2012-05-18 Sergio Durigan Junior <sergiodj@redhat.com>
[deliverable/binutils-gdb.git] / gdb / dwarf2expr.c
CommitLineData
852483bc
MK
1/* DWARF 2 Expression Evaluator.
2
0b302171
JB
3 Copyright (C) 2001-2003, 2005, 2007-2012 Free Software Foundation,
4 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"
fa8f86ff 28#include "dwarf2.h"
4c2df51b 29#include "dwarf2expr.h"
1e3a102a 30#include "gdb_assert.h"
4c2df51b
DJ
31
32/* Local prototypes. */
33
34static void execute_stack_op (struct dwarf_expr_context *,
0d45f56e 35 const gdb_byte *, const gdb_byte *);
4c2df51b 36
8a9b8146
TT
37/* Cookie for gdbarch data. */
38
39static struct gdbarch_data *dwarf_arch_cookie;
40
41/* This holds gdbarch-specific types used by the DWARF expression
42 evaluator. See comments in execute_stack_op. */
43
44struct dwarf_gdbarch_types
45{
46 struct type *dw_types[3];
47};
48
49/* Allocate and fill in dwarf_gdbarch_types for an arch. */
50
51static void *
52dwarf_gdbarch_types_init (struct gdbarch *gdbarch)
53{
54 struct dwarf_gdbarch_types *types
55 = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct dwarf_gdbarch_types);
56
57 /* The types themselves are lazily initialized. */
58
59 return types;
60}
61
62/* Return the type used for DWARF operations where the type is
63 unspecified in the DWARF spec. Only certain sizes are
64 supported. */
65
66static struct type *
67dwarf_expr_address_type (struct dwarf_expr_context *ctx)
68{
69 struct dwarf_gdbarch_types *types = gdbarch_data (ctx->gdbarch,
70 dwarf_arch_cookie);
71 int ndx;
72
73 if (ctx->addr_size == 2)
74 ndx = 0;
75 else if (ctx->addr_size == 4)
76 ndx = 1;
77 else if (ctx->addr_size == 8)
78 ndx = 2;
79 else
80 error (_("Unsupported address size in DWARF expressions: %d bits"),
81 8 * ctx->addr_size);
82
83 if (types->dw_types[ndx] == NULL)
84 types->dw_types[ndx]
85 = arch_integer_type (ctx->gdbarch,
86 8 * ctx->addr_size,
87 0, "<signed DWARF address type>");
88
89 return types->dw_types[ndx];
90}
91
4c2df51b
DJ
92/* Create a new context for the expression evaluator. */
93
94struct dwarf_expr_context *
e4adbba9 95new_dwarf_expr_context (void)
4c2df51b
DJ
96{
97 struct dwarf_expr_context *retval;
9a619af0 98
4c2df51b 99 retval = xcalloc (1, sizeof (struct dwarf_expr_context));
18ec9831
KB
100 retval->stack_len = 0;
101 retval->stack_allocated = 10;
b966cb8a
TT
102 retval->stack = xmalloc (retval->stack_allocated
103 * sizeof (struct dwarf_stack_value));
87808bd6
JB
104 retval->num_pieces = 0;
105 retval->pieces = 0;
1e3a102a 106 retval->max_recursion_depth = 0x100;
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DJ
107 return retval;
108}
109
110/* Release the memory allocated to CTX. */
111
112void
113free_dwarf_expr_context (struct dwarf_expr_context *ctx)
114{
115 xfree (ctx->stack);
87808bd6 116 xfree (ctx->pieces);
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DJ
117 xfree (ctx);
118}
119
4a227398
TT
120/* Helper for make_cleanup_free_dwarf_expr_context. */
121
122static void
123free_dwarf_expr_context_cleanup (void *arg)
124{
125 free_dwarf_expr_context (arg);
126}
127
128/* Return a cleanup that calls free_dwarf_expr_context. */
129
130struct cleanup *
131make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx)
132{
133 return make_cleanup (free_dwarf_expr_context_cleanup, ctx);
134}
135
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DJ
136/* Expand the memory allocated to CTX's stack to contain at least
137 NEED more elements than are currently used. */
138
139static void
140dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need)
141{
142 if (ctx->stack_len + need > ctx->stack_allocated)
143 {
18ec9831 144 size_t newlen = ctx->stack_len + need + 10;
9a619af0 145
4c2df51b 146 ctx->stack = xrealloc (ctx->stack,
44353522 147 newlen * sizeof (struct dwarf_stack_value));
18ec9831 148 ctx->stack_allocated = newlen;
4c2df51b
DJ
149 }
150}
151
152/* Push VALUE onto CTX's stack. */
153
8a9b8146
TT
154static void
155dwarf_expr_push (struct dwarf_expr_context *ctx, struct value *value,
44353522 156 int in_stack_memory)
4c2df51b 157{
44353522
DE
158 struct dwarf_stack_value *v;
159
4c2df51b 160 dwarf_expr_grow_stack (ctx, 1);
44353522
DE
161 v = &ctx->stack[ctx->stack_len++];
162 v->value = value;
163 v->in_stack_memory = in_stack_memory;
4c2df51b
DJ
164}
165
8a9b8146 166/* Push VALUE onto CTX's stack. */
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DJ
167
168void
8a9b8146
TT
169dwarf_expr_push_address (struct dwarf_expr_context *ctx, CORE_ADDR value,
170 int in_stack_memory)
171{
172 dwarf_expr_push (ctx,
173 value_from_ulongest (dwarf_expr_address_type (ctx), value),
174 in_stack_memory);
175}
176
177/* Pop the top item off of CTX's stack. */
178
179static void
4c2df51b
DJ
180dwarf_expr_pop (struct dwarf_expr_context *ctx)
181{
182 if (ctx->stack_len <= 0)
8a3fe4f8 183 error (_("dwarf expression stack underflow"));
4c2df51b
DJ
184 ctx->stack_len--;
185}
186
187/* Retrieve the N'th item on CTX's stack. */
188
8a9b8146 189struct value *
4c2df51b
DJ
190dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n)
191{
ef0fdf07 192 if (ctx->stack_len <= n)
3e43a32a
MS
193 error (_("Asked for position %d of stack, "
194 "stack only has %d elements on it."),
4c2df51b 195 n, ctx->stack_len);
44353522 196 return ctx->stack[ctx->stack_len - (1 + n)].value;
8a9b8146
TT
197}
198
199/* Require that TYPE be an integral type; throw an exception if not. */
44353522 200
8a9b8146
TT
201static void
202dwarf_require_integral (struct type *type)
203{
204 if (TYPE_CODE (type) != TYPE_CODE_INT
205 && TYPE_CODE (type) != TYPE_CODE_CHAR
206 && TYPE_CODE (type) != TYPE_CODE_BOOL)
207 error (_("integral type expected in DWARF expression"));
208}
209
210/* Return the unsigned form of TYPE. TYPE is necessarily an integral
211 type. */
212
213static struct type *
214get_unsigned_type (struct gdbarch *gdbarch, struct type *type)
215{
216 switch (TYPE_LENGTH (type))
