Commit | Line | Data |
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4c2df51b | 1 | /* DWARF 2 location expression support for GDB. |
feb13ab0 AC |
2 | |
3 | Copyright 2003, 2005 Free Software Foundation, Inc. | |
4 | ||
4c2df51b DJ |
5 | Contributed by Daniel Jacobowitz, MontaVista Software, Inc. |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or (at | |
12 | your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
23 | ||
24 | #include "defs.h" | |
25 | #include "ui-out.h" | |
26 | #include "value.h" | |
27 | #include "frame.h" | |
28 | #include "gdbcore.h" | |
29 | #include "target.h" | |
30 | #include "inferior.h" | |
a55cc764 DJ |
31 | #include "ax.h" |
32 | #include "ax-gdb.h" | |
e4adbba9 | 33 | #include "regcache.h" |
c3228f12 | 34 | #include "objfiles.h" |
93ad78a7 | 35 | #include "exceptions.h" |
4c2df51b DJ |
36 | |
37 | #include "elf/dwarf2.h" | |
38 | #include "dwarf2expr.h" | |
39 | #include "dwarf2loc.h" | |
40 | ||
41 | #include "gdb_string.h" | |
42 | ||
43 | #ifndef DWARF2_REG_TO_REGNUM | |
44 | #define DWARF2_REG_TO_REGNUM(REG) (REG) | |
45 | #endif | |
46 | ||
0d53c4c4 DJ |
47 | /* A helper function for dealing with location lists. Given a |
48 | symbol baton (BATON) and a pc value (PC), find the appropriate | |
49 | location expression, set *LOCEXPR_LENGTH, and return a pointer | |
50 | to the beginning of the expression. Returns NULL on failure. | |
51 | ||
52 | For now, only return the first matching location expression; there | |
53 | can be more than one in the list. */ | |
54 | ||
55 | static char * | |
56 | find_location_expression (struct dwarf2_loclist_baton *baton, | |
b6b08ebf | 57 | size_t *locexpr_length, CORE_ADDR pc) |
0d53c4c4 | 58 | { |
0d53c4c4 DJ |
59 | CORE_ADDR low, high; |
60 | char *loc_ptr, *buf_end; | |
61 | unsigned int addr_size = TARGET_ADDR_BIT / TARGET_CHAR_BIT, length; | |
62 | CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1)); | |
8edfa926 BM |
63 | /* Adjust base_address for relocatable objects. */ |
64 | CORE_ADDR base_offset = ANOFFSET (baton->objfile->section_offsets, | |
65 | SECT_OFF_TEXT (baton->objfile)); | |
66 | CORE_ADDR base_address = baton->base_address + base_offset; | |
0d53c4c4 DJ |
67 | |
68 | loc_ptr = baton->data; | |
69 | buf_end = baton->data + baton->size; | |
70 | ||
71 | while (1) | |
72 | { | |
73 | low = dwarf2_read_address (loc_ptr, buf_end, &length); | |
74 | loc_ptr += length; | |
75 | high = dwarf2_read_address (loc_ptr, buf_end, &length); | |
76 | loc_ptr += length; | |
77 | ||
78 | /* An end-of-list entry. */ | |
79 | if (low == 0 && high == 0) | |
80 | return NULL; | |
81 | ||
82 | /* A base-address-selection entry. */ | |
83 | if ((low & base_mask) == base_mask) | |
84 | { | |
85 | base_address = high; | |
86 | continue; | |
87 | } | |
88 | ||
89 | /* Otherwise, a location expression entry. */ | |
90 | low += base_address; | |
91 | high += base_address; | |
92 | ||
93 | length = extract_unsigned_integer (loc_ptr, 2); | |
94 | loc_ptr += 2; | |
95 | ||
96 | if (pc >= low && pc < high) | |
97 | { | |
98 | *locexpr_length = length; | |
99 | return loc_ptr; | |
100 | } | |
101 | ||
102 | loc_ptr += length; | |
103 | } | |
104 | } | |
105 | ||
4c2df51b DJ |
106 | /* This is the baton used when performing dwarf2 expression |
107 | evaluation. */ | |
108 | struct dwarf_expr_baton | |
109 | { | |
110 | struct frame_info *frame; | |
111 | struct objfile *objfile; | |
112 | }; | |
