1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 Contributed by Daniel Jacobowitz, MontaVista Software, Inc.
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/>. */
34 #include "exceptions.h"
38 #include "dwarf2expr.h"
39 #include "dwarf2loc.h"
40 #include "dwarf2-frame.h"
42 #include "gdb_string.h"
43 #include "gdb_assert.h"
45 extern int dwarf2_always_disassemble;
48 dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
49 const gdb_byte **start, size_t *length);
52 dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
53 const gdb_byte *data, unsigned short size,
54 struct dwarf2_per_cu_data *per_cu,
57 /* A function for dealing with location lists. Given a
58 symbol baton (BATON) and a pc value (PC), find the appropriate
59 location expression, set *LOCEXPR_LENGTH, and return a pointer
60 to the beginning of the expression. Returns NULL on failure.
62 For now, only return the first matching location expression; there
63 can be more than one in the list. */
66 dwarf2_find_location_expression (struct dwarf2_loclist_baton *baton,
67 size_t *locexpr_length, CORE_ADDR pc)
70 const gdb_byte *loc_ptr, *buf_end;
72 struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu);
73 struct gdbarch *gdbarch = get_objfile_arch (objfile);
74 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
75 unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu);
76 int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
77 CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
78 /* Adjust base_address for relocatable objects. */
79 CORE_ADDR base_offset = dwarf2_per_cu_text_offset (baton->per_cu);
80 CORE_ADDR base_address = baton->base_address + base_offset;
82 loc_ptr = baton->data;
83 buf_end = baton->data + baton->size;
87 if (buf_end - loc_ptr < 2 * addr_size)
88 error (_("dwarf2_find_location_expression: "
89 "Corrupted DWARF expression."));
92 low = extract_signed_integer (loc_ptr, addr_size, byte_order);
94 low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
98 high = extract_signed_integer (loc_ptr, addr_size, byte_order);
100 high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
101 loc_ptr += addr_size;
103 /* A base-address-selection entry. */
104 if ((low & base_mask) == base_mask)
106 base_address = high + base_offset;
110 /* An end-of-list entry. */
111 if (low == 0 && high == 0)
114 /* Otherwise, a location expression entry. */
116 high += base_address;
118 length = extract_unsigned_integer (loc_ptr, 2, byte_order);
121 if (pc >= low && pc < high)
123 *locexpr_length = length;
131 /* This is the baton used when performing dwarf2 expression
133 struct dwarf_expr_baton
135 struct frame_info *frame;
136 struct dwarf2_per_cu_data *per_cu;
139 /* Helper functions for dwarf2_evaluate_loc_desc. */
141 /* Using the frame specified in BATON, return the value of register
142 REGNUM, treated as a pointer. */
144 dwarf_expr_read_reg (void *baton, int dwarf_regnum)
146 struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
147 struct gdbarch *gdbarch = get_frame_arch (debaton->frame);
151 regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
152 result = address_from_register (builtin_type (gdbarch)->builtin_data_ptr,
153 regnum, debaton->frame);
157 /* Read memory at ADDR (length LEN) into BUF. */
160 dwarf_expr_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
162 read_memory (addr, buf, len);
165 /* Using the frame specified in BATON, find the location expression
166 describing the frame base. Return a pointer to it in START and
167 its length in LENGTH. */
169 dwarf_expr_frame_base (void *baton, const gdb_byte **start, size_t * length)
171 /* FIXME: cagney/2003-03-26: This code should be using
172 get_frame_base_address(), and then implement a dwarf2 specific
174 struct symbol *framefunc;
175 struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
177 /* Use block_linkage_function, which returns a real (not inlined)
178 function, instead of get_frame_function, which may return an
180 framefunc = block_linkage_function (get_frame_block (debaton->frame, NULL));
182 /* If we found a frame-relative symbol then it was certainly within
183 some function associated with a frame. If we can't find the frame,
184 something has gone wrong. */
185 gdb_assert (framefunc != NULL);
187 dwarf_expr_frame_base_1 (framefunc,
188 get_frame_address_in_block (debaton->frame),
193 dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
194 const gdb_byte **start, size_t *length)
196 if (SYMBOL_LOCATION_BATON (framefunc) == NULL)
198 else if (SYMBOL_COMPUTED_OPS (framefunc) == &dwarf2_loclist_funcs)
200 struct dwarf2_loclist_baton *symbaton;
202 symbaton = SYMBOL_LOCATION_BATON (framefunc);
203 *start = dwarf2_find_location_expression (symbaton, length, pc);
207 struct dwarf2_locexpr_baton *symbaton;
209 symbaton = SYMBOL_LOCATION_BATON (framefunc);
210 if (symbaton != NULL)
212 *length = symbaton->size;
213 *start = symbaton->data;
220 error (_("Could not find the frame base for \"%s\"."),