217 {
218 case 1:
219 return builtin_type (gdbarch)->builtin_uint8;
220 case 2:
221 return builtin_type (gdbarch)->builtin_uint16;
222 case 4:
223 return builtin_type (gdbarch)->builtin_uint32;
224 case 8:
225 return builtin_type (gdbarch)->builtin_uint64;
226 default:
227 error (_("no unsigned variant found for type, while evaluating "
228 "DWARF expression"));
229 }
44353522
DE
230}
231
8ddd9a20
TT
232/* Return the signed form of TYPE. TYPE is necessarily an integral
233 type. */
234
235static struct type *
236get_signed_type (struct gdbarch *gdbarch, struct type *type)
237{
238 switch (TYPE_LENGTH (type))
239 {
240 case 1:
241 return builtin_type (gdbarch)->builtin_int8;
242 case 2:
243 return builtin_type (gdbarch)->builtin_int16;
244 case 4:
245 return builtin_type (gdbarch)->builtin_int32;
246 case 8:
247 return builtin_type (gdbarch)->builtin_int64;
248 default:
249 error (_("no signed variant found for type, while evaluating "
250 "DWARF expression"));
251 }
252}
253
f2c7657e
UW
254/* Retrieve the N'th item on CTX's stack, converted to an address. */
255
256CORE_ADDR
257dwarf_expr_fetch_address (struct dwarf_expr_context *ctx, int n)
258{
8a9b8146
TT
259 struct value *result_val = dwarf_expr_fetch (ctx, n);
260 enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
261 ULONGEST result;
262
263 dwarf_require_integral (value_type (result_val));
264 result = extract_unsigned_integer (value_contents (result_val),
265 TYPE_LENGTH (value_type (result_val)),
266 byte_order);
f2c7657e
UW
267
268 /* For most architectures, calling extract_unsigned_integer() alone
269 is sufficient for extracting an address. However, some
270 architectures (e.g. MIPS) use signed addresses and using
271 extract_unsigned_integer() will not produce a correct
272 result. Make sure we invoke gdbarch_integer_to_address()
273 for those architectures which require it. */
274 if (gdbarch_integer_to_address_p (ctx->gdbarch))
275 {
f2c7657e 276 gdb_byte *buf = alloca (ctx->addr_size);
8a9b8146
TT
277 struct type *int_type = get_unsigned_type (ctx->gdbarch,
278 value_type (result_val));
f2c7657e
UW
279
280 store_unsigned_integer (buf, ctx->addr_size, byte_order, result);
281 return gdbarch_integer_to_address (ctx->gdbarch, int_type, buf);
282 }
283
284 return (CORE_ADDR) result;
285}
286
44353522
DE
287/* Retrieve the in_stack_memory flag of the N'th item on CTX's stack. */
288
289int
290dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n)
291{
292 if (ctx->stack_len <= n)
3e43a32a
MS
293 error (_("Asked for position %d of stack, "
294 "stack only has %d elements on it."),
44353522
DE
295 n, ctx->stack_len);
296 return ctx->stack[ctx->stack_len - (1 + n)].in_stack_memory;
4c2df51b
DJ
297}
298
cb826367
TT
299/* Return true if the expression stack is empty. */
300
301static int
302dwarf_expr_stack_empty_p (struct dwarf_expr_context *ctx)
303{
304 return ctx->stack_len == 0;
305}
306
87808bd6
JB
307/* Add a new piece to CTX's piece list. */
308static void
d3b1e874 309add_piece (struct dwarf_expr_context *ctx, ULONGEST size, ULONGEST offset)
87808bd6
JB
310{
311 struct dwarf_expr_piece *p;
312
313 ctx->num_pieces++;
314
d3b1e874
TT
315 ctx->pieces = xrealloc (ctx->pieces,
316 (ctx->num_pieces
317 * sizeof (struct dwarf_expr_piece)));
87808bd6
JB
318
319 p = &ctx->pieces[ctx->num_pieces - 1];
cec03d70 320 p->location = ctx->location;
87808bd6 321 p->size = size;
d3b1e874
TT
322 p->offset = offset;
323
cec03d70
TT
324 if (p->location == DWARF_VALUE_LITERAL)
325 {
326 p->v.literal.data = ctx->data;
327 p->v.literal.length = ctx->len;
328 }
cb826367
TT
329 else if (dwarf_expr_stack_empty_p (ctx))
330 {
331 p->location = DWARF_VALUE_OPTIMIZED_OUT;
332 /* Also reset the context's location, for our callers. This is
333 a somewhat strange approach, but this lets us avoid setting
334 the location to DWARF_VALUE_MEMORY in all the individual
335 cases in the evaluator. */
336 ctx->location = DWARF_VALUE_OPTIMIZED_OUT;
337 }
f2c7657e
UW
338 else if (p->location == DWARF_VALUE_MEMORY)
339 {
340 p->v.mem.addr = dwarf_expr_fetch_address (ctx, 0);
341 p->v.mem.in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
342 }
8cf6f0b1
TT
343 else if (p->location == DWARF_VALUE_IMPLICIT_POINTER)
344 {
b64f50a1 345 p->v.ptr.die.cu_off = ctx->len;
8a9b8146 346 p->v.ptr.offset = value_as_long (dwarf_expr_fetch (ctx, 0));
8cf6f0b1 347 }
8a9b8146
TT
348 else if (p->location == DWARF_VALUE_REGISTER)
349 p->v.regno = value_as_long (dwarf_expr_fetch (ctx, 0));
cec03d70 350 else
44353522 351 {
f2c7657e 352 p->v.value = dwarf_expr_fetch (ctx, 0);
44353522 353 }
87808bd6
JB
354}
355
4c2df51b
DJ
356/* Evaluate the expression at ADDR (LEN bytes long) using the context
357 CTX. */
358
359void
0d45f56e
TT
360dwarf_expr_eval (struct dwarf_expr_context *ctx, const gdb_byte *addr,
361 size_t len)
4c2df51b 362{
1e3a102a
JK
363 int old_recursion_depth = ctx->recursion_depth;
364
4c2df51b 365 execute_stack_op (ctx, addr, addr + len);
1e3a102a
JK
366
367 /* CTX RECURSION_DEPTH becomes invalid if an exception was thrown here. */
368
369 gdb_assert (ctx->recursion_depth == old_recursion_depth);
4c2df51b
DJ
370}
371
372/* Decode the unsigned LEB128 constant at BUF into the variable pointed to
373 by R, and return the new value of BUF. Verify that it doesn't extend
8e3b41a9 374 past BUF_END. R can be NULL, the constant is then only skipped. */
4c2df51b 375
0d45f56e
TT
376const gdb_byte *
377read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end, ULONGEST * r)
4c2df51b
DJ
378{
379 unsigned shift = 0;
380 ULONGEST result = 0;
852483bc 381 gdb_byte byte;
4c2df51b
DJ
382
383 while (1)
384 {
385 if (buf >= buf_end)
8a3fe4f8 386 error (_("read_uleb128: Corrupted DWARF expression."));
4c2df51b
DJ
387
388 byte = *buf++;
9930639c 389 result |= ((ULONGEST) (byte & 0x7f)) << shift;
4c2df51b
DJ
390 if ((byte & 0x80) == 0)
391 break;
392 shift += 7;
393 }
8e3b41a9
JK
394 if (r)
