |
841 | paddress (arch, dwarf_regnum)); | |
cec03d70 TT |
842 | } |
843 | break; | |
844 | ||
845 | case DWARF_VALUE_MEMORY: | |
846 | { | |
847 | CORE_ADDR address = dwarf_expr_fetch (ctx, 0); | |
44353522 | 848 | int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0); |
cec03d70 | 849 | |
a2d33775 | 850 | retval = allocate_value (type); |
cec03d70 TT |
851 | VALUE_LVAL (retval) = lval_memory; |
852 | set_value_lazy (retval, 1); | |
44353522 DE |
853 | if (in_stack_memory) |
854 | set_value_stack (retval, 1); | |
cec03d70 TT |
855 | set_value_address (retval, address); |
856 | } | |
857 | break; | |
858 | ||
859 | case DWARF_VALUE_STACK: | |
860 | { | |
cec03d70 TT |
861 | ULONGEST value = (ULONGEST) dwarf_expr_fetch (ctx, 0); |
862 | bfd_byte *contents; | |
863 | size_t n = ctx->addr_size; | |
864 | ||
a2d33775 | 865 | retval = allocate_value (type); |
cec03d70 | 866 | contents = value_contents_raw (retval); |
a2d33775 JK |
867 | if (n > TYPE_LENGTH (type)) |
868 | n = TYPE_LENGTH (type); | |
05566b3b TT |
869 | store_unsigned_integer (contents, n, |
870 | gdbarch_byte_order (ctx->gdbarch), | |
871 | value); | |
cec03d70 TT |
872 | } |
873 | break; | |
874 | ||
875 | case DWARF_VALUE_LITERAL: | |
876 | { | |
877 | bfd_byte *contents; | |
878 | size_t n = ctx->len; | |
879 | ||
a2d33775 | 880 | retval = allocate_value (type); |
cec03d70 | 881 | contents = value_contents_raw (retval); |
a2d33775 JK |
882 | if (n > TYPE_LENGTH (type)) |
883 | n = TYPE_LENGTH (type); | |
cec03d70 TT |
884 | memcpy (contents, ctx->data, n); |
885 | } | |
886 | break; | |
887 | ||
cb826367 TT |
888 | /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context -- |
889 | it can only be encountered when making a piece. */ | |
890 | case DWARF_VALUE_OPTIMIZED_OUT: | |
cec03d70 TT |
891 | default: |
892 | internal_error (__FILE__, __LINE__, _("invalid location type")); | |
893 | } | |
4c2df51b DJ |
894 | } |
895 | ||
42be36b3 CT |
896 | set_value_initialized (retval, ctx->initialized); |
897 | ||
4a227398 | 898 | do_cleanups (old_chain); |
4c2df51b DJ |
899 | |
900 | return retval; | |
901 | } | |
4c2df51b DJ |
902 | \f |
903 | /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */ | |
904 | ||
905 | struct needs_frame_baton | |
906 | { | |
907 | int needs_frame; | |
908 | }; | |
909 | ||
910 | /* Reads from registers do require a frame. */ | |
911 | static CORE_ADDR | |
61fbb938 | 912 | needs_frame_read_reg (void *baton, int regnum) |
4c2df51b DJ |
913 | { |
914 | struct needs_frame_baton *nf_baton = baton; | |
9a619af0 | 915 | |
4c2df51b DJ |
916 | nf_baton->needs_frame = 1; |
917 | return 1; | |
918 | } | |
919 | ||
920 | /* Reads from memory do not require a frame. */ | |
921 | static void | |
852483bc | 922 | needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
4c2df51b DJ |
923 | { |
924 | memset (buf, 0, len); | |
925 | } | |
926 | ||
927 | /* Frame-relative accesses do require a frame. */ | |
928 | static void | |
0d45f56e | 929 | needs_frame_frame_base (void *baton, const gdb_byte **start, size_t * length) |
4c2df51b | 930 | { |
852483bc | 931 | static gdb_byte lit0 = DW_OP_lit0; |
4c2df51b DJ |
932 | struct needs_frame_baton *nf_baton = baton; |
933 | ||
934 | *start = &lit0; | |
935 | *length = 1; | |
936 | ||
937 | nf_baton->needs_frame = 1; | |
938 | } | |
939 | ||
e7802207 TT |
940 | /* CFA accesses require a frame. */ |
941 | ||
942 | static CORE_ADDR | |
943 | needs_frame_frame_cfa (void *baton) | |
944 | { | |
945 | struct needs_frame_baton *nf_baton = baton; | |
9a619af0 | 946 | |
e7802207 TT |
947 | nf_baton->needs_frame = 1; |
948 | return 1; | |
949 | } | |
950 | ||
4c2df51b DJ |
951 | /* Thread-local accesses do require a frame. */ |
952 | static CORE_ADDR | |
953 | needs_frame_tls_address (void *baton, CORE_ADDR offset) | |
954 | { | |
955 | struct needs_frame_baton *nf_baton = baton; | |
