1 /* DWARF 2 Expression Evaluator.
3 Copyright (C) 2001, 2002, 2003, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 Contributed by Daniel Berlin (dan@dberlin.org)
8 This file is part of GDB.
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.
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.
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/>. */
29 #include "dwarf2expr.h"
30 #include "gdb_assert.h"
32 /* Local prototypes. */
34 static void execute_stack_op (struct dwarf_expr_context *,
35 const gdb_byte *, const gdb_byte *);
37 /* Cookie for gdbarch data. */
39 static struct gdbarch_data *dwarf_arch_cookie;
41 /* This holds gdbarch-specific types used by the DWARF expression
42 evaluator. See comments in execute_stack_op. */
44 struct dwarf_gdbarch_types
46 struct type *dw_types[3];
49 /* Allocate and fill in dwarf_gdbarch_types for an arch. */
52 dwarf_gdbarch_types_init (struct gdbarch *gdbarch)
54 struct dwarf_gdbarch_types *types
55 = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct dwarf_gdbarch_types);
57 /* The types themselves are lazily initialized. */
62 /* Return the type used for DWARF operations where the type is
63 unspecified in the DWARF spec. Only certain sizes are
67 dwarf_expr_address_type (struct dwarf_expr_context *ctx)
69 struct dwarf_gdbarch_types *types = gdbarch_data (ctx->gdbarch,
73 if (ctx->addr_size == 2)
75 else if (ctx->addr_size == 4)
77 else if (ctx->addr_size == 8)
80 error (_("Unsupported address size in DWARF expressions: %d bits"),
83 if (types->dw_types[ndx] == NULL)
85 = arch_integer_type (ctx->gdbarch,
87 0, "<signed DWARF address type>");
89 return types->dw_types[ndx];
92 /* Create a new context for the expression evaluator. */
94 struct dwarf_expr_context *
95 new_dwarf_expr_context (void)
97 struct dwarf_expr_context *retval;
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;
106 retval->max_recursion_depth = 0x100;
110 /* Release the memory allocated to CTX. */
113 free_dwarf_expr_context (struct dwarf_expr_context *ctx)
120 /* Helper for make_cleanup_free_dwarf_expr_context. */
123 free_dwarf_expr_context_cleanup (void *arg)
125 free_dwarf_expr_context (arg);
128 /* Return a cleanup that calls free_dwarf_expr_context. */
131 make_cleanup_free_dwarf_expr_context (struct dwarf_expr_context *ctx)
133 return make_cleanup (free_dwarf_expr_context_cleanup, ctx);
136 /* Expand the memory allocated to CTX's stack to contain at least
137 NEED more elements than are currently used. */
140 dwarf_expr_grow_stack (struct dwarf_expr_context *ctx, size_t need)
142 if (ctx->stack_len + need > ctx->stack_allocated)
144 size_t newlen = ctx->stack_len + need + 10;
146 ctx->stack = xrealloc (ctx->stack,
147 newlen * sizeof (struct dwarf_stack_value));
148 ctx->stack_allocated = newlen;
152 /* Push VALUE onto CTX's stack. */
155 dwarf_expr_push (struct dwarf_expr_context *ctx, struct value *value,
158 struct dwarf_stack_value *v;
160 dwarf_expr_grow_stack (ctx, 1);
161 v = &ctx->stack[ctx->stack_len++];
163 v->in_stack_memory = in_stack_memory;
166 /* Push VALUE onto CTX's stack. */
169 dwarf_expr_push_address (struct dwarf_expr_context *ctx, CORE_ADDR value,
172 dwarf_expr_push (ctx,
173 value_from_ulongest (dwarf_expr_address_type (ctx), value),
177 /* Pop the top item off of CTX's stack. */
180 dwarf_expr_pop (struct dwarf_expr_context *ctx)
182 if (ctx->stack_len <= 0)
183 error (_("dwarf expression stack underflow"));
187 /* Retrieve the N'th item on CTX's stack. */
190 dwarf_expr_fetch (struct dwarf_expr_context *ctx, int n)
192 if (ctx->stack_len <= n)
193 error (_("Asked for position %d of stack, "
194 "stack only has %d elements on it."),
196 return ctx->stack[ctx->stack_len - (1 + n)].value;
