Commit | Line | Data |
---|---|---|
852483bc MK |
1 | /* DWARF 2 Expression Evaluator. |
2 | ||
9b254dd1 DJ |
3 | Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008 |
4 | Free Software Foundation, Inc. | |
852483bc | 5 | |
4c2df51b DJ |
6 | Contributed by Daniel Berlin (dan@dberlin.org) |
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 | 12 | the Free Software Foundation; either version 3 of the License, or |
4c2df51b DJ |
13 | (at your option) any later version. |
14 | ||
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. | |
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 "symtab.h" | |
25 | #include "gdbtypes.h" | |
26 | #include "value.h" | |
27 | #include "gdbcore.h" | |
28 | #include "elf/dwarf2.h" | |
29 | #include "dwarf2expr.h" | |
30 | ||
31 | /* Local prototypes. */ | |
32 | ||
33 | static void execute_stack_op (struct dwarf_expr_context *, | |
852483bc | 34 | gdb_byte *, gdb_byte *); |
ace186d4 | 35 | static struct type *unsigned_address_type (void); |
4c2df51b DJ |
36 | |
37 | /* Create a new context for the expression evaluator. */ | |
38 | ||
39 | struct dwarf_expr_context * | |
e4adbba9 | 40 | new_dwarf_expr_context (void) |
4c2df51b DJ |
41 | { |
42 | struct dwarf_expr_context *retval; | |
43 | retval = xcalloc (1, sizeof (struct dwarf_expr_context)); | |
18ec9831 KB |
44 | retval->stack_len = 0; |
45 | retval->stack_allocated = 10; | |
46 | retval->stack = xmalloc (retval->stack_allocated * sizeof (CORE_ADDR)); | |
87808bd6 JB |
47 | retval->num_pieces = 0; |
48 | retval->pieces = 0; | |
4c2df51b DJ |
49 | return retval; |
50 | } | |
51 | ||
52 | /* Release the memory allocated to CTX. */ | |
53 | ||
54 | void | |
55 | free_dwarf_expr_context (struct dwarf_expr_context *ctx) | |
56 | { | |
57 | xfree (ctx->stack); | |
87808bd6 | 58 | xfree (ctx->pieces); |
4c2df51b DJ |
59 | xfree (ctx); |
60 | } | |
61 | ||
62 | /* Expand the memory allocated to CTX's stack to contain at least | |
63 | NEED more elements than are currently used. */ | |
64 | ||
65 | static void | |
66 | dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need) | |
67 | { | |
68 | if (ctx->stack_len + need > ctx->stack_allocated) | |
69 | { | |
18ec9831 | 70 | size_t newlen = ctx->stack_len + need + 10; |
4c2df51b | 71 | ctx->stack = xrealloc (ctx->stack, |
18ec9831 KB |
72 | newlen * sizeof (CORE_ADDR)); |
73 | ctx->stack_allocated = newlen; | |
4c2df51b DJ |
74 | } |
75 | } | |
76 | ||
77 | /* Push VALUE onto CTX's stack. */ | |
78 | ||
79 | void | |
80 | dwarf_expr_push (struct dwarf_expr_context *ctx, CORE_ADDR value) | |
81 | { | |
82 | dwarf_expr_grow_stack (ctx, 1); | |
83 | ctx->stack[ctx->stack_len++] = value; | |
84 | } | |
85 | ||
86 | /* Pop the top item off of CTX's stack. */ | |
87 | ||
88 | void | |
89 | dwarf_expr_pop (struct dwarf_expr_context *ctx) | |
90 | { | |
91 | if (ctx->stack_len <= 0) | |
8a3fe4f8 | 92 | error (_("dwarf expression stack underflow")); |
4c2df51b DJ |
93 | ctx->stack_len--; |
94 | } | |
95 | ||
96 | /* Retrieve the N'th item on CTX's stack. */ | |
97 | ||
98 | CORE_ADDR | |
99 | dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n) | |
