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, | |
47 | gdb_byte **start, size_t *length); | |
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 | ||
852483bc | 57 | static 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; |
852483bc MK |
62 | gdb_byte *loc_ptr, *buf_end; |
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 | |
852483bc | 156 | dwarf_expr_frame_base (void *baton, 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, | |
181 | gdb_byte **start, size_t *length) | |
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; | |
195 | symbaton = SYMBOL_LOCATION_BATON (framefunc); | |
ebd3bcc1 JK |
196 | if (symbaton != NULL) |
197 | { | |
198 | *length = symbaton->size; | |
199 | *start = symbaton->data; | |
200 | } | |
201 | else | |
202 | *start = NULL; | |
0d53c4c4 DJ |
203 | } |
204 | ||
205 | if (*start == NULL) | |
8a3fe4f8 | 206 | error (_("Could not find the frame base for \"%s\"."), |
0d53c4c4 | 207 | SYMBOL_NATURAL_NAME (framefunc)); |
4c2df51b DJ |
208 | } |
209 | ||
e7802207 TT |
210 | /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for |
211 | the frame in BATON. */ | |
212 | ||
213 | static CORE_ADDR | |
214 | dwarf_expr_frame_cfa (void *baton) | |
215 | { | |
216 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; | |
217 | return dwarf2_frame_cfa (debaton->frame); | |
218 | } | |
219 | ||
4c2df51b DJ |
220 | /* Using the objfile specified in BATON, find the address for the |
221 | current thread's thread-local storage with offset OFFSET. */ | |
222 | static CORE_ADDR | |
223 | dwarf_expr_tls_address (void *baton, CORE_ADDR offset) | |
224 | { | |
225 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; | |
4c2df51b | 226 | |
9e35dae4 | 227 | return target_translate_tls_address (debaton->objfile, offset); |
4c2df51b DJ |
228 | } |
229 | ||
052b9502 NF |
230 | struct piece_closure |
231 | { | |
232 | /* The number of pieces used to describe this variable. */ | |
233 | int n_pieces; | |
234 | ||
6063c216 UW |
235 | /* The target address size, used only for DWARF_VALUE_STACK. */ |
236 | int addr_size; | |
cec03d70 | 237 | |
052b9502 NF |
238 | /* The pieces themselves. */ |
239 | struct dwarf_expr_piece *pieces; | |
240 | }; | |
241 | ||
242 | /* Allocate a closure for a value formed from separately-described | |
243 | PIECES. */ | |
244 | ||
245 | static struct piece_closure * | |
cec03d70 | 246 | allocate_piece_closure (int n_pieces, struct dwarf_expr_piece *pieces, |
6063c216 | 247 | int addr_size) |
052b9502 NF |
248 | { |
249 | struct piece_closure *c = XZALLOC (struct piece_closure); | |
250 | ||
251 | c->n_pieces = n_pieces; | |
6063c216 | 252 | c->addr_size = addr_size; |
052b9502 NF |
253 | c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece); |
254 | ||
255 | memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece)); | |
256 | ||
257 | return c; | |
258 | } | |
259 | ||
260 | static void | |
261 | read_pieced_value (struct value *v) | |
262 | { | |
263 | int i; | |
264 | long offset = 0; | |
265 | gdb_byte *contents; | |
266 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); | |
267 | struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v)); | |
268 | ||
269 | contents = value_contents_raw (v); | |
270 | for (i = 0; i < c->n_pieces; i++) | |
271 | { | |
272 | struct dwarf_expr_piece *p = &c->pieces[i]; | |
cec03d70 | 273 | switch (p->location) |
052b9502 | 274 | { |
cec03d70 TT |
275 | case DWARF_VALUE_REGISTER: |
276 | { | |
277 | struct gdbarch *arch = get_frame_arch (frame); | |
cec03d70 | 278 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, |
44353522 | 279 | p->v.expr.value); |
dcbf108f UW |
280 | int reg_offset = 0; |
281 | ||
282 | if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG | |
283 | && p->size < register_size (arch, gdb_regnum)) | |
284 | /* Big-endian, and we want less than full size. */ | |
285 | reg_offset = register_size (arch, gdb_regnum) - p->size; | |
286 | ||
287 | get_frame_register_bytes (frame, gdb_regnum, reg_offset, p->size, | |
288 | contents + offset); | |
cec03d70 TT |
289 | } |
290 | break; | |
291 | ||
292 | case DWARF_VALUE_MEMORY: | |
44353522 DE |
293 | if (p->v.expr.in_stack_memory) |
294 | read_stack (p->v.expr.value, contents + offset, p->size); | |
295 | else | |
296 | read_memory (p->v.expr.value, contents + offset, p->size); | |
cec03d70 TT |
297 | break; |
298 | ||
299 | case DWARF_VALUE_STACK: | |
300 | { | |
6063c216 UW |
301 | struct gdbarch *gdbarch = get_type_arch (value_type (v)); |
302 | size_t n = p->size; | |
303 | if (n > c->addr_size) | |
304 | n = c->addr_size; | |
05566b3b | 305 | store_unsigned_integer (contents + offset, n, |
6063c216 | 306 | gdbarch_byte_order (gdbarch), |
05566b3b | 307 | p->v.expr.value); |
cec03d70 TT |
308 | } |
309 | break; | |
310 | ||
311 | case DWARF_VALUE_LITERAL: | |
312 | { | |
313 | size_t n = p->size; | |
314 | if (n > p->v.literal.length) | |
315 | n = p->v.literal.length; | |
316 | memcpy (contents + offset, p->v.literal.data, n); | |