199 /* Require that TYPE be an integral type; throw an exception if not. */
202 dwarf_require_integral (struct type *type)
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"));
210 /* Return the unsigned form of TYPE. TYPE is necessarily an integral
214 get_unsigned_type (struct gdbarch *gdbarch, struct type *type)
216 switch (TYPE_LENGTH (type))
219 return builtin_type (gdbarch)->builtin_uint8;
221 return builtin_type (gdbarch)->builtin_uint16;
223 return builtin_type (gdbarch)->builtin_uint32;
225 return builtin_type (gdbarch)->builtin_uint64;
227 error (_("no unsigned variant found for type, while evaluating "
228 "DWARF expression"));
232 /* Return the signed form of TYPE. TYPE is necessarily an integral
236 get_signed_type (struct gdbarch *gdbarch, struct type *type)
238 switch (TYPE_LENGTH (type))
241 return builtin_type (gdbarch)->builtin_int8;
243 return builtin_type (gdbarch)->builtin_int16;
245 return builtin_type (gdbarch)->builtin_int32;
247 return builtin_type (gdbarch)->builtin_int64;
249 error (_("no signed variant found for type, while evaluating "
250 "DWARF expression"));
254 /* Retrieve the N'th item on CTX's stack, converted to an address. */
257 dwarf_expr_fetch_address (struct dwarf_expr_context *ctx, int n)
259 struct value *result_val = dwarf_expr_fetch (ctx, n);
260 enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
263 dwarf_require_integral (value_type (result_val));
264 result = extract_unsigned_integer (value_contents (result_val),
265 TYPE_LENGTH (value_type (result_val)),
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))
276 gdb_byte *buf = alloca (ctx->addr_size);
277 struct type *int_type = get_unsigned_type (ctx->gdbarch,
278 value_type (result_val));
280 store_unsigned_integer (buf, ctx->addr_size, byte_order, result);
281 return gdbarch_integer_to_address (ctx->gdbarch, int_type, buf);
284 return (CORE_ADDR) result;
287 /* Retrieve the in_stack_memory flag of the N'th item on CTX's stack. */
290 dwarf_expr_fetch_in_stack_memory (struct dwarf_expr_context *ctx, int n)
292 if (ctx->stack_len <= n)
293 error (_("Asked for position %d of stack, "
294 "stack only has %d elements on it."),
296 return ctx->stack[ctx->stack_len - (1 + n)].in_stack_memory;
299 /* Return true if the expression stack is empty. */
302 dwarf_expr_stack_empty_p (struct dwarf_expr_context *ctx)
304 return ctx->stack_len == 0;
307 /* Add a new piece to CTX's piece list. */
309 add_piece (struct dwarf_expr_context *ctx, ULONGEST size, ULONGEST offset)
311 struct dwarf_expr_piece *p;
315 ctx->pieces = xrealloc (ctx->pieces,
317 * sizeof (struct dwarf_expr_piece)));
319 p = &ctx->pieces[ctx->num_pieces - 1];
320 p->location = ctx->location;
324 if (p->location == DWARF_VALUE_LITERAL)
326 p->v.literal.data = ctx->data;
327 p->v.literal.length = ctx->len;
329 else if (dwarf_expr_stack_empty_p (ctx))
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;
338 else if (p->location == DWARF_VALUE_MEMORY)
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);
343 else if (p->location == DWARF_VALUE_IMPLICIT_POINTER)
345 p->v.ptr.die = ctx->len;
346 p->v.ptr.offset = value_as_long (dwarf_expr_fetch (ctx, 0));
348 else if (p->location == DWARF_VALUE_REGISTER)
349 p->v.regno = value_as_long (dwarf_expr_fetch (ctx, 0));
352 p->v.value = dwarf_expr_fetch (ctx, 0);
356 /* Evaluate the expression at ADDR (LEN bytes long) using the context
360 dwarf_expr_eval (struct dwarf_expr_context *ctx, const gdb_byte *addr,
363 int old_recursion_depth = ctx->recursion_depth;
365 execute_stack_op (ctx, addr, addr + len);
367 /* CTX RECURSION_DEPTH becomes invalid if an exception was thrown here. */
369 gdb_assert (ctx->recursion_depth == old_recursion_depth);