100 | { | |
ef0fdf07 | 101 | if (ctx->stack_len <= n) |
8a3fe4f8 | 102 | error (_("Asked for position %d of stack, stack only has %d elements on it."), |
4c2df51b DJ |
103 | n, ctx->stack_len); |
104 | return ctx->stack[ctx->stack_len - (1 + n)]; | |
105 | ||
106 | } | |
107 | ||
87808bd6 JB |
108 | /* Add a new piece to CTX's piece list. */ |
109 | static void | |
110 | add_piece (struct dwarf_expr_context *ctx, | |
111 | int in_reg, CORE_ADDR value, ULONGEST size) | |
112 | { | |
113 | struct dwarf_expr_piece *p; | |
114 | ||
115 | ctx->num_pieces++; | |
116 | ||
117 | if (ctx->pieces) | |
118 | ctx->pieces = xrealloc (ctx->pieces, | |
119 | (ctx->num_pieces | |
120 | * sizeof (struct dwarf_expr_piece))); | |
121 | else | |
122 | ctx->pieces = xmalloc (ctx->num_pieces | |
123 | * sizeof (struct dwarf_expr_piece)); | |
124 | ||
125 | p = &ctx->pieces[ctx->num_pieces - 1]; | |
126 | p->in_reg = in_reg; | |
127 | p->value = value; | |
128 | p->size = size; | |
129 | } | |
130 | ||
4c2df51b DJ |
131 | /* Evaluate the expression at ADDR (LEN bytes long) using the context |
132 | CTX. */ | |
133 | ||
134 | void | |
852483bc | 135 | dwarf_expr_eval (struct dwarf_expr_context *ctx, gdb_byte *addr, size_t len) |
4c2df51b DJ |
136 | { |
137 | execute_stack_op (ctx, addr, addr + len); | |
138 | } | |
139 | ||
140 | /* Decode the unsigned LEB128 constant at BUF into the variable pointed to | |
141 | by R, and return the new value of BUF. Verify that it doesn't extend | |
142 | past BUF_END. */ | |
143 | ||
852483bc MK |
144 | gdb_byte * |
145 | read_uleb128 (gdb_byte *buf, gdb_byte *buf_end, ULONGEST * r) | |
4c2df51b DJ |
146 | { |
147 | unsigned shift = 0; | |
148 | ULONGEST result = 0; | |
852483bc | 149 | gdb_byte byte; |
4c2df51b DJ |
150 | |
151 | while (1) | |
152 | { | |
153 | if (buf >= buf_end) | |
8a3fe4f8 | 154 | error (_("read_uleb128: Corrupted DWARF expression.")); |
4c2df51b DJ |
155 | |
156 | byte = *buf++; | |
157 | result |= (byte & 0x7f) << shift; | |
158 | if ((byte & 0x80) == 0) | |
159 | break; | |
160 | shift += 7; | |
161 | } | |
162 | *r = result; | |
163 | return buf; | |
164 | } | |
165 | ||
166 | /* Decode the signed LEB128 constant at BUF into the variable pointed to | |
167 | by R, and return the new value of BUF. Verify that it doesn't extend | |
168 | past BUF_END. */ | |
169 | ||
852483bc MK |
170 | gdb_byte * |
171 | read_sleb128 (gdb_byte *buf, gdb_byte *buf_end, LONGEST * r) | |
4c2df51b DJ |
172 | { |
173 | unsigned shift = 0; | |
174 | LONGEST result = 0; | |
852483bc | 175 | gdb_byte byte; |
4c2df51b DJ |
176 | |
177 | while (1) | |
178 | { | |
179 | if (buf >= buf_end) | |
8a3fe4f8 | 180 | error (_("read_sleb128: Corrupted DWARF expression.")); |
4c2df51b DJ |
181 | |
182 | byte = *buf++; | |
183 | result |= (byte & 0x7f) << shift; | |
184 | shift += 7; | |
185 | if ((byte & 0x80) == 0) | |
186 | break; | |
187 | } | |
188 | if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0) | |
189 | result |= -(1 << shift); | |
190 | ||
191 | *r = result; | |
192 | return buf; | |
193 | } | |
194 | ||