113 | ||
114 | /* Helper functions for dwarf2_evaluate_loc_desc. */ | |
115 | ||
116 | /* Using the frame specified in BATON, read register REGNUM. The lval | |
117 | type will be returned in LVALP, and for lval_memory the register | |
118 | save address will be returned in ADDRP. */ | |
119 | static CORE_ADDR | |
61fbb938 | 120 | dwarf_expr_read_reg (void *baton, int dwarf_regnum) |
4c2df51b | 121 | { |
4c2df51b | 122 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
61fbb938 DJ |
123 | CORE_ADDR result, save_addr; |
124 | enum lval_type lval_type; | |
e4adbba9 DJ |
125 | char *buf; |
126 | int optimized, regnum, realnum, regsize; | |
127 | ||
128 | regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum); | |
129 | regsize = register_size (current_gdbarch, regnum); | |
130 | buf = (char *) alloca (regsize); | |
4c2df51b | 131 | |
61fbb938 DJ |
132 | frame_register (debaton->frame, regnum, &optimized, &lval_type, &save_addr, |
133 | &realnum, buf); | |
af1342ab AC |
134 | /* NOTE: cagney/2003-05-22: This extract is assuming that a DWARF 2 |
135 | address is always unsigned. That may or may not be true. */ | |
136 | result = extract_unsigned_integer (buf, regsize); | |
4c2df51b DJ |
137 | |
138 | return result; | |
139 | } | |
140 | ||
141 | /* Read memory at ADDR (length LEN) into BUF. */ | |
142 | ||
143 | static void | |
144 | dwarf_expr_read_mem (void *baton, char *buf, CORE_ADDR addr, size_t len) | |
145 | { | |
146 | read_memory (addr, buf, len); | |
147 | } | |
148 | ||
149 | /* Using the frame specified in BATON, find the location expression | |
150 | describing the frame base. Return a pointer to it in START and | |
151 | its length in LENGTH. */ | |
152 | static void | |
153 | dwarf_expr_frame_base (void *baton, unsigned char **start, size_t * length) | |
154 | { | |
da62e633 AC |
155 | /* FIXME: cagney/2003-03-26: This code should be using |
156 | get_frame_base_address(), and then implement a dwarf2 specific | |
157 | this_base method. */ | |
4c2df51b | 158 | struct symbol *framefunc; |
4c2df51b | 159 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; |
0d53c4c4 | 160 | |
4c2df51b | 161 | framefunc = get_frame_function (debaton->frame); |
0d53c4c4 | 162 | |
a67af2b9 | 163 | if (SYMBOL_OPS (framefunc) == &dwarf2_loclist_funcs) |
0d53c4c4 DJ |
164 | { |
165 | struct dwarf2_loclist_baton *symbaton; | |
166 | symbaton = SYMBOL_LOCATION_BATON (framefunc); | |
167 | *start = find_location_expression (symbaton, length, | |
168 | get_frame_pc (debaton->frame)); | |
169 | } | |
170 | else | |
171 | { | |
172 | struct dwarf2_locexpr_baton *symbaton; | |
173 | symbaton = SYMBOL_LOCATION_BATON (framefunc); | |
174 | *length = symbaton->size; | |
175 | *start = symbaton->data; | |
176 | } | |
177 | ||
178 | if (*start == NULL) | |
8a3fe4f8 | 179 | error (_("Could not find the frame base for \"%s\"."), |
0d53c4c4 | 180 | SYMBOL_NATURAL_NAME (framefunc)); |
4c2df51b DJ |
181 | } |
182 | ||
183 | /* Using the objfile specified in BATON, find the address for the | |
184 | current thread's thread-local storage with offset OFFSET. */ | |
185 | static CORE_ADDR | |
186 | dwarf_expr_tls_address (void *baton, CORE_ADDR offset) | |
187 | { | |
188 | struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton; | |
4dd04433 | 189 | volatile CORE_ADDR addr = 0; |
4c2df51b | 190 | |
b2756930 KB |
191 | if (target_get_thread_local_address_p () |
192 | && gdbarch_fetch_tls_load_module_address_p (current_gdbarch)) | |