317 | } | |
318 | break; | |
319 | ||
320 | default: | |
321 | internal_error (__FILE__, __LINE__, _("invalid location type")); | |
052b9502 NF |
322 | } |
323 | offset += p->size; | |
324 | } | |
325 | } | |
326 | ||
327 | static void | |
328 | write_pieced_value (struct value *to, struct value *from) | |
329 | { | |
330 | int i; | |
331 | long offset = 0; | |
332 | gdb_byte *contents; | |
333 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (to); | |
334 | struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to)); | |
335 | ||
336 | if (frame == NULL) | |
337 | { | |
338 | set_value_optimized_out (to, 1); | |
339 | return; | |
340 | } | |
341 | ||
342 | contents = value_contents_raw (from); | |
343 | for (i = 0; i < c->n_pieces; i++) | |
344 | { | |
345 | struct dwarf_expr_piece *p = &c->pieces[i]; | |
cec03d70 | 346 | switch (p->location) |
052b9502 | 347 | { |
cec03d70 TT |
348 | case DWARF_VALUE_REGISTER: |
349 | { | |
350 | struct gdbarch *arch = get_frame_arch (frame); | |
44353522 | 351 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.expr.value); |
dcbf108f UW |
352 | int reg_offset = 0; |
353 | ||
354 | if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG | |
355 | && p->size < register_size (arch, gdb_regnum)) | |
356 | /* Big-endian, and we want less than full size. */ | |
357 | reg_offset = register_size (arch, gdb_regnum) - p->size; | |
358 | ||
359 | put_frame_register_bytes (frame, gdb_regnum, reg_offset, p->size, | |
360 | contents + offset); | |
cec03d70 TT |
361 | } |
362 | break; | |
363 | case DWARF_VALUE_MEMORY: | |
44353522 | 364 | write_memory (p->v.expr.value, contents + offset, p->size); |
cec03d70 TT |
365 | break; |
366 | default: | |
367 | set_value_optimized_out (to, 1); | |
368 | return; | |
052b9502 NF |
369 | } |
370 | offset += p->size; | |
371 | } | |
372 | } | |
373 | ||
374 | static void * | |
375 | copy_pieced_value_closure (struct value *v) | |
376 | { | |
377 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); | |
378 | ||
6063c216 | 379 | return allocate_piece_closure (c->n_pieces, c->pieces, c->addr_size); |
052b9502 NF |
380 | } |
381 | ||
382 | static void | |
383 | free_pieced_value_closure (struct value *v) | |
384 | { | |
385 | struct piece_closure *c = (struct piece_closure *) value_computed_closure (v); | |
386 | ||
387 | xfree (c->pieces); | |
388 | xfree (c); | |
389 | } | |
390 | ||
391 | /* Functions for accessing a variable described by DW_OP_piece. */ | |
392 | static struct lval_funcs pieced_value_funcs = { | |
393 | read_pieced_value, | |
394 | write_pieced_value, | |
395 | copy_pieced_value_closure, | |
396 | free_pieced_value_closure | |
397 | }; | |
398 | ||
4c2df51b DJ |
399 | /* Evaluate a location description, starting at DATA and with length |
400 | SIZE, to find the current location of variable VAR in the context | |
401 | of FRAME. */ | |
402 | static struct value * | |
403 | dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame, | |
852483bc | 404 | gdb_byte *data, unsigned short size, |
ae0d2f24 | 405 | struct dwarf2_per_cu_data *per_cu) |
4c2df51b | 406 | { |
4c2df51b DJ |
407 | struct value *retval; |
408 | struct dwarf_expr_baton baton; | |
409 | struct dwarf_expr_context *ctx; | |
4a227398 | 410 | struct cleanup *old_chain; |
4c2df51b | 411 | |
0d53c4c4 DJ |
412 | if (size == 0) |
413 | { | |
414 | retval = allocate_value (SYMBOL_TYPE (var)); | |
415 | VALUE_LVAL (retval) = not_lval; | |
feb13ab0 | 416 | set_value_optimized_out (retval, 1); |
10fb19b6 | 417 | return retval; |
0d53c4c4 DJ |
418 | } |
419 | ||
4c2df51b | 420 | baton.frame = frame; |
ae0d2f24 | 421 | baton.objfile = dwarf2_per_cu_objfile (per_cu); |
4c2df51b DJ |
422 | |
423 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
424 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
425 | ||
f7fd4728 | 426 | ctx->gdbarch = get_objfile_arch (baton.objfile); |
ae0d2f24 | 427 | ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); |
4c2df51b DJ |
428 | ctx->baton = &baton; |
429 | ctx->read_reg = dwarf_expr_read_reg; | |
430 | ctx->read_mem = dwarf_expr_read_mem; | |
431 | ctx->get_frame_base = dwarf_expr_frame_base; | |
e7802207 | 432 | ctx->get_frame_cfa = dwarf_expr_frame_cfa; |
4c2df51b DJ |
433 | ctx->get_tls_address = dwarf_expr_tls_address; |
434 | ||
435 | dwarf_expr_eval (ctx, data, size); | |
87808bd6 JB |
436 | if (ctx->num_pieces > 0) |
437 | { | |
052b9502 NF |
438 | struct piece_closure *c; |
439 | struct frame_id frame_id = get_frame_id (frame); | |
440 | ||
6063c216 UW |
441 | c = allocate_piece_closure (ctx->num_pieces, ctx->pieces, |
442 | ctx->addr_size); | |
052b9502 NF |
443 | retval = allocate_computed_value (SYMBOL_TYPE (var), |
444 | &pieced_value_funcs, | |
445 | c); | |
446 | VALUE_FRAME_ID (retval) = frame_id; | |
87808bd6 | 447 | } |
4c2df51b DJ |
448 | else |
449 | { | |
cec03d70 TT |
450 | switch (ctx->location) |
451 | { | |
452 | case DWARF_VALUE_REGISTER: | |
453 | { | |
454 | struct gdbarch *arch = get_frame_arch (frame); | |