395 *r = result;
4c2df51b
DJ
396 return buf;
397}
398
399/* Decode the signed LEB128 constant at BUF into the variable pointed to
400 by R, and return the new value of BUF. Verify that it doesn't extend
8e3b41a9 401 past BUF_END. R can be NULL, the constant is then only skipped. */
4c2df51b 402
0d45f56e
TT
403const gdb_byte *
404read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end, LONGEST * r)
4c2df51b
DJ
405{
406 unsigned shift = 0;
407 LONGEST result = 0;
852483bc 408 gdb_byte byte;
4c2df51b
DJ
409
410 while (1)
411 {
412 if (buf >= buf_end)
8a3fe4f8 413 error (_("read_sleb128: Corrupted DWARF expression."));
4c2df51b
DJ
414
415 byte = *buf++;
9930639c 416 result |= ((ULONGEST) (byte & 0x7f)) << shift;
4c2df51b
DJ
417 shift += 7;
418 if ((byte & 0x80) == 0)
419 break;
420 }
421 if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0)
04ad99e6 422 result |= -(((LONGEST) 1) << shift);
4c2df51b 423
8e3b41a9
JK
424 if (r)
425 *r = result;
4c2df51b
DJ
426 return buf;
427}
4c2df51b 428\f
cec03d70
TT
429
430/* Check that the current operator is either at the end of an
431 expression, or that it is followed by a composition operator. */
432
3cf03773
TT
433void
434dwarf_expr_require_composition (const gdb_byte *op_ptr, const gdb_byte *op_end,
435 const char *op_name)
cec03d70
TT
436{
437 /* It seems like DW_OP_GNU_uninit should be handled here. However,
438 it doesn't seem to make sense for DW_OP_*_value, and it was not
439 checked at the other place that this function is called. */
440 if (op_ptr != op_end && *op_ptr != DW_OP_piece && *op_ptr != DW_OP_bit_piece)
441 error (_("DWARF-2 expression error: `%s' operations must be "
64b9b334 442 "used either alone or in conjunction with DW_OP_piece "
cec03d70
TT
443 "or DW_OP_bit_piece."),
444 op_name);
445}
446
8a9b8146
TT
447/* Return true iff the types T1 and T2 are "the same". This only does
448 checks that might reasonably be needed to compare DWARF base
449 types. */
450
451static int
452base_types_equal_p (struct type *t1, struct type *t2)
453{
454 if (TYPE_CODE (t1) != TYPE_CODE (t2))
455 return 0;
456 if (TYPE_UNSIGNED (t1) != TYPE_UNSIGNED (t2))
457 return 0;
458 return TYPE_LENGTH (t1) == TYPE_LENGTH (t2);
459}
460
461/* A convenience function to call get_base_type on CTX and return the
462 result. DIE is the DIE whose type we need. SIZE is non-zero if
463 this function should verify that the resulting type has the correct
464 size. */
465
466static struct type *
b64f50a1 467dwarf_get_base_type (struct dwarf_expr_context *ctx, cu_offset die, int size)
8a9b8146
TT
468{
469 struct type *result;
470
9e8b7a03 471 if (ctx->funcs->get_base_type)
8a9b8146 472 {
9e8b7a03 473 result = ctx->funcs->get_base_type (ctx, die);
9ff3b74f
TT
474 if (result == NULL)
475 error (_("Could not find type for DW_OP_GNU_const_type"));
8a9b8146
TT
476 if (size != 0 && TYPE_LENGTH (result) != size)
477 error (_("DW_OP_GNU_const_type has different sizes for type and data"));
478 }
479 else
480 /* Anything will do. */
481 result = builtin_type (ctx->gdbarch)->builtin_int;
482
483 return result;
484}
485
8e3b41a9
JK
486/* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_reg* return the
487 DWARF register number. Otherwise return -1. */
488
489int
490dwarf_block_to_dwarf_reg (const gdb_byte *buf, const gdb_byte *buf_end)
491{
492 ULONGEST dwarf_reg;
493
494 if (buf_end <= buf)
495 return -1;
496 if (*buf >= DW_OP_reg0 && *buf <= DW_OP_reg31)
497 {
498 if (buf_end - buf != 1)
499 return -1;
500 return *buf - DW_OP_reg0;
501 }
502
503 if (*buf == DW_OP_GNU_regval_type)
504 {
505 buf++;
506 buf = read_uleb128 (buf, buf_end, &dwarf_reg);
507 buf = read_uleb128 (buf, buf_end, NULL);
508 }
509 else if (*buf == DW_OP_regx)
510 {
511 buf++;
512 buf = read_uleb128 (buf, buf_end, &dwarf_reg);
513 }
514 else
515 return -1;
516 if (buf != buf_end || (int) dwarf_reg != dwarf_reg)
517 return -1;
518 return dwarf_reg;
519}
520
a471c594
JK
521/* If <BUF..BUF_END] contains DW_FORM_block* with just DW_OP_breg*(0) and
522 DW_OP_deref* return the DWARF register number. Otherwise return -1.
523 DEREF_SIZE_RETURN contains -1 for DW_OP_deref; otherwise it contains the
524 size from DW_OP_deref_size. */
525
526int
527dwarf_block_to_dwarf_reg_deref (const gdb_byte *buf, const gdb_byte *buf_end,
528 CORE_ADDR *deref_size_return)
529{
530 ULONGEST dwarf_reg;
531 LONGEST offset;
532
533 if (buf_end <= buf)
534 return -1;
535 if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31)
536 {
537 dwarf_reg = *buf - DW_OP_breg0;
538 buf++;
539 }
540 else if (*buf == DW_OP_bregx)
541 {
542 buf++;
543 buf = read_uleb128 (buf, buf_end, &dwarf_reg);
544 if ((int) dwarf_reg != dwarf_reg)
545 return -1;
546 }
547 else
548 return -1;
549
550 buf = read_sleb128 (buf, buf_end, &offset);
551 if (offset != 0)
552 return -1;
553
554 if (buf >= buf_end)
555 return -1;
556
557 if (*buf == DW_OP_deref)
558 {
559 buf++;
560 *deref_size_return = -1;
561 }
562 else if (*buf == DW_OP_deref_size)
563 {
564 buf++;
565 if (buf >= buf_end)
566 return -1;
567 *deref_size_return = *buf++;
568 }
569 else
570 return -1;
571
572 if (buf != buf_end)
573 return -1;
574
575 return dwarf_reg;
576}
577
e18b2753
JK
578/* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_fbreg(X) fill
579 in FB_OFFSET_RETURN with the X offset and return 1. Otherwise return 0. */
580
581int
582dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end,
583 CORE_ADDR *fb_offset_return)
584{
585 LONGEST fb_offset;
586
587 if (buf_end <= buf)
588 return 0;
589
590 if (*buf != DW_OP_fbreg)
591 return 0;
592 buf++;
593
594 buf = read_sleb128 (buf, buf_end, &fb_offset);
595 *fb_offset_return = fb_offset;
596 if (buf != buf_end || fb_offset != (LONGEST) *fb_offset_return)
597 return 0;
598
599 return 1;
600}
601
602/* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_bregSP(X) fill
603 in SP_OFFSET_RETURN with the X offset and return 1. Otherwise return 0.