9a619af0 | 956 | |
4c2df51b DJ |
957 | nf_baton->needs_frame = 1; |
958 | return 1; | |
959 | } | |
960 | ||
961 | /* Return non-zero iff the location expression at DATA (length SIZE) | |
962 | requires a frame to evaluate. */ | |
963 | ||
964 | static int | |
947bb88f | 965 | dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size, |
ae0d2f24 | 966 | struct dwarf2_per_cu_data *per_cu) |
4c2df51b DJ |
967 | { |
968 | struct needs_frame_baton baton; | |
969 | struct dwarf_expr_context *ctx; | |
f630a401 | 970 | int in_reg; |
4a227398 | 971 | struct cleanup *old_chain; |
4c2df51b DJ |
972 | |
973 | baton.needs_frame = 0; | |
974 | ||
975 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
976 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
977 | ||
f7fd4728 | 978 | ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (per_cu)); |
ae0d2f24 | 979 | ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); |
4c2df51b DJ |
980 | ctx->baton = &baton; |
981 | ctx->read_reg = needs_frame_read_reg; | |
982 | ctx->read_mem = needs_frame_read_mem; | |
983 | ctx->get_frame_base = needs_frame_frame_base; | |
e7802207 | 984 | ctx->get_frame_cfa = needs_frame_frame_cfa; |
4c2df51b DJ |
985 | ctx->get_tls_address = needs_frame_tls_address; |
986 | ||
987 | dwarf_expr_eval (ctx, data, size); | |
988 | ||
cec03d70 | 989 | in_reg = ctx->location == DWARF_VALUE_REGISTER; |
f630a401 | 990 | |
87808bd6 JB |
991 | if (ctx->num_pieces > 0) |
992 | { | |
993 | int i; | |
994 | ||
995 | /* If the location has several pieces, and any of them are in | |
996 | registers, then we will need a frame to fetch them from. */ | |
997 | for (i = 0; i < ctx->num_pieces; i++) | |
cec03d70 | 998 | if (ctx->pieces[i].location == DWARF_VALUE_REGISTER) |
87808bd6 JB |
999 | in_reg = 1; |
1000 | } | |
1001 | ||
4a227398 | 1002 | do_cleanups (old_chain); |
4c2df51b | 1003 | |
f630a401 | 1004 | return baton.needs_frame || in_reg; |
4c2df51b DJ |
1005 | } |
1006 | ||
08922a10 SS |
1007 | /* This struct keeps track of the pieces that make up a multi-location |
1008 | object, for use in agent expression generation. It is | |
1009 | superficially similar to struct dwarf_expr_piece, but | |
1010 | dwarf_expr_piece is designed for use in immediate evaluation, and | |
1011 | does not, for example, have a way to record both base register and | |
1012 | offset. */ | |
1013 | ||
1014 | struct axs_var_loc | |
0d53c4c4 | 1015 | { |
08922a10 SS |
1016 | /* Memory vs register, etc */ |
1017 | enum axs_lvalue_kind kind; | |
1018 | ||
1019 | /* If non-zero, number of bytes in this fragment */ | |
1020 | unsigned bytes; | |
1021 | ||
1022 | /* (GDB-numbered) reg, or base reg if >= 0 */ | |
1023 | int reg; | |
1024 | ||
1025 | /* offset from reg */ | |
1026 | LONGEST offset; | |
1027 | }; | |
1028 | ||
0d45f56e | 1029 | static const gdb_byte * |
08922a10 SS |
1030 | dwarf2_tracepoint_var_loc (struct symbol *symbol, |
1031 | struct agent_expr *ax, | |
1032 | struct axs_var_loc *loc, | |
1033 | struct gdbarch *gdbarch, | |
0d45f56e | 1034 | const gdb_byte *data, const gdb_byte *end) |
08922a10 SS |
1035 | { |
1036 | if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) | |
0d53c4c4 | 1037 | { |
08922a10 SS |
1038 | loc->kind = axs_lvalue_register; |
1039 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0); | |
1040 | data += 1; | |
0d53c4c4 DJ |
1041 | } |
1042 | else if (data[0] == DW_OP_regx) | |
1043 | { | |
1044 | ULONGEST reg; | |
9a619af0 | 1045 | |
08922a10 SS |
1046 | data = read_uleb128 (data + 1, end, ®); |
1047 | loc->kind = axs_lvalue_register; | |
1048 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); | |
0d53c4c4 DJ |
1049 | } |
1050 | else if (data[0] == DW_OP_fbreg) | |
1051 | { | |
0936ad1d SS |
1052 | struct block *b; |
1053 | struct symbol *framefunc; | |
1054 | int frame_reg = 0; | |