195 | /* Read an address from BUF, and verify that it doesn't extend past | |
196 | BUF_END. The address is returned, and *BYTES_READ is set to the | |
197 | number of bytes read from BUF. */ | |
198 | ||
0d53c4c4 | 199 | CORE_ADDR |
852483bc | 200 | dwarf2_read_address (gdb_byte *buf, gdb_byte *buf_end, int *bytes_read) |
4c2df51b DJ |
201 | { |
202 | CORE_ADDR result; | |
203 | ||
17a912b6 | 204 | if (buf_end - buf < gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT) |
8a3fe4f8 | 205 | error (_("dwarf2_read_address: Corrupted DWARF expression.")); |
4c2df51b | 206 | |
17a912b6 | 207 | *bytes_read = gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT; |
ace186d4 KB |
208 | |
209 | /* For most architectures, calling extract_unsigned_integer() alone | |
210 | is sufficient for extracting an address. However, some | |
211 | architectures (e.g. MIPS) use signed addresses and using | |
212 | extract_unsigned_integer() will not produce a correct | |
213 | result. Turning the unsigned integer into a value and then | |
214 | decomposing that value as an address will cause | |
215 | gdbarch_integer_to_address() to be invoked for those | |
216 | architectures which require it. Thus, using value_as_address() | |
217 | will produce the correct result for both types of architectures. | |
218 | ||
219 | One concern regarding the use of values for this purpose is | |
220 | efficiency. Obviously, these extra calls will take more time to | |
221 | execute and creating a value takes more space, space which will | |
222 | have to be garbage collected at a later time. If constructing | |
223 | and then decomposing a value for this purpose proves to be too | |
224 | inefficient, then gdbarch_integer_to_address() can be called | |
225 | directly. | |
226 | ||
227 | The use of `unsigned_address_type' in the code below refers to | |
228 | the type of buf and has no bearing on the signedness of the | |
229 | address being returned. */ | |
230 | ||
231 | result = value_as_address (value_from_longest | |
232 | (unsigned_address_type (), | |
233 | extract_unsigned_integer | |
234 | (buf, | |
17a912b6 UW |
235 | gdbarch_addr_bit (current_gdbarch) |
236 | / TARGET_CHAR_BIT))); | |
ace186d4 | 237 | |
4c2df51b DJ |
238 | return result; |
239 | } | |
240 | ||
241 | /* Return the type of an address, for unsigned arithmetic. */ | |
242 | ||
243 | static struct type * | |
244 | unsigned_address_type (void) | |
245 | { | |
17a912b6 | 246 | switch (gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT) |
4c2df51b DJ |
247 | { |
248 | case 2: | |
249 | return builtin_type_uint16; | |
250 | case 4: | |
251 | return builtin_type_uint32; | |
252 | case 8: | |
253 | return builtin_type_uint64; | |
254 | default: | |
255 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 256 | _("Unsupported address size.\n")); |
4c2df51b DJ |
257 | } |
258 | } | |
259 | ||
260 | /* Return the type of an address, for signed arithmetic. */ | |
261 | ||
262 | static struct type * | |
263 | signed_address_type (void) | |
264 | { | |
17a912b6 | 265 | switch (gdbarch_addr_bit (current_gdbarch) / TARGET_CHAR_BIT) |
4c2df51b DJ |