604 The matched SP register number depends on GDBARCH. */
605
606int
607dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf,
608 const gdb_byte *buf_end, CORE_ADDR *sp_offset_return)
609{
610 ULONGEST dwarf_reg;
611 LONGEST sp_offset;
612
613 if (buf_end <= buf)
614 return 0;
615 if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31)
616 {
617 dwarf_reg = *buf - DW_OP_breg0;
618 buf++;
619 }
620 else
621 {
622 if (*buf != DW_OP_bregx)
623 return 0;
624 buf++;
625 buf = read_uleb128 (buf, buf_end, &dwarf_reg);
626 }
627
628 if (gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_reg)
629 != gdbarch_sp_regnum (gdbarch))
630 return 0;
631
632 buf = read_sleb128 (buf, buf_end, &sp_offset);
633 *sp_offset_return = sp_offset;
634 if (buf != buf_end || sp_offset != (LONGEST) *sp_offset_return)
635 return 0;
636
637 return 1;
638}
639
4c2df51b
DJ
640/* The engine for the expression evaluator. Using the context in CTX,
641 evaluate the expression between OP_PTR and OP_END. */
642
643static void
852483bc 644execute_stack_op (struct dwarf_expr_context *ctx,
0d45f56e 645 const gdb_byte *op_ptr, const gdb_byte *op_end)
4c2df51b 646{
e17a4113 647 enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
8a9b8146
TT
648 /* Old-style "untyped" DWARF values need special treatment in a
649 couple of places, specifically DW_OP_mod and DW_OP_shr. We need
650 a special type for these values so we can distinguish them from
651 values that have an explicit type, because explicitly-typed
652 values do not need special treatment. This special type must be
653 different (in the `==' sense) from any base type coming from the
654 CU. */
655 struct type *address_type = dwarf_expr_address_type (ctx);
9a619af0 656
cec03d70 657 ctx->location = DWARF_VALUE_MEMORY;
42be36b3 658 ctx->initialized = 1; /* Default is initialized. */
18ec9831 659
1e3a102a
JK
660 if (ctx->recursion_depth > ctx->max_recursion_depth)
661 error (_("DWARF-2 expression error: Loop detected (%d)."),
662 ctx->recursion_depth);
663 ctx->recursion_depth++;
664
4c2df51b
DJ
665 while (op_ptr < op_end)
666 {
667 enum dwarf_location_atom op = *op_ptr++;
f2c7657e 668 ULONGEST result;
44353522
DE
669 /* Assume the value is not in stack memory.
670 Code that knows otherwise sets this to 1.
671 Some arithmetic on stack addresses can probably be assumed to still
672 be a stack address, but we skip this complication for now.
673 This is just an optimization, so it's always ok to punt
674 and leave this as 0. */
675 int in_stack_memory = 0;
4c2df51b
DJ
676 ULONGEST uoffset, reg;
677 LONGEST offset;
8a9b8146 678 struct value *result_val = NULL;
4c2df51b 679
e0e9434c
TT
680 /* The DWARF expression might have a bug causing an infinite
681 loop. In that case, quitting is the only way out. */
682 QUIT;
683
4c2df51b
DJ
684 switch (op)
685 {
686 case DW_OP_lit0:
687 case DW_OP_lit1:
688 case DW_OP_lit2:
689 case DW_OP_lit3:
690 case DW_OP_lit4:
691 case DW_OP_lit5:
692 case DW_OP_lit6:
693 case DW_OP_lit7:
694 case DW_OP_lit8:
695 case DW_OP_lit9:
696 case DW_OP_lit10:
697 case DW_OP_lit11:
698 case DW_OP_lit12:
699 case DW_OP_lit13:
700 case DW_OP_lit14:
701 case DW_OP_lit15:
702 case DW_OP_lit16:
703 case DW_OP_lit17:
704 case DW_OP_lit18:
705 case DW_OP_lit19:
706 case DW_OP_lit20:
707 case DW_OP_lit21:
708 case DW_OP_lit22:
709 case DW_OP_lit23:
710 case DW_OP_lit24:
711 case DW_OP_lit25:
712 case DW_OP_lit26:
713 case DW_OP_lit27:
714 case DW_OP_lit28:
715 case DW_OP_lit29:
716 case DW_OP_lit30:
717 case DW_OP_lit31:
718 result = op - DW_OP_lit0;
8a9b8146 719 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
720 break;
721
722 case DW_OP_addr:
f2c7657e
UW
723 result = extract_unsigned_integer (op_ptr,
724 ctx->addr_size, byte_order);
ae0d2f24 725 op_ptr += ctx->addr_size;
ac56253d
TT
726 /* Some versions of GCC emit DW_OP_addr before
727 DW_OP_GNU_push_tls_address. In this case the value is an
728 index, not an address. We don't support things like
729 branching between the address and the TLS op. */
730 if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
731 result += ctx->offset;
8a9b8146 732 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
733 break;
734
3019eac3
DE
735 case DW_OP_GNU_addr_index:
736 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
737 result = (ctx->funcs->get_addr_index) (ctx->baton, uoffset);
738 result_val = value_from_ulongest (address_type, result);
739 break;
740
4c2df51b 741 case DW_OP_const1u:
e17a4113 742 result = extract_unsigned_integer (op_ptr, 1, byte_order);
8a9b8146 743 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
744 op_ptr += 1;
745 break;
746 case DW_OP_const1s:
e17a4113 747 result = extract_signed_integer (op_ptr, 1, byte_order);
8a9b8146 748 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
749 op_ptr += 1;
750 break;
751 case DW_OP_const2u:
e17a4113 752 result = extract_unsigned_integer (op_ptr, 2, byte_order);
8a9b8146 753 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
754 op_ptr += 2;
755 break;
756 case DW_OP_const2s:
e17a4113 757 result = extract_signed_integer (op_ptr, 2, byte_order);
8a9b8146 758 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
759 op_ptr += 2;
760 break;
761 case DW_OP_const4u:
e17a4113 762 result = extract_unsigned_integer (op_ptr, 4, byte_order);
8a9b8146 763 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
764 op_ptr += 4;
765 break;
766 case DW_OP_const4s:
e17a4113 767 result = extract_signed_integer (op_ptr, 4, byte_order);
8a9b8146 768 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
769 op_ptr += 4;
770 break;
771 case DW_OP_const8u:
e17a4113 772 result = extract_unsigned_integer (op_ptr, 8, byte_order);
8a9b8146 773 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
774 op_ptr += 8;
775 break;
776 case DW_OP_const8s:
e17a4113 777 result = extract_signed_integer (op_ptr, 8, byte_order);
8a9b8146 778 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
779 op_ptr += 8;
780 break;
781 case DW_OP_constu:
782 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
783 result = uoffset;
8a9b8146 784 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
785 break;
786 case DW_OP_consts:
787 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