93ad78a7 KB |
193 | { |
194 | ptid_t ptid = inferior_ptid; | |
195 | struct objfile *objfile = debaton->objfile; | |
71fff37b | 196 | volatile struct gdb_exception ex; |
93ad78a7 KB |
197 | |
198 | TRY_CATCH (ex, RETURN_MASK_ALL) | |
199 | { | |
b2756930 KB |
200 | CORE_ADDR lm_addr; |
201 | ||
202 | /* Fetch the load module address for this objfile. */ | |
203 | lm_addr = gdbarch_fetch_tls_load_module_address (current_gdbarch, | |
204 | objfile); | |
205 | /* If it's 0, throw the appropriate exception. */ | |
206 | if (lm_addr == 0) | |
207 | { | |
71fff37b | 208 | struct gdb_exception e |
b2756930 KB |
209 | = { RETURN_ERROR, TLS_LOAD_MODULE_NOT_FOUND_ERROR, 0 }; |
210 | ||
211 | throw_exception (e); | |
212 | } | |
213 | ||
214 | addr = target_get_thread_local_address (ptid, lm_addr, offset); | |
93ad78a7 KB |
215 | } |
216 | /* If an error occurred, print TLS related messages here. Otherwise, | |
217 | throw the error to some higher catcher. */ | |
218 | if (ex.reason < 0) | |
219 | { | |
220 | int objfile_is_library = (objfile->flags & OBJF_SHARED); | |
221 | ||
222 | switch (ex.error) | |
223 | { | |
224 | case TLS_NO_LIBRARY_SUPPORT_ERROR: | |
225 | error (_("Cannot find thread-local variables in this thread library.")); | |
226 | break; | |
227 | case TLS_LOAD_MODULE_NOT_FOUND_ERROR: | |
228 | if (objfile_is_library) | |
229 | error (_("Cannot find shared library `%s' in dynamic" | |
230 | " linker's load module list"), objfile->name); | |
231 | else | |
232 | error (_("Cannot find executable file `%s' in dynamic" | |
233 | " linker's load module list"), objfile->name); | |
234 | break; | |
235 | case TLS_NOT_ALLOCATED_YET_ERROR: | |
236 | if (objfile_is_library) | |
237 | error (_("The inferior has not yet allocated storage for" | |
238 | " thread-local variables in\n" | |
239 | "the shared library `%s'\n" | |
240 | "for %s"), | |
241 | objfile->name, target_pid_to_str (ptid)); | |
242 | else | |
243 | error (_("The inferior has not yet allocated storage for" | |
244 | " thread-local variables in\n" | |
245 | "the executable `%s'\n" | |
246 | "for %s"), | |
247 | objfile->name, target_pid_to_str (ptid)); | |
248 | break; | |
249 | case TLS_GENERIC_ERROR: | |
250 | if (objfile_is_library) | |
251 | error (_("Cannot find thread-local storage for %s, " | |
252 | "shared library %s:\n%s"), | |
253 | target_pid_to_str (ptid), | |
254 | objfile->name, ex.message); | |
255 | else | |
256 | error (_("Cannot find thread-local storage for %s, " | |
257 | "executable file %s:\n%s"), | |
258 | target_pid_to_str (ptid), | |
259 | objfile->name, ex.message); | |
260 | break; | |
261 | default: | |
262 | throw_exception (ex); | |
263 | break; | |
264 | } | |
265 | } | |
266 | } | |
c3228f12 EZ |
267 | /* It wouldn't be wrong here to try a gdbarch method, too; finding |
268 | TLS is an ABI-specific thing. But we don't do that yet. */ | |
4c2df51b | 269 | else |
8a3fe4f8 | 270 | error (_("Cannot find thread-local variables on this target")); |
4c2df51b DJ |
271 | |
272 | return addr; | |
273 | } | |
274 | ||
275 | /* Evaluate a location description, starting at DATA and with length | |
276 | SIZE, to find the current location of variable VAR in the context | |
277 | of FRAME. */ | |
278 | static struct value * | |
279 | dwarf2_evaluate_loc_desc (struct symbol *var, struct frame_info *frame, | |
280 | unsigned char *data, unsigned short size, | |