455 | CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0); | |
456 | int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum); | |
457 | retval = value_from_register (SYMBOL_TYPE (var), gdb_regnum, frame); | |
458 | } | |
459 | break; | |
460 | ||
461 | case DWARF_VALUE_MEMORY: | |
462 | { | |
463 | CORE_ADDR address = dwarf_expr_fetch (ctx, 0); | |
44353522 | 464 | int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0); |
cec03d70 TT |
465 | |
466 | retval = allocate_value (SYMBOL_TYPE (var)); | |
467 | VALUE_LVAL (retval) = lval_memory; | |
468 | set_value_lazy (retval, 1); | |
44353522 DE |
469 | if (in_stack_memory) |
470 | set_value_stack (retval, 1); | |
cec03d70 TT |
471 | set_value_address (retval, address); |
472 | } | |
473 | break; | |
474 | ||
475 | case DWARF_VALUE_STACK: | |
476 | { | |
cec03d70 TT |
477 | ULONGEST value = (ULONGEST) dwarf_expr_fetch (ctx, 0); |
478 | bfd_byte *contents; | |
479 | size_t n = ctx->addr_size; | |
480 | ||
cec03d70 TT |
481 | retval = allocate_value (SYMBOL_TYPE (var)); |
482 | contents = value_contents_raw (retval); | |
483 | if (n > TYPE_LENGTH (SYMBOL_TYPE (var))) | |
484 | n = TYPE_LENGTH (SYMBOL_TYPE (var)); | |
05566b3b TT |
485 | store_unsigned_integer (contents, n, |
486 | gdbarch_byte_order (ctx->gdbarch), | |
487 | value); | |
cec03d70 TT |
488 | } |
489 | break; | |
490 | ||
491 | case DWARF_VALUE_LITERAL: | |
492 | { | |
493 | bfd_byte *contents; | |
494 | size_t n = ctx->len; | |
495 | ||
496 | retval = allocate_value (SYMBOL_TYPE (var)); | |
497 | contents = value_contents_raw (retval); | |
498 | if (n > TYPE_LENGTH (SYMBOL_TYPE (var))) | |
499 | n = TYPE_LENGTH (SYMBOL_TYPE (var)); | |
500 | memcpy (contents, ctx->data, n); | |
501 | } | |
502 | break; | |
503 | ||
504 | default: | |
505 | internal_error (__FILE__, __LINE__, _("invalid location type")); | |
506 | } | |
4c2df51b DJ |
507 | } |
508 | ||
42be36b3 CT |
509 | set_value_initialized (retval, ctx->initialized); |
510 | ||
4a227398 | 511 | do_cleanups (old_chain); |
4c2df51b DJ |
512 | |
513 | return retval; | |
514 | } | |
4c2df51b DJ |
515 | \f |
516 | /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */ | |
517 | ||
518 | struct needs_frame_baton | |
519 | { | |
520 | int needs_frame; | |
521 | }; | |
522 | ||
523 | /* Reads from registers do require a frame. */ | |
524 | static CORE_ADDR | |
61fbb938 | 525 | needs_frame_read_reg (void *baton, int regnum) |
4c2df51b DJ |
526 | { |
527 | struct needs_frame_baton *nf_baton = baton; | |
528 | nf_baton->needs_frame = 1; | |
529 | return 1; | |
530 | } | |
531 | ||
532 | /* Reads from memory do not require a frame. */ | |
533 | static void | |
852483bc | 534 | needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len) |
4c2df51b DJ |
535 | { |
536 | memset (buf, 0, len); | |
537 | } | |
538 | ||
539 | /* Frame-relative accesses do require a frame. */ | |
540 | static void | |
852483bc | 541 | needs_frame_frame_base (void *baton, gdb_byte **start, size_t * length) |
4c2df51b | 542 | { |
852483bc | 543 | static gdb_byte lit0 = DW_OP_lit0; |
4c2df51b DJ |
544 | struct needs_frame_baton *nf_baton = baton; |
545 | ||
546 | *start = &lit0; | |
547 | *length = 1; | |
548 | ||
549 | nf_baton->needs_frame = 1; | |
550 | } | |
551 | ||
e7802207 TT |
552 | /* CFA accesses require a frame. */ |
553 | ||
554 | static CORE_ADDR | |
555 | needs_frame_frame_cfa (void *baton) | |
556 | { | |
557 | struct needs_frame_baton *nf_baton = baton; | |
558 | nf_baton->needs_frame = 1; | |
559 | return 1; | |
560 | } | |
561 | ||
4c2df51b DJ |
562 | /* Thread-local accesses do require a frame. */ |
563 | static CORE_ADDR | |
564 | needs_frame_tls_address (void *baton, CORE_ADDR offset) | |
565 | { | |
566 | struct needs_frame_baton *nf_baton = baton; | |
567 | nf_baton->needs_frame = 1; | |
568 | return 1; | |
569 | } | |
570 | ||
571 | /* Return non-zero iff the location expression at DATA (length SIZE) | |
572 | requires a frame to evaluate. */ | |
573 | ||
574 | static int | |
ae0d2f24 UW |
575 | dwarf2_loc_desc_needs_frame (gdb_byte *data, unsigned short size, |
576 | struct dwarf2_per_cu_data *per_cu) | |
4c2df51b DJ |
577 | { |
578 | struct needs_frame_baton baton; | |
579 | struct dwarf_expr_context *ctx; | |
f630a401 | 580 | int in_reg; |
4a227398 | 581 | struct cleanup *old_chain; |
4c2df51b DJ |
582 | |
583 | baton.needs_frame = 0; | |
584 | ||
585 | ctx = new_dwarf_expr_context (); | |
4a227398 TT |
586 | old_chain = make_cleanup_free_dwarf_expr_context (ctx); |
587 | ||
f7fd4728 | 588 | ctx->gdbarch = get_objfile_arch (dwarf2_per_cu_objfile (per_cu)); |
ae0d2f24 | 589 | ctx->addr_size = dwarf2_per_cu_addr_size (per_cu); |
4c2df51b DJ |
590 | ctx->baton = &baton; |
591 | ctx->read_reg = needs_frame_read_reg; | |
592 | ctx->read_mem = needs_frame_read_mem; | |
593 | ctx->get_frame_base = needs_frame_frame_base; | |
e7802207 | 594 | ctx->get_frame_cfa = needs_frame_frame_cfa; |
4c2df51b DJ |