788 result = offset;
8a9b8146 789 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
790 break;
791
792 /* The DW_OP_reg operations are required to occur alone in
793 location expressions. */
794 case DW_OP_reg0:
795 case DW_OP_reg1:
796 case DW_OP_reg2:
797 case DW_OP_reg3:
798 case DW_OP_reg4:
799 case DW_OP_reg5:
800 case DW_OP_reg6:
801 case DW_OP_reg7:
802 case DW_OP_reg8:
803 case DW_OP_reg9:
804 case DW_OP_reg10:
805 case DW_OP_reg11:
806 case DW_OP_reg12:
807 case DW_OP_reg13:
808 case DW_OP_reg14:
809 case DW_OP_reg15:
810 case DW_OP_reg16:
811 case DW_OP_reg17:
812 case DW_OP_reg18:
813 case DW_OP_reg19:
814 case DW_OP_reg20:
815 case DW_OP_reg21:
816 case DW_OP_reg22:
817 case DW_OP_reg23:
818 case DW_OP_reg24:
819 case DW_OP_reg25:
820 case DW_OP_reg26:
821 case DW_OP_reg27:
822 case DW_OP_reg28:
823 case DW_OP_reg29:
824 case DW_OP_reg30:
825 case DW_OP_reg31:
42be36b3
CT
826 if (op_ptr != op_end
827 && *op_ptr != DW_OP_piece
d3b1e874 828 && *op_ptr != DW_OP_bit_piece
42be36b3 829 && *op_ptr != DW_OP_GNU_uninit)
8a3fe4f8 830 error (_("DWARF-2 expression error: DW_OP_reg operations must be "
64b9b334 831 "used either alone or in conjunction with DW_OP_piece "
d3b1e874 832 "or DW_OP_bit_piece."));
4c2df51b 833
61fbb938 834 result = op - DW_OP_reg0;
8a9b8146 835 result_val = value_from_ulongest (address_type, result);
cec03d70 836 ctx->location = DWARF_VALUE_REGISTER;
4c2df51b
DJ
837 break;
838
839 case DW_OP_regx:
840 op_ptr = read_uleb128 (op_ptr, op_end, &reg);
3cf03773 841 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
4c2df51b 842
61fbb938 843 result = reg;
8a9b8146 844 result_val = value_from_ulongest (address_type, result);
cec03d70 845 ctx->location = DWARF_VALUE_REGISTER;
4c2df51b
DJ
846 break;
847
cec03d70
TT
848 case DW_OP_implicit_value:
849 {
850 ULONGEST len;
9a619af0 851
cec03d70
TT
852 op_ptr = read_uleb128 (op_ptr, op_end, &len);
853 if (op_ptr + len > op_end)
854 error (_("DW_OP_implicit_value: too few bytes available."));
855 ctx->len = len;
856 ctx->data = op_ptr;
857 ctx->location = DWARF_VALUE_LITERAL;
858 op_ptr += len;
3cf03773
TT
859 dwarf_expr_require_composition (op_ptr, op_end,
860 "DW_OP_implicit_value");
cec03d70
TT
861 }
862 goto no_push;
863
864 case DW_OP_stack_value:
865 ctx->location = DWARF_VALUE_STACK;
3cf03773 866 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
cec03d70
TT
867 goto no_push;
868
8cf6f0b1
TT
869 case DW_OP_GNU_implicit_pointer:
870 {
8cf6f0b1
TT
871 LONGEST len;
872
181cebd4
JK
873 if (ctx->ref_addr_size == -1)
874 error (_("DWARF-2 expression error: DW_OP_GNU_implicit_pointer "
875 "is not allowed in frame context"));
876
b64f50a1 877 /* The referred-to DIE of cu_offset kind. */
181cebd4 878 ctx->len = extract_unsigned_integer (op_ptr, ctx->ref_addr_size,
8cf6f0b1 879 byte_order);
181cebd4 880 op_ptr += ctx->ref_addr_size;
8cf6f0b1
TT
881
882 /* The byte offset into the data. */
883 op_ptr = read_sleb128 (op_ptr, op_end, &len);
884 result = (ULONGEST) len;
8a9b8146 885 result_val = value_from_ulongest (address_type, result);
8cf6f0b1
TT
886
887 ctx->location = DWARF_VALUE_IMPLICIT_POINTER;
888 dwarf_expr_require_composition (op_ptr, op_end,
889 "DW_OP_GNU_implicit_pointer");
890 }
891 break;
892
4c2df51b
DJ
893 case DW_OP_breg0:
894 case DW_OP_breg1:
895 case DW_OP_breg2:
896 case DW_OP_breg3:
897 case DW_OP_breg4:
898 case DW_OP_breg5:
899 case DW_OP_breg6:
900 case DW_OP_breg7:
901 case DW_OP_breg8:
902 case DW_OP_breg9:
903 case DW_OP_breg10:
904 case DW_OP_breg11:
905 case DW_OP_breg12:
906 case DW_OP_breg13:
907 case DW_OP_breg14:
908 case DW_OP_breg15:
909 case DW_OP_breg16:
910 case DW_OP_breg17:
911 case DW_OP_breg18:
912 case DW_OP_breg19:
913 case DW_OP_breg20:
914 case DW_OP_breg21:
915 case DW_OP_breg22:
916 case DW_OP_breg23:
917 case DW_OP_breg24:
918 case DW_OP_breg25:
919 case DW_OP_breg26:
920 case DW_OP_breg27:
921 case DW_OP_breg28:
922 case DW_OP_breg29:
923 case DW_OP_breg30:
924 case DW_OP_breg31:
925 {
926 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
9e8b7a03 927 result = (ctx->funcs->read_reg) (ctx->baton, op - DW_OP_breg0);
4c2df51b 928 result += offset;
8a9b8146 929 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
930 }
931 break;
932 case DW_OP_bregx:
933 {
934 op_ptr = read_uleb128 (op_ptr, op_end, &reg);
935 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
9e8b7a03 936 result = (ctx->funcs->read_reg) (ctx->baton, reg);
4c2df51b 937 result += offset;
8a9b8146 938 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
939 }
940 break;
941 case DW_OP_fbreg:
942 {
0d45f56e 943 const gdb_byte *datastart;
4c2df51b
DJ
944 size_t datalen;
945 unsigned int before_stack_len;
946
947 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
948 /* Rather than create a whole new context, we simply
949 record the stack length before execution, then reset it
950 afterwards, effectively erasing whatever the recursive
951 call put there. */
952 before_stack_len = ctx->stack_len;
da62e633
AC
953 /* FIXME: cagney/2003-03-26: This code should be using
954 get_frame_base_address(), and then implement a dwarf2
955 specific this_base method. */
9e8b7a03 956 (ctx->funcs->get_frame_base) (ctx->baton, &datastart, &datalen);
4c2df51b 957 dwarf_expr_eval (ctx, datastart, datalen);
f2c7657e
UW
958 if (ctx->location == DWARF_VALUE_MEMORY)
959 result = dwarf_expr_fetch_address (ctx, 0);
960 else if (ctx->location == DWARF_VALUE_REGISTER)
9e8b7a03
JK
961 result = (ctx->funcs->read_reg) (ctx->baton,
962 value_as_long (dwarf_expr_fetch (ctx, 0)));
f2c7657e 963 else
3e43a32a
MS
964 error (_("Not implemented: computing frame "
965 "base using explicit value operator"));
4c2df51b 966 result = result + offset;
8a9b8146 967 result_val = value_from_ulongest (address_type, result);
44353522 968 in_stack_memory = 1;
4c2df51b 969 ctx->stack_len = before_stack_len;
cec03d70 970 ctx->location = DWARF_VALUE_MEMORY;
4c2df51b
DJ
971 }
972 break;
44353522 973
4c2df51b 974 case DW_OP_dup:
8a9b8146 975 result_val = dwarf_expr_fetch (ctx, 0);
44353522 976 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
4c2df51b
DJ
977 break;
978
979 case DW_OP_drop:
980 dwarf_expr_pop (ctx);
981 goto no_push;
982
983 case DW_OP_pick:
984 offset = *op_ptr++;