266 | { |
267 | case 2: | |
268 | return builtin_type_int16; | |
269 | case 4: | |
270 | return builtin_type_int32; | |
271 | case 8: | |
272 | return builtin_type_int64; | |
273 | default: | |
274 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 275 | _("Unsupported address size.\n")); |
4c2df51b DJ |
276 | } |
277 | } | |
278 | \f | |
279 | /* The engine for the expression evaluator. Using the context in CTX, | |
280 | evaluate the expression between OP_PTR and OP_END. */ | |
281 | ||
282 | static void | |
852483bc MK |
283 | execute_stack_op (struct dwarf_expr_context *ctx, |
284 | gdb_byte *op_ptr, gdb_byte *op_end) | |
4c2df51b | 285 | { |
18ec9831 | 286 | ctx->in_reg = 0; |
42be36b3 | 287 | ctx->initialized = 1; /* Default is initialized. */ |
18ec9831 | 288 | |
4c2df51b DJ |
289 | while (op_ptr < op_end) |
290 | { | |
291 | enum dwarf_location_atom op = *op_ptr++; | |
61fbb938 | 292 | CORE_ADDR result; |
4c2df51b DJ |
293 | ULONGEST uoffset, reg; |
294 | LONGEST offset; | |
295 | int bytes_read; | |
4c2df51b | 296 | |
4c2df51b DJ |
297 | switch (op) |
298 | { | |
299 | case DW_OP_lit0: | |
300 | case DW_OP_lit1: | |
301 | case DW_OP_lit2: | |
302 | case DW_OP_lit3: | |
303 | case DW_OP_lit4: | |
304 | case DW_OP_lit5: | |
305 | case DW_OP_lit6: | |
306 | case DW_OP_lit7: | |
307 | case DW_OP_lit8: | |
308 | case DW_OP_lit9: | |
309 | case DW_OP_lit10: | |
310 | case DW_OP_lit11: | |
311 | case DW_OP_lit12: | |
312 | case DW_OP_lit13: | |
313 | case DW_OP_lit14: | |
314 | case DW_OP_lit15: | |
315 | case DW_OP_lit16: | |
316 | case DW_OP_lit17: | |
317 | case DW_OP_lit18: | |
318 | case DW_OP_lit19: | |
319 | case DW_OP_lit20: | |
320 | case DW_OP_lit21: | |
321 | case DW_OP_lit22: | |
322 | case DW_OP_lit23: | |
323 | case DW_OP_lit24: | |
324 | case DW_OP_lit25: | |
325 | case DW_OP_lit26: | |
326 | case DW_OP_lit27: | |
327 | case DW_OP_lit28: | |
328 | case DW_OP_lit29: | |
329 | case DW_OP_lit30: | |
330 | case DW_OP_lit31: | |
331 | result = op - DW_OP_lit0; | |
332 | break; | |
333 | ||
334 | case DW_OP_addr: | |
0d53c4c4 | 335 | result = dwarf2_read_address (op_ptr, op_end, &bytes_read); |
4c2df51b DJ |
336 | op_ptr += bytes_read; |
337 | break; | |
338 | ||
339 | case DW_OP_const1u: | |
340 | result = extract_unsigned_integer (op_ptr, 1); | |
341 | op_ptr += 1; | |
342 | break; | |
343 | case DW_OP_const1s: | |
344 | result = extract_signed_integer (op_ptr, 1); | |
345 | op_ptr += 1; | |
346 | break; | |
347 | case DW_OP_const2u: | |
348 | result = extract_unsigned_integer (op_ptr, 2); | |
349 | op_ptr += 2; | |
350 | break; | |
351 | case DW_OP_const2s: | |
352 | result = extract_signed_integer (op_ptr, 2); | |
353 | op_ptr += 2; | |
354 | break; | |
355 | case DW_OP_const4u: | |
356 | result = extract_unsigned_integer (op_ptr, 4); | |
357 | op_ptr += 4; | |
358 | break; | |
359 | case DW_OP_const4s: | |
360 | result = extract_signed_integer (op_ptr, 4); | |
361 | op_ptr += 4; | |
362 | break; | |
363 | case DW_OP_const8u: | |
364 | result = extract_unsigned_integer (op_ptr, 8); | |
365 | op_ptr += 8; | |
366 | break; | |
367 | case DW_OP_const8s: | |