281 | struct objfile *objfile) | |
282 | { | |
87808bd6 | 283 | struct gdbarch *arch = get_frame_arch (frame); |
4c2df51b DJ |
284 | struct value *retval; |
285 | struct dwarf_expr_baton baton; | |
286 | struct dwarf_expr_context *ctx; | |
287 | ||
0d53c4c4 DJ |
288 | if (size == 0) |
289 | { | |
290 | retval = allocate_value (SYMBOL_TYPE (var)); | |
291 | VALUE_LVAL (retval) = not_lval; | |
feb13ab0 | 292 | set_value_optimized_out (retval, 1); |
0d53c4c4 DJ |
293 | } |
294 | ||
4c2df51b DJ |
295 | baton.frame = frame; |
296 | baton.objfile = objfile; | |
297 | ||
298 | ctx = new_dwarf_expr_context (); | |
299 | ctx->baton = &baton; | |
300 | ctx->read_reg = dwarf_expr_read_reg; | |
301 | ctx->read_mem = dwarf_expr_read_mem; | |
302 | ctx->get_frame_base = dwarf_expr_frame_base; | |
303 | ctx->get_tls_address = dwarf_expr_tls_address; | |
304 | ||
305 | dwarf_expr_eval (ctx, data, size); | |
87808bd6 JB |
306 | if (ctx->num_pieces > 0) |
307 | { | |
308 | /* We haven't implemented splicing together pieces from | |
309 | arbitrary sources yet. */ | |
8a3fe4f8 AC |
310 | error (_("The value of variable '%s' is distributed across several\n" |
311 | "locations, and GDB cannot access its value.\n"), | |
87808bd6 JB |
312 | SYMBOL_NATURAL_NAME (var)); |
313 | } | |
314 | else if (ctx->in_reg) | |
051caad9 | 315 | { |
5ca2e327 JB |
316 | CORE_ADDR dwarf_regnum = dwarf_expr_fetch (ctx, 0); |
317 | int gdb_regnum = DWARF2_REG_TO_REGNUM (dwarf_regnum); | |
318 | retval = value_from_register (SYMBOL_TYPE (var), gdb_regnum, frame); | |
051caad9 | 319 | } |
4c2df51b DJ |
320 | else |
321 | { | |
5ca2e327 JB |
322 | CORE_ADDR address = dwarf_expr_fetch (ctx, 0); |
323 | ||
61fbb938 | 324 | retval = allocate_value (SYMBOL_TYPE (var)); |
4c2df51b | 325 | VALUE_LVAL (retval) = lval_memory; |
dfa52d88 | 326 | set_value_lazy (retval, 1); |
5ca2e327 | 327 | VALUE_ADDRESS (retval) = address; |
4c2df51b DJ |
328 | } |
329 | ||
330 | free_dwarf_expr_context (ctx); | |
331 | ||
332 | return retval; | |
333 | } | |
334 | ||
335 | ||
336 | ||
337 | ||
338 | \f | |
339 | /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */ | |
340 | ||
341 | struct needs_frame_baton | |
342 | { | |
343 | int needs_frame; | |
344 | }; | |
345 | ||
346 | /* Reads from registers do require a frame. */ | |
347 | static CORE_ADDR | |
61fbb938 | 348 | needs_frame_read_reg (void *baton, int regnum) |
4c2df51b DJ |
349 | { |
350 | struct needs_frame_baton *nf_baton = baton; | |
351 | nf_baton->needs_frame = 1; | |
352 | return 1; | |
353 | } | |
354 | ||
355 | /* Reads from memory do not require a frame. */ | |
356 | static void | |
357 | needs_frame_read_mem (void *baton, char *buf, CORE_ADDR addr, size_t len) | |
358 | { | |
359 | memset (buf, 0, len); | |
360 | } | |
361 | ||
362 | /* Frame-relative accesses do require a frame. */ | |
363 | static void | |
364 | needs_frame_frame_base (void *baton, unsigned char **start, size_t * length) | |
365 | { | |
366 | static char lit0 = DW_OP_lit0; | |
367 | struct needs_frame_baton *nf_baton = baton; | |
368 | ||
369 | *start = &lit0; | |
370 | *length = 1; | |
371 | ||
372 | nf_baton->needs_frame = 1; | |
373 | } | |
374 | ||
375 | /* Thread-local accesses do require a frame. */ | |
376 | static CORE_ADDR | |
377 | needs_frame_tls_address (void *baton, CORE_ADDR offset) | |
378 | { | |
379 | struct needs_frame_baton *nf_baton = baton; | |
380 | nf_baton->needs_frame = 1; | |