221 SYMBOL_NATURAL_NAME (framefunc));
224 /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
225 the frame in BATON. */
228 dwarf_expr_frame_cfa (void *baton)
230 struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
232 return dwarf2_frame_cfa (debaton->frame);
235 /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
236 the frame in BATON. */
239 dwarf_expr_frame_pc (void *baton)
241 struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
243 return get_frame_address_in_block (debaton->frame);
246 /* Using the objfile specified in BATON, find the address for the
247 current thread's thread-local storage with offset OFFSET. */
249 dwarf_expr_tls_address (void *baton, CORE_ADDR offset)
251 struct dwarf_expr_baton *debaton = (struct dwarf_expr_baton *) baton;
252 struct objfile *objfile = dwarf2_per_cu_objfile (debaton->per_cu);
254 return target_translate_tls_address (objfile, offset);
257 /* Call DWARF subroutine from DW_AT_location of DIE at DIE_OFFSET in
258 current CU (as is PER_CU). State of the CTX is not affected by the
262 per_cu_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset,
263 struct dwarf2_per_cu_data *per_cu,
264 CORE_ADDR (*get_frame_pc) (void *baton),
267 struct dwarf2_locexpr_baton block;
269 block = dwarf2_fetch_die_location_block (die_offset, per_cu,
270 get_frame_pc, baton);
272 /* DW_OP_call_ref is currently not supported. */
273 gdb_assert (block.per_cu == per_cu);
275 dwarf_expr_eval (ctx, block.data, block.size);
278 /* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */
281 dwarf_expr_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
283 struct dwarf_expr_baton *debaton = ctx->baton;
285 per_cu_dwarf_call (ctx, die_offset, debaton->per_cu,
286 ctx->get_frame_pc, ctx->baton);
291 /* Reference count. */
294 /* The CU from which this closure's expression came. */
295 struct dwarf2_per_cu_data *per_cu;
297 /* The number of pieces used to describe this variable. */
300 /* The target address size, used only for DWARF_VALUE_STACK. */
303 /* The pieces themselves. */
304 struct dwarf_expr_piece *pieces;
307 /* Allocate a closure for a value formed from separately-described
310 static struct piece_closure *
311 allocate_piece_closure (struct dwarf2_per_cu_data *per_cu,
312 int n_pieces, struct dwarf_expr_piece *pieces,
315 struct piece_closure *c = XZALLOC (struct piece_closure);
319 c->n_pieces = n_pieces;
320 c->addr_size = addr_size;
321 c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece);
323 memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece));
328 /* The lowest-level function to extract bits from a byte buffer.
329 SOURCE is the buffer. It is updated if we read to the end of a
331 SOURCE_OFFSET_BITS is the offset of the first bit to read. It is
332 updated to reflect the number of bits actually read.
333 NBITS is the number of bits we want to read. It is updated to
334 reflect the number of bits actually read. This function may read
336 BITS_BIG_ENDIAN is taken directly from gdbarch.
337 This function returns the extracted bits. */
340 extract_bits_primitive (const gdb_byte **source,
341 unsigned int *source_offset_bits,
342 int *nbits, int bits_big_endian)
344 unsigned int avail, mask, datum;
346 gdb_assert (*source_offset_bits < 8);
348 avail = 8 - *source_offset_bits;
352 mask = (1 << avail) - 1;
355 datum >>= 8 - (*source_offset_bits + *nbits);
357 datum >>= *source_offset_bits;
361 *source_offset_bits += avail;
362 if (*source_offset_bits >= 8)
364 *source_offset_bits -= 8;
371 /* Extract some bits from a source buffer and move forward in the
374 SOURCE is the source buffer. It is updated as bytes are read.
375 SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as
377 NBITS is the number of bits to read.
378 BITS_BIG_ENDIAN is taken directly from gdbarch.
380 This function returns the bits that were read. */
383 extract_bits (const gdb_byte **source, unsigned int *source_offset_bits,
384 int nbits, int bits_big_endian)
388 gdb_assert (nbits > 0 && nbits <= 8);
390 datum = extract_bits_primitive (source, source_offset_bits, &nbits,
396 more = extract_bits_primitive (source, source_offset_bits, &nbits,
408 /* Write some bits into a buffer and move forward in the buffer.
410 DATUM is the bits to write. The low-order bits of DATUM are used.
411 DEST is the destination buffer. It is updated as bytes are
413 DEST_OFFSET_BITS is the bit offset in DEST at which writing is
415 NBITS is the number of valid bits in DATUM.
416 BITS_BIG_ENDIAN is taken directly from gdbarch. */
419 insert_bits (unsigned int datum,
420 gdb_byte *dest, unsigned int dest_offset_bits,
421 int nbits, int bits_big_endian)
425 gdb_assert (dest_offset_bits + nbits <= 8);
427 mask = (1 << nbits) - 1;
430 datum <<= 8 - (dest_offset_bits + nbits);
431 mask <<= 8 - (dest_offset_bits + nbits);
435 datum <<= dest_offset_bits;
436 mask <<= dest_offset_bits;
439 gdb_assert ((datum & ~mask) == 0);
441 *dest = (*dest & ~mask) | datum;
444 /* Copy bits from a source to a destination.