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
377 read_uleb128 (const gdb_byte *buf, const gdb_byte *buf_end, ULONGEST * r)
386 error (_("read_uleb128: Corrupted DWARF expression."));
389 result |= ((ULONGEST) (byte & 0x7f)) << shift;
390 if ((byte & 0x80) == 0)
398 /* Decode the signed LEB128 constant at BUF into the variable pointed to
399 by R, and return the new value of BUF. Verify that it doesn't extend
403 read_sleb128 (const gdb_byte *buf, const gdb_byte *buf_end, LONGEST * r)
412 error (_("read_sleb128: Corrupted DWARF expression."));
415 result |= ((ULONGEST) (byte & 0x7f)) << shift;
417 if ((byte & 0x80) == 0)
420 if (shift < (sizeof (*r) * 8) && (byte & 0x40) != 0)
421 result |= -(((LONGEST) 1) << shift);
428 /* Check that the current operator is either at the end of an
429 expression, or that it is followed by a composition operator. */
432 dwarf_expr_require_composition (const gdb_byte *op_ptr, const gdb_byte *op_end,
435 /* It seems like DW_OP_GNU_uninit should be handled here. However,
436 it doesn't seem to make sense for DW_OP_*_value, and it was not
437 checked at the other place that this function is called. */
438 if (op_ptr != op_end && *op_ptr != DW_OP_piece && *op_ptr != DW_OP_bit_piece)
439 error (_("DWARF-2 expression error: `%s' operations must be "
440 "used either alone or in conjunction with DW_OP_piece "
441 "or DW_OP_bit_piece."),
445 /* Return true iff the types T1 and T2 are "the same". This only does
446 checks that might reasonably be needed to compare DWARF base
450 base_types_equal_p (struct type *t1, struct type *t2)
452 if (TYPE_CODE (t1) != TYPE_CODE (t2))
454 if (TYPE_UNSIGNED (t1) != TYPE_UNSIGNED (t2))
456 return TYPE_LENGTH (t1) == TYPE_LENGTH (t2);
459 /* A convenience function to call get_base_type on CTX and return the
460 result. DIE is the DIE whose type we need. SIZE is non-zero if
461 this function should verify that the resulting type has the correct
465 dwarf_get_base_type (struct dwarf_expr_context *ctx, ULONGEST die, int size)
469 if (ctx->get_base_type)
471 result = ctx->get_base_type (ctx, die);
473 error (_("Could not find type for DW_OP_GNU_const_type"));
474 if (size != 0 && TYPE_LENGTH (result) != size)
475 error (_("DW_OP_GNU_const_type has different sizes for type and data"));
478 /* Anything will do. */
479 result = builtin_type (ctx->gdbarch)->builtin_int;
484 /* The engine for the expression evaluator. Using the context in CTX,
485 evaluate the expression between OP_PTR and OP_END. */
488 execute_stack_op (struct dwarf_expr_context *ctx,
489 const gdb_byte *op_ptr, const gdb_byte *op_end)
491 enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
492 /* Old-style "untyped" DWARF values need special treatment in a
493 couple of places, specifically DW_OP_mod and DW_OP_shr. We need
494 a special type for these values so we can distinguish them from
495 values that have an explicit type, because explicitly-typed
496 values do not need special treatment. This special type must be
497 different (in the `==' sense) from any base type coming from the
499 struct type *address_type = dwarf_expr_address_type (ctx);
501 ctx->location = DWARF_VALUE_MEMORY;
502 ctx->initialized = 1; /* Default is initialized. */
504 if (ctx->recursion_depth > ctx->max_recursion_depth)
505 error (_("DWARF-2 expression error: Loop detected (%d)."),
506 ctx->recursion_depth);
507 ctx->recursion_depth++;
509 while (op_ptr < op_end)
511 enum dwarf_location_atom op = *op_ptr++;
513 /* Assume the value is not in stack memory.
514 Code that knows otherwise sets this to 1.
515 Some arithmetic on stack addresses can probably be assumed to still
516 be a stack address, but we skip this complication for now.