381 | return 1; | |
382 | } | |
383 | ||
384 | /* Return non-zero iff the location expression at DATA (length SIZE) | |
385 | requires a frame to evaluate. */ | |
386 | ||
387 | static int | |
388 | dwarf2_loc_desc_needs_frame (unsigned char *data, unsigned short size) | |
389 | { | |
390 | struct needs_frame_baton baton; | |
391 | struct dwarf_expr_context *ctx; | |
f630a401 | 392 | int in_reg; |
4c2df51b DJ |
393 | |
394 | baton.needs_frame = 0; | |
395 | ||
396 | ctx = new_dwarf_expr_context (); | |
397 | ctx->baton = &baton; | |
398 | ctx->read_reg = needs_frame_read_reg; | |
399 | ctx->read_mem = needs_frame_read_mem; | |
400 | ctx->get_frame_base = needs_frame_frame_base; | |
401 | ctx->get_tls_address = needs_frame_tls_address; | |
402 | ||
403 | dwarf_expr_eval (ctx, data, size); | |
404 | ||
f630a401 DJ |
405 | in_reg = ctx->in_reg; |
406 | ||
87808bd6 JB |
407 | if (ctx->num_pieces > 0) |
408 | { | |
409 | int i; | |
410 | ||
411 | /* If the location has several pieces, and any of them are in | |
412 | registers, then we will need a frame to fetch them from. */ | |
413 | for (i = 0; i < ctx->num_pieces; i++) | |
414 | if (ctx->pieces[i].in_reg) | |
415 | in_reg = 1; | |
416 | } | |
417 | ||
4c2df51b DJ |
418 | free_dwarf_expr_context (ctx); |
419 | ||
f630a401 | 420 | return baton.needs_frame || in_reg; |
4c2df51b DJ |
421 | } |
422 | ||
0d53c4c4 DJ |
423 | static void |
424 | dwarf2_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax, | |
425 | struct axs_value * value, unsigned char *data, | |
426 | int size) | |
427 | { | |
428 | if (size == 0) | |
8a3fe4f8 | 429 | error (_("Symbol \"%s\" has been optimized out."), |
0d53c4c4 DJ |
430 | SYMBOL_PRINT_NAME (symbol)); |
431 | ||
432 | if (size == 1 | |
433 | && data[0] >= DW_OP_reg0 | |
434 | && data[0] <= DW_OP_reg31) | |
435 | { | |
436 | value->kind = axs_lvalue_register; | |
437 | value->u.reg = data[0] - DW_OP_reg0; | |
438 | } | |
439 | else if (data[0] == DW_OP_regx) | |
440 | { | |
441 | ULONGEST reg; | |
442 | read_uleb128 (data + 1, data + size, ®); | |
443 | value->kind = axs_lvalue_register; | |
444 | value->u.reg = reg; | |
445 | } | |
446 | else if (data[0] == DW_OP_fbreg) | |
447 | { | |
448 | /* And this is worse than just minimal; we should honor the frame base | |
449 | as above. */ | |
450 | int frame_reg; | |
451 | LONGEST frame_offset; | |
452 | unsigned char *buf_end; | |
453 | ||
454 | buf_end = read_sleb128 (data + 1, data + size, &frame_offset); | |
455 | if (buf_end != data + size) | |
8a3fe4f8 | 456 | error (_("Unexpected opcode after DW_OP_fbreg for symbol \"%s\"."), |
0d53c4c4 | 457 | SYMBOL_PRINT_NAME (symbol)); |
4c2df51b | 458 | |
0d53c4c4 DJ |
459 | TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset); |
460 | ax_reg (ax, frame_reg); | |
461 | ax_const_l (ax, frame_offset); | |
462 | ax_simple (ax, aop_add); | |
4c2df51b | 463 | |
0d53c4c4 DJ |
464 | ax_const_l (ax, frame_offset); |
465 | ax_simple (ax, aop_add); | |
466 | value->kind = axs_lvalue_memory; | |
467 | } | |
468 | else | |
8a3fe4f8 | 469 | error (_("Unsupported DWARF opcode in the location of \"%s\"."), |
0d53c4c4 DJ |
470 | SYMBOL_PRINT_NAME (symbol)); |
471 | } | |
4c2df51b DJ |
472 | \f |
473 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression | |
474 | evaluator to calculate the location. */ | |
475 | static struct value * | |
476 | locexpr_read_variable (struct symbol *symbol, struct frame_info *frame) | |