595 | ctx->get_tls_address = needs_frame_tls_address; |
596 | ||
597 | dwarf_expr_eval (ctx, data, size); | |
598 | ||
cec03d70 | 599 | in_reg = ctx->location == DWARF_VALUE_REGISTER; |
f630a401 | 600 | |
87808bd6 JB |
601 | if (ctx->num_pieces > 0) |
602 | { | |
603 | int i; | |
604 | ||
605 | /* If the location has several pieces, and any of them are in | |
606 | registers, then we will need a frame to fetch them from. */ | |
607 | for (i = 0; i < ctx->num_pieces; i++) | |
cec03d70 | 608 | if (ctx->pieces[i].location == DWARF_VALUE_REGISTER) |
87808bd6 JB |
609 | in_reg = 1; |
610 | } | |
611 | ||
4a227398 | 612 | do_cleanups (old_chain); |
4c2df51b | 613 | |
f630a401 | 614 | return baton.needs_frame || in_reg; |
4c2df51b DJ |
615 | } |
616 | ||
08922a10 SS |
617 | /* This struct keeps track of the pieces that make up a multi-location |
618 | object, for use in agent expression generation. It is | |
619 | superficially similar to struct dwarf_expr_piece, but | |
620 | dwarf_expr_piece is designed for use in immediate evaluation, and | |
621 | does not, for example, have a way to record both base register and | |
622 | offset. */ | |
623 | ||
624 | struct axs_var_loc | |
0d53c4c4 | 625 | { |
08922a10 SS |
626 | /* Memory vs register, etc */ |
627 | enum axs_lvalue_kind kind; | |
628 | ||
629 | /* If non-zero, number of bytes in this fragment */ | |
630 | unsigned bytes; | |
631 | ||
632 | /* (GDB-numbered) reg, or base reg if >= 0 */ | |
633 | int reg; | |
634 | ||
635 | /* offset from reg */ | |
636 | LONGEST offset; | |
637 | }; | |
638 | ||
639 | static gdb_byte * | |
640 | dwarf2_tracepoint_var_loc (struct symbol *symbol, | |
641 | struct agent_expr *ax, | |
642 | struct axs_var_loc *loc, | |
643 | struct gdbarch *gdbarch, | |
644 | gdb_byte *data, gdb_byte *end) | |
645 | { | |
646 | if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) | |
0d53c4c4 | 647 | { |
08922a10 SS |
648 | loc->kind = axs_lvalue_register; |
649 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0); | |
650 | data += 1; | |
0d53c4c4 DJ |
651 | } |
652 | else if (data[0] == DW_OP_regx) | |
653 | { | |
654 | ULONGEST reg; | |
08922a10 SS |
655 | data = read_uleb128 (data + 1, end, ®); |
656 | loc->kind = axs_lvalue_register; | |
657 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); | |
0d53c4c4 DJ |
658 | } |
659 | else if (data[0] == DW_OP_fbreg) | |
660 | { | |
0936ad1d SS |
661 | struct block *b; |
662 | struct symbol *framefunc; | |
663 | int frame_reg = 0; | |
0d53c4c4 | 664 | LONGEST frame_offset; |
0936ad1d SS |
665 | gdb_byte *base_data; |
666 | size_t base_size; | |
667 | LONGEST base_offset = 0; | |
668 | ||
669 | b = block_for_pc (ax->scope); | |
670 | ||
671 | if (!b) | |
672 | error (_("No block found for address")); | |
673 | ||
674 | framefunc = block_linkage_function (b); | |
675 | ||
676 | if (!framefunc) | |
677 | error (_("No function found for block")); | |
678 | ||
679 | dwarf_expr_frame_base_1 (framefunc, ax->scope, | |
680 | &base_data, &base_size); | |
681 | ||
08922a10 | 682 | if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) |
0936ad1d | 683 | { |
08922a10 SS |
684 | gdb_byte *buf_end; |
685 | ||
0936ad1d | 686 | frame_reg = base_data[0] - DW_OP_breg0; |
08922a10 SS |
687 | buf_end = read_sleb128 (base_data + 1, |
688 | base_data + base_size, &base_offset); | |
0936ad1d SS |
689 | if (buf_end != base_data + base_size) |
690 | error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."), | |
691 | frame_reg, SYMBOL_PRINT_NAME (symbol)); | |
692 | } | |
08922a10 SS |
693 | else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) |
694 | { | |
695 | /* The frame base is just the register, with no offset. */ | |
696 | frame_reg = base_data[0] - DW_OP_reg0; | |
697 | base_offset = 0; | |
698 | } | |
0936ad1d SS |
699 | else |
700 | { | |
701 | /* We don't know what to do with the frame base expression, | |
702 | so we can't trace this variable; give up. */ | |
08922a10 SS |
703 | error (_("Cannot generate expression to collect symbol \"%s\"; DWARF 2 encoding not handled, first opcode in base data is 0x%x."), |
704 | SYMBOL_PRINT_NAME (symbol), base_data[0]); | |
0936ad1d | 705 | } |
0d53c4c4 | 706 | |
08922a10 | 707 | data = read_sleb128 (data + 1, end, &frame_offset); |
4c2df51b | 708 | |
08922a10 SS |
709 | loc->kind = axs_lvalue_memory; |
710 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); | |
711 | loc->offset = base_offset + frame_offset; | |
9c238357 | 712 | } |
08922a10 | 713 | else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31) |
9c238357 RC |
714 | { |
715 | unsigned int reg; | |
716 | LONGEST offset; | |
9c238357 RC |
717 | |
718 | reg = data[0] - DW_OP_breg0; | |
08922a10 | 719 | data = read_sleb128 (data + 1, end, &offset); |
9c238357 | 720 | |
08922a10 SS |
721 | loc->kind = axs_lvalue_memory; |
722 | loc->reg = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); | |
723 | loc->offset = offset; | |
0d53c4c4 DJ |
724 | } |
725 | else | |
9c238357 RC |