368 | result = extract_signed_integer (op_ptr, 8); | |
369 | op_ptr += 8; | |
370 | break; | |
371 | case DW_OP_constu: | |
372 | op_ptr = read_uleb128 (op_ptr, op_end, &uoffset); | |
373 | result = uoffset; | |
374 | break; | |
375 | case DW_OP_consts: | |
376 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); | |
377 | result = offset; | |
378 | break; | |
379 | ||
380 | /* The DW_OP_reg operations are required to occur alone in | |
381 | location expressions. */ | |
382 | case DW_OP_reg0: | |
383 | case DW_OP_reg1: | |
384 | case DW_OP_reg2: | |
385 | case DW_OP_reg3: | |
386 | case DW_OP_reg4: | |
387 | case DW_OP_reg5: | |
388 | case DW_OP_reg6: | |
389 | case DW_OP_reg7: | |
390 | case DW_OP_reg8: | |
391 | case DW_OP_reg9: | |
392 | case DW_OP_reg10: | |
393 | case DW_OP_reg11: | |
394 | case DW_OP_reg12: | |
395 | case DW_OP_reg13: | |
396 | case DW_OP_reg14: | |
397 | case DW_OP_reg15: | |
398 | case DW_OP_reg16: | |
399 | case DW_OP_reg17: | |
400 | case DW_OP_reg18: | |
401 | case DW_OP_reg19: | |
402 | case DW_OP_reg20: | |
403 | case DW_OP_reg21: | |
404 | case DW_OP_reg22: | |
405 | case DW_OP_reg23: | |
406 | case DW_OP_reg24: | |
407 | case DW_OP_reg25: | |
408 | case DW_OP_reg26: | |
409 | case DW_OP_reg27: | |
410 | case DW_OP_reg28: | |
411 | case DW_OP_reg29: | |
412 | case DW_OP_reg30: | |
413 | case DW_OP_reg31: | |
42be36b3 CT |
414 | if (op_ptr != op_end |
415 | && *op_ptr != DW_OP_piece | |
416 | && *op_ptr != DW_OP_GNU_uninit) | |
8a3fe4f8 AC |
417 | error (_("DWARF-2 expression error: DW_OP_reg operations must be " |
418 | "used either alone or in conjuction with DW_OP_piece.")); | |
4c2df51b | 419 | |
61fbb938 DJ |
420 | result = op - DW_OP_reg0; |
421 | ctx->in_reg = 1; | |
4c2df51b DJ |
422 | |
423 | break; | |
424 | ||
425 | case DW_OP_regx: | |
426 | op_ptr = read_uleb128 (op_ptr, op_end, ®); | |
18ec9831 | 427 | if (op_ptr != op_end && *op_ptr != DW_OP_piece) |
8a3fe4f8 AC |
428 | error (_("DWARF-2 expression error: DW_OP_reg operations must be " |
429 | "used either alone or in conjuction with DW_OP_piece.")); | |
4c2df51b | 430 | |
61fbb938 DJ |
431 | result = reg; |
432 | ctx->in_reg = 1; | |
4c2df51b DJ |
433 | break; |
434 | ||
435 | case DW_OP_breg0: | |
436 | case DW_OP_breg1: | |
437 | case DW_OP_breg2: | |
438 | case DW_OP_breg3: | |
439 | case DW_OP_breg4: | |
440 | case DW_OP_breg5: | |
441 | case DW_OP_breg6: | |
442 | case DW_OP_breg7: | |
443 | case DW_OP_breg8: | |
444 | case DW_OP_breg9: | |
445 | case DW_OP_breg10: | |
446 | case DW_OP_breg11: | |
447 | case DW_OP_breg12: | |
448 | case DW_OP_breg13: | |
449 | case DW_OP_breg14: | |
450 | case DW_OP_breg15: | |
451 | case DW_OP_breg16: | |
452 | case DW_OP_breg17: | |
453 | case DW_OP_breg18: | |
454 | case DW_OP_breg19: | |
455 | case DW_OP_breg20: | |
456 | case DW_OP_breg21: | |
457 | case DW_OP_breg22: | |
458 | case DW_OP_breg23: | |
459 | case DW_OP_breg24: | |
460 | case DW_OP_breg25: | |
461 | case DW_OP_breg26: | |
462 | case DW_OP_breg27: | |
463 | case DW_OP_breg28: | |
464 | case DW_OP_breg29: | |
465 | case DW_OP_breg30: | |