446 DEST is where the bits should be written.
447 DEST_OFFSET_BITS is the bit offset into DEST.
448 SOURCE is the source of bits.
449 SOURCE_OFFSET_BITS is the bit offset into SOURCE.
450 BIT_COUNT is the number of bits to copy.
451 BITS_BIG_ENDIAN is taken directly from gdbarch. */
454 copy_bitwise (gdb_byte *dest, unsigned int dest_offset_bits,
455 const gdb_byte *source, unsigned int source_offset_bits,
456 unsigned int bit_count,
459 unsigned int dest_avail;
462 /* Reduce everything to byte-size pieces. */
463 dest += dest_offset_bits / 8;
464 dest_offset_bits %= 8;
465 source += source_offset_bits / 8;
466 source_offset_bits %= 8;
468 dest_avail = 8 - dest_offset_bits % 8;
470 /* See if we can fill the first destination byte. */
471 if (dest_avail < bit_count)
473 datum = extract_bits (&source, &source_offset_bits, dest_avail,
475 insert_bits (datum, dest, dest_offset_bits, dest_avail, bits_big_endian);
477 dest_offset_bits = 0;
478 bit_count -= dest_avail;
481 /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer
482 than 8 bits remaining. */
483 gdb_assert (dest_offset_bits % 8 == 0 || bit_count < 8);
484 for (; bit_count >= 8; bit_count -= 8)
486 datum = extract_bits (&source, &source_offset_bits, 8, bits_big_endian);
487 *dest++ = (gdb_byte) datum;
490 /* Finally, we may have a few leftover bits. */
491 gdb_assert (bit_count <= 8 - dest_offset_bits % 8);
494 datum = extract_bits (&source, &source_offset_bits, bit_count,
496 insert_bits (datum, dest, dest_offset_bits, bit_count, bits_big_endian);
501 read_pieced_value (struct value *v)
505 ULONGEST bits_to_skip;
507 struct piece_closure *c
508 = (struct piece_closure *) value_computed_closure (v);
509 struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v));
511 size_t buffer_size = 0;
513 struct cleanup *cleanup;
515 = gdbarch_bits_big_endian (get_type_arch (value_type (v)));
517 if (value_type (v) != value_enclosing_type (v))
518 internal_error (__FILE__, __LINE__,
519 _("Should not be able to create a lazy value with "
520 "an enclosing type"));
522 cleanup = make_cleanup (free_current_contents, &buffer);
524 contents = value_contents_raw (v);
525 bits_to_skip = 8 * value_offset (v);
526 if (value_bitsize (v))
528 bits_to_skip += value_bitpos (v);
529 type_len = value_bitsize (v);
532 type_len = 8 * TYPE_LENGTH (value_type (v));
534 for (i = 0; i < c->n_pieces && offset < type_len; i++)
536 struct dwarf_expr_piece *p = &c->pieces[i];
537 size_t this_size, this_size_bits;
538 long dest_offset_bits, source_offset_bits, source_offset;
539 const gdb_byte *intermediate_buffer;
541 /* Compute size, source, and destination offsets for copying, in
543 this_size_bits = p->size;
544 if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
546 bits_to_skip -= this_size_bits;
549 if (this_size_bits > type_len - offset)
550 this_size_bits = type_len - offset;
551 if (bits_to_skip > 0)
553 dest_offset_bits = 0;
554 source_offset_bits = bits_to_skip;
555 this_size_bits -= bits_to_skip;
560 dest_offset_bits = offset;
561 source_offset_bits = 0;
564 this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
565 source_offset = source_offset_bits / 8;
566 if (buffer_size < this_size)
568 buffer_size = this_size;
569 buffer = xrealloc (buffer, buffer_size);
571 intermediate_buffer = buffer;
573 /* Copy from the source to DEST_BUFFER. */
576 case DWARF_VALUE_REGISTER:
578 struct gdbarch *arch = get_frame_arch (frame);
579 int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.value);
580 int reg_offset = source_offset;
582 if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
583 && this_size < register_size (arch, gdb_regnum))
585 /* Big-endian, and we want less than full size. */
586 reg_offset = register_size (arch, gdb_regnum) - this_size;
587 /* We want the lower-order THIS_SIZE_BITS of the bytes
588 we extract from the register. */
589 source_offset_bits += 8 * this_size - this_size_bits;
592 if (gdb_regnum != -1)
596 if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
600 /* Just so garbage doesn't ever shine through. */
601 memset (buffer, 0, this_size);
604 set_value_optimized_out (v, 1);
606 mark_value_bytes_unavailable (v, offset, this_size);
611 error (_("Unable to access DWARF register number %s"),
612 paddress (arch, p->v.value));
617 case DWARF_VALUE_MEMORY:
618 read_value_memory (v, offset,
619 p->v.mem.in_stack_memory,
620 p->v.mem.addr + source_offset,
624 case DWARF_VALUE_STACK:
626 struct gdbarch *gdbarch = get_type_arch (value_type (v));
627 size_t n = this_size;