0d53c4c4 | 1055 | LONGEST frame_offset; |
0d45f56e | 1056 | const gdb_byte *base_data; |
0936ad1d SS |
1057 | size_t base_size; |
1058 | LONGEST base_offset = 0; | |
1059 | ||
1060 | b = block_for_pc (ax->scope); | |
1061 | ||
1062 | if (!b) | |
1063 | error (_("No block found for address")); | |
1064 | ||
1065 | framefunc = block_linkage_function (b); | |
1066 | ||
1067 | if (!framefunc) | |
1068 | error (_("No function found for block")); | |
1069 | ||
1070 | dwarf_expr_frame_base_1 (framefunc, ax->scope, | |
1071 | &base_data, &base_size); | |
1072 | ||
08922a10 | 1073 | if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) |
0936ad1d | 1074 | { |
0d45f56e TT |
1075 | const gdb_byte *buf_end; |
1076 | ||
0936ad1d | 1077 | frame_reg = base_data[0] - DW_OP_breg0; |
08922a10 SS |
1078 | buf_end = read_sleb128 (base_data + 1, |
1079 | base_data + base_size, &base_offset); | |
0936ad1d SS |
1080 | if (buf_end != base_data + base_size) |
1081 | error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."), | |
1082 | frame_reg, SYMBOL_PRINT_NAME (symbol)); | |
1083 | } | |
08922a10 SS |
1084 | else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) |
1085 | { | |
1086 | /* The frame base is just the register, with no offset. */ | |
1087 | frame_reg = base_data[0] - DW_OP_reg0; | |
1088 | base_offset = 0; | |
1089 | } | |
0936ad1d SS |
1090 | else |
1091 | { | |
1092 | /* We don't know what to do with the frame base expression, | |
1093 | so we can't trace this variable; give up. */ | |
08922a10 SS |
1094 | error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled, first opcode in base data is 0x%x."), |
1095 | SYMBOL_PRINT_NAME (symbol), base_data[0]); | |
0936ad1d | 1096 | } |
0d53c4c4 | 1097 | |
08922a10 | 1098 | data = read_sleb128 (data + 1, end, &frame_offset); |
4c2df51b | 1099 | |
08922a10 SS |
1100 | loc->kind = axs_lvalue_memory; |
1101 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); | |
1102 | loc->offset = base_offset + frame_offset; | |
9c238357 | 1103 | } |
08922a10 | 1104 | else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31) |
9c238357 RC |
1105 | { |
1106 | unsigned int reg; | |
1107 | LONGEST offset; | |
9c238357 RC |
1108 | |
1109 | reg = data[0] - DW_OP_breg0; | |
08922a10 | 1110 | data = read_sleb128 (data + 1, end, &offset); |
9c238357 | 1111 | |
08922a10 SS |
1112 | loc->kind = axs_lvalue_memory; |
1113 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); | |
1114 | loc->offset = offset; | |
0d53c4c4 DJ |
1115 | } |
1116 | else | |
9c238357 RC |
1117 | error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."), |
1118 | data[0], SYMBOL_PRINT_NAME (symbol)); | |
08922a10 SS |
1119 | |
1120 | return data; | |
0d53c4c4 | 1121 | } |
08922a10 SS |
1122 | |
1123 | /* Given the location of a piece, issue bytecodes that will access it. */ | |
1124 | ||
1125 | static void | |
1126 | dwarf2_tracepoint_var_access (struct agent_expr *ax, | |
1127 | struct axs_value *value, | |
1128 | struct axs_var_loc *loc) | |
1129 | { | |
1130 | value->kind = loc->kind; | |
1131 | ||
1132 | switch (loc->kind) | |
1133 | { | |
1134 | case axs_lvalue_register: | |
1135 | value->u.reg = loc->reg; | |
1136 | break; | |
1137 | ||
1138 | case axs_lvalue_memory: | |
1139 | ax_reg (ax, loc->reg); | |
1140 | if (loc->offset) | |
1141 | { | |
1142 | ax_const_l (ax, loc->offset); | |
1143 | ax_simple (ax, aop_add); | |
1144 | } | |
1145 | break; | |
1146 | ||
1147 | default: | |
1148 | internal_error (__FILE__, __LINE__, _("Unhandled value kind in dwarf2_tracepoint_var_access")); | |
1149 | } | |
1150 | } | |
1151 | ||
1152 | static void | |
1153 | dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, | |
1154 | struct agent_expr *ax, struct axs_value *value, | |
0d45f56e | 1155 | const gdb_byte *data, int size) |
08922a10 | 1156 | { |