466 | case DW_OP_breg31: | |
467 | { | |
468 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); | |
61fbb938 | 469 | result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0); |
4c2df51b DJ |
470 | result += offset; |
471 | } | |
472 | break; | |
473 | case DW_OP_bregx: | |
474 | { | |
475 | op_ptr = read_uleb128 (op_ptr, op_end, ®); | |
476 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); | |
61fbb938 | 477 | result = (ctx->read_reg) (ctx->baton, reg); |
4c2df51b DJ |
478 | result += offset; |
479 | } | |
480 | break; | |
481 | case DW_OP_fbreg: | |
482 | { | |
852483bc | 483 | gdb_byte *datastart; |
4c2df51b DJ |
484 | size_t datalen; |
485 | unsigned int before_stack_len; | |
486 | ||
487 | op_ptr = read_sleb128 (op_ptr, op_end, &offset); | |
488 | /* Rather than create a whole new context, we simply | |
489 | record the stack length before execution, then reset it | |
490 | afterwards, effectively erasing whatever the recursive | |
491 | call put there. */ | |
492 | before_stack_len = ctx->stack_len; | |
da62e633 AC |
493 | /* FIXME: cagney/2003-03-26: This code should be using |
494 | get_frame_base_address(), and then implement a dwarf2 | |
495 | specific this_base method. */ | |
4c2df51b DJ |
496 | (ctx->get_frame_base) (ctx->baton, &datastart, &datalen); |
497 | dwarf_expr_eval (ctx, datastart, datalen); | |
498 | result = dwarf_expr_fetch (ctx, 0); | |
61fbb938 DJ |
499 | if (ctx->in_reg) |
500 | result = (ctx->read_reg) (ctx->baton, result); | |
4c2df51b DJ |
501 | result = result + offset; |
502 | ctx->stack_len = before_stack_len; | |
503 | ctx->in_reg = 0; | |
504 | } | |
505 | break; | |
506 | case DW_OP_dup: | |
507 | result = dwarf_expr_fetch (ctx, 0); | |
508 | break; | |
509 | ||
510 | case DW_OP_drop: | |
511 | dwarf_expr_pop (ctx); | |
512 | goto no_push; | |
513 | ||
514 | case DW_OP_pick: | |
515 | offset = *op_ptr++; | |
516 | result = dwarf_expr_fetch (ctx, offset); | |
517 | break; | |
518 | ||
519 | case DW_OP_over: | |
520 | result = dwarf_expr_fetch (ctx, 1); | |
521 | break; | |
522 | ||
523 | case DW_OP_rot: | |
524 | { | |
525 | CORE_ADDR t1, t2, t3; | |
526 | ||
527 | if (ctx->stack_len < 3) | |
8a3fe4f8 | 528 | error (_("Not enough elements for DW_OP_rot. Need 3, have %d."), |
4c2df51b DJ |
529 | ctx->stack_len); |
530 | t1 = ctx->stack[ctx->stack_len - 1]; | |
531 | t2 = ctx->stack[ctx->stack_len - 2]; | |
532 | t3 = ctx->stack[ctx->stack_len - 3]; | |
533 | ctx->stack[ctx->stack_len - 1] = t2; | |
534 | ctx->stack[ctx->stack_len - 2] = t3; | |
535 | ctx->stack[ctx->stack_len - 3] = t1; | |
536 | goto no_push; | |
537 | } | |
538 | ||
539 | case DW_OP_deref: | |
540 | case DW_OP_deref_size: | |
541 | case DW_OP_abs: | |
542 | case DW_OP_neg: | |
543 | case DW_OP_not: | |
544 | case DW_OP_plus_uconst: | |
545 | /* Unary operations. */ | |
546 | result = dwarf_expr_fetch (ctx, 0); | |
547 | dwarf_expr_pop (ctx); | |
548 | ||
549 | switch (op) | |
550 | { | |
551 | case DW_OP_deref: | |
552 | { | |
17a912b6 UW |
553 | gdb_byte *buf = alloca (gdbarch_addr_bit (current_gdbarch) |
554 | / TARGET_CHAR_BIT); | |
4c2df51b DJ |
