* dwarf2-frame.c (struct dwarf2_cie): Make initial_instructions, end
[deliverable/binutils-gdb.git] / gdb / dwarf2expr.c
1 /* DWARF 2 Expression Evaluator.
2
3 Copyright (C) 2001-2003, 2005, 2007-2012 Free Software Foundation,
4 Inc.
5
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
12 the Free Software Foundation; either version 3 of the License, or
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
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22
23 #include "defs.h"
24 #include "symtab.h"
25 #include "gdbtypes.h"
26 #include "value.h"
27 #include "gdbcore.h"
28 #include "dwarf2.h"
29 #include "dwarf2expr.h"
30 #include "gdb_assert.h"
31
32 /* Local prototypes. */
33
34 static void execute_stack_op (struct dwarf_expr_context *,
35 const gdb_byte *, const gdb_byte *);
36
37 /* Cookie for gdbarch data. */
38
39 static 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
44 struct dwarf_gdbarch_types
45 {
46 struct type *dw_types[3];
47 };
48
49 /* Allocate and fill in dwarf_gdbarch_types for an arch. */
50
51 static void *
52 dwarf_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
66 static struct type *
67 dwarf_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
92 /* Create a new context for the expression evaluator. */
93
94 struct dwarf_expr_context *
95 new_dwarf_expr_context (void)
96 {
97 struct dwarf_expr_context *retval;
98
99 retval = xcalloc (1, sizeof (struct dwarf_expr_context));
100 retval->stack_len = 0;
101 retval->stack_allocated = 10;
102 retval->stack = xmalloc (retval->stack_allocated
103 * sizeof (struct dwarf_stack_value));
104 retval->num_pieces = 0;
105 retval->pieces = 0;
106 retval->max_recursion_depth = 0x100;
107 return retval;
108 }
109
110 /* Release the memory allocated to CTX. */
111
112 void
113 free_dwarf_expr_context (struct dwarf_expr_context *ctx)
114 {
115 xfree (ctx->stack);
116 xfree (ctx->pieces);
117 xfree (ctx);
118 }
119
120 /* Helper for make_cleanup_free_dwarf_expr_context. */
121
122 static void
123 free_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
130 struct cleanup *
131 make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx)
132 {
133 return make_cleanup (free_dwarf_expr_context_cleanup, ctx);
134 }
135
136 /* Expand the memory allocated to CTX's stack to contain at least
137 NEED more elements than are currently used. */
138
139 static void
140 dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need)
141 {
142 if (ctx->stack_len + need > ctx->stack_allocated)
143 {
144 size_t newlen = ctx->stack_len + need + 10;
145
146 ctx->stack = xrealloc (ctx->stack,
147 newlen * sizeof (struct dwarf_stack_value));
148 ctx->stack_allocated = newlen;
149 }
150 }
151
152 /* Push VALUE onto CTX's stack. */
153
154 static void
155 dwarf_expr_push (struct dwarf_expr_context *ctx, struct value *value,
156 int in_stack_memory)
157 {
158 struct dwarf_stack_value *v;
159
160 dwarf_expr_grow_stack (ctx, 1);
161 v = &ctx->stack[ctx->stack_len++];
162 v->value = value;
163 v->in_stack_memory = in_stack_memory;
164 }
165
166 /* Push VALUE onto CTX's stack. */
167
168 void
169 dwarf_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
179 static void
180 dwarf_expr_pop (struct dwarf_expr_context *ctx)
181 {
182 if (ctx->stack_len <= 0)
183 error (_("dwarf expression stack underflow"));
184 ctx->stack_len--;
185 }
186
187 /* Retrieve the N'th item on CTX's stack. */
188
189 struct value *
190 dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n)
191 {
192 if (ctx->stack_len <= n)
193 error (_("Asked for position %d of stack, "
194 "stack only has %d elements on it."),
195 n, ctx->stack_len);
196 return ctx->stack[ctx->stack_len - (1 + n)].value;
197 }
198
199 /* Require that TYPE be an integral type; throw an exception if not. */
200
201 static void
202 dwarf_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
213 static struct type *
214 get_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 }
230 }
231
232 /* Return the signed form of TYPE. TYPE is necessarily an integral
233 type. */
234
235 static struct type *
236 get_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
254 /* Retrieve the N'th item on CTX's stack, converted to an address. */
255
256 CORE_ADDR
257 dwarf_expr_fetch_address (struct dwarf_expr_context *ctx, int n)
258 {
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);
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 {
276 gdb_byte *buf = alloca (ctx->addr_size);
277 struct type *int_type = get_unsigned_type (ctx->gdbarch,
278 value_type (result_val));
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
287 /* Retrieve the in_stack_memory flag of the N'th item on CTX's stack. */
288
289 int
290 dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n)
291 {
292 if (ctx->stack_len <= n)
293 error (_("Asked for position %d of stack, "
294 "stack only has %d elements on it."),
295 n, ctx->stack_len);
296 return ctx->stack[ctx->stack_len - (1 + n)].in_stack_memory;
297 }
298
299 /* Return true if the expression stack is empty. */
300
301 static int
302 dwarf_expr_stack_empty_p (struct dwarf_expr_context *ctx)
303 {
304 return ctx->stack_len == 0;
305 }
306
307 /* Add a new piece to CTX's piece list. */
308 static void
309 add_piece (struct dwarf_expr_context *ctx, ULONGEST size, ULONGEST offset)