629 if (n > c->addr_size - source_offset)
630 n = (c->addr_size >= source_offset
631 ? c->addr_size - source_offset
637 else if (source_offset == 0)
638 store_unsigned_integer (buffer, n,
639 gdbarch_byte_order (gdbarch),
643 gdb_byte bytes[sizeof (ULONGEST)];
645 store_unsigned_integer (bytes, n + source_offset,
646 gdbarch_byte_order (gdbarch),
648 memcpy (buffer, bytes + source_offset, n);
653 case DWARF_VALUE_LITERAL:
655 size_t n = this_size;
657 if (n > p->v.literal.length - source_offset)
658 n = (p->v.literal.length >= source_offset
659 ? p->v.literal.length - source_offset
662 intermediate_buffer = p->v.literal.data + source_offset;
666 /* These bits show up as zeros -- but do not cause the value
667 to be considered optimized-out. */
668 case DWARF_VALUE_IMPLICIT_POINTER:
671 case DWARF_VALUE_OPTIMIZED_OUT:
672 set_value_optimized_out (v, 1);
676 internal_error (__FILE__, __LINE__, _("invalid location type"));
679 if (p->location != DWARF_VALUE_OPTIMIZED_OUT
680 && p->location != DWARF_VALUE_IMPLICIT_POINTER)
681 copy_bitwise (contents, dest_offset_bits,
682 intermediate_buffer, source_offset_bits % 8,
683 this_size_bits, bits_big_endian);
685 offset += this_size_bits;
688 do_cleanups (cleanup);
692 write_pieced_value (struct value *to, struct value *from)
696 ULONGEST bits_to_skip;
697 const gdb_byte *contents;
698 struct piece_closure *c
699 = (struct piece_closure *) value_computed_closure (to);
700 struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to));
702 size_t buffer_size = 0;
704 struct cleanup *cleanup;
706 = gdbarch_bits_big_endian (get_type_arch (value_type (to)));
710 set_value_optimized_out (to, 1);
714 cleanup = make_cleanup (free_current_contents, &buffer);
716 contents = value_contents (from);
717 bits_to_skip = 8 * value_offset (to);
718 if (value_bitsize (to))
720 bits_to_skip += value_bitpos (to);
721 type_len = value_bitsize (to);
724 type_len = 8 * TYPE_LENGTH (value_type (to));
726 for (i = 0; i < c->n_pieces && offset < type_len; i++)
728 struct dwarf_expr_piece *p = &c->pieces[i];
729 size_t this_size_bits, this_size;
730 long dest_offset_bits, source_offset_bits, dest_offset, source_offset;
732 const gdb_byte *source_buffer;
734 this_size_bits = p->size;
735 if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
737 bits_to_skip -= this_size_bits;
740 if (this_size_bits > type_len - offset)
741 this_size_bits = type_len - offset;
742 if (bits_to_skip > 0)
744 dest_offset_bits = bits_to_skip;
745 source_offset_bits = 0;
746 this_size_bits -= bits_to_skip;
751 dest_offset_bits = 0;
752 source_offset_bits = offset;
755 this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
756 source_offset = source_offset_bits / 8;
757 dest_offset = dest_offset_bits / 8;
758 if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0)
760 source_buffer = contents + source_offset;
765 if (buffer_size < this_size)
767 buffer_size = this_size;
768 buffer = xrealloc (buffer, buffer_size);
770 source_buffer = buffer;
776 case DWARF_VALUE_REGISTER:
778 struct gdbarch *arch = get_frame_arch (frame);
779 int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.value);
780 int reg_offset = dest_offset;
782 if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
783 && this_size <= register_size (arch, gdb_regnum))
784 /* Big-endian, and we want less than full size. */
785 reg_offset = register_size (arch, gdb_regnum) - this_size;
787 if (gdb_regnum != -1)
793 if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
798 error (_("Can't do read-modify-write to "
799 "update bitfield; containing word has been "
802 throw_error (NOT_AVAILABLE_ERROR,
803 _("Can't do read-modify-write to update "
804 "bitfield; containing word "
807 copy_bitwise (buffer, dest_offset_bits,
808 contents, source_offset_bits,
813 put_frame_register_bytes (frame, gdb_regnum, reg_offset,
814 this_size, source_buffer);
818 error (_("Unable to write to DWARF register number %s"),
819 paddress (arch, p->v.value));
823 case DWARF_VALUE_MEMORY:
826 /* Only the first and last bytes can possibly have any
828 read_memory (p->v.mem.addr + dest_offset, buffer, 1);
829 read_memory (p->v.mem.addr + dest_offset + this_size - 1,
830 buffer + this_size - 1, 1);
831 copy_bitwise (buffer, dest_offset_bits,
832 contents, source_offset_bits,
837 write_memory (p->v.mem.addr + dest_offset,
838 source_buffer, this_size);
841 set_value_optimized_out (to, 1);
844 offset += this_size_bits;
847 do_cleanups (cleanup);
850 /* A helper function that checks bit validity in a pieced value.