726 | error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."), |
727 | data[0], SYMBOL_PRINT_NAME (symbol)); | |
08922a10 SS |
728 | |
729 | return data; | |
0d53c4c4 | 730 | } |
08922a10 SS |
731 | |
732 | /* Given the location of a piece, issue bytecodes that will access it. */ | |
733 | ||
734 | static void | |
735 | dwarf2_tracepoint_var_access (struct agent_expr *ax, | |
736 | struct axs_value *value, | |
737 | struct axs_var_loc *loc) | |
738 | { | |
739 | value->kind = loc->kind; | |
740 | ||
741 | switch (loc->kind) | |
742 | { | |
743 | case axs_lvalue_register: | |
744 | value->u.reg = loc->reg; | |
745 | break; | |
746 | ||
747 | case axs_lvalue_memory: | |
748 | ax_reg (ax, loc->reg); | |
749 | if (loc->offset) | |
750 | { | |
751 | ax_const_l (ax, loc->offset); | |
752 | ax_simple (ax, aop_add); | |
753 | } | |
754 | break; | |
755 | ||
756 | default: | |
757 | internal_error (__FILE__, __LINE__, _("Unhandled value kind in dwarf2_tracepoint_var_access")); | |
758 | } | |
759 | } | |
760 | ||
761 | static void | |
762 | dwarf2_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, | |
763 | struct agent_expr *ax, struct axs_value *value, | |
764 | gdb_byte *data, int size) | |
765 | { | |
766 | gdb_byte *end = data + size; | |
767 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
768 | /* In practice, a variable is not going to be spread across | |
769 | dozens of registers or memory locations. If someone comes up | |
770 | with a real-world example, revisit this. */ | |
771 | #define MAX_FRAGS 16 | |
772 | struct axs_var_loc fragments[MAX_FRAGS]; | |
773 | int nfrags = 0, frag; | |
774 | int length = 0; | |
775 | int piece_ok = 0; | |
776 | int bad = 0; | |
777 | int first = 1; | |
778 | ||
779 | if (!data || size == 0) | |
780 | { | |
781 | value->optimized_out = 1; | |
782 | return; | |
783 | } | |
784 | ||
785 | while (data < end) | |
786 | { | |
787 | if (!piece_ok) | |
788 | { | |
789 | if (nfrags == MAX_FRAGS) | |
790 | error (_("Too many pieces in location for \"%s\"."), | |
791 | SYMBOL_PRINT_NAME (symbol)); | |
792 | ||
793 | fragments[nfrags].bytes = 0; | |
794 | data = dwarf2_tracepoint_var_loc (symbol, ax, &fragments[nfrags], | |
795 | gdbarch, data, end); | |
796 | nfrags++; | |
797 | piece_ok = 1; | |
798 | } | |
799 | else if (data[0] == DW_OP_piece) | |
800 | { | |
801 | ULONGEST bytes; | |
802 | ||
803 | data = read_uleb128 (data + 1, end, &bytes); | |
804 | /* Only deal with 4 byte fragments for now. */ | |
805 | if (bytes != 4) | |
806 | error (_("DW_OP_piece %s not supported in location for \"%s\"."), | |
807 | pulongest (bytes), SYMBOL_PRINT_NAME (symbol)); | |
808 | fragments[nfrags - 1].bytes = bytes; | |
809 | length += bytes; | |
810 | piece_ok = 0; | |
811 | } | |
812 | else | |
813 | { | |
814 | bad = 1; | |
815 | break; | |
816 | } | |
817 | } | |
818 | ||
819 | if (bad || data > end) | |
820 | error (_("Corrupted DWARF expression for \"%s\"."), | |
821 | SYMBOL_PRINT_NAME (symbol)); | |
822 | ||
823 | /* If single expression, no pieces, convert to external format. */ | |
824 | if (length == 0) | |
825 | { | |
826 | dwarf2_tracepoint_var_access (ax, value, &fragments[0]); | |
827 | return; | |
828 | } | |
829 | ||
830 | if (length != TYPE_LENGTH (value->type)) | |
831 | error (_("Inconsistent piece information for \"%s\"."), | |
832 | SYMBOL_PRINT_NAME (symbol)); | |
833 | ||
834 | /* Emit bytecodes to assemble the pieces into a single stack entry. */ | |
835 | ||
836 | for ((frag = (byte_order == BFD_ENDIAN_BIG ? 0 : nfrags - 1)); | |
837 | nfrags--; | |
838 | (frag += (byte_order == BFD_ENDIAN_BIG ? 1 : -1))) | |
839 | { | |
840 | if (!first) | |
841 | { | |
842 | /* shift the previous fragment up 32 bits */ | |
843 | ax_const_l (ax, 32); | |
844 | ax_simple (ax, aop_lsh); | |
845 | } | |
846 | ||
847 | dwarf2_tracepoint_var_access (ax, value, &fragments[frag]); | |
848 | ||
849 | switch (value->kind) | |
850 | { | |
851 | case axs_lvalue_register: | |
852 | ax_reg (ax, value->u.reg); | |
853 | break; | |
854 | ||
855 | case axs_lvalue_memory: | |
856 | { | |
857 | extern int trace_kludge; /* Ugh. */ | |
858 | ||
859 | gdb_assert (fragments[frag].bytes == 4); | |
860 | if (trace_kludge) | |
861 | ax_trace_quick (ax, 4); | |
862 | ax_simple (ax, aop_ref32); | |
863 | } | |
864 | break; | |
865 | } | |
866 | ||
867 | if (!first) | |
868 | { | |
869 | /* or the new fragment into the previous */ | |
870 | ax_zero_ext (ax, 32); | |
871 | ax_simple (ax, aop_bit_or); | |
872 | } | |
873 | first = 0; | |
874 | } | |
875 | value->kind = axs_rvalue; | |
876 | } | |
877 | ||
4c2df51b DJ |
878 | \f |
879 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression | |
880 | evaluator to calculate the location. */ | |
881 | static struct value * | |
882 | locexpr_read_variable (struct symbol *symbol, struct frame_info *frame) | |
883 | { | |
884 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
885 | struct value *val; | |
886 | val = dwarf2_evaluate_loc_desc (symbol, frame, dlbaton->data, dlbaton->size, | |