310 {
311 struct dwarf_expr_piece *p;
312
313 ctx->num_pieces++;
314
315 ctx->pieces = xrealloc (ctx->pieces,
316 (ctx->num_pieces
317 * sizeof (struct dwarf_expr_piece)));
318
319 p = &ctx->pieces[ctx->num_pieces - 1];
320 p->location = ctx->location;
321 p->size = size;
322 p->offset = offset;
323
324 if (p->location == DWARF_VALUE_LITERAL)
325 {
326 p->v.literal.data = ctx->data;
327 p->v.literal.length = ctx->len;
328 }
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 }
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 }
343 else if (p->location == DWARF_VALUE_IMPLICIT_POINTER)
344 {
345 p->v.ptr.die.cu_off = ctx->len;
346 p->v.ptr.offset = value_as_long (dwarf_expr_fetch (ctx, 0));
347 }
348 else if (p->location == DWARF_VALUE_REGISTER)
349 p->v.regno = value_as_long (dwarf_expr_fetch (ctx, 0));
350 else
351 {
352 p->v.value = dwarf_expr_fetch (ctx, 0);
353 }
354 }
355
356 /* Evaluate the expression at ADDR (LEN bytes long) using the context
357 CTX. */
358
359 void
360 dwarf_expr_eval (struct dwarf_expr_context *ctx, const gdb_byte *addr,
361 size_t len)
362 {
363 int old_recursion_depth = ctx->recursion_depth;
364
365 execute_stack_op (ctx, addr, addr + len);
366
367 /* CTX RECURSION_DEPTH becomes invalid if an exception was thrown here. */
368
369 gdb_assert (ctx->recursion_depth == old_recursion_depth);
370 }
371
372 /* Helper to read a uleb128 value or throw an error. */
373
374 const gdb_byte *
375 safe_read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end,
376 unsigned long long *r)
377 {
378 buf = gdb_read_uleb128 (buf, buf_end, r);
379 if (buf == NULL)
380 error (_("DWARF expression error: ran off end of buffer reading uleb128 value"));
381 return buf;
382 }
383
384 /* Helper to read a sleb128 value or throw an error. */
385
386 const gdb_byte *
387 safe_read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end,
388 long long *r)
389 {
390 buf = gdb_read_sleb128 (buf, buf_end, r);
391 if (buf == NULL)
392 error (_("DWARF expression error: ran off end of buffer reading sleb128 value"));
393 return buf;
394 }
395
396 const gdb_byte *
397 safe_skip_leb128 (const gdb_byte *buf, const gdb_byte *buf_end)
398 {
399 buf = gdb_skip_leb128 (buf, buf_end);
400 if (buf == NULL)
401 error (_("DWARF expression error: ran off end of buffer reading leb128 value"));
402 return buf;
403 }
404 \f
405
406 /* Check that the current operator is either at the end of an
407 expression, or that it is followed by a composition operator. */
408
409 void
410 dwarf_expr_require_composition (const gdb_byte *op_ptr, const gdb_byte *op_end,
411 const char *op_name)
412 {
413 /* It seems like DW_OP_GNU_uninit should be handled here. However,
414 it doesn't seem to make sense for DW_OP_*_value, and it was not
415 checked at the other place that this function is called. */
416 if (op_ptr != op_end && *op_ptr != DW_OP_piece && *op_ptr != DW_OP_bit_piece)
417 error (_("DWARF-2 expression error: `%s' operations must be "
418 "used either alone or in conjunction with DW_OP_piece "
419 "or DW_OP_bit_piece."),
420 op_name);
421 }
422
423 /* Return true iff the types T1 and T2 are "the same". This only does
424 checks that might reasonably be needed to compare DWARF base
425 types. */
426
427 static int
428 base_types_equal_p (struct type *t1, struct type *t2)
429 {
430 if (TYPE_CODE (t1) != TYPE_CODE (t2))
431 return 0;
432 if (TYPE_UNSIGNED (t1) != TYPE_UNSIGNED (t2))
433 return 0;
434 return TYPE_LENGTH (t1) == TYPE_LENGTH (t2);
435 }
436
437 /* A convenience function to call get_base_type on CTX and return the
438 result. DIE is the DIE whose type we need. SIZE is non-zero if
439 this function should verify that the resulting type has the correct
440 size. */
441
442 static struct type *
443 dwarf_get_base_type (struct dwarf_expr_context *ctx, cu_offset die, int size)
444 {
445 struct type *result;
446
447 if (ctx->funcs->get_base_type)
448 {
449 result = ctx->funcs->get_base_type (ctx, die);
450 if (result == NULL)
451 error (_("Could not find type for DW_OP_GNU_const_type"));
452 if (size != 0 && TYPE_LENGTH (result) != size)
453 error (_("DW_OP_GNU_const_type has different sizes for type and data"));
454 }
455 else
456 /* Anything will do. */
457 result = builtin_type (ctx->gdbarch)->builtin_int;
458
459 return result;
460 }
461
462 /* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_reg* return the
463 DWARF register number. Otherwise return -1. */
464
465 int
466 dwarf_block_to_dwarf_reg (const gdb_byte *buf, const gdb_byte *buf_end)
467 {
468 unsigned long long dwarf_reg;
469
470 if (buf_end <= buf)
471 return -1;
472 if (*buf >= DW_OP_reg0 && *buf <= DW_OP_reg31)
473 {
474 if (buf_end - buf != 1)
475 return -1;
476 return *buf - DW_OP_reg0;
477 }
478
479 if (*buf == DW_OP_GNU_regval_type)
480 {
481 buf++;
482 buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
483 if (buf == NULL)
484 return -1;
485 buf = gdb_skip_leb128 (buf, buf_end);
486 if (buf == NULL)
487 return -1;
488 }
489 else if (*buf == DW_OP_regx)
490 {
491 buf++;
492 buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
493 if (buf == NULL)
494 return -1;
495 }
496 else
497 return -1;
498 if (buf != buf_end || (int) dwarf_reg != dwarf_reg)
499 return -1;
500 return dwarf_reg;