517 This is just an optimization, so it's always ok to punt
518 and leave this as 0. */
519 int in_stack_memory = 0;
520 ULONGEST uoffset, reg;
522 struct value *result_val = NULL;
524 /* The DWARF expression might have a bug causing an infinite
525 loop. In that case, quitting is the only way out. */
562 result = op - DW_OP_lit0;
563 result_val = value_from_ulongest (address_type, result);
567 result = extract_unsigned_integer (op_ptr,
568 ctx->addr_size, byte_order);
569 op_ptr += ctx->addr_size;
570 /* Some versions of GCC emit DW_OP_addr before
571 DW_OP_GNU_push_tls_address. In this case the value is an
572 index, not an address. We don't support things like
573 branching between the address and the TLS op. */
574 if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
575 result += ctx->offset;
576 result_val = value_from_ulongest (address_type, result);
580 result = extract_unsigned_integer (op_ptr, 1, byte_order);
581 result_val = value_from_ulongest (address_type, result);
585 result = extract_signed_integer (op_ptr, 1, byte_order);
586 result_val = value_from_ulongest (address_type, result);
590 result = extract_unsigned_integer (op_ptr, 2, byte_order);
591 result_val = value_from_ulongest (address_type, result);
595 result = extract_signed_integer (op_ptr, 2, byte_order);
596 result_val = value_from_ulongest (address_type, result);
600 result = extract_unsigned_integer (op_ptr, 4, byte_order);
601 result_val = value_from_ulongest (address_type, result);
605 result = extract_signed_integer (op_ptr, 4, byte_order);
606 result_val = value_from_ulongest (address_type, result);
610 result = extract_unsigned_integer (op_ptr, 8, byte_order);
611 result_val = value_from_ulongest (address_type, result);
615 result = extract_signed_integer (op_ptr, 8, byte_order);
616 result_val = value_from_ulongest (address_type, result);
620 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
622 result_val = value_from_ulongest (address_type, result);
625 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
627 result_val = value_from_ulongest (address_type, result);
630 /* The DW_OP_reg operations are required to occur alone in
631 location expressions. */
665 && *op_ptr != DW_OP_piece
666 && *op_ptr != DW_OP_bit_piece
667 && *op_ptr != DW_OP_GNU_uninit)
668 error (_("DWARF-2 expression error: DW_OP_reg operations must be "
669 "used either alone or in conjunction with DW_OP_piece "
670 "or DW_OP_bit_piece."));
672 result = op - DW_OP_reg0;
673 result_val = value_from_ulongest (address_type, result);
674 ctx->location = DWARF_VALUE_REGISTER;
678 op_ptr = read_uleb128 (op_ptr, op_end, ®);
679 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
682 result_val = value_from_ulongest (address_type, result);
683 ctx->location = DWARF_VALUE_REGISTER;
686 case DW_OP_implicit_value:
690 op_ptr = read_uleb128 (op_ptr, op_end, &len);
691 if (op_ptr + len > op_end)
692 error (_("DW_OP_implicit_value: too few bytes available."));
695 ctx->location = DWARF_VALUE_LITERAL;
697 dwarf_expr_require_composition (op_ptr, op_end,
698 "DW_OP_implicit_value");
702 case DW_OP_stack_value:
703 ctx->location = DWARF_VALUE_STACK;
704 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
707 case DW_OP_GNU_implicit_pointer:
712 /* The referred-to DIE. */
713 ctx->len = extract_unsigned_integer (op_ptr, ctx->addr_size,
715 op_ptr += ctx->addr_size;
717 /* The byte offset into the data. */
718 op_ptr = read_sleb128 (op_ptr, op_end, &len);
719 result = (ULONGEST) len;
720 result_val = value_from_ulongest (address_type, result);
722 ctx->location = DWARF_VALUE_IMPLICIT_POINTER;
723 dwarf_expr_require_composition (op_ptr, op_end,
724 "DW_OP_GNU_implicit_pointer");
761 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
762 result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0);
764 result_val = value_from_ulongest (address_type, result);