851 CHECK_FOR indicates the kind of validity checking.
852 DWARF_VALUE_MEMORY means to check whether any bit is valid.
853 DWARF_VALUE_OPTIMIZED_OUT means to check whether any bit is
855 DWARF_VALUE_IMPLICIT_POINTER means to check whether the bits are an
859 check_pieced_value_bits (const struct value *value, int bit_offset,
861 enum dwarf_value_location check_for)
863 struct piece_closure *c
864 = (struct piece_closure *) value_computed_closure (value);
866 int validity = (check_for == DWARF_VALUE_MEMORY
867 || check_for == DWARF_VALUE_IMPLICIT_POINTER);
869 bit_offset += 8 * value_offset (value);
870 if (value_bitsize (value))
871 bit_offset += value_bitpos (value);
873 for (i = 0; i < c->n_pieces && bit_length > 0; i++)
875 struct dwarf_expr_piece *p = &c->pieces[i];
876 size_t this_size_bits = p->size;
880 if (bit_offset >= this_size_bits)
882 bit_offset -= this_size_bits;
886 bit_length -= this_size_bits - bit_offset;
890 bit_length -= this_size_bits;
892 if (check_for == DWARF_VALUE_IMPLICIT_POINTER)
894 if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
897 else if (p->location == DWARF_VALUE_OPTIMIZED_OUT
898 || p->location == DWARF_VALUE_IMPLICIT_POINTER)
914 check_pieced_value_validity (const struct value *value, int bit_offset,
917 return check_pieced_value_bits (value, bit_offset, bit_length,
922 check_pieced_value_invalid (const struct value *value)
924 return check_pieced_value_bits (value, 0,
925 8 * TYPE_LENGTH (value_type (value)),
926 DWARF_VALUE_OPTIMIZED_OUT);
929 /* An implementation of an lval_funcs method to see whether a value is
930 a synthetic pointer. */
933 check_pieced_synthetic_pointer (const struct value *value, int bit_offset,
936 return check_pieced_value_bits (value, bit_offset, bit_length,
937 DWARF_VALUE_IMPLICIT_POINTER);
940 /* A wrapper function for get_frame_address_in_block. */
943 get_frame_address_in_block_wrapper (void *baton)
945 return get_frame_address_in_block (baton);
948 /* An implementation of an lval_funcs method to indirect through a
949 pointer. This handles the synthetic pointer case when needed. */
951 static struct value *
952 indirect_pieced_value (struct value *value)
954 struct piece_closure *c
955 = (struct piece_closure *) value_computed_closure (value);
957 struct frame_info *frame;
958 struct dwarf2_locexpr_baton baton;
959 int i, bit_offset, bit_length;
960 struct dwarf_expr_piece *piece = NULL;
961 struct value *result;
964 type = value_type (value);
965 if (TYPE_CODE (type) != TYPE_CODE_PTR)
968 bit_length = 8 * TYPE_LENGTH (type);
969 bit_offset = 8 * value_offset (value);
970 if (value_bitsize (value))
971 bit_offset += value_bitpos (value);
973 for (i = 0; i < c->n_pieces && bit_length > 0; i++)
975 struct dwarf_expr_piece *p = &c->pieces[i];
976 size_t this_size_bits = p->size;
980 if (bit_offset >= this_size_bits)
982 bit_offset -= this_size_bits;
986 bit_length -= this_size_bits - bit_offset;
990 bit_length -= this_size_bits;
992 if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
996 error (_("Invalid use of DW_OP_GNU_implicit_pointer"));
1002 frame = get_selected_frame (_("No frame selected."));
1003 byte_offset = value_as_address (value);
1006 baton = dwarf2_fetch_die_location_block (piece->v.ptr.die, c->per_cu,
1007 get_frame_address_in_block_wrapper,
1010 result = dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
1011 baton.data, baton.size, baton.per_cu,
1018 copy_pieced_value_closure (const struct value *v)
1020 struct piece_closure *c
1021 = (struct piece_closure *) value_computed_closure (v);
1028 free_pieced_value_closure (struct value *v)
1030 struct piece_closure *c
1031 = (struct piece_closure *) value_computed_closure (v);
1041 /* Functions for accessing a variable described by DW_OP_piece. */
1042 static struct lval_funcs pieced_value_funcs = {
1045 check_pieced_value_validity,
1046 check_pieced_value_invalid,
1047 indirect_pieced_value,
1048 check_pieced_synthetic_pointer,
1049 copy_pieced_value_closure,
1050 free_pieced_value_closure
1053 /* Helper function which throws an error if a synthetic pointer is
1057 invalid_synthetic_pointer (void)
1059 error (_("access outside bounds of object "
1060 "referenced via synthetic pointer"));
1063 /* Evaluate a location description, starting at DATA and with length
1064 SIZE, to find the current location of variable of TYPE in the
1065 context of FRAME. BYTE_OFFSET is applied after the contents are
1068 static struct value *
1069 dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
1070 const gdb_byte *data, unsigned short size,
1071 struct dwarf2_per_cu_data *per_cu,
1072 LONGEST byte_offset)
1074 struct value *retval;
1075 struct dwarf_expr_baton baton;
1076 struct dwarf_expr_context *ctx;
1077 struct cleanup *old_chain;
1078 struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
1079 volatile struct gdb_exception ex;
1081 if (byte_offset < 0)
1082 invalid_synthetic_pointer ();
1086 retval = allocate_value (type);
1087 VALUE_LVAL (retval) = not_lval;
1088 set_value_optimized_out (retval, 1);
1092 baton.frame = frame;
1093 baton.per_cu = per_cu;
1095 ctx = new_dwarf_expr_context ();
1096 old_chain = make_cleanup_free_dwarf_expr_context (ctx);
1098 ctx->gdbarch = get_objfile_arch (objfile);
1099 ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
1100 ctx->offset = dwarf2_per_cu_text_offset (per_cu);
1101 ctx->baton = &baton;
1102 ctx->read_reg = dwarf_expr_read_reg;
1103 ctx->read_mem = dwarf_expr_read_mem;
1104 ctx->get_frame_base = dwarf_expr_frame_base;
1105 ctx->get_frame_cfa = dwarf_expr_frame_cfa;
1106 ctx->get_frame_pc = dwarf_expr_frame_pc;
1107 ctx->get_tls_address = dwarf_expr_tls_address;
1108 ctx->dwarf_call = dwarf_expr_dwarf_call;
1110 TRY_CATCH (ex, RETURN_MASK_ERROR)
1112 dwarf_expr_eval (ctx, data, size);
1116 if (ex.error == NOT_AVAILABLE_ERROR)
1118 retval = allocate_value (type);
1119 mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type));
1123 throw_exception (ex);
1126 if (ctx->num_pieces > 0)
1128 struct piece_closure *c;
1129 struct frame_id frame_id = get_frame_id (frame);
1130 ULONGEST bit_size = 0;
1133 for (i = 0; i < ctx->num_pieces; ++i)