8a9b8146 985 result_val = dwarf_expr_fetch (ctx, offset);
44353522 986 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, offset);
4c2df51b 987 break;
9f3fe11c
TG
988
989 case DW_OP_swap:
990 {
44353522 991 struct dwarf_stack_value t1, t2;
9f3fe11c
TG
992
993 if (ctx->stack_len < 2)
3e43a32a 994 error (_("Not enough elements for "
0963b4bd 995 "DW_OP_swap. Need 2, have %d."),
9f3fe11c
TG
996 ctx->stack_len);
997 t1 = ctx->stack[ctx->stack_len - 1];
998 t2 = ctx->stack[ctx->stack_len - 2];
999 ctx->stack[ctx->stack_len - 1] = t2;
1000 ctx->stack[ctx->stack_len - 2] = t1;
1001 goto no_push;
1002 }
4c2df51b
DJ
1003
1004 case DW_OP_over:
8a9b8146 1005 result_val = dwarf_expr_fetch (ctx, 1);
44353522 1006 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 1);
4c2df51b
DJ
1007 break;
1008
1009 case DW_OP_rot:
1010 {
44353522 1011 struct dwarf_stack_value t1, t2, t3;
4c2df51b
DJ
1012
1013 if (ctx->stack_len < 3)
0963b4bd
MS
1014 error (_("Not enough elements for "
1015 "DW_OP_rot. Need 3, have %d."),
4c2df51b
DJ
1016 ctx->stack_len);
1017 t1 = ctx->stack[ctx->stack_len - 1];
1018 t2 = ctx->stack[ctx->stack_len - 2];
1019 t3 = ctx->stack[ctx->stack_len - 3];
1020 ctx->stack[ctx->stack_len - 1] = t2;
1021 ctx->stack[ctx->stack_len - 2] = t3;
1022 ctx->stack[ctx->stack_len - 3] = t1;
1023 goto no_push;
1024 }
1025
1026 case DW_OP_deref:
1027 case DW_OP_deref_size:
8a9b8146 1028 case DW_OP_GNU_deref_type:
f2c7657e
UW
1029 {
1030 int addr_size = (op == DW_OP_deref ? ctx->addr_size : *op_ptr++);
1031 gdb_byte *buf = alloca (addr_size);
1032 CORE_ADDR addr = dwarf_expr_fetch_address (ctx, 0);
8a9b8146
TT
1033 struct type *type;
1034
f2c7657e
UW
1035 dwarf_expr_pop (ctx);
1036
8a9b8146
TT
1037 if (op == DW_OP_GNU_deref_type)
1038 {
b64f50a1 1039 cu_offset type_die;
8a9b8146 1040
b64f50a1
JK
1041 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
1042 type_die.cu_off = uoffset;
8a9b8146
TT
1043 type = dwarf_get_base_type (ctx, type_die, 0);
1044 }
1045 else
1046 type = address_type;
1047
9e8b7a03 1048 (ctx->funcs->read_mem) (ctx->baton, buf, addr, addr_size);
325663dc
JB
1049
1050 /* If the size of the object read from memory is different
1051 from the type length, we need to zero-extend it. */
1052 if (TYPE_LENGTH (type) != addr_size)
1053 {
1054 ULONGEST result =
1055 extract_unsigned_integer (buf, addr_size, byte_order);
1056
1057 buf = alloca (TYPE_LENGTH (type));
1058 store_unsigned_integer (buf, TYPE_LENGTH (type),
1059 byte_order, result);
1060 }
1061
8a9b8146 1062 result_val = value_from_contents_and_address (type, buf, addr);
f2c7657e
UW
1063 break;
1064 }
1065
4c2df51b
DJ
1066 case DW_OP_abs:
1067 case DW_OP_neg:
1068 case DW_OP_not:
1069 case DW_OP_plus_uconst:
8a9b8146
TT
1070 {
1071 /* Unary operations. */
1072 result_val = dwarf_expr_fetch (ctx, 0);
1073 dwarf_expr_pop (ctx);
4c2df51b 1074
8a9b8146
TT
1075 switch (op)
1076 {
1077 case DW_OP_abs:
1078 if (value_less (result_val,
1079 value_zero (value_type (result_val), not_lval)))
1080 result_val = value_neg (result_val);
1081 break;
1082 case DW_OP_neg:
1083 result_val = value_neg (result_val);
1084 break;
1085 case DW_OP_not:
1086 dwarf_require_integral (value_type (result_val));
1087 result_val = value_complement (result_val);
1088 break;
1089 case DW_OP_plus_uconst:
1090 dwarf_require_integral (value_type (result_val));
1091 result = value_as_long (result_val);
1092 op_ptr = read_uleb128 (op_ptr, op_end, &reg);
1093 result += reg;
1094 result_val = value_from_ulongest (address_type, result);
1095 break;
1096 }
1097 }
4c2df51b
DJ
1098 break;
1099
1100 case DW_OP_and:
1101 case DW_OP_div:
1102 case DW_OP_minus:
1103 case DW_OP_mod:
1104 case DW_OP_mul:
1105 case DW_OP_or:
1106 case DW_OP_plus:
1107 case DW_OP_shl:
1108 case DW_OP_shr:
1109 case DW_OP_shra:
1110 case DW_OP_xor:
1111 case DW_OP_le:
1112 case DW_OP_ge:
1113 case DW_OP_eq:
1114 case DW_OP_lt:
1115 case DW_OP_gt:
1116 case DW_OP_ne:
1117 {
f2c7657e 1118 /* Binary operations. */
8a9b8146 1119 struct value *first, *second;
4c2df51b
DJ
1120
1121 second = dwarf_expr_fetch (ctx, 0);
1122 dwarf_expr_pop (ctx);
1123
b263358a 1124 first = dwarf_expr_fetch (ctx, 0);
4c2df51b
DJ
1125 dwarf_expr_pop (ctx);
1126
8a9b8146
TT
1127 if (! base_types_equal_p (value_type (first), value_type (second)))
1128 error (_("Incompatible types on DWARF stack"));
1129
4c2df51b
DJ
1130 switch (op)
1131 {
1132 case DW_OP_and:
8a9b8146
TT
1133 dwarf_require_integral (value_type (first));
1134 dwarf_require_integral (value_type (second));
1135 result_val = value_binop (first, second, BINOP_BITWISE_AND);
4c2df51b
DJ
1136 break;
1137 case DW_OP_div:
8a9b8146 1138 result_val = value_binop (first, second, BINOP_DIV);
99c87dab 1139 break;
4c2df51b 1140 case DW_OP_minus:
8a9b8146 1141 result_val = value_binop (first, second, BINOP_SUB);
4c2df51b
DJ
1142 break;
1143 case DW_OP_mod:
8a9b8146
TT
1144 {
1145 int cast_back = 0;
1146 struct type *orig_type = value_type (first);
1147
1148 /* We have to special-case "old-style" untyped values
1149 -- these must have mod computed using unsigned
1150 math. */
1151 if (orig_type == address_type)
1152 {
1153 struct type *utype
1154 = get_unsigned_type (ctx->gdbarch, orig_type);
1155
1156 cast_back = 1;
1157 first = value_cast (utype, first);
1158 second = value_cast (utype, second);
1159 }
1160 /* Note that value_binop doesn't handle float or
1161 decimal float here. This seems unimportant. */
1162 result_val = value_binop (first, second, BINOP_MOD);
1163 if (cast_back)
1164 result_val = value_cast (orig_type, result_val);
1165 }
4c2df51b
DJ
1166 break;
1167 case DW_OP_mul:
8a9b8146 1168 result_val = value_binop (first, second, BINOP_MUL);
4c2df51b
DJ
1169 break;
1170 case DW_OP_or:
8a9b8146
TT
1171 dwarf_require_integral (value_type (first));
1172 dwarf_require_integral (value_type (second));
1173 result_val = value_binop (first, second, BINOP_BITWISE_IOR);
4c2df51b
DJ
1174 break;
1175 case DW_OP_plus:
8a9b8146 1176 result_val = value_binop (first, second, BINOP_ADD);
4c2df51b
DJ
1177 break;
1178 case DW_OP_shl:
8a9b8146
TT
1179 dwarf_require_integral (value_type (first));
1180 dwarf_require_integral (value_type (second));
1181 result_val = value_binop (first, second, BINOP_LSH);