769 op_ptr = read_uleb128 (op_ptr, op_end, ®);
770 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
771 result = (ctx->read_reg) (ctx->baton, reg);
773 result_val = value_from_ulongest (address_type, result);
778 const gdb_byte *datastart;
780 unsigned int before_stack_len;
782 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
783 /* Rather than create a whole new context, we simply
784 record the stack length before execution, then reset it
785 afterwards, effectively erasing whatever the recursive
787 before_stack_len = ctx->stack_len;
788 /* FIXME: cagney/2003-03-26: This code should be using
789 get_frame_base_address(), and then implement a dwarf2
790 specific this_base method. */
791 (ctx->get_frame_base) (ctx->baton, &datastart, &datalen);
792 dwarf_expr_eval (ctx, datastart, datalen);
793 if (ctx->location == DWARF_VALUE_MEMORY)
794 result = dwarf_expr_fetch_address (ctx, 0);
795 else if (ctx->location == DWARF_VALUE_REGISTER)
797 = (ctx->read_reg) (ctx->baton,
798 value_as_long (dwarf_expr_fetch (ctx, 0)));
800 error (_("Not implemented: computing frame "
801 "base using explicit value operator"));
802 result = result + offset;
803 result_val = value_from_ulongest (address_type, result);
805 ctx->stack_len = before_stack_len;
806 ctx->location = DWARF_VALUE_MEMORY;
811 result_val = dwarf_expr_fetch (ctx, 0);
812 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
816 dwarf_expr_pop (ctx);
821 result_val = dwarf_expr_fetch (ctx, offset);
822 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, offset);
827 struct dwarf_stack_value t1, t2;
829 if (ctx->stack_len < 2)
830 error (_("Not enough elements for "
831 "DW_OP_swap. Need 2, have %d."),
833 t1 = ctx->stack[ctx->stack_len - 1];
834 t2 = ctx->stack[ctx->stack_len - 2];
835 ctx->stack[ctx->stack_len - 1] = t2;
836 ctx->stack[ctx->stack_len - 2] = t1;
841 result_val = dwarf_expr_fetch (ctx, 1);
842 in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 1);
847 struct dwarf_stack_value t1, t2, t3;
849 if (ctx->stack_len < 3)
850 error (_("Not enough elements for "
851 "DW_OP_rot. Need 3, have %d."),
853 t1 = ctx->stack[ctx->stack_len - 1];
854 t2 = ctx->stack[ctx->stack_len - 2];
855 t3 = ctx->stack[ctx->stack_len - 3];
856 ctx->stack[ctx->stack_len - 1] = t2;
857 ctx->stack[ctx->stack_len - 2] = t3;
858 ctx->stack[ctx->stack_len - 3] = t1;
863 case DW_OP_deref_size:
864 case DW_OP_GNU_deref_type:
866 int addr_size = (op == DW_OP_deref ? ctx->addr_size : *op_ptr++);
867 gdb_byte *buf = alloca (addr_size);
868 CORE_ADDR addr = dwarf_expr_fetch_address (ctx, 0);
871 dwarf_expr_pop (ctx);
873 if (op == DW_OP_GNU_deref_type)
877 op_ptr = read_uleb128 (op_ptr, op_end, &type_die);
878 type = dwarf_get_base_type (ctx, type_die, 0);
883 (ctx->read_mem) (ctx->baton, buf, addr, addr_size);
885 /* If the size of the object read from memory is different
886 from the type length, we need to zero-extend it. */
887 if (TYPE_LENGTH (type) != addr_size)
890 extract_unsigned_integer (buf, addr_size, byte_order);
892 buf = alloca (TYPE_LENGTH (type));
893 store_unsigned_integer (buf, TYPE_LENGTH (type),
897 result_val = value_from_contents_and_address (type, buf, addr);
904 case DW_OP_plus_uconst:
906 /* Unary operations. */
907 result_val = dwarf_expr_fetch (ctx, 0);
908 dwarf_expr_pop (ctx);
913 if (value_less (result_val,
914 value_zero (value_type (result_val), not_lval)))
915 result_val = value_neg (result_val);
918 result_val = value_neg (result_val);
921 dwarf_require_integral (value_type (result_val));
922 result_val = value_complement (result_val);
924 case DW_OP_plus_uconst:
925 dwarf_require_integral (value_type (result_val));
926 result = value_as_long (result_val);
927 op_ptr = read_uleb128 (op_ptr, op_end, ®);
929 result_val = value_from_ulongest (address_type, result);
953 /* Binary operations. */
954 struct value *first, *second;