477 | { | |
478 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
479 | struct value *val; | |
480 | val = dwarf2_evaluate_loc_desc (symbol, frame, dlbaton->data, dlbaton->size, | |
481 | dlbaton->objfile); | |
482 | ||
483 | return val; | |
484 | } | |
485 | ||
486 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ | |
487 | static int | |
488 | locexpr_read_needs_frame (struct symbol *symbol) | |
489 | { | |
490 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
491 | return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size); | |
492 | } | |
493 | ||
494 | /* Print a natural-language description of SYMBOL to STREAM. */ | |
495 | static int | |
496 | locexpr_describe_location (struct symbol *symbol, struct ui_file *stream) | |
497 | { | |
498 | /* FIXME: be more extensive. */ | |
499 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
500 | ||
501 | if (dlbaton->size == 1 | |
502 | && dlbaton->data[0] >= DW_OP_reg0 | |
503 | && dlbaton->data[0] <= DW_OP_reg31) | |
504 | { | |
505 | int regno = DWARF2_REG_TO_REGNUM (dlbaton->data[0] - DW_OP_reg0); | |
506 | fprintf_filtered (stream, | |
507 | "a variable in register %s", REGISTER_NAME (regno)); | |
508 | return 1; | |
509 | } | |
510 | ||
c3228f12 EZ |
511 | /* The location expression for a TLS variable looks like this (on a |
512 | 64-bit LE machine): | |
513 | ||
514 | DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0 | |
515 | (DW_OP_addr: 4; DW_OP_GNU_push_tls_address) | |
516 | ||
517 | 0x3 is the encoding for DW_OP_addr, which has an operand as long | |
518 | as the size of an address on the target machine (here is 8 | |
519 | bytes). 0xe0 is the encoding for DW_OP_GNU_push_tls_address. | |
520 | The operand represents the offset at which the variable is within | |
521 | the thread local storage. */ | |
522 | ||
523 | if (dlbaton->size > 1 | |
524 | && dlbaton->data[dlbaton->size - 1] == DW_OP_GNU_push_tls_address) | |
525 | if (dlbaton->data[0] == DW_OP_addr) | |
526 | { | |
527 | int bytes_read; | |
528 | CORE_ADDR offset = dwarf2_read_address (&dlbaton->data[1], | |
c193f044 | 529 | &dlbaton->data[dlbaton->size - 1], |
c3228f12 EZ |
530 | &bytes_read); |
531 | fprintf_filtered (stream, | |
32ffcbed | 532 | "a thread-local variable at offset %s in the " |
c3228f12 EZ |
533 | "thread-local storage for `%s'", |
534 | paddr_nz (offset), dlbaton->objfile->name); | |
535 | return 1; | |
536 | } | |
537 | ||
538 | ||
4c2df51b DJ |
539 | fprintf_filtered (stream, |
540 | "a variable with complex or multiple locations (DWARF2)"); | |
541 | return 1; | |
542 | } | |
543 | ||
a55cc764 DJ |
544 | |
545 | /* Describe the location of SYMBOL as an agent value in VALUE, generating | |
546 | any necessary bytecode in AX. | |
547 | ||
548 | NOTE drow/2003-02-26: This function is extremely minimal, because | |
549 | doing it correctly is extremely complicated and there is no | |
550 | publicly available stub with tracepoint support for me to test | |
551 | against. When there is one this function should be revisited. */ | |
552 | ||
0d53c4c4 | 553 | static void |
a55cc764 DJ |
554 | locexpr_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax, |
555 | struct axs_value * value) | |
556 | { | |
557 | struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
558 | ||
0d53c4c4 | 559 | dwarf2_tracepoint_var_ref (symbol, ax, value, dlbaton->data, dlbaton->size); |
a55cc764 DJ |
560 | } |
561 | ||
4c2df51b DJ |