4c2df51b
DJ
1182 break;
1183 case DW_OP_shr:
8a9b8146
TT
1184 dwarf_require_integral (value_type (first));
1185 dwarf_require_integral (value_type (second));
b087e0ed 1186 if (!TYPE_UNSIGNED (value_type (first)))
8a9b8146
TT
1187 {
1188 struct type *utype
1189 = get_unsigned_type (ctx->gdbarch, value_type (first));
1190
1191 first = value_cast (utype, first);
1192 }
1193
1194 result_val = value_binop (first, second, BINOP_RSH);
1195 /* Make sure we wind up with the same type we started
1196 with. */
1197 if (value_type (result_val) != value_type (second))
1198 result_val = value_cast (value_type (second), result_val);
99c87dab 1199 break;
4c2df51b 1200 case DW_OP_shra:
8a9b8146
TT
1201 dwarf_require_integral (value_type (first));
1202 dwarf_require_integral (value_type (second));
8ddd9a20
TT
1203 if (TYPE_UNSIGNED (value_type (first)))
1204 {
1205 struct type *stype
1206 = get_signed_type (ctx->gdbarch, value_type (first));
1207
1208 first = value_cast (stype, first);
1209 }
1210
8a9b8146 1211 result_val = value_binop (first, second, BINOP_RSH);
8ddd9a20
TT
1212 /* Make sure we wind up with the same type we started
1213 with. */
1214 if (value_type (result_val) != value_type (second))
1215 result_val = value_cast (value_type (second), result_val);
4c2df51b
DJ
1216 break;
1217 case DW_OP_xor:
8a9b8146
TT
1218 dwarf_require_integral (value_type (first));
1219 dwarf_require_integral (value_type (second));
1220 result_val = value_binop (first, second, BINOP_BITWISE_XOR);
4c2df51b
DJ
1221 break;
1222 case DW_OP_le:
8a9b8146
TT
1223 /* A <= B is !(B < A). */
1224 result = ! value_less (second, first);
1225 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1226 break;
1227 case DW_OP_ge:
8a9b8146
TT
1228 /* A >= B is !(A < B). */
1229 result = ! value_less (first, second);
1230 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1231 break;
1232 case DW_OP_eq:
8a9b8146
TT
1233 result = value_equal (first, second);
1234 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1235 break;
1236 case DW_OP_lt:
8a9b8146
TT
1237 result = value_less (first, second);
1238 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1239 break;
1240 case DW_OP_gt:
8a9b8146
TT
1241 /* A > B is B < A. */
1242 result = value_less (second, first);
1243 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1244 break;
1245 case DW_OP_ne:
8a9b8146
TT
1246 result = ! value_equal (first, second);
1247 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1248 break;
1249 default:
1250 internal_error (__FILE__, __LINE__,
e2e0b3e5 1251 _("Can't be reached."));
4c2df51b 1252 }
4c2df51b
DJ
1253 }
1254 break;
1255
e7802207 1256 case DW_OP_call_frame_cfa:
9e8b7a03 1257 result = (ctx->funcs->get_frame_cfa) (ctx->baton);
8a9b8146 1258 result_val = value_from_ulongest (address_type, result);
44353522 1259 in_stack_memory = 1;
e7802207
TT
1260 break;
1261
4c2df51b 1262 case DW_OP_GNU_push_tls_address:
c3228f12
EZ
1263 /* Variable is at a constant offset in the thread-local
1264 storage block into the objfile for the current thread and
0963b4bd 1265 the dynamic linker module containing this expression. Here
c3228f12
EZ
1266 we return returns the offset from that base. The top of the
1267 stack has the offset from the beginning of the thread
1268 control block at which the variable is located. Nothing
1269 should follow this operator, so the top of stack would be
1270 returned. */
8a9b8146 1271 result = value_as_long (dwarf_expr_fetch (ctx, 0));
4c2df51b 1272 dwarf_expr_pop (ctx);
9e8b7a03 1273 result = (ctx->funcs->get_tls_address) (ctx->baton, result);
8a9b8146 1274 result_val = value_from_ulongest (address_type, result);
4c2df51b
DJ
1275 break;
1276
1277 case DW_OP_skip:
e17a4113 1278 offset = extract_signed_integer (op_ptr, 2, byte_order);
4c2df51b
DJ
1279 op_ptr += 2;
1280 op_ptr += offset;
1281 goto no_push;
1282
1283 case DW_OP_bra:
8a9b8146
TT
1284 {
1285 struct value *val;
1286
1287 offset = extract_signed_integer (op_ptr, 2, byte_order);
1288 op_ptr += 2;
1289 val = dwarf_expr_fetch (ctx, 0);
1290 dwarf_require_integral (value_type (val));
1291 if (value_as_long (val) != 0)
1292 op_ptr += offset;
1293 dwarf_expr_pop (ctx);
1294 }
4c2df51b
DJ
1295 goto no_push;
1296
1297 case DW_OP_nop:
1298 goto no_push;
1299
87808bd6
JB
1300 case DW_OP_piece:
1301 {
1302 ULONGEST size;
87808bd6
JB
1303
1304 /* Record the piece. */
1305 op_ptr = read_uleb128 (op_ptr, op_end, &size);
d3b1e874 1306 add_piece (ctx, 8 * size, 0);
87808bd6 1307
cec03d70
TT
1308 /* Pop off the address/regnum, and reset the location
1309 type. */
cb826367
TT
1310 if (ctx->location != DWARF_VALUE_LITERAL
1311 && ctx->location != DWARF_VALUE_OPTIMIZED_OUT)
cec03d70
TT
1312 dwarf_expr_pop (ctx);
1313 ctx->location = DWARF_VALUE_MEMORY;
87808bd6
JB
1314 }
1315 goto no_push;
1316
d3b1e874
TT
1317 case DW_OP_bit_piece:
1318 {
1319 ULONGEST size, offset;
1320
1321 /* Record the piece. */
1322 op_ptr = read_uleb128 (op_ptr, op_end, &size);
1323 op_ptr = read_uleb128 (op_ptr, op_end, &offset);
1324 add_piece (ctx, size, offset);
1325
1326 /* Pop off the address/regnum, and reset the location
1327 type. */
1328 if (ctx->location != DWARF_VALUE_LITERAL
1329 && ctx->location != DWARF_VALUE_OPTIMIZED_OUT)
1330 dwarf_expr_pop (ctx);
1331 ctx->location = DWARF_VALUE_MEMORY;
1332 }
1333 goto no_push;
1334
42be36b3
CT
1335 case DW_OP_GNU_uninit:
1336 if (op_ptr != op_end)
9c482037 1337 error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always "
42be36b3
CT
1338 "be the very last op."));
1339
1340 ctx->initialized = 0;
1341 goto no_push;
1342
5c631832 1343 case DW_OP_call2:
b64f50a1
JK
1344 {
1345 cu_offset offset;
1346
1347 offset.cu_off = extract_unsigned_integer (op_ptr, 2, byte_order);
1348 op_ptr += 2;
1349 ctx->funcs->dwarf_call (ctx, offset);
1350 }
5c631832
JK
1351 goto no_push;
1352
1353 case DW_OP_call4:
b64f50a1
JK
1354 {
1355 cu_offset offset;
1356
1357 offset.cu_off = extract_unsigned_integer (op_ptr, 4, byte_order);
1358 op_ptr += 4;
1359 ctx->funcs->dwarf_call (ctx, offset);
1360 }
5c631832 1361 goto no_push;
dd90784c
JK
1362
1363 case DW_OP_GNU_entry_value:
8e3b41a9
JK
1364 {
1365 ULONGEST len;
1366 int dwarf_reg;
1367 CORE_ADDR deref_size;
1368