1134 bit_size += ctx->pieces[i].size;
1135 if (8 * (byte_offset + TYPE_LENGTH (type)) > bit_size)
1136 invalid_synthetic_pointer ();
1138 c = allocate_piece_closure (per_cu, ctx->num_pieces, ctx->pieces,
1140 retval = allocate_computed_value (type, &pieced_value_funcs, c);
1141 VALUE_FRAME_ID (retval) = frame_id;
1142 set_value_offset (retval, byte_offset);
1146 switch (ctx->location)
1148 case DWARF_VALUE_REGISTER:
1150 struct gdbarch *arch = get_frame_arch (frame);
1151 ULONGEST dwarf_regnum = dwarf_expr_fetch (ctx, 0);
1152 int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum);
1154 if (byte_offset != 0)
1155 error (_("cannot use offset on synthetic pointer to register"));
1156 if (gdb_regnum != -1)
1157 retval = value_from_register (type, gdb_regnum, frame);
1159 error (_("Unable to access DWARF register number %s"),
1160 paddress (arch, dwarf_regnum));
1164 case DWARF_VALUE_MEMORY:
1166 CORE_ADDR address = dwarf_expr_fetch_address (ctx, 0);
1167 int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
1169 retval = allocate_value_lazy (type);
1170 VALUE_LVAL (retval) = lval_memory;
1171 if (in_stack_memory)
1172 set_value_stack (retval, 1);
1173 set_value_address (retval, address + byte_offset);
1177 case DWARF_VALUE_STACK:
1179 ULONGEST value = dwarf_expr_fetch (ctx, 0);
1180 bfd_byte *contents, *tem;
1181 size_t n = ctx->addr_size;
1183 if (byte_offset + TYPE_LENGTH (type) > n)
1184 invalid_synthetic_pointer ();
1187 store_unsigned_integer (tem, n,
1188 gdbarch_byte_order (ctx->gdbarch),
1194 retval = allocate_value (type);
1195 contents = value_contents_raw (retval);
1196 if (n > TYPE_LENGTH (type))
1197 n = TYPE_LENGTH (type);
1198 memcpy (contents, tem, n);
1202 case DWARF_VALUE_LITERAL:
1205 const bfd_byte *ldata;
1206 size_t n = ctx->len;
1208 if (byte_offset + TYPE_LENGTH (type) > n)
1209 invalid_synthetic_pointer ();
1211 retval = allocate_value (type);
1212 contents = value_contents_raw (retval);
1214 ldata = ctx->data + byte_offset;
1217 if (n > TYPE_LENGTH (type))
1218 n = TYPE_LENGTH (type);
1219 memcpy (contents, ldata, n);
1223 /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
1224 operation by execute_stack_op. */
1225 case DWARF_VALUE_IMPLICIT_POINTER:
1226 /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
1227 it can only be encountered when making a piece. */
1228 case DWARF_VALUE_OPTIMIZED_OUT:
1230 internal_error (__FILE__, __LINE__, _("invalid location type"));
1234 set_value_initialized (retval, ctx->initialized);
1236 do_cleanups (old_chain);
1241 /* The exported interface to dwarf2_evaluate_loc_desc_full; it always
1242 passes 0 as the byte_offset. */
1245 dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
1246 const gdb_byte *data, unsigned short size,
1247 struct dwarf2_per_cu_data *per_cu)
1249 return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0);
1253 /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
1255 struct needs_frame_baton
1258 struct dwarf2_per_cu_data *per_cu;
1261 /* Reads from registers do require a frame. */
1263 needs_frame_read_reg (void *baton, int regnum)
1265 struct needs_frame_baton *nf_baton = baton;
1267 nf_baton->needs_frame = 1;
1271 /* Reads from memory do not require a frame. */
1273 needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
1275 memset (buf, 0, len);
1278 /* Frame-relative accesses do require a frame. */
1280 needs_frame_frame_base (void *baton, const gdb_byte **start, size_t * length)
1282 static gdb_byte lit0 = DW_OP_lit0;
1283 struct needs_frame_baton *nf_baton = baton;
1288 nf_baton->needs_frame = 1;
1291 /* CFA accesses require a frame. */
1294 needs_frame_frame_cfa (void *baton)
1296 struct needs_frame_baton *nf_baton = baton;
1298 nf_baton->needs_frame = 1;
1302 /* Thread-local accesses do require a frame. */
1304 needs_frame_tls_address (void *baton, CORE_ADDR offset)
1306 struct needs_frame_baton *nf_baton = baton;
1308 nf_baton->needs_frame = 1;
1312 /* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */
1315 needs_frame_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
1317 struct needs_frame_baton *nf_baton = ctx->baton;
1319 per_cu_dwarf_call (ctx, die_offset, nf_baton->per_cu,
1320 ctx->get_frame_pc, ctx->baton);
1323 /* Return non-zero iff the location expression at DATA (length SIZE)
1324 requires a frame to evaluate. */
1327 dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size,
1328 struct dwarf2_per_cu_data *per_cu)
1330 struct needs_frame_baton baton;
1331 struct dwarf_expr_context *ctx;
1333 struct cleanup *old_chain;
1334 struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
1336 baton.needs_frame = 0;
1337 baton.per_cu = per_cu;
1339 ctx = new_dwarf_expr_context ();
1340 old_chain = make_cleanup_free_dwarf_expr_context (ctx);
1342 ctx->gdbarch = get_objfile_arch (objfile);
1343 ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
1344 ctx->offset = dwarf2_per_cu_text_offset (per_cu);
1345 ctx->baton = &baton;
1346 ctx->read_reg = needs_frame_read_reg;
1347 ctx->read_mem = needs_frame_read_mem;
1348 ctx->get_frame_base = needs_frame_frame_base;
1349 ctx->get_frame_cfa = needs_frame_frame_cfa;
1350 ctx->get_frame_pc = needs_frame_frame_cfa;
1351 ctx->get_tls_address = needs_frame_tls_address;
1352 ctx->dwarf_call = needs_frame_dwarf_call;
1354 dwarf_expr_eval (ctx, data, size);
1356 in_reg = ctx->location == DWARF_VALUE_REGISTER;
1358 if (ctx->num_pieces > 0)
1362 /* If the location has several pieces, and any of them are in
1363 registers, then we will need a frame to fetch them from. */
1364 for (i = 0; i < ctx->num_pieces; i++)
1365 if (ctx->pieces[i].location == DWARF_VALUE_REGISTER)
1369 do_cleanups (old_chain);
1371 return baton.needs_frame || in_reg;
1374 /* A helper function that throws an unimplemented error mentioning a
1375 given DWARF operator. */
1378 unimplemented (unsigned int op)
1380 const char *name = dwarf_stack_op_name (op);
1383 error (_("DWARF operator %s cannot be translated to an agent expression"),
1386 error (_("Unknown DWARF operator 0x%02x cannot be translated "
1387 "to an agent expression"),
1391 /* A helper function to convert a DWARF register to an arch register.