501 }
502
503 /* If <BUF..BUF_END] contains DW_FORM_block* with just DW_OP_breg*(0) and
504 DW_OP_deref* return the DWARF register number. Otherwise return -1.
505 DEREF_SIZE_RETURN contains -1 for DW_OP_deref; otherwise it contains the
506 size from DW_OP_deref_size. */
507
508 int
509 dwarf_block_to_dwarf_reg_deref (const gdb_byte *buf, const gdb_byte *buf_end,
510 CORE_ADDR *deref_size_return)
511 {
512 unsigned long long dwarf_reg;
513 long long offset;
514
515 if (buf_end <= buf)
516 return -1;
517
518 if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31)
519 {
520 dwarf_reg = *buf - DW_OP_breg0;
521 buf++;
522 if (buf >= buf_end)
523 return -1;
524 }
525 else if (*buf == DW_OP_bregx)
526 {
527 buf++;
528 buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
529 if (buf == NULL)
530 return -1;
531 if ((int) dwarf_reg != dwarf_reg)
532 return -1;
533 }
534 else
535 return -1;
536
537 buf = gdb_read_sleb128 (buf, buf_end, &offset);
538 if (buf == NULL)
539 return -1;
540 if (offset != 0)
541 return -1;
542
543 if (*buf == DW_OP_deref)
544 {
545 buf++;
546 *deref_size_return = -1;
547 }
548 else if (*buf == DW_OP_deref_size)
549 {
550 buf++;
551 if (buf >= buf_end)
552 return -1;
553 *deref_size_return = *buf++;
554 }
555 else
556 return -1;
557
558 if (buf != buf_end)
559 return -1;
560
561 return dwarf_reg;
562 }
563
564 /* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_fbreg(X) fill
565 in FB_OFFSET_RETURN with the X offset and return 1. Otherwise return 0. */
566
567 int
568 dwarf_block_to_fb_offset (const gdb_byte *buf, const gdb_byte *buf_end,
569 CORE_ADDR *fb_offset_return)
570 {
571 long long fb_offset;
572
573 if (buf_end <= buf)
574 return 0;
575
576 if (*buf != DW_OP_fbreg)
577 return 0;
578 buf++;
579
580 buf = gdb_read_sleb128 (buf, buf_end, &fb_offset);
581 if (buf == NULL)
582 return 0;
583 *fb_offset_return = fb_offset;
584 if (buf != buf_end || fb_offset != (LONGEST) *fb_offset_return)
585 return 0;
586
587 return 1;
588 }
589
590 /* If <BUF..BUF_END] contains DW_FORM_block* with single DW_OP_bregSP(X) fill
591 in SP_OFFSET_RETURN with the X offset and return 1. Otherwise return 0.
592 The matched SP register number depends on GDBARCH. */
593
594 int
595 dwarf_block_to_sp_offset (struct gdbarch *gdbarch, const gdb_byte *buf,
596 const gdb_byte *buf_end, CORE_ADDR *sp_offset_return)
597 {
598 unsigned long long dwarf_reg;
599 long long sp_offset;
600
601 if (buf_end <= buf)
602 return 0;
603 if (*buf >= DW_OP_breg0 && *buf <= DW_OP_breg31)
604 {
605 dwarf_reg = *buf - DW_OP_breg0;
606 buf++;
607 }
608 else
609 {
610 if (*buf != DW_OP_bregx)
611 return 0;
612 buf++;
613 buf = gdb_read_uleb128 (buf, buf_end, &dwarf_reg);
614 if (buf == NULL)
615 return 0;
616 }
617
618 if (gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_reg)
619 != gdbarch_sp_regnum (gdbarch))
620 return 0;
621
622 buf = gdb_read_sleb128 (buf, buf_end, &sp_offset);
623 if (buf == NULL)
624 return 0;
625 *sp_offset_return = sp_offset;
626 if (buf != buf_end || sp_offset != (LONGEST) *sp_offset_return)
627 return 0;
628
629 return 1;
630 }
631
632 /* The engine for the expression evaluator. Using the context in CTX,
633 evaluate the expression between OP_PTR and OP_END. */
634
635 static void
636 execute_stack_op (struct dwarf_expr_context *ctx,
637 const gdb_byte *op_ptr, const gdb_byte *op_end)
638 {
639 enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
640 /* Old-style "untyped" DWARF values need special treatment in a
641 couple of places, specifically DW_OP_mod and DW_OP_shr. We need
642 a special type for these values so we can distinguish them from
643 values that have an explicit type, because explicitly-typed
644 values do not need special treatment. This special type must be
645 different (in the `==' sense) from any base type coming from the
646 CU. */
647 struct type *address_type = dwarf_expr_address_type (ctx);
648
649 ctx->location = DWARF_VALUE_MEMORY;
650 ctx->initialized = 1; /* Default is initialized. */
651
652 if (ctx->recursion_depth > ctx->max_recursion_depth)
653 error (_("DWARF-2 expression error: Loop detected (%d)."),
654 ctx->recursion_depth);
655 ctx->recursion_depth++;
656
657 while (op_ptr < op_end)
658 {
659 enum dwarf_location_atom op = *op_ptr++;
660 ULONGEST result;
661 /* Assume the value is not in stack memory.
662 Code that knows otherwise sets this to 1.
663 Some arithmetic on stack addresses can probably be assumed to still
664 be a stack address, but we skip this complication for now.