1369 op_ptr = read_uleb128 (op_ptr, op_end, &len);
1370 if (op_ptr + len > op_end)
1371 error (_("DW_OP_GNU_entry_value: too few bytes available."));
1372
1373 dwarf_reg = dwarf_block_to_dwarf_reg (op_ptr, op_ptr + len);
1374 if (dwarf_reg != -1)
1375 {
1376 op_ptr += len;
1377 ctx->funcs->push_dwarf_reg_entry_value (ctx, dwarf_reg,
a471c594
JK
1378 0 /* unused */,
1379 -1 /* deref_size */);
1380 goto no_push;
1381 }
1382
1383 dwarf_reg = dwarf_block_to_dwarf_reg_deref (op_ptr, op_ptr + len,
1384 &deref_size);
1385 if (dwarf_reg != -1)
1386 {
1387 if (deref_size == -1)
1388 deref_size = ctx->addr_size;
1389 op_ptr += len;
1390 ctx->funcs->push_dwarf_reg_entry_value (ctx, dwarf_reg,
1391 0 /* unused */,
1392 deref_size);
8e3b41a9
JK
1393 goto no_push;
1394 }
1395
1396 error (_("DWARF-2 expression error: DW_OP_GNU_entry_value is "
a471c594
JK
1397 "supported only for single DW_OP_reg* "
1398 "or for DW_OP_breg*(0)+DW_OP_deref*"));
8e3b41a9 1399 }
5c631832 1400
8a9b8146
TT
1401 case DW_OP_GNU_const_type:
1402 {
b64f50a1 1403 cu_offset type_die;
8a9b8146
TT
1404 int n;
1405 const gdb_byte *data;
1406 struct type *type;
1407
b64f50a1
JK
1408 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
1409 type_die.cu_off = uoffset;
8a9b8146
TT
1410 n = *op_ptr++;
1411 data = op_ptr;
1412 op_ptr += n;
1413
1414 type = dwarf_get_base_type (ctx, type_die, n);
1415 result_val = value_from_contents (type, data);
1416 }
1417 break;
1418
1419 case DW_OP_GNU_regval_type:
1420 {
b64f50a1 1421 cu_offset type_die;
8a9b8146
TT
1422 struct type *type;
1423
1424 op_ptr = read_uleb128 (op_ptr, op_end, &reg);
b64f50a1
JK
1425 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
1426 type_die.cu_off = uoffset;
8a9b8146
TT
1427
1428 type = dwarf_get_base_type (ctx, type_die, 0);
9e8b7a03 1429 result = (ctx->funcs->read_reg) (ctx->baton, reg);
d1b66e6d
TT
1430 result_val = value_from_ulongest (address_type, result);
1431 result_val = value_from_contents (type,
1432 value_contents_all (result_val));
8a9b8146
TT
1433 }
1434 break;
1435
1436 case DW_OP_GNU_convert:
1437 case DW_OP_GNU_reinterpret:
1438 {
b64f50a1 1439 cu_offset type_die;
8a9b8146
TT
1440 struct type *type;
1441
b64f50a1
JK
1442 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
1443 type_die.cu_off = uoffset;
8a9b8146 1444
b64f50a1 1445 if (type_die.cu_off == 0)
c38c4bc5
TT
1446 type = address_type;
1447 else
1448 type = dwarf_get_base_type (ctx, type_die, 0);
8a9b8146
TT
1449
1450 result_val = dwarf_expr_fetch (ctx, 0);
1451 dwarf_expr_pop (ctx);
1452
1453 if (op == DW_OP_GNU_convert)
1454 result_val = value_cast (type, result_val);
1455 else if (type == value_type (result_val))
1456 {
1457 /* Nothing. */
1458 }
1459 else if (TYPE_LENGTH (type)
1460 != TYPE_LENGTH (value_type (result_val)))
1461 error (_("DW_OP_GNU_reinterpret has wrong size"));
1462 else
1463 result_val
1464 = value_from_contents (type,
1465 value_contents_all (result_val));
1466 }
1467 break;
1468
4c2df51b 1469 default:
8a3fe4f8 1470 error (_("Unhandled dwarf expression opcode 0x%x"), op);
4c2df51b
DJ
1471 }
1472
1473 /* Most things push a result value. */
8a9b8146
TT
1474 gdb_assert (result_val != NULL);
1475 dwarf_expr_push (ctx, result_val, in_stack_memory);
82ae4854 1476 no_push:
b27cf2b3 1477 ;
4c2df51b 1478 }
1e3a102a 1479
8cf6f0b1
TT
1480 /* To simplify our main caller, if the result is an implicit
1481 pointer, then make a pieced value. This is ok because we can't
1482 have implicit pointers in contexts where pieces are invalid. */
1483 if (ctx->location == DWARF_VALUE_IMPLICIT_POINTER)
1484 add_piece (ctx, 8 * ctx->addr_size, 0);
1485
dd90784c 1486abort_expression:
1e3a102a
JK
1487 ctx->recursion_depth--;
1488 gdb_assert (ctx->recursion_depth >= 0);
8a9b8146
TT
1489}
1490
523f3620
JK
1491/* Stub dwarf_expr_context_funcs.get_frame_base implementation. */
1492
1493void
1494ctx_no_get_frame_base (void *baton, const gdb_byte **start, size_t *length)
1495{
1496 error (_("%s is invalid in this context"), "DW_OP_fbreg");
1497}
1498
1499/* Stub dwarf_expr_context_funcs.get_frame_cfa implementation. */
1500
1501CORE_ADDR
1502ctx_no_get_frame_cfa (void *baton)
1503{
1504 error (_("%s is invalid in this context"), "DW_OP_call_frame_cfa");
1505}
1506
1507/* Stub dwarf_expr_context_funcs.get_frame_pc implementation. */
1508
1509CORE_ADDR
1510ctx_no_get_frame_pc (void *baton)
1511{
1512 error (_("%s is invalid in this context"), "DW_OP_GNU_implicit_pointer");
1513}
1514
1515/* Stub dwarf_expr_context_funcs.get_tls_address implementation. */
1516
1517CORE_ADDR
1518ctx_no_get_tls_address (void *baton, CORE_ADDR offset)
1519{
1520 error (_("%s is invalid in this context"), "DW_OP_GNU_push_tls_address");
1521}
1522
1523/* Stub dwarf_expr_context_funcs.dwarf_call implementation. */
1524
1525void
b64f50a1 1526ctx_no_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset)
523f3620
JK
1527{
1528 error (_("%s is invalid in this context"), "DW_OP_call*");
1529}
1530
1531/* Stub dwarf_expr_context_funcs.get_base_type implementation. */
1532
1533struct type *
b64f50a1 1534ctx_no_get_base_type (struct dwarf_expr_context *ctx, cu_offset die)
523f3620
JK
1535{
1536 error (_("Support for typed DWARF is not supported in this context"));
1537}
1538
8e3b41a9
JK
1539/* Stub dwarf_expr_context_funcs.push_dwarf_block_entry_value
1540 implementation. */
1541
1542void
1543ctx_no_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx,
a471c594
JK
1544 int dwarf_reg, CORE_ADDR fb_offset,
1545 int deref_size)
8e3b41a9
JK
1546{
1547 internal_error (__FILE__, __LINE__,
1548 _("Support for DW_OP_GNU_entry_value is unimplemented"));
1549}
1550
3019eac3
DE
1551/* Stub dwarf_expr_context_funcs.get_addr_index implementation. */
1552
1553CORE_ADDR
1554ctx_no_get_addr_index (void *baton, unsigned int index)
1555{
1556 error (_("%s is invalid in this context"), "DW_OP_GNU_addr_index");
1557}
1558
70221824
PA
1559/* Provide a prototype to silence -Wmissing-prototypes. */
1560extern initialize_file_ftype _initialize_dwarf2expr;
1561
8a9b8146
TT
1562void
1563_initialize_dwarf2expr (void)
1564{
1565 dwarf_arch_cookie
1566 = gdbarch_data_register_post_init (dwarf_gdbarch_types_init);
4c2df51b 1567}
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