956 second = dwarf_expr_fetch (ctx, 0);
957 dwarf_expr_pop (ctx);
959 first = dwarf_expr_fetch (ctx, 0);
960 dwarf_expr_pop (ctx);
962 if (! base_types_equal_p (value_type (first), value_type (second)))
963 error (_("Incompatible types on DWARF stack"));
968 dwarf_require_integral (value_type (first));
969 dwarf_require_integral (value_type (second));
970 result_val = value_binop (first, second, BINOP_BITWISE_AND);
973 result_val = value_binop (first, second, BINOP_DIV);
976 result_val = value_binop (first, second, BINOP_SUB);
981 struct type *orig_type = value_type (first);
983 /* We have to special-case "old-style" untyped values
984 -- these must have mod computed using unsigned
986 if (orig_type == address_type)
989 = get_unsigned_type (ctx->gdbarch, orig_type);
992 first = value_cast (utype, first);
993 second = value_cast (utype, second);
995 /* Note that value_binop doesn't handle float or
996 decimal float here. This seems unimportant. */
997 result_val = value_binop (first, second, BINOP_MOD);
999 result_val = value_cast (orig_type, result_val);
1003 result_val = value_binop (first, second, BINOP_MUL);
1006 dwarf_require_integral (value_type (first));
1007 dwarf_require_integral (value_type (second));
1008 result_val = value_binop (first, second, BINOP_BITWISE_IOR);
1011 result_val = value_binop (first, second, BINOP_ADD);
1014 dwarf_require_integral (value_type (first));
1015 dwarf_require_integral (value_type (second));
1016 result_val = value_binop (first, second, BINOP_LSH);
1019 dwarf_require_integral (value_type (first));
1020 dwarf_require_integral (value_type (second));
1021 if (!TYPE_UNSIGNED (value_type (first)))
1024 = get_unsigned_type (ctx->gdbarch, value_type (first));
1026 first = value_cast (utype, first);
1029 result_val = value_binop (first, second, BINOP_RSH);
1030 /* Make sure we wind up with the same type we started
1032 if (value_type (result_val) != value_type (second))
1033 result_val = value_cast (value_type (second), result_val);
1036 dwarf_require_integral (value_type (first));
1037 dwarf_require_integral (value_type (second));
1038 if (TYPE_UNSIGNED (value_type (first)))
1041 = get_signed_type (ctx->gdbarch, value_type (first));
1043 first = value_cast (stype, first);
1046 result_val = value_binop (first, second, BINOP_RSH);
1047 /* Make sure we wind up with the same type we started
1049 if (value_type (result_val) != value_type (second))
1050 result_val = value_cast (value_type (second), result_val);
1053 dwarf_require_integral (value_type (first));
1054 dwarf_require_integral (value_type (second));
1055 result_val = value_binop (first, second, BINOP_BITWISE_XOR);
1058 /* A <= B is !(B < A). */
1059 result = ! value_less (second, first);
1060 result_val = value_from_ulongest (address_type, result);
1063 /* A >= B is !(A < B). */
1064 result = ! value_less (first, second);
1065 result_val = value_from_ulongest (address_type, result);
1068 result = value_equal (first, second);
1069 result_val = value_from_ulongest (address_type, result);
1072 result = value_less (first, second);
1073 result_val = value_from_ulongest (address_type, result);
1076 /* A > B is B < A. */
1077 result = value_less (second, first);
1078 result_val = value_from_ulongest (address_type, result);
1081 result = ! value_equal (first, second);
1082 result_val = value_from_ulongest (address_type, result);
1085 internal_error (__FILE__, __LINE__,
1086 _("Can't be reached."));
1091 case DW_OP_call_frame_cfa:
1092 result = (ctx->get_frame_cfa) (ctx->baton);
1093 result_val = value_from_ulongest (address_type, result);
1094 in_stack_memory = 1;
1097 case DW_OP_GNU_push_tls_address:
1098 /* Variable is at a constant offset in the thread-local
1099 storage block into the objfile for the current thread and
1100 the dynamic linker module containing this expression. Here