665 This is just an optimization, so it's always ok to punt
666 and leave this as 0. */
667 int in_stack_memory = 0;
668 unsigned long long uoffset, reg;
669 long long offset;
670 struct value *result_val = NULL;
671
672 /* The DWARF expression might have a bug causing an infinite
673 loop. In that case, quitting is the only way out. */
674 QUIT;
675
676 switch (op)
677 {
678 case DW_OP_lit0:
679 case DW_OP_lit1:
680 case DW_OP_lit2:
681 case DW_OP_lit3:
682 case DW_OP_lit4:
683 case DW_OP_lit5:
684 case DW_OP_lit6:
685 case DW_OP_lit7:
686 case DW_OP_lit8:
687 case DW_OP_lit9:
688 case DW_OP_lit10:
689 case DW_OP_lit11:
690 case DW_OP_lit12:
691 case DW_OP_lit13:
692 case DW_OP_lit14:
693 case DW_OP_lit15:
694 case DW_OP_lit16:
695 case DW_OP_lit17:
696 case DW_OP_lit18:
697 case DW_OP_lit19:
698 case DW_OP_lit20:
699 case DW_OP_lit21:
700 case DW_OP_lit22:
701 case DW_OP_lit23:
702 case DW_OP_lit24:
703 case DW_OP_lit25:
704 case DW_OP_lit26:
705 case DW_OP_lit27:
706 case DW_OP_lit28:
707 case DW_OP_lit29:
708 case DW_OP_lit30:
709 case DW_OP_lit31:
710 result = op - DW_OP_lit0;
711 result_val = value_from_ulongest (address_type, result);
712 break;
713
714 case DW_OP_addr:
715 result = extract_unsigned_integer (op_ptr,
716 ctx->addr_size, byte_order);
717 op_ptr += ctx->addr_size;
718 /* Some versions of GCC emit DW_OP_addr before
719 DW_OP_GNU_push_tls_address. In this case the value is an
720 index, not an address. We don't support things like
721 branching between the address and the TLS op. */
722 if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
723 result += ctx->offset;
724 result_val = value_from_ulongest (address_type, result);
725 break;
726
727 case DW_OP_GNU_addr_index:
728 op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
729 result = (ctx->funcs->get_addr_index) (ctx->baton, uoffset);
730 result_val = value_from_ulongest (address_type, result);
731 break;
732
733 case DW_OP_const1u:
734 result = extract_unsigned_integer (op_ptr, 1, byte_order);
735 result_val = value_from_ulongest (address_type, result);
736 op_ptr += 1;
737 break;
738 case DW_OP_const1s:
739 result = extract_signed_integer (op_ptr, 1, byte_order);
740 result_val = value_from_ulongest (address_type, result);
741 op_ptr += 1;
742 break;
743 case DW_OP_const2u:
744 result = extract_unsigned_integer (op_ptr, 2, byte_order);
745 result_val = value_from_ulongest (address_type, result);
746 op_ptr += 2;
747 break;
748 case DW_OP_const2s:
749 result = extract_signed_integer (op_ptr, 2, byte_order);
750 result_val = value_from_ulongest (address_type, result);
751 op_ptr += 2;
752 break;
753 case DW_OP_const4u:
754 result = extract_unsigned_integer (op_ptr, 4, byte_order);
755 result_val = value_from_ulongest (address_type, result);
756 op_ptr += 4;
757 break;
758 case DW_OP_const4s:
759 result = extract_signed_integer (op_ptr, 4, byte_order);
760 result_val = value_from_ulongest (address_type, result);
761 op_ptr += 4;
762 break;
763 case DW_OP_const8u:
764 result = extract_unsigned_integer (op_ptr, 8, byte_order);
765 result_val = value_from_ulongest (address_type, result);
766 op_ptr += 8;
767 break;
768 case DW_OP_const8s:
769 result = extract_signed_integer (op_ptr, 8, byte_order);
770 result_val = value_from_ulongest (address_type, result);
771 op_ptr += 8;
772 break;
773 case DW_OP_constu:
774 op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
775 result = uoffset;
776 result_val = value_from_ulongest (address_type, result);
777 break;
778 case DW_OP_consts:
779 op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
780 result = offset;
781 result_val = value_from_ulongest (address_type, result);
782 break;
783
784 /* The DW_OP_reg operations are required to occur alone in
785 location expressions. */
786 case DW_OP_reg0:
787 case DW_OP_reg1:
788 case DW_OP_reg2:
789 case DW_OP_reg3:
790 case DW_OP_reg4:
791 case DW_OP_reg5:
792 case DW_OP_reg6:
793 case DW_OP_reg7:
794 case DW_OP_reg8:
795 case DW_OP_reg9:
796 case DW_OP_reg10:
797 case DW_OP_reg11:
798 case DW_OP_reg12:
799 case DW_OP_reg13:
800 case DW_OP_reg14:
801 case DW_OP_reg15:
802 case DW_OP_reg16:
803 case DW_OP_reg17:
804 case DW_OP_reg18:
805 case DW_OP_reg19:
806 case DW_OP_reg20:
807 case DW_OP_reg21:
808 case DW_OP_reg22:
809 case DW_OP_reg23:
810 case DW_OP_reg24:
811 case DW_OP_reg25:
812 case DW_OP_reg26:
813 case DW_OP_reg27:
814 case DW_OP_reg28:
815 case DW_OP_reg29:
816 case DW_OP_reg30:
817 case DW_OP_reg31:
818 if (op_ptr != op_end
819 && *op_ptr != DW_OP_piece
820 && *op_ptr != DW_OP_bit_piece
821 && *op_ptr != DW_OP_GNU_uninit)
822 error (_("DWARF-2 expression error: DW_OP_reg operations must be "
823 "used either alone or in conjunction with DW_OP_piece "
824 "or DW_OP_bit_piece."));
825
826 result = op - DW_OP_reg0;
827 result_val = value_from_ulongest (address_type, result);
828 ctx->location = DWARF_VALUE_REGISTER;
829 break;
830
831 case DW_OP_regx:
832 op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
833 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
834
835 result = reg;
836 result_val = value_from_ulongest (address_type, result);
837 ctx->location = DWARF_VALUE_REGISTER;
838 break;
839
840 case DW_OP_implicit_value:
841 {
842 unsigned long long len;
843