0d45f56e | 1157 | const gdb_byte *end = data + size; |
08922a10 SS |
1158 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
1159 | /* In practice, a variable is not going to be spread across | |
1160 | dozens of registers or memory locations. If someone comes up | |
1161 | with a real-world example, revisit this. */ | |
1162 | #define MAX_FRAGS 16 | |
1163 | struct axs_var_loc fragments[MAX_FRAGS]; | |
1164 | int nfrags = 0, frag; | |
1165 | int length = 0; | |
1166 | int piece_ok = 0; | |
1167 | int bad = 0; | |
1168 | int first = 1; | |
1169 | ||
1170 | if (!data || size == 0) | |
1171 | { | |
1172 | value->optimized_out = 1; | |
1173 | return; | |
1174 | } | |
1175 | ||
1176 | while (data < end) | |
1177 | { | |
1178 | if (!piece_ok) | |
1179 | { | |
1180 | if (nfrags == MAX_FRAGS) | |
1181 | error (_("Too many pieces in location for \"%s\"."), | |
1182 | SYMBOL_PRINT_NAME (symbol)); | |
1183 | ||
1184 | fragments[nfrags].bytes = 0; | |
1185 | data = dwarf2_tracepoint_var_loc (symbol, ax, &fragments[nfrags], | |
1186 | gdbarch, data, end); | |
1187 | nfrags++; | |
1188 | piece_ok = 1; | |
1189 | } | |
1190 | else if (data[0] == DW_OP_piece) | |
1191 | { | |
1192 | ULONGEST bytes; | |
1193 | ||
1194 | data = read_uleb128 (data + 1, end, &bytes); | |
1195 | /* Only deal with 4 byte fragments for now. */ | |
1196 | if (bytes != 4) | |
1197 | error (_("DW_OP_piece %s not supported in location for \"%s\"."), | |
1198 | pulongest (bytes), SYMBOL_PRINT_NAME (symbol)); | |
1199 | fragments[nfrags - 1].bytes = bytes; | |
1200 | length += bytes; | |
1201 | piece_ok = 0; | |
1202 | } | |
1203 | else | |
1204 | { | |
1205 | bad = 1; | |
1206 | break; | |
1207 | } | |
1208 | } | |
1209 | ||
1210 | if (bad || data > end) | |
1211 | error (_("Corrupted DWARF expression for \"%s\"."), | |
1212 | SYMBOL_PRINT_NAME (symbol)); | |
1213 | ||
1214 | /* If single expression, no pieces, convert to external format. */ | |
1215 | if (length == 0) | |
1216 | { | |
1217 | dwarf2_tracepoint_var_access (ax, value, &fragments[0]); | |
1218 | return; | |
1219 | } | |
1220 | ||
1221 | if (length != TYPE_LENGTH (value->type)) | |
1222 | error (_("Inconsistent piece information for \"%s\"."), | |
1223 | SYMBOL_PRINT_NAME (symbol)); | |
1224 | ||
1225 | /* Emit bytecodes to assemble the pieces into a single stack entry. */ | |
1226 | ||
1227 | for ((frag = (byte_order == BFD_ENDIAN_BIG ? 0 : nfrags - 1)); | |
1228 | nfrags--; | |
1229 | (frag += (byte_order == BFD_ENDIAN_BIG ? 1 : -1))) | |
1230 | { | |
1231 | if (!first) | |
1232 | { | |
1233 | /* shift the previous fragment up 32 bits */ | |
1234 | ax_const_l (ax, 32); | |
1235 | ax_simple (ax, aop_lsh); | |
1236 | } | |
1237 | ||
1238 | dwarf2_tracepoint_var_access (ax, value, &fragments[frag]); | |
1239 | ||
1240 | switch (value->kind) | |
1241 | { | |
1242 | case axs_lvalue_register: | |
1243 | ax_reg (ax, value->u.reg); | |
1244 | break; | |
1245 | ||
1246 | case axs_lvalue_memory: | |
1247 | { | |
1248 | extern int trace_kludge; /* Ugh. */ | |
1249 | ||
1250 | gdb_assert (fragments[frag].bytes == 4); | |
1251 | if (trace_kludge) | |
1252 | ax_trace_quick (ax, 4); | |
1253 | ax_simple (ax, aop_ref32); | |
1254 | } | |
1255 | break; | |
1256 | } | |
1257 | ||
1258 | if (!first) | |
1259 | { | |
1260 | /* or the new fragment into the previous */ | |
1261 | ax_zero_ext (ax, 32); | |
1262 | ax_simple (ax, aop_bit_or); | |
1263 | } | |
1264 | first = 0; | |
1265 | } | |
1266 | value->kind = axs_rvalue; | |
1267 | } | |
1268 | ||
4c2df51b DJ |
1269 | \f |
1270 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression | |
1271 | evaluator to calculate the location. */ | |
1272 | static struct value * | |
1273 | locexpr_read_variable (struct symbol *symbol, struct frame_info *frame) | |
1274 | { | |
1275 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1276 | struct value *val; | |