1392 ARCH is the architecture.
1393 DWARF_REG is the register.
1394 This will throw an exception if the DWARF register cannot be
1395 translated to an architecture register. */
1398 translate_register (struct gdbarch *arch, int dwarf_reg)
1400 int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg);
1402 error (_("Unable to access DWARF register number %d"), dwarf_reg);
1406 /* A helper function that emits an access to memory. ARCH is the
1407 target architecture. EXPR is the expression which we are building.
1408 NBITS is the number of bits we want to read. This emits the
1409 opcodes needed to read the memory and then extract the desired
1413 access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits)
1415 ULONGEST nbytes = (nbits + 7) / 8;
1417 gdb_assert (nbits > 0 && nbits <= sizeof (LONGEST));
1420 ax_trace_quick (expr, nbytes);
1423 ax_simple (expr, aop_ref8);
1424 else if (nbits <= 16)
1425 ax_simple (expr, aop_ref16);
1426 else if (nbits <= 32)
1427 ax_simple (expr, aop_ref32);
1429 ax_simple (expr, aop_ref64);
1431 /* If we read exactly the number of bytes we wanted, we're done. */
1432 if (8 * nbytes == nbits)
1435 if (gdbarch_bits_big_endian (arch))
1437 /* On a bits-big-endian machine, we want the high-order
1439 ax_const_l (expr, 8 * nbytes - nbits);
1440 ax_simple (expr, aop_rsh_unsigned);
1444 /* On a bits-little-endian box, we want the low-order NBITS. */
1445 ax_zero_ext (expr, nbits);
1449 /* A helper function to return the frame's PC. */
1452 get_ax_pc (void *baton)
1454 struct agent_expr *expr = baton;
1459 /* Compile a DWARF location expression to an agent expression.
1461 EXPR is the agent expression we are building.
1462 LOC is the agent value we modify.
1463 ARCH is the architecture.
1464 ADDR_SIZE is the size of addresses, in bytes.
1465 OP_PTR is the start of the location expression.
1466 OP_END is one past the last byte of the location expression.
1468 This will throw an exception for various kinds of errors -- for
1469 example, if the expression cannot be compiled, or if the expression
1473 dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc,
1474 struct gdbarch *arch, unsigned int addr_size,
1475 const gdb_byte *op_ptr, const gdb_byte *op_end,
1476 struct dwarf2_per_cu_data *per_cu)
1478 struct cleanup *cleanups;
1480 VEC(int) *dw_labels = NULL, *patches = NULL;
1481 const gdb_byte * const base = op_ptr;
1482 const gdb_byte *previous_piece = op_ptr;
1483 enum bfd_endian byte_order = gdbarch_byte_order (arch);
1484 ULONGEST bits_collected = 0;
1485 unsigned int addr_size_bits = 8 * addr_size;
1486 int bits_big_endian = gdbarch_bits_big_endian (arch);
1488 offsets = xmalloc ((op_end - op_ptr) * sizeof (int));
1489 cleanups = make_cleanup (xfree, offsets);
1491 for (i = 0; i < op_end - op_ptr; ++i)
1494 make_cleanup (VEC_cleanup (int), &dw_labels);
1495 make_cleanup (VEC_cleanup (int), &patches);
1497 /* By default we are making an address. */
1498 loc->kind = axs_lvalue_memory;
1500 while (op_ptr < op_end)
1502 enum dwarf_location_atom op = *op_ptr;
1503 ULONGEST uoffset, reg;
1507 offsets[op_ptr - base] = expr->len;