ae0d2f24 | 887 | dlbaton->per_cu); |
4c2df51b DJ |
888 | |
889 | return val; | |
890 | } | |
891 | ||
892 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ | |
893 | static int | |
894 | locexpr_read_needs_frame (struct symbol *symbol) | |
895 | { | |
896 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
ae0d2f24 UW |
897 | return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size, |
898 | dlbaton->per_cu); | |
4c2df51b DJ |
899 | } |
900 | ||
08922a10 SS |
901 | /* Describe a single piece of a location, returning an updated |
902 | position in the bytecode sequence. */ | |
903 | ||
904 | static gdb_byte * | |
905 | locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream, | |
906 | CORE_ADDR addr, struct objfile *objfile, | |
907 | gdb_byte *data, int size, unsigned int addr_size) | |
4c2df51b | 908 | { |
08922a10 SS |
909 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
910 | int regno; | |
911 | ||
912 | if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31) | |
913 | { | |
914 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0); | |
915 | fprintf_filtered (stream, _("a variable in $%s"), | |
916 | gdbarch_register_name (gdbarch, regno)); | |
917 | data += 1; | |
918 | } | |
919 | else if (data[0] == DW_OP_regx) | |
920 | { | |
921 | ULONGEST reg; | |
4c2df51b | 922 | |
08922a10 SS |
923 | data = read_uleb128 (data + 1, data + size, ®); |
924 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg); | |
925 | fprintf_filtered (stream, _("a variable in $%s"), | |
926 | gdbarch_register_name (gdbarch, regno)); | |
927 | } | |
928 | else if (data[0] == DW_OP_fbreg) | |
4c2df51b | 929 | { |
08922a10 SS |
930 | struct block *b; |
931 | struct symbol *framefunc; | |
932 | int frame_reg = 0; | |
933 | LONGEST frame_offset; | |
934 | gdb_byte *base_data; | |
935 | size_t base_size; | |
936 | LONGEST base_offset = 0; | |
937 | ||
938 | b = block_for_pc (addr); | |
939 | ||
940 | if (!b) | |
941 | error (_("No block found for address for symbol \"%s\"."), | |
942 | SYMBOL_PRINT_NAME (symbol)); | |
943 | ||
944 | framefunc = block_linkage_function (b); | |
945 | ||
946 | if (!framefunc) | |
947 | error (_("No function found for block for symbol \"%s\"."), | |
948 | SYMBOL_PRINT_NAME (symbol)); | |
949 | ||
950 | dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size); | |
951 | ||
952 | if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31) | |
953 | { | |
954 | gdb_byte *buf_end; | |
955 | ||
956 | frame_reg = base_data[0] - DW_OP_breg0; | |
957 | buf_end = read_sleb128 (base_data + 1, | |
958 | base_data + base_size, &base_offset); | |
959 | if (buf_end != base_data + base_size) | |
960 | error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."), | |
961 | frame_reg, SYMBOL_PRINT_NAME (symbol)); | |
962 | } | |
963 | else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31) | |
964 | { | |
965 | /* The frame base is just the register, with no offset. */ | |
966 | frame_reg = base_data[0] - DW_OP_reg0; | |
967 | base_offset = 0; | |
968 | } | |
969 | else | |
970 | { | |
971 | /* We don't know what to do with the frame base expression, | |
972 | so we can't trace this variable; give up. */ | |
973 | error (_("Cannot describe location of symbol \"%s\"; " | |
974 | "DWARF 2 encoding not handled, " | |
975 | "first opcode in base data is 0x%x."), | |
976 | SYMBOL_PRINT_NAME (symbol), base_data[0]); | |
977 | } | |
978 | ||
979 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg); | |
980 | ||
981 | data = read_sleb128 (data + 1, data + size, &frame_offset); | |
982 | ||
983 | fprintf_filtered (stream, _("a variable at frame base reg $%s offset %s+%s"), | |
984 | gdbarch_register_name (gdbarch, regno), | |
985 | plongest (base_offset), plongest (frame_offset)); | |
986 | } | |
987 | else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31) | |
988 | { | |
989 | LONGEST offset; | |
990 | ||
991 | regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0); | |
992 | ||
993 | data = read_sleb128 (data + 1, data + size, &offset); | |
994 | ||
4c2df51b | 995 | fprintf_filtered (stream, |
08922a10 SS |
996 | _("a variable at offset %s from base reg $%s"), |
997 | plongest (offset), | |
5e2b427d | 998 | gdbarch_register_name (gdbarch, regno)); |
4c2df51b DJ |
999 | } |
1000 | ||
c3228f12 EZ |
1001 | /* The location expression for a TLS variable looks like this (on a |
1002 | 64-bit LE machine): | |
1003 | ||
1004 | DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0 | |
1005 | (DW_OP_addr: 4; DW_OP_GNU_push_tls_address) | |
1006 | ||
1007 | 0x3 is the encoding for DW_OP_addr, which has an operand as long | |
1008 | as the size of an address on the target machine (here is 8 | |
1009 | bytes). 0xe0 is the encoding for DW_OP_GNU_push_tls_address. | |
1010 | The operand represents the offset at which the variable is within | |
1011 | the thread local storage. */ | |
1012 | ||
08922a10 SS |
1013 | else if (size > 1 |
1014 | && data[size - 1] == DW_OP_GNU_push_tls_address | |