9a619af0 | 1277 | |
a2d33775 JK |
1278 | val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data, |
1279 | dlbaton->size, dlbaton->per_cu); | |
4c2df51b DJ |
1280 | |
1281 | return val; | |
1282 | } | |
1283 | ||
1284 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ | |
1285 | static int | |
1286 | locexpr_read_needs_frame (struct symbol *symbol) | |
1287 | { | |
1288 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
9a619af0 | 1289 | |
ae0d2f24 UW |
1290 | return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size, |
1291 | dlbaton->per_cu); | |
4c2df51b DJ |
1292 | } |
1293 | ||
08922a10 SS |
1294 | /* Describe a single piece of a location, returning an updated |
1295 | position in the bytecode sequence. */ | |
1296 | ||
0d45f56e | 1297 | static const gdb_byte * |
08922a10 SS |
1298 | locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, |
1299 | CORE_ADDR addr, struct objfile *objfile, | |
0d45f56e TT |
1300 | const gdb_byte *data, int size, |
1301 | unsigned int addr_size) | |
4c2df51b | 1302 | { |
08922a10 SS |
1303 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
1304 | int regno; | |
1305 | ||
1306 | if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) | |
1307 | { | |
1308 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0); | |
1309 | fprintf_filtered (stream, _("a variable in $%s"), | |
1310 | gdbarch_register_name (gdbarch, regno)); | |
1311 | data += 1; | |
1312 | } | |
1313 | else if (data[0] == DW_OP_regx) | |
1314 | { | |
1315 | ULONGEST reg; | |
4c2df51b | 1316 | |
08922a10 SS |
1317 | data = read_uleb128 (data + 1, data + size, ®); |
1318 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); | |
1319 | fprintf_filtered (stream, _("a variable in $%s"), | |
1320 | gdbarch_register_name (gdbarch, regno)); | |
1321 | } | |
1322 | else if (data[0] == DW_OP_fbreg) | |
4c2df51b | 1323 | { |
08922a10 SS |
1324 | struct block *b; |
1325 | struct symbol *framefunc; | |
1326 | int frame_reg = 0; | |
1327 | LONGEST frame_offset; | |
0d45f56e | 1328 | const gdb_byte *base_data; |
08922a10 SS |
1329 | size_t base_size; |
1330 | LONGEST base_offset = 0; | |
1331 | ||
1332 | b = block_for_pc (addr); | |
1333 | ||
1334 | if (!b) | |
1335 | error (_("No block found for address for symbol \"%s\"."), | |
1336 | SYMBOL_PRINT_NAME (symbol)); | |
1337 | ||
1338 | framefunc = block_linkage_function (b); | |
1339 | ||
1340 | if (!framefunc) | |
1341 | error (_("No function found for block for symbol \"%s\"."), | |
1342 | SYMBOL_PRINT_NAME (symbol)); | |
1343 | ||
1344 | dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size); | |
1345 | ||
1346 | if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) | |
1347 | { | |
0d45f56e | 1348 | const gdb_byte *buf_end; |
08922a10 SS |
1349 | |
1350 | frame_reg = base_data[0] - DW_OP_breg0; | |
1351 | buf_end = read_sleb128 (base_data + 1, | |
1352 | base_data + base_size, &base_offset); | |
1353 | if (buf_end != base_data + base_size) | |
1354 | error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."), | |
1355 | frame_reg, SYMBOL_PRINT_NAME (symbol)); | |
1356 | } | |
1357 | else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) | |
1358 | { | |
1359 | /* The frame base is just the register, with no offset. */ | |
1360 | frame_reg = base_data[0] - DW_OP_reg0; | |
1361 | base_offset = 0; | |
1362 | } | |
1363 | else | |
1364 | { | |
1365 | /* We don't know what to do with the frame base expression, | |
1366 | so we can't trace this variable; give up. */ | |
1367 | error (_("Cannot describe location of symbol \"%s\"; " | |
1368 | "DWARF 2 encoding not handled, " | |
1369 | "first opcode in base data is 0x%x."), | |
1370 | SYMBOL_PRINT_NAME (symbol), base_data[0]); | |
1371 | } | |
1372 | ||
1373 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); | |
1374 | ||