844 op_ptr = safe_read_uleb128 (op_ptr, op_end, &len);
845 if (op_ptr + len > op_end)
846 error (_("DW_OP_implicit_value: too few bytes available."));
847 ctx->len = len;
848 ctx->data = op_ptr;
849 ctx->location = DWARF_VALUE_LITERAL;
850 op_ptr += len;
851 dwarf_expr_require_composition (op_ptr, op_end,
852 "DW_OP_implicit_value");
853 }
854 goto no_push;
855
856 case DW_OP_stack_value:
857 ctx->location = DWARF_VALUE_STACK;
858 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
859 goto no_push;
860
861 case DW_OP_GNU_implicit_pointer:
862 {
863 long long len;
864
865 if (ctx->ref_addr_size == -1)
866 error (_("DWARF-2 expression error: DW_OP_GNU_implicit_pointer "
867 "is not allowed in frame context"));
868
869 /* The referred-to DIE of cu_offset kind. */
870 ctx->len = extract_unsigned_integer (op_ptr, ctx->ref_addr_size,
871 byte_order);
872 op_ptr += ctx->ref_addr_size;
873
874 /* The byte offset into the data. */
875 op_ptr = safe_read_sleb128 (op_ptr, op_end, &len);
876 result = (ULONGEST) len;
877 result_val = value_from_ulongest (address_type, result);
878
879 ctx->location = DWARF_VALUE_IMPLICIT_POINTER;
880 dwarf_expr_require_composition (op_ptr, op_end,
881 "DW_OP_GNU_implicit_pointer");
882 }
883 break;
884
885 case DW_OP_breg0:
886 case DW_OP_breg1:
887 case DW_OP_breg2:
888 case DW_OP_breg3:
889 case DW_OP_breg4:
890 case DW_OP_breg5:
891 case DW_OP_breg6:
892 case DW_OP_breg7:
893 case DW_OP_breg8:
894 case DW_OP_breg9:
895 case DW_OP_breg10:
896 case DW_OP_breg11:
897 case DW_OP_breg12:
898 case DW_OP_breg13:
899 case DW_OP_breg14:
900 case DW_OP_breg15:
901 case DW_OP_breg16:
902 case DW_OP_breg17:
903 case DW_OP_breg18:
904 case DW_OP_breg19:
905 case DW_OP_breg20:
906 case DW_OP_breg21:
907 case DW_OP_breg22:
908 case DW_OP_breg23:
909 case DW_OP_breg24:
910 case DW_OP_breg25:
911 case DW_OP_breg26:
912 case DW_OP_breg27:
913 case DW_OP_breg28:
914 case DW_OP_breg29:
915 case DW_OP_breg30:
916 case DW_OP_breg31:
917 {
918 op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
919 result = (ctx->funcs->read_reg) (ctx->baton, op - DW_OP_breg0);
920 result += offset;
921 result_val = value_from_ulongest (address_type, result);
922 }
923 break;
924 case DW_OP_bregx:
925 {
926 op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
927 op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
928 result = (ctx->funcs->read_reg) (ctx->baton, reg);
929 result += offset;
930 result_val = value_from_ulongest (address_type, result);
931 }
932 break;
933 case DW_OP_fbreg:
934 {
935 const gdb_byte *datastart;
936 size_t datalen;
937 unsigned int before_stack_len;
938
939 op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
940 /* Rather than create a whole new context, we simply
941 record the stack length before execution, then reset it
942 afterwards, effectively erasing whatever the recursive
943 call put there. */
944 before_stack_len = ctx->stack_len;
945 /* FIXME: cagney/2003-03-26: This code should be using
946 get_frame_base_address(), and then implement a dwarf2
947 specific this_base method. */
948 (ctx->funcs->get_frame_base) (ctx->baton, &datastart, &datalen);
949 dwarf_expr_eval (ctx, datastart, datalen);
950 if (ctx->location == DWARF_VALUE_MEMORY)
951 result = dwarf_expr_fetch_address (ctx, 0);
952 else if (ctx->location == DWARF_VALUE_REGISTER)
953 result = (ctx->funcs->read_reg) (ctx->baton,
954 value_as_long (dwarf_expr_fetch (ctx, 0)));
955 else
956 error (_("Not implemented: computing frame "
957 "base using explicit value operator"));
958 result = result + offset;
959 result_val = value_from_ulongest (address_type, result);
960 in_stack_memory = 1;
961 ctx->stack_len = before_stack_len;
962 ctx->location = DWARF_VALUE_MEMORY;
963 }
964 break;
965
966 case DW_OP_dup:
967 result_val = dwarf_expr_fetch (ctx, 0);
968 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
969 break;
970
971 case DW_OP_drop:
972 dwarf_expr_pop (ctx);
973 goto no_push;
974
975 case DW_OP_pick:
976 offset = *op_ptr++;
977 result_val = dwarf_expr_fetch (ctx, offset);
978 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, offset);
979 break;
980
981 case DW_OP_swap:
982 {
983 struct dwarf_stack_value t1, t2;
984
985 if (ctx->stack_len < 2)
986 error (_("Not enough elements for "
987 "DW_OP_swap. Need 2, have %d."),
988 ctx->stack_len);
989 t1 = ctx->stack[ctx->stack_len - 1];
990 t2 = ctx->stack[ctx->stack_len - 2];
991 ctx->stack[ctx->stack_len - 1] = t2;
992 ctx->stack[ctx->stack_len - 2] = t1;
993 goto no_push;
994 }
995
996 case DW_OP_over:
997 result_val = dwarf_expr_fetch (ctx, 1);
998 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 1);
999 break;
1000
1001 case DW_OP_rot:
1002 {
1003 struct dwarf_stack_value t1, t2, t3;
1004
1005 if (ctx->stack_len < 3)
1006 error (_("Not enough elements for "
1007 "DW_OP_rot. Need 3, have %d."),
1008 ctx->stack_len);
1009 t1 = ctx->stack[ctx->stack_len - 1];
1010 t2 = ctx->stack[ctx->stack_len - 2];
1011 t3 = ctx->stack[ctx->stack_len - 3];
1012 ctx->stack[ctx->stack_len - 1] = t2;
1013 ctx->stack[ctx->stack_len - 2] = t3;
1014 ctx->stack[ctx->stack_len - 3] = t1;
1015 goto no_push;
1016 }
1017
1018 case DW_OP_deref:
1019 case DW_OP_deref_size:
1020 case DW_OP_GNU_deref_type:
1021 {