1015 | && data[0] == DW_OP_addr) | |
1016 | { | |
1017 | CORE_ADDR offset = dwarf2_read_address (gdbarch, | |
1018 | data + 1, | |
1019 | data + size - 1, | |
1020 | addr_size); | |
1021 | fprintf_filtered (stream, | |
1022 | _("a thread-local variable at offset %s " | |
1023 | "in the thread-local storage for `%s'"), | |
1024 | paddress (gdbarch, offset), objfile->name); | |
1025 | ||
1026 | data += 1 + addr_size + 1; | |
1027 | } | |
1028 | else | |
1029 | fprintf_filtered (stream, | |
1030 | _("a variable with complex or multiple locations (DWARF2)")); | |
c3228f12 | 1031 | |
08922a10 | 1032 | return data; |
4c2df51b DJ |
1033 | } |
1034 | ||
08922a10 SS |
1035 | /* Describe a single location, which may in turn consist of multiple |
1036 | pieces. */ | |
a55cc764 | 1037 | |
08922a10 SS |
1038 | static void |
1039 | locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr, | |
1040 | struct ui_file *stream, gdb_byte *data, int size, | |
1041 | struct objfile *objfile, unsigned int addr_size) | |
1042 | { | |
1043 | gdb_byte *end = data + size; | |
1044 | int piece_done = 0, first_piece = 1, bad = 0; | |
1045 | ||
1046 | /* A multi-piece description consists of multiple sequences of bytes | |
1047 | each followed by DW_OP_piece + length of piece. */ | |
1048 | while (data < end) | |
1049 | { | |
1050 | if (!piece_done) | |
1051 | { | |
1052 | if (first_piece) | |
1053 | first_piece = 0; | |
1054 | else | |
1055 | fprintf_filtered (stream, _(", and ")); | |
1056 | ||
1057 | data = locexpr_describe_location_piece (symbol, stream, addr, objfile, | |
1058 | data, size, addr_size); | |
1059 | piece_done = 1; | |
1060 | } | |
1061 | else if (data[0] == DW_OP_piece) | |
1062 | { | |
1063 | ULONGEST bytes; | |
1064 | ||
1065 | data = read_uleb128 (data + 1, end, &bytes); | |
1066 | ||
1067 | fprintf_filtered (stream, _(" [%s-byte piece]"), pulongest (bytes)); | |
1068 | ||
1069 | piece_done = 0; | |
1070 | } | |
1071 | else | |
1072 | { | |
1073 | bad = 1; | |
1074 | break; | |
1075 | } | |
1076 | } | |
1077 | ||
1078 | if (bad || data > end) | |
1079 | error (_("Corrupted DWARF2 expression for \"%s\"."), | |
1080 | SYMBOL_PRINT_NAME (symbol)); | |
1081 | } | |
1082 | ||
1083 | /* Print a natural-language description of SYMBOL to STREAM. This | |
1084 | version is for a symbol with a single location. */ | |
a55cc764 | 1085 | |
08922a10 SS |
1086 | static void |
1087 | locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr, | |
1088 | struct ui_file *stream) | |
1089 | { | |
1090 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1091 | struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); | |
1092 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); | |
1093 | ||
1094 | locexpr_describe_location_1 (symbol, addr, stream, dlbaton->data, dlbaton->size, | |
1095 | objfile, addr_size); | |
1096 | } | |
1097 | ||
1098 | /* Describe the location of SYMBOL as an agent value in VALUE, generating | |
1099 | any necessary bytecode in AX. */ | |
a55cc764 | 1100 | |
0d53c4c4 | 1101 | static void |
505e835d UW |
1102 | locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
1103 | struct agent_expr *ax, struct axs_value *value) | |
a55cc764 DJ |
1104 | { |
1105 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1106 | ||
505e835d UW |
1107 | dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, |
1108 | dlbaton->data, dlbaton->size); | |
a55cc764 DJ |
1109 | } |
1110 | ||
4c2df51b DJ |
1111 | /* The set of location functions used with the DWARF-2 expression |
1112 | evaluator. */ | |
768a979c | 1113 | const struct symbol_computed_ops dwarf2_locexpr_funcs = { |
4c2df51b DJ |
1114 | locexpr_read_variable, |
1115 | locexpr_read_needs_frame, | |
1116 | locexpr_describe_location, | |
a55cc764 | 1117 | locexpr_tracepoint_var_ref |
4c2df51b | 1118 | }; |
0d53c4c4 DJ |
1119 | |
1120 | ||
1121 | /* Wrapper functions for location lists. These generally find | |
1122 | the appropriate location expression and call something above. */ | |
1123 | ||
1124 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression | |
1125 | evaluator to calculate the location. */ | |
1126 | static struct value * | |
1127 | loclist_read_variable (struct symbol *symbol, struct frame_info *frame) | |
1128 | { | |
1129 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
1130 | struct value *val; | |
852483bc | 1131 | gdb_byte *data; |
b6b08ebf | 1132 | size_t size; |
0d53c4c4 DJ |
1133 | |
1134 | data = find_location_expression (dlbaton, &size, | |
22c6caba JW |
1135 | frame ? get_frame_address_in_block (frame) |
1136 | : 0); | |
0d53c4c4 | 1137 | if (data == NULL) |
806048c6 DJ |
1138 | { |
1139 | val = allocate_value (SYMBOL_TYPE (symbol)); | |
1140 | VALUE_LVAL (val) = not_lval; | |
1141 | set_value_optimized_out (val, 1); | |
1142 | } | |
1143 | else | |
1144 | val = dwarf2_evaluate_loc_desc (symbol, frame, data, size, | |
ae0d2f24 | 1145 | dlbaton->per_cu); |
0d53c4c4 DJ |
1146 | |
1147 | return val; | |