555 | int bytes_read; |
556 | ||
557 | (ctx->read_mem) (ctx->baton, buf, result, | |
17a912b6 UW |
558 | gdbarch_addr_bit (current_gdbarch) |
559 | / TARGET_CHAR_BIT); | |
0d53c4c4 | 560 | result = dwarf2_read_address (buf, |
17a912b6 UW |
561 | buf + (gdbarch_addr_bit |
562 | (current_gdbarch) | |
0d53c4c4 DJ |
563 | / TARGET_CHAR_BIT), |
564 | &bytes_read); | |
4c2df51b DJ |
565 | } |
566 | break; | |
567 | ||
568 | case DW_OP_deref_size: | |
569 | { | |
17a912b6 UW |
570 | gdb_byte *buf |
571 | = alloca (gdbarch_addr_bit (current_gdbarch) | |
572 | / TARGET_CHAR_BIT); | |
4c2df51b DJ |
573 | int bytes_read; |
574 | ||
575 | (ctx->read_mem) (ctx->baton, buf, result, *op_ptr++); | |
0d53c4c4 | 576 | result = dwarf2_read_address (buf, |
17a912b6 UW |
577 | buf + (gdbarch_addr_bit |
578 | (current_gdbarch) | |
0d53c4c4 DJ |
579 | / TARGET_CHAR_BIT), |
580 | &bytes_read); | |
4c2df51b DJ |
581 | } |
582 | break; | |
583 | ||
584 | case DW_OP_abs: | |
585 | if ((signed int) result < 0) | |
586 | result = -result; | |
587 | break; | |
588 | case DW_OP_neg: | |
589 | result = -result; | |
590 | break; | |
591 | case DW_OP_not: | |
592 | result = ~result; | |
593 | break; | |
594 | case DW_OP_plus_uconst: | |
595 | op_ptr = read_uleb128 (op_ptr, op_end, ®); | |
596 | result += reg; | |
597 | break; | |
598 | } | |
599 | break; | |
600 | ||
601 | case DW_OP_and: | |
602 | case DW_OP_div: | |
603 | case DW_OP_minus: | |
604 | case DW_OP_mod: | |
605 | case DW_OP_mul: | |
606 | case DW_OP_or: | |
607 | case DW_OP_plus: | |
608 | case DW_OP_shl: | |
609 | case DW_OP_shr: | |
610 | case DW_OP_shra: | |
611 | case DW_OP_xor: | |
612 | case DW_OP_le: | |
613 | case DW_OP_ge: | |
614 | case DW_OP_eq: | |
615 | case DW_OP_lt: | |
616 | case DW_OP_gt: | |
617 | case DW_OP_ne: | |
618 | { | |
619 | /* Binary operations. Use the value engine to do computations in | |
620 | the right width. */ | |
621 | CORE_ADDR first, second; | |
622 | enum exp_opcode binop; | |
623 | struct value *val1, *val2; | |
624 | ||
625 | second = dwarf_expr_fetch (ctx, 0); | |
626 | dwarf_expr_pop (ctx); | |
627 | ||
b263358a | 628 | first = dwarf_expr_fetch (ctx, 0); |
4c2df51b DJ |
629 | dwarf_expr_pop (ctx); |
630 | ||
631 | val1 = value_from_longest (unsigned_address_type (), first); | |
632 | val2 = value_from_longest (unsigned_address_type (), second); | |
633 | ||
634 | switch (op) | |
635 | { | |
636 | case DW_OP_and: | |
637 | binop = BINOP_BITWISE_AND; | |
638 | break; | |
639 | case DW_OP_div: | |
640 | binop = BINOP_DIV; | |
99c87dab | 641 | break; |
4c2df51b DJ |
642 | case DW_OP_minus: |
643 | binop = BINOP_SUB; | |
644 | break; | |
645 | case DW_OP_mod: | |
646 | binop = BINOP_MOD; | |
647 | break; | |
648 | case DW_OP_mul: | |
649 | binop = BINOP_MUL; | |
650 | break; | |
651 | case DW_OP_or: | |
652 | binop = BINOP_BITWISE_IOR; | |
653 | break; | |
654 | case DW_OP_plus: | |
655 | binop = BINOP_ADD; | |
656 | break; | |
657 | case DW_OP_shl: | |
658 | binop = BINOP_LSH; | |
659 | break; | |
660 | case DW_OP_shr: | |
661 | binop = BINOP_RSH; | |
99c87dab | 662 | break; |
4c2df51b DJ |
663 | case DW_OP_shra: |