562 | /* The set of location functions used with the DWARF-2 expression |
563 | evaluator. */ | |
a67af2b9 | 564 | const struct symbol_ops dwarf2_locexpr_funcs = { |
4c2df51b DJ |
565 | locexpr_read_variable, |
566 | locexpr_read_needs_frame, | |
567 | locexpr_describe_location, | |
a55cc764 | 568 | locexpr_tracepoint_var_ref |
4c2df51b | 569 | }; |
0d53c4c4 DJ |
570 | |
571 | ||
572 | /* Wrapper functions for location lists. These generally find | |
573 | the appropriate location expression and call something above. */ | |
574 | ||
575 | /* Return the value of SYMBOL in FRAME using the DWARF-2 expression | |
576 | evaluator to calculate the location. */ | |
577 | static struct value * | |
578 | loclist_read_variable (struct symbol *symbol, struct frame_info *frame) | |
579 | { | |
580 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
581 | struct value *val; | |
582 | unsigned char *data; | |
b6b08ebf | 583 | size_t size; |
0d53c4c4 DJ |
584 | |
585 | data = find_location_expression (dlbaton, &size, | |
586 | frame ? get_frame_pc (frame) : 0); | |
587 | if (data == NULL) | |
806048c6 DJ |
588 | { |
589 | val = allocate_value (SYMBOL_TYPE (symbol)); | |
590 | VALUE_LVAL (val) = not_lval; | |
591 | set_value_optimized_out (val, 1); | |
592 | } | |
593 | else | |
594 | val = dwarf2_evaluate_loc_desc (symbol, frame, data, size, | |
595 | dlbaton->objfile); | |
0d53c4c4 DJ |
596 | |
597 | return val; | |
598 | } | |
599 | ||
600 | /* Return non-zero iff we need a frame to evaluate SYMBOL. */ | |
601 | static int | |
602 | loclist_read_needs_frame (struct symbol *symbol) | |
603 | { | |
604 | /* If there's a location list, then assume we need to have a frame | |
605 | to choose the appropriate location expression. With tracking of | |
606 | global variables this is not necessarily true, but such tracking | |
607 | is disabled in GCC at the moment until we figure out how to | |
608 | represent it. */ | |
609 | ||
610 | return 1; | |
611 | } | |
612 | ||
613 | /* Print a natural-language description of SYMBOL to STREAM. */ | |
614 | static int | |
615 | loclist_describe_location (struct symbol *symbol, struct ui_file *stream) | |
616 | { | |
617 | /* FIXME: Could print the entire list of locations. */ | |
618 | fprintf_filtered (stream, "a variable with multiple locations"); | |
619 | return 1; | |
620 | } | |
621 | ||
622 | /* Describe the location of SYMBOL as an agent value in VALUE, generating | |
623 | any necessary bytecode in AX. */ | |
624 | static void | |
625 | loclist_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax, | |
626 | struct axs_value * value) | |
627 | { | |
628 | struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol); | |
629 | unsigned char *data; | |
b6b08ebf | 630 | size_t size; |
0d53c4c4 DJ |
631 | |
632 | data = find_location_expression (dlbaton, &size, ax->scope); | |
633 | if (data == NULL) | |
8a3fe4f8 | 634 | error (_("Variable \"%s\" is not available."), SYMBOL_NATURAL_NAME (symbol)); |
0d53c4c4 DJ |
635 | |
636 | dwarf2_tracepoint_var_ref (symbol, ax, value, data, size); | |
637 | } | |
638 | ||
639 | /* The set of location functions used with the DWARF-2 expression | |
640 | evaluator and location lists. */ | |
a67af2b9 | 641 | const struct symbol_ops dwarf2_loclist_funcs = { |
0d53c4c4 DJ |
642 | loclist_read_variable, |
643 | loclist_read_needs_frame, | |
644 | loclist_describe_location, | |
645 | loclist_tracepoint_var_ref | |
646 | }; |