1375 | data = read_sleb128 (data + 1, data + size, &frame_offset); | |
1376 | ||
1377 | fprintf_filtered (stream, _("a variable at frame base reg $%s offset %s+%s"), | |
1378 | gdbarch_register_name (gdbarch, regno), | |
1379 | plongest (base_offset), plongest (frame_offset)); | |
1380 | } | |
1381 | else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31) | |
1382 | { | |
1383 | LONGEST offset; | |
1384 | ||
1385 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0); | |
1386 | ||
1387 | data = read_sleb128 (data + 1, data + size, &offset); | |
1388 | ||
4c2df51b | 1389 | fprintf_filtered (stream, |
08922a10 SS |
1390 | _("a variable at offset %s from base reg $%s"), |
1391 | plongest (offset), | |
5e2b427d | 1392 | gdbarch_register_name (gdbarch, regno)); |
4c2df51b DJ |
1393 | } |
1394 | ||
c3228f12 EZ |
1395 | /* The location expression for a TLS variable looks like this (on a |
1396 | 64-bit LE machine): | |
1397 | ||
1398 | DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0 | |
1399 | (DW_OP_addr: 4; DW_OP_GNU_push_tls_address) | |
1400 | ||
1401 | 0x3 is the encoding for DW_OP_addr, which has an operand as long | |
1402 | as the size of an address on the target machine (here is 8 | |
1403 | bytes). 0xe0 is the encoding for DW_OP_GNU_push_tls_address. | |
1404 | The operand represents the offset at which the variable is within | |
1405 | the thread local storage. */ | |
1406 | ||
08922a10 SS |
1407 | else if (size > 1 |
1408 | && data[size - 1] == DW_OP_GNU_push_tls_address | |
1409 | && data[0] == DW_OP_addr) | |
1410 | { | |
1411 | CORE_ADDR offset = dwarf2_read_address (gdbarch, | |
1412 | data + 1, | |
1413 | data + size - 1, | |
1414 | addr_size); | |
9a619af0 | 1415 | |
08922a10 SS |
1416 | fprintf_filtered (stream, |
1417 | _("a thread-local variable at offset %s " | |
1418 | "in the thread-local storage for `%s'"), | |
1419 | paddress (gdbarch, offset), objfile->name); | |
1420 | ||
1421 | data += 1 + addr_size + 1; | |
1422 | } | |
1423 | else | |
1424 | fprintf_filtered (stream, | |
1425 | _("a variable with complex or multiple locations (DWARF2)")); | |
c3228f12 | 1426 | |
08922a10 | 1427 | return data; |
4c2df51b DJ |
1428 | } |
1429 | ||
08922a10 SS |
1430 | /* Describe a single location, which may in turn consist of multiple |
1431 | pieces. */ | |
a55cc764 | 1432 | |
08922a10 SS |
1433 | static void |
1434 | locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, | |
0d45f56e TT |
1435 | struct ui_file *stream, |
1436 | const gdb_byte *data, int size, | |
08922a10 SS |
1437 | struct objfile *objfile, unsigned int addr_size) |
1438 | { | |
0d45f56e | 1439 | const gdb_byte *end = data + size; |
08922a10 SS |
1440 | int piece_done = 0, first_piece = 1, bad = 0; |
1441 | ||
1442 | /* A multi-piece description consists of multiple sequences of bytes | |
1443 | each followed by DW_OP_piece + length of piece. */ | |
1444 | while (data < end) | |
1445 | { | |
1446 | if (!piece_done) | |
1447 | { | |
1448 | if (first_piece) | |
1449 | first_piece = 0; | |
1450 | else | |
1451 | fprintf_filtered (stream, _(", and ")); | |
1452 | ||
1453 | data = locexpr_describe_location_piece (symbol, stream, addr, objfile, | |
1454 | data, size, addr_size); | |
1455 | piece_done = 1; | |
1456 | } | |
1457 | else if (data[0] == DW_OP_piece) | |
1458 | { | |
1459 | ULONGEST bytes; | |
1460 | ||
1461 | data = read_uleb128 (data + 1, end, &bytes); | |
1462 | ||
1463 | fprintf_filtered (stream, _(" [%s-byte piece]"), pulongest (bytes)); | |
1464 | ||
1465 | piece_done = 0; | |
1466 | } | |
1467 | else | |
1468 | { | |
1469 | bad = 1; | |
1470 | break; | |
1471 | } | |
1472 | } | |
1473 | ||
1474 | if (bad || data > end) | |
1475 | error (_("Corrupted DWARF2 expression for \"%s\"."), | |
1476 | SYMBOL_PRINT_NAME (symbol)); | |
1477 | } | |
1478 | ||
1479 | /* Print a natural-language description of SYMBOL to STREAM. This | |