664 | binop = BINOP_RSH; | |
665 | val1 = value_from_longest (signed_address_type (), first); | |
666 | break; | |
667 | case DW_OP_xor: | |
668 | binop = BINOP_BITWISE_XOR; | |
669 | break; | |
670 | case DW_OP_le: | |
671 | binop = BINOP_LEQ; | |
672 | break; | |
673 | case DW_OP_ge: | |
674 | binop = BINOP_GEQ; | |
675 | break; | |
676 | case DW_OP_eq: | |
677 | binop = BINOP_EQUAL; | |
678 | break; | |
679 | case DW_OP_lt: | |
680 | binop = BINOP_LESS; | |
681 | break; | |
682 | case DW_OP_gt: | |
683 | binop = BINOP_GTR; | |
684 | break; | |
685 | case DW_OP_ne: | |
686 | binop = BINOP_NOTEQUAL; | |
687 | break; | |
688 | default: | |
689 | internal_error (__FILE__, __LINE__, | |
e2e0b3e5 | 690 | _("Can't be reached.")); |
4c2df51b DJ |
691 | } |
692 | result = value_as_long (value_binop (val1, val2, binop)); | |
693 | } | |
694 | break; | |
695 | ||
696 | case DW_OP_GNU_push_tls_address: | |
c3228f12 EZ |
697 | /* Variable is at a constant offset in the thread-local |
698 | storage block into the objfile for the current thread and | |
699 | the dynamic linker module containing this expression. Here | |
700 | we return returns the offset from that base. The top of the | |
701 | stack has the offset from the beginning of the thread | |
702 | control block at which the variable is located. Nothing | |
703 | should follow this operator, so the top of stack would be | |
704 | returned. */ | |
4c2df51b DJ |
705 | result = dwarf_expr_fetch (ctx, 0); |
706 | dwarf_expr_pop (ctx); | |
707 | result = (ctx->get_tls_address) (ctx->baton, result); | |
708 | break; | |
709 | ||
710 | case DW_OP_skip: | |
711 | offset = extract_signed_integer (op_ptr, 2); | |
712 | op_ptr += 2; | |
713 | op_ptr += offset; | |
714 | goto no_push; | |
715 | ||
716 | case DW_OP_bra: | |
717 | offset = extract_signed_integer (op_ptr, 2); | |
718 | op_ptr += 2; | |
719 | if (dwarf_expr_fetch (ctx, 0) != 0) | |
720 | op_ptr += offset; | |
721 | dwarf_expr_pop (ctx); | |
722 | goto no_push; | |
723 | ||
724 | case DW_OP_nop: | |
725 | goto no_push; | |
726 | ||
87808bd6 JB |
727 | case DW_OP_piece: |
728 | { | |
729 | ULONGEST size; | |
730 | CORE_ADDR addr_or_regnum; | |
731 | ||
732 | /* Record the piece. */ | |
733 | op_ptr = read_uleb128 (op_ptr, op_end, &size); | |
734 | addr_or_regnum = dwarf_expr_fetch (ctx, 0); | |
735 | add_piece (ctx, ctx->in_reg, addr_or_regnum, size); | |
736 | ||
737 | /* Pop off the address/regnum, and clear the in_reg flag. */ | |
738 | dwarf_expr_pop (ctx); | |
739 | ctx->in_reg = 0; | |
740 | } | |
741 | goto no_push; | |
742 | ||
42be36b3 CT |
743 | case DW_OP_GNU_uninit: |
744 | if (op_ptr != op_end) | |
745 | error (_("DWARF-2 expression error: DW_OP_GNU_unint must always " | |
746 | "be the very last op.")); | |
747 | ||
748 | ctx->initialized = 0; | |
749 | goto no_push; | |
750 | ||
4c2df51b | 751 | default: |
8a3fe4f8 | 752 | error (_("Unhandled dwarf expression opcode 0x%x"), op); |
4c2df51b DJ |
753 | } |
754 | ||
755 | /* Most things push a result value. */ | |
756 | dwarf_expr_push (ctx, result); | |
757 | no_push:; | |
758 | } | |
759 | } |