1101 we return returns the offset from that base. The top of the
1102 stack has the offset from the beginning of the thread
1103 control block at which the variable is located. Nothing
1104 should follow this operator, so the top of stack would be
1106 result = value_as_long (dwarf_expr_fetch (ctx, 0));
1107 dwarf_expr_pop (ctx);
1108 result = (ctx->get_tls_address) (ctx->baton, result);
1109 result_val = value_from_ulongest (address_type, result);
1113 offset = extract_signed_integer (op_ptr, 2, byte_order);
1122 offset = extract_signed_integer (op_ptr, 2, byte_order);
1124 val = dwarf_expr_fetch (ctx, 0);
1125 dwarf_require_integral (value_type (val));
1126 if (value_as_long (val) != 0)
1128 dwarf_expr_pop (ctx);
1139 /* Record the piece. */
1140 op_ptr = read_uleb128 (op_ptr, op_end, &size);
1141 add_piece (ctx, 8 * size, 0);
1143 /* Pop off the address/regnum, and reset the location
1145 if (ctx->location != DWARF_VALUE_LITERAL
1146 && ctx->location != DWARF_VALUE_OPTIMIZED_OUT)
1147 dwarf_expr_pop (ctx);
1148 ctx->location = DWARF_VALUE_MEMORY;
1152 case DW_OP_bit_piece:
1154 ULONGEST size, offset;
1156 /* Record the piece. */
1157 op_ptr = read_uleb128 (op_ptr, op_end, &size);
1158 op_ptr = read_uleb128 (op_ptr, op_end, &offset);
1159 add_piece (ctx, size, offset);
1161 /* Pop off the address/regnum, and reset the location
1163 if (ctx->location != DWARF_VALUE_LITERAL
1164 && ctx->location != DWARF_VALUE_OPTIMIZED_OUT)
1165 dwarf_expr_pop (ctx);
1166 ctx->location = DWARF_VALUE_MEMORY;
1170 case DW_OP_GNU_uninit:
1171 if (op_ptr != op_end)
1172 error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always "
1173 "be the very last op."));
1175 ctx->initialized = 0;
1179 result = extract_unsigned_integer (op_ptr, 2, byte_order);
1181 ctx->dwarf_call (ctx, result);
1185 result = extract_unsigned_integer (op_ptr, 4, byte_order);
1187 ctx->dwarf_call (ctx, result);
1190 case DW_OP_GNU_entry_value:
1191 /* This operation is not yet supported by GDB. */
1192 ctx->location = DWARF_VALUE_OPTIMIZED_OUT;
1194 ctx->num_pieces = 0;
1195 goto abort_expression;
1197 case DW_OP_GNU_const_type:
1201 const gdb_byte *data;
1204 op_ptr = read_uleb128 (op_ptr, op_end, &type_die);
1209 type = dwarf_get_base_type (ctx, type_die, n);
1210 result_val = value_from_contents (type, data);
1214 case DW_OP_GNU_regval_type:
1219 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1220 op_ptr = read_uleb128 (op_ptr, op_end, &type_die);
1222 type = dwarf_get_base_type (ctx, type_die, 0);
1223 result = (ctx->read_reg) (ctx->baton, reg);
1224 result_val = value_from_ulongest (type, result);
1228 case DW_OP_GNU_convert:
1229 case DW_OP_GNU_reinterpret:
1234 op_ptr = read_uleb128 (op_ptr, op_end, &type_die);
1237 type = address_type;
1239 type = dwarf_get_base_type (ctx, type_die, 0);
1241 result_val = dwarf_expr_fetch (ctx, 0);
1242 dwarf_expr_pop (ctx);
1244 if (op == DW_OP_GNU_convert)
1245 result_val = value_cast (type, result_val);
1246 else if (type == value_type (result_val))
1250 else if (TYPE_LENGTH (type)
1251 != TYPE_LENGTH (value_type (result_val)))
1252 error (_("DW_OP_GNU_reinterpret has wrong size"));
1255 = value_from_contents (type,
1256 value_contents_all (result_val));
1261 error (_("Unhandled dwarf expression opcode 0x%x"), op);
1264 /* Most things push a result value. */
1265 gdb_assert (result_val != NULL);
1266 dwarf_expr_push (ctx, result_val, in_stack_memory);
1271 /* To simplify our main caller, if the result is an implicit
1272 pointer, then make a pieced value. This is ok because we can't
1273 have implicit pointers in contexts where pieces are invalid. */
1274 if (ctx->location == DWARF_VALUE_IMPLICIT_POINTER)
1275 add_piece (ctx, 8 * ctx->addr_size, 0);
1278 ctx->recursion_depth--;
1279 gdb_assert (ctx->recursion_depth >= 0);
1283 _initialize_dwarf2expr (void)
1286 = gdbarch_data_register_post_init (dwarf_gdbarch_types_init);