1480 | version is for a symbol with a single location. */ | |
a55cc764 | 1481 | |
08922a10 SS |
1482 | static void |
1483 | locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr, | |
1484 | struct ui_file *stream) | |
1485 | { | |
1486 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1487 | struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); | |
1488 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); | |
1489 | ||
1490 | locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size, | |
1491 | objfile, addr_size); | |
1492 | } | |
1493 | ||
1494 | /* Describe the location of SYMBOL as an agent value in VALUE, generating | |
1495 | any necessary bytecode in AX. */ | |
a55cc764 | 1496 | |
0d53c4c4 | 1497 | static void |
505e835d UW |
1498 | locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
1499 | struct agent_expr *ax, struct axs_value *value) | |
a55cc764 DJ |
1500 | { |
1501 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1502 | ||
505e835d UW |
1503 | dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, |
1504 | dlbaton->data, dlbaton->size); | |
a55cc764 DJ |
1505 | } |
1506 | ||
4c2df51b DJ |
1507 | /* The set of location functions used with the DWARF-2 expression |
1508 | evaluator. */ | |
768a979c | 1509 | const struct symbol_computed_ops dwarf2_locexpr_funcs = { |
4c2df51b DJ |
1510 | locexpr_read_variable, |
1511 | locexpr_read_needs_frame, | |
1512 | locexpr_describe_location, | |
a55cc764 | 1513 | locexpr_tracepoint_var_ref |
4c2df51b | 1514 | }; |
0d53c4c4 DJ |
1515 | |
1516 | ||
1517 | /* Wrapper functions for location lists. These generally find | |
1518 | the appropriate location expression and call something above. */ | |
1519 | ||
1520 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression | |
1521 | evaluator to calculate the location. */ | |
1522 | static struct value * | |
1523 | loclist_read_variable (struct symbol *symbol, struct frame_info *frame) | |
1524 | { | |
1525 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1526 | struct value *val; | |
947bb88f | 1527 | const gdb_byte *data; |
b6b08ebf | 1528 | size_t size; |
0d53c4c4 DJ |
1529 | |
1530 | data = find_location_expression (dlbaton, &size, | |
22c6caba JW |
1531 | frame ? get_frame_address_in_block (frame) |
1532 | : 0); | |
0d53c4c4 | 1533 | if (data == NULL) |
806048c6 DJ |
1534 | { |
1535 | val = allocate_value (SYMBOL_TYPE (symbol)); | |
1536 | VALUE_LVAL (val) = not_lval; | |
1537 | set_value_optimized_out (val, 1); | |
1538 | } | |
1539 | else | |
a2d33775 | 1540 | val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size, |
ae0d2f24 | 1541 | dlbaton->per_cu); |
0d53c4c4 DJ |
1542 | |
1543 | return val; | |
1544 | } | |
1545 | ||
1546 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ | |
1547 | static int | |
1548 | loclist_read_needs_frame (struct symbol *symbol) | |
1549 | { | |
1550 | /* If there's a location list, then assume we need to have a frame | |
1551 | to choose the appropriate location expression. With tracking of | |
1552 | global variables this is not necessarily true, but such tracking | |
1553 | is disabled in GCC at the moment until we figure out how to | |
1554 | represent it. */ | |
1555 | ||
1556 | return 1; | |
1557 | } | |
1558 | ||
08922a10 SS |
1559 | /* Print a natural-language description of SYMBOL to STREAM. This |
1560 | version applies when there is a list of different locations, each | |
1561 | with a specified address range. */ | |
1562 | ||
1563 | static void | |
1564 | loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, | |
1565 | struct ui_file *stream) | |
0d53c4c4 | 1566 | { |
08922a10 SS |
1567 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
1568 | CORE_ADDR low, high; | |
947bb88f | 1569 | const gdb_byte *loc_ptr, *buf_end; |
08922a10 SS |
1570 | int length, first = 1; |