1022 int addr_size = (op == DW_OP_deref ? ctx->addr_size : *op_ptr++);
1023 gdb_byte *buf = alloca (addr_size);
1024 CORE_ADDR addr = dwarf_expr_fetch_address (ctx, 0);
1025 struct type *type;
1026
1027 dwarf_expr_pop (ctx);
1028
1029 if (op == DW_OP_GNU_deref_type)
1030 {
1031 cu_offset type_die;
1032
1033 op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
1034 type_die.cu_off = uoffset;
1035 type = dwarf_get_base_type (ctx, type_die, 0);
1036 }
1037 else
1038 type = address_type;
1039
1040 (ctx->funcs->read_mem) (ctx->baton, buf, addr, addr_size);
1041
1042 /* If the size of the object read from memory is different
1043 from the type length, we need to zero-extend it. */
1044 if (TYPE_LENGTH (type) != addr_size)
1045 {
1046 ULONGEST result =
1047 extract_unsigned_integer (buf, addr_size, byte_order);
1048
1049 buf = alloca (TYPE_LENGTH (type));
1050 store_unsigned_integer (buf, TYPE_LENGTH (type),
1051 byte_order, result);
1052 }
1053
1054 result_val = value_from_contents_and_address (type, buf, addr);
1055 break;
1056 }
1057
1058 case DW_OP_abs:
1059 case DW_OP_neg:
1060 case DW_OP_not:
1061 case DW_OP_plus_uconst:
1062 {
1063 /* Unary operations. */
1064 result_val = dwarf_expr_fetch (ctx, 0);
1065 dwarf_expr_pop (ctx);
1066
1067 switch (op)
1068 {
1069 case DW_OP_abs:
1070 if (value_less (result_val,
1071 value_zero (value_type (result_val), not_lval)))
1072 result_val = value_neg (result_val);
1073 break;
1074 case DW_OP_neg:
1075 result_val = value_neg (result_val);
1076 break;
1077 case DW_OP_not:
1078 dwarf_require_integral (value_type (result_val));
1079 result_val = value_complement (result_val);
1080 break;
1081 case DW_OP_plus_uconst:
1082 dwarf_require_integral (value_type (result_val));
1083 result = value_as_long (result_val);
1084 op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
1085 result += reg;
1086 result_val = value_from_ulongest (address_type, result);
1087 break;
1088 }
1089 }
1090 break;
1091
1092 case DW_OP_and:
1093 case DW_OP_div:
1094 case DW_OP_minus:
1095 case DW_OP_mod:
1096 case DW_OP_mul:
1097 case DW_OP_or:
1098 case DW_OP_plus:
1099 case DW_OP_shl:
1100 case DW_OP_shr:
1101 case DW_OP_shra:
1102 case DW_OP_xor:
1103 case DW_OP_le:
1104 case DW_OP_ge:
1105 case DW_OP_eq:
1106 case DW_OP_lt:
1107 case DW_OP_gt:
1108 case DW_OP_ne:
1109 {
1110 /* Binary operations. */
1111 struct value *first, *second;
1112
1113 second = dwarf_expr_fetch (ctx, 0);
1114 dwarf_expr_pop (ctx);
1115
1116 first = dwarf_expr_fetch (ctx, 0);
1117 dwarf_expr_pop (ctx);
1118
1119 if (! base_types_equal_p (value_type (first), value_type (second)))
1120 error (_("Incompatible types on DWARF stack"));
1121
1122 switch (op)
1123 {
1124 case DW_OP_and:
1125 dwarf_require_integral (value_type (first));
1126 dwarf_require_integral (value_type (second));
1127 result_val = value_binop (first, second, BINOP_BITWISE_AND);
1128 break;
1129 case DW_OP_div:
1130 result_val = value_binop (first, second, BINOP_DIV);
1131 break;
1132 case DW_OP_minus:
1133 result_val = value_binop (first, second, BINOP_SUB);
1134 break;
1135 case DW_OP_mod:
1136 {
1137 int cast_back = 0;
1138 struct type *orig_type = value_type (first);
1139
1140 /* We have to special-case "old-style" untyped values
1141 -- these must have mod computed using unsigned
1142 math. */
1143 if (orig_type == address_type)
1144 {
1145 struct type *utype
1146 = get_unsigned_type (ctx->gdbarch, orig_type);
1147
1148 cast_back = 1;
1149 first = value_cast (utype, first);
1150 second = value_cast (utype, second);
1151 }
1152 /* Note that value_binop doesn't handle float or
1153 decimal float here. This seems unimportant. */
1154 result_val = value_binop (first, second, BINOP_MOD);
1155 if (cast_back)
1156 result_val = value_cast (orig_type, result_val);
1157 }
1158 break;
1159 case DW_OP_mul:
1160 result_val = value_binop (first, second, BINOP_MUL);
1161 break;
1162 case DW_OP_or:
1163 dwarf_require_integral (value_type (first));
1164 dwarf_require_integral (value_type (second));
1165 result_val = value_binop (first, second, BINOP_BITWISE_IOR);
1166 break;
1167 case DW_OP_plus:
1168 result_val = value_binop (first, second, BINOP_ADD);
1169 break;
1170 case DW_OP_shl:
1171 dwarf_require_integral (value_type (first));
1172 dwarf_require_integral (value_type (second));
1173 result_val = value_binop (first, second, BINOP_LSH);
1174 break;
1175 case DW_OP_shr:
1176 dwarf_require_integral (value_type (first));
1177 dwarf_require_integral (value_type (second));
1178 if (!TYPE_UNSIGNED (value_type (first)))
1179 {
1180 struct type *utype
1181 = get_unsigned_type (ctx->gdbarch, value_type (first));
1182
1183 first = value_cast (utype, first);
1184 }
1185
1186 result_val = value_binop (first, second, BINOP_RSH);
1187 /* Make sure we wind up with the same type we started
1188 with. */
1189 if (value_type (result_val) != value_type (second))
1190 result_val = value_cast (value_type (second), result_val);
1191 break;
1192 case DW_OP_shra:
1193 dwarf_require_integral (value_type (first));
1194 dwarf_require_integral (value_type (second));
1195 if (TYPE_UNSIGNED (value_type (first)))
1196 {
1197 struct type *stype
1198 = get_signed_type (ctx->gdbarch, value_type (first));
1199
1200 first = value_cast (stype, first);
1201 }