1148 | } | |
1149 | ||
1150 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ | |
1151 | static int | |
1152 | loclist_read_needs_frame (struct symbol *symbol) | |
1153 | { | |
1154 | /* If there's a location list, then assume we need to have a frame | |
1155 | to choose the appropriate location expression. With tracking of | |
1156 | global variables this is not necessarily true, but such tracking | |
1157 | is disabled in GCC at the moment until we figure out how to | |
1158 | represent it. */ | |
1159 | ||
1160 | return 1; | |
1161 | } | |
1162 | ||
08922a10 SS |
1163 | /* Print a natural-language description of SYMBOL to STREAM. This |
1164 | version applies when there is a list of different locations, each | |
1165 | with a specified address range. */ | |
1166 | ||
1167 | static void | |
1168 | loclist_describe_location (struct symbol *symbol, CORE_ADDR addr, | |
1169 | struct ui_file *stream) | |
0d53c4c4 | 1170 | { |
08922a10 SS |
1171 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); |
1172 | CORE_ADDR low, high; | |
1173 | gdb_byte *loc_ptr, *buf_end; | |
1174 | int length, first = 1; | |
1175 | struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu); | |
1176 | struct gdbarch *gdbarch = get_objfile_arch (objfile); | |
1177 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
1178 | unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu); | |
1179 | CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); | |
1180 | /* Adjust base_address for relocatable objects. */ | |
1181 | CORE_ADDR base_offset = ANOFFSET (objfile->section_offsets, | |
1182 | SECT_OFF_TEXT (objfile)); | |
1183 | CORE_ADDR base_address = dlbaton->base_address + base_offset; | |
1184 | ||
1185 | loc_ptr = dlbaton->data; | |
1186 | buf_end = dlbaton->data + dlbaton->size; | |
1187 | ||
1188 | fprintf_filtered (stream, _("multi-location (")); | |
1189 | ||
1190 | /* Iterate through locations until we run out. */ | |
1191 | while (1) | |
1192 | { | |
1193 | if (buf_end - loc_ptr < 2 * addr_size) | |
1194 | error (_("Corrupted DWARF expression for symbol \"%s\"."), | |
1195 | SYMBOL_PRINT_NAME (symbol)); | |
1196 | ||
1197 | low = extract_unsigned_integer (loc_ptr, addr_size, byte_order); | |
1198 | loc_ptr += addr_size; | |
1199 | ||
1200 | /* A base-address-selection entry. */ | |
1201 | if (low == base_mask) | |
1202 | { | |
1203 | base_address = dwarf2_read_address (gdbarch, | |
1204 | loc_ptr, buf_end, addr_size); | |
1205 | fprintf_filtered (stream, _("[base address %s]"), | |
1206 | paddress (gdbarch, base_address)); | |
1207 | loc_ptr += addr_size; | |
1208 | continue; | |
1209 | } | |
1210 | ||
1211 | high = extract_unsigned_integer (loc_ptr, addr_size, byte_order); | |
1212 | loc_ptr += addr_size; | |
1213 | ||
1214 | /* An end-of-list entry. */ | |
1215 | if (low == 0 && high == 0) | |
1216 | { | |
1217 | /* Indicate the end of the list, for readability. */ | |
1218 | fprintf_filtered (stream, _(")")); | |
1219 | return; | |
1220 | } | |
1221 | ||
1222 | /* Otherwise, a location expression entry. */ | |
1223 | low += base_address; | |
1224 | high += base_address; | |
1225 | ||
1226 | length = extract_unsigned_integer (loc_ptr, 2, byte_order); | |
1227 | loc_ptr += 2; | |
1228 | ||
1229 | /* Separate the different locations with a semicolon. */ | |
1230 | if (first) | |
1231 | first = 0; | |
1232 | else | |
1233 | fprintf_filtered (stream, _("; ")); | |
1234 | ||
1235 | /* (It would improve readability to print only the minimum | |
1236 | necessary digits of the second number of the range.) */ | |
1237 | fprintf_filtered (stream, _("range %s-%s, "), | |
1238 | paddress (gdbarch, low), paddress (gdbarch, high)); | |
1239 | ||
1240 | /* Now describe this particular location. */ | |
1241 | locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length, | |
1242 | objfile, addr_size); | |
1243 | ||
1244 | loc_ptr += length; | |
1245 | } | |
0d53c4c4 DJ |
1246 | } |
1247 | ||
1248 | /* Describe the location of SYMBOL as an agent value in VALUE, generating | |
1249 | any necessary bytecode in AX. */ | |
1250 | static void | |
505e835d UW |
1251 | loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch, |
1252 | struct agent_expr *ax, struct axs_value *value) | |
0d53c4c4 DJ |
1253 | { |
1254 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
852483bc | 1255 | gdb_byte *data; |
b6b08ebf | 1256 | size_t size; |
0d53c4c4 DJ |
1257 | |
1258 | data = find_location_expression (dlbaton, &size, ax->scope); | |
0d53c4c4 | 1259 | |
505e835d | 1260 | dwarf2_tracepoint_var_ref (symbol, gdbarch, ax, value, data, size); |
0d53c4c4 DJ |
1261 | } |
1262 | ||
1263 | /* The set of location functions used with the DWARF-2 expression | |
1264 | evaluator and location lists. */ | |
768a979c | 1265 | const struct symbol_computed_ops dwarf2_loclist_funcs = { |
0d53c4c4 DJ |
1266 | loclist_read_variable, |
1267 | loclist_read_needs_frame, | |
1268 | loclist_describe_location, | |
1269 | loclist_tracepoint_var_ref | |
1270 | }; |