1571 | struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); | |
1572 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
1573 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
1574 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); | |
1575 | CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); | |
1576 | /* Adjust base_address for relocatable objects. */ | |
1577 | CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets, | |
1578 | SECT_OFF_TEXT (objfile)); | |
1579 | CORE_ADDR base_address = dlbaton->base_address + base_offset; | |
1580 | ||
1581 | loc_ptr = dlbaton->data; | |
1582 | buf_end = dlbaton->data + dlbaton->size; | |
1583 | ||
1584 | fprintf_filtered (stream, _("multi-location (")); | |
1585 | ||
1586 | /* Iterate through locations until we run out. */ | |
1587 | while (1) | |
1588 | { | |
1589 | if (buf_end - loc_ptr < 2 * addr_size) | |
1590 | error (_("Corrupted DWARF expression for symbol \"%s\"."), | |
1591 | SYMBOL_PRINT_NAME (symbol)); | |
1592 | ||
1593 | low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); | |
1594 | loc_ptr += addr_size; | |
1595 | ||
1596 | /* A base-address-selection entry. */ | |
1597 | if (low == base_mask) | |
1598 | { | |
1599 | base_address = dwarf2_read_address (gdbarch, | |
1600 | loc_ptr, buf_end, addr_size); | |
1601 | fprintf_filtered (stream, _("[base address %s]"), | |
1602 | paddress (gdbarch, base_address)); | |
1603 | loc_ptr += addr_size; | |
1604 | continue; | |
1605 | } | |
1606 | ||
1607 | high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); | |
1608 | loc_ptr += addr_size; | |
1609 | ||
1610 | /* An end-of-list entry. */ | |
1611 | if (low == 0 && high == 0) | |
1612 | { | |
1613 | /* Indicate the end of the list, for readability. */ | |
1614 | fprintf_filtered (stream, _(")")); | |
1615 | return; | |
1616 | } | |
1617 | ||
1618 | /* Otherwise, a location expression entry. */ | |
1619 | low += base_address; | |
1620 | high += base_address; | |
1621 | ||
1622 | length = extract_unsigned_integer (loc_ptr, 2, byte_order); | |
1623 | loc_ptr += 2; | |
1624 | ||
1625 | /* Separate the different locations with a semicolon. */ | |
1626 | if (first) | |
1627 | first = 0; | |
1628 | else | |
1629 | fprintf_filtered (stream, _("; ")); | |
1630 | ||
1631 | /* (It would improve readability to print only the minimum | |
1632 | necessary digits of the second number of the range.) */ | |
1633 | fprintf_filtered (stream, _("range %s-%s, "), | |
1634 | paddress (gdbarch, low), paddress (gdbarch, high)); | |
1635 | ||
1636 | /* Now describe this particular location. */ | |
1637 | locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length, | |
1638 | objfile, addr_size); | |
1639 | ||
1640 | loc_ptr += length; | |
1641 | } | |
0d53c4c4 DJ |
1642 | } |
1643 | ||
1644 | /* Describe the location of SYMBOL as an agent value in VALUE, generating | |
1645 | any necessary bytecode in AX. */ | |
1646 | static void | |
505e835d UW |
1647 | loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
1648 | struct agent_expr *ax, struct axs_value *value) | |
0d53c4c4 DJ |
1649 | { |
1650 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
947bb88f | 1651 | const gdb_byte *data; |
b6b08ebf | 1652 | size_t size; |
0d53c4c4 DJ |
1653 | |
1654 | data = find_location_expression (dlbaton, &size, ax->scope); | |
0d53c4c4 | 1655 | |
505e835d | 1656 | dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, data, size); |
0d53c4c4 DJ |
1657 | } |
1658 | ||
1659 | /* The set of location functions used with the DWARF-2 expression | |
1660 | evaluator and location lists. */ | |
768a979c | 1661 | const struct symbol_computed_ops dwarf2_loclist_funcs = { |
0d53c4c4 DJ |
1662 | loclist_read_variable, |
1663 | loclist_read_needs_frame, | |
1664 | loclist_describe_location, | |
1665 | loclist_tracepoint_var_ref | |
1666 | }; |