1202
1203 result_val = value_binop (first, second, BINOP_RSH);
1204 /* Make sure we wind up with the same type we started
1205 with. */
1206 if (value_type (result_val) != value_type (second))
1207 result_val = value_cast (value_type (second), result_val);
1208 break;
1209 case DW_OP_xor:
1210 dwarf_require_integral (value_type (first));
1211 dwarf_require_integral (value_type (second));
1212 result_val = value_binop (first, second, BINOP_BITWISE_XOR);
1213 break;
1214 case DW_OP_le:
1215 /* A <= B is !(B < A). */
1216 result = ! value_less (second, first);
1217 result_val = value_from_ulongest (address_type, result);
1218 break;
1219 case DW_OP_ge:
1220 /* A >= B is !(A < B). */
1221 result = ! value_less (first, second);
1222 result_val = value_from_ulongest (address_type, result);
1223 break;
1224 case DW_OP_eq:
1225 result = value_equal (first, second);
1226 result_val = value_from_ulongest (address_type, result);
1227 break;
1228 case DW_OP_lt:
1229 result = value_less (first, second);
1230 result_val = value_from_ulongest (address_type, result);
1231 break;
1232 case DW_OP_gt:
1233 /* A > B is B < A. */
1234 result = value_less (second, first);
1235 result_val = value_from_ulongest (address_type, result);
1236 break;
1237 case DW_OP_ne:
1238 result = ! value_equal (first, second);
1239 result_val = value_from_ulongest (address_type, result);
1240 break;
1241 default:
1242 internal_error (__FILE__, __LINE__,
1243 _("Can't be reached."));
1244 }
1245 }
1246 break;
1247
1248 case DW_OP_call_frame_cfa:
1249 result = (ctx->funcs->get_frame_cfa) (ctx->baton);
1250 result_val = value_from_ulongest (address_type, result);
1251 in_stack_memory = 1;
1252 break;
1253
1254 case DW_OP_GNU_push_tls_address:
1255 /* Variable is at a constant offset in the thread-local
1256 storage block into the objfile for the current thread and
1257 the dynamic linker module containing this expression. Here
1258 we return returns the offset from that base. The top of the
1259 stack has the offset from the beginning of the thread
1260 control block at which the variable is located. Nothing
1261 should follow this operator, so the top of stack would be
1262 returned. */
1263 result = value_as_long (dwarf_expr_fetch (ctx, 0));
1264 dwarf_expr_pop (ctx);
1265 result = (ctx->funcs->get_tls_address) (ctx->baton, result);
1266 result_val = value_from_ulongest (address_type, result);
1267 break;
1268
1269 case DW_OP_skip:
1270 offset = extract_signed_integer (op_ptr, 2, byte_order);
1271 op_ptr += 2;
1272 op_ptr += offset;
1273 goto no_push;
1274
1275 case DW_OP_bra:
1276 {
1277 struct value *val;
1278
1279 offset = extract_signed_integer (op_ptr, 2, byte_order);
1280 op_ptr += 2;
1281 val = dwarf_expr_fetch (ctx, 0);
1282 dwarf_require_integral (value_type (val));
1283 if (value_as_long (val) != 0)
1284 op_ptr += offset;
1285 dwarf_expr_pop (ctx);
1286 }
1287 goto no_push;
1288
1289 case DW_OP_nop:
1290 goto no_push;
1291
1292 case DW_OP_piece:
1293 {
1294 unsigned long long size;
1295
1296 /* Record the piece. */
1297 op_ptr = safe_read_uleb128 (op_ptr, op_end, &size);
1298 add_piece (ctx, 8 * size, 0);
1299
1300 /* Pop off the address/regnum, and reset the location
1301 type. */
1302 if (ctx->location != DWARF_VALUE_LITERAL
1303 && ctx->location != DWARF_VALUE_OPTIMIZED_OUT)
1304 dwarf_expr_pop (ctx);
1305 ctx->location = DWARF_VALUE_MEMORY;
1306 }
1307 goto no_push;
1308
1309 case DW_OP_bit_piece:
1310 {
1311 unsigned long long size, offset;
1312
1313 /* Record the piece. */
1314 op_ptr = safe_read_uleb128 (op_ptr, op_end, &size);
1315 op_ptr = safe_read_uleb128 (op_ptr, op_end, &offset);
1316 add_piece (ctx, size, offset);
1317
1318 /* Pop off the address/regnum, and reset the location
1319 type. */
1320 if (ctx->location != DWARF_VALUE_LITERAL
1321 && ctx->location != DWARF_VALUE_OPTIMIZED_OUT)
1322 dwarf_expr_pop (ctx);
1323 ctx->location = DWARF_VALUE_MEMORY;
1324 }
1325 goto no_push;
1326
1327 case DW_OP_GNU_uninit:
1328 if (op_ptr != op_end)
1329 error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always "
1330 "be the very last op."));
1331
1332 ctx->initialized = 0;
1333 goto no_push;
1334
1335 case DW_OP_call2:
1336 {
1337 cu_offset offset;
1338
1339 offset.cu_off = extract_unsigned_integer (op_ptr, 2, byte_order);
1340 op_ptr += 2;
1341 ctx->funcs->dwarf_call (ctx, offset);
1342 }
1343 goto no_push;
1344
1345 case DW_OP_call4:
1346 {
1347 cu_offset offset;
1348
1349 offset.cu_off = extract_unsigned_integer (op_ptr, 4, byte_order);
1350 op_ptr += 4;
1351 ctx->funcs->dwarf_call (ctx, offset);
1352 }
1353 goto no_push;
1354
1355 case DW_OP_GNU_entry_value:
1356 {
1357 unsigned long long len;
1358 int dwarf_reg;
1359 CORE_ADDR deref_size;
1360
1361 op_ptr = safe_read_uleb128 (op_ptr, op_end, &len);
1362 if (op_ptr + len > op_end)
1363 error (_("DW_OP_GNU_entry_value: too few bytes available."));
1364
1365 dwarf_reg = dwarf_block_to_dwarf_reg (op_ptr, op_ptr + len);
1366 if (dwarf_reg != -1)
1367 {
1368 op_ptr += len;
1369 ctx->funcs->push_dwarf_reg_entry_value (ctx, dwarf_reg,
1370 0 /* unused */,
1371 -1 /* deref_size */);
1372 goto no_push;
1373 }
1374
1375 dwarf_reg = dwarf_block_to_dwarf_reg_deref (op_ptr, op_ptr + len,
1376 &deref_size);
1377 if (dwarf_reg != -1)
1378 {
1379 if (deref_size == -1)
1380 deref_size = ctx->addr_size;
1381 op_ptr += len;
1382 ctx->funcs->push_dwarf_reg_entry_value (ctx, dwarf_reg,
1383 0 /* unused */,
1384 deref_size);
1385 goto no_push;
1386 }
1387
1388 error (_("DWARF-2 expression error: DW_OP_GNU_entry_value is "
1389 "supported only for single DW_OP_reg* "
1390 "or for DW_OP_breg*(0)+DW_OP_deref*"));
1391 }
1392
1393 case DW_OP_GNU_const_type:
1394 {
1395 cu_offset type_die;
1396 int n;
1397 const gdb_byte *data;
1398 struct type *type;
1399
1400 op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
1401 type_die.cu_off = uoffset;
1402 n = *op_ptr++;
1403 data = op_ptr;
1404 op_ptr += n;
1405
1406 type = dwarf_get_base_type (ctx, type_die, n);
1407 result_val = value_from_contents (type, data);
1408 }
1409 break;
1410
1411 case DW_OP_GNU_regval_type:
1412 {
1413 cu_offset type_die;
1414 struct type *type;
1415
1416 op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
1417 op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
1418 type_die.cu_off = uoffset;
1419
1420 type = dwarf_get_base_type (ctx, type_die, 0);
1421 result = (ctx->funcs->read_reg) (ctx->baton, reg);
1422 result_val = value_from_ulongest (address_type, result);
1423 result_val = value_from_contents (type,
1424 value_contents_all (result_val));
1425 }
1426 break;
1427
1428 case DW_OP_GNU_convert:
1429 case DW_OP_GNU_reinterpret:
1430 {
1431 cu_offset type_die;
1432 struct type *type;
1433
1434 op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
1435 type_die.cu_off = uoffset;
1436
1437 if (type_die.cu_off == 0)
1438 type = address_type;
1439 else
1440 type = dwarf_get_base_type (ctx, type_die, 0);
1441
1442 result_val = dwarf_expr_fetch (ctx, 0);
1443 dwarf_expr_pop (ctx);
1444
1445 if (op == DW_OP_GNU_convert)
1446 result_val = value_cast (type, result_val);
1447 else if (type == value_type (result_val))
1448 {
1449 /* Nothing. */
1450 }
1451 else if (TYPE_LENGTH (type)
1452 != TYPE_LENGTH (value_type (result_val)))
1453 error (_("DW_OP_GNU_reinterpret has wrong size"));
1454 else
1455 result_val
1456 = value_from_contents (type,
1457 value_contents_all (result_val));
1458 }
1459 break;
1460
1461 default:
1462 error (_("Unhandled dwarf expression opcode 0x%x"), op);
1463 }
1464
1465 /* Most things push a result value. */
1466 gdb_assert (result_val != NULL);
1467 dwarf_expr_push (ctx, result_val, in_stack_memory);
1468 no_push:
1469 ;
1470 }
1471
1472 /* To simplify our main caller, if the result is an implicit
1473 pointer, then make a pieced value. This is ok because we can't
1474 have implicit pointers in contexts where pieces are invalid. */
1475 if (ctx->location == DWARF_VALUE_IMPLICIT_POINTER)
1476 add_piece (ctx, 8 * ctx->addr_size, 0);
1477
1478 abort_expression:
1479 ctx->recursion_depth--;
1480 gdb_assert (ctx->recursion_depth >= 0);
1481 }
1482
1483 /* Stub dwarf_expr_context_funcs.get_frame_base implementation. */
1484
1485 void
1486 ctx_no_get_frame_base (void *baton, const gdb_byte **start, size_t *length)
1487 {
1488 error (_("%s is invalid in this context"), "DW_OP_fbreg");
1489 }
1490
1491 /* Stub dwarf_expr_context_funcs.get_frame_cfa implementation. */
1492
1493 CORE_ADDR
1494 ctx_no_get_frame_cfa (void *baton)
1495 {
1496 error (_("%s is invalid in this context"), "DW_OP_call_frame_cfa");
1497 }
1498
1499 /* Stub dwarf_expr_context_funcs.get_frame_pc implementation. */
1500
1501 CORE_ADDR
1502 ctx_no_get_frame_pc (void *baton)
1503 {
1504 error (_("%s is invalid in this context"), "DW_OP_GNU_implicit_pointer");
1505 }
1506
1507 /* Stub dwarf_expr_context_funcs.get_tls_address implementation. */
1508
1509 CORE_ADDR
1510 ctx_no_get_tls_address (void *baton, CORE_ADDR offset)
1511 {
1512 error (_("%s is invalid in this context"), "DW_OP_GNU_push_tls_address");
1513 }
1514
1515 /* Stub dwarf_expr_context_funcs.dwarf_call implementation. */
1516
1517 void
1518 ctx_no_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset)
1519 {
1520 error (_("%s is invalid in this context"), "DW_OP_call*");
1521 }
1522
1523 /* Stub dwarf_expr_context_funcs.get_base_type implementation. */
1524
1525 struct type *
1526 ctx_no_get_base_type (struct dwarf_expr_context *ctx, cu_offset die)
1527 {
1528 error (_("Support for typed DWARF is not supported in this context"));
1529 }
1530
1531 /* Stub dwarf_expr_context_funcs.push_dwarf_block_entry_value
1532 implementation. */
1533
1534 void
1535 ctx_no_push_dwarf_reg_entry_value (struct dwarf_expr_context *ctx,
1536 int dwarf_reg, CORE_ADDR fb_offset,
1537 int deref_size)
1538 {
1539 internal_error (__FILE__, __LINE__,
1540 _("Support for DW_OP_GNU_entry_value is unimplemented"));
1541 }
1542
1543 /* Stub dwarf_expr_context_funcs.get_addr_index implementation. */
1544
1545 CORE_ADDR
1546 ctx_no_get_addr_index (void *baton, unsigned int index)
1547 {
1548 error (_("%s is invalid in this context"), "DW_OP_GNU_addr_index");
1549 }
1550
1551 /* Provide a prototype to silence -Wmissing-prototypes. */
1552 extern initialize_file_ftype _initialize_dwarf2expr;
1553
1554 void
1555 _initialize_dwarf2expr (void)
1556 {
1557 dwarf_arch_cookie
1558 = gdbarch_data_register_post_init (dwarf_gdbarch_types_init);
1559 }
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