1510 /* Our basic approach to code generation is to map DWARF
1511 operations directly to AX operations. However, there are
1514 First, DWARF works on address-sized units, but AX always uses
1515 LONGEST. For most operations we simply ignore this
1516 difference; instead we generate sign extensions as needed
1517 before division and comparison operations. It would be nice
1518 to omit the sign extensions, but there is no way to determine
1519 the size of the target's LONGEST. (This code uses the size
1520 of the host LONGEST in some cases -- that is a bug but it is
1523 Second, some DWARF operations cannot be translated to AX.
1524 For these we simply fail. See
1525 http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
1560 ax_const_l (expr, op - DW_OP_lit0);
1564 uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order);
1565 op_ptr += addr_size;
1566 /* Some versions of GCC emit DW_OP_addr before
1567 DW_OP_GNU_push_tls_address. In this case the value is an
1568 index, not an address. We don't support things like
1569 branching between the address and the TLS op. */
1570 if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
1571 uoffset += dwarf2_per_cu_text_offset (per_cu);
1572 ax_const_l (expr, uoffset);
1576 ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order));
1580 ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order));
1584 ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order));
1588 ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order));
1592 ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order));
1596 ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order));
1600 ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order));
1604 ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order));
1608 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
1609 ax_const_l (expr, uoffset);
1612 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1613 ax_const_l (expr, offset);
1648 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
1649 loc->u.reg = translate_register (arch, op - DW_OP_reg0);
1650 loc->kind = axs_lvalue_register;
1654 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1655 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
1656 loc->u.reg = translate_register (arch, reg);
1657 loc->kind = axs_lvalue_register;
1660 case DW_OP_implicit_value:
1664 op_ptr = read_uleb128 (op_ptr, op_end, &len);
1665 if (op_ptr + len > op_end)
1666 error (_("DW_OP_implicit_value: too few bytes available."));
1667 if (len > sizeof (ULONGEST))
1668 error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
1671 ax_const_l (expr, extract_unsigned_integer (op_ptr, len,
1674 dwarf_expr_require_composition (op_ptr, op_end,
1675 "DW_OP_implicit_value");
1677 loc->kind = axs_rvalue;
1681 case DW_OP_stack_value:
1682 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
1683 loc->kind = axs_rvalue;
1718 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1719 i = translate_register (arch, op - DW_OP_breg0);
1723 ax_const_l (expr, offset);
1724 ax_simple (expr, aop_add);
1729 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1730 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1731 i = translate_register (arch, reg);
1735 ax_const_l (expr, offset);
1736 ax_simple (expr, aop_add);
1742 const gdb_byte *datastart;
1744 unsigned int before_stack_len;
1746 struct symbol *framefunc;
1747 LONGEST base_offset = 0;
1749 b = block_for_pc (expr->scope);
1752 error (_("No block found for address"));
1754 framefunc = block_linkage_function (b);
1757 error (_("No function found for block"));
1759 dwarf_expr_frame_base_1 (framefunc, expr->scope,
1760 &datastart, &datalen);
1762 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1763 dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, datastart,
1764 datastart + datalen, per_cu);
1768 ax_const_l (expr, offset);
1769 ax_simple (expr, aop_add);
1772 loc->kind = axs_lvalue_memory;
1777 ax_simple (expr, aop_dup);
1781 ax_simple (expr, aop_pop);
1786 ax_pick (expr, offset);
1790 ax_simple (expr, aop_swap);
1798 ax_simple (expr, aop_rot);
1802 case DW_OP_deref_size:
1806 if (op == DW_OP_deref_size)
1814 ax_simple (expr, aop_ref8);
1817 ax_simple (expr, aop_ref16);
1820 ax_simple (expr, aop_ref32);
1823 ax_simple (expr, aop_ref64);
1826 /* Note that dwarf_stack_op_name will never return
1828 error (_("Unsupported size %d in %s"),
1829 size, dwarf_stack_op_name (op));
1835 /* Sign extend the operand. */
1836 ax_ext (expr, addr_size_bits);
1837 ax_simple (expr, aop_dup);
1838 ax_const_l (expr, 0);
1839 ax_simple (expr, aop_less_signed);
1840 ax_simple (expr, aop_log_not);
1841 i = ax_goto (expr, aop_if_goto);
1842 /* We have to emit 0 - X. */
1843 ax_const_l (expr, 0);
1844 ax_simple (expr, aop_swap);
1845 ax_simple (expr, aop_sub);
1846 ax_label (expr, i, expr->len);
1850 /* No need to sign extend here. */
1851 ax_const_l (expr, 0);
1852 ax_simple (expr, aop_swap);
1853 ax_simple (expr, aop_sub);
1857 /* Sign extend the operand. */
1858 ax_ext (expr, addr_size_bits);
1859 ax_simple (expr, aop_bit_not);
1862 case DW_OP_plus_uconst:
1863 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1864 /* It would be really weird to emit `DW_OP_plus_uconst 0',
1865 but we micro-optimize anyhow. */
1868 ax_const_l (expr, reg);
1869 ax_simple (expr, aop_add);
1874 ax_simple (expr, aop_bit_and);
1878 /* Sign extend the operands. */
1879 ax_ext (expr, addr_size_bits);
1880 ax_simple (expr, aop_swap);
1881 ax_ext (expr, addr_size_bits);
1882 ax_simple (expr, aop_swap);
1883 ax_simple (expr, aop_div_signed);
1887 ax_simple (expr, aop_sub);
1891 ax_simple (expr, aop_rem_unsigned);
1895 ax_simple (expr, aop_mul);
1899 ax_simple (expr, aop_bit_or);
1903 ax_simple (expr, aop_add);
1907 ax_simple (expr, aop_lsh);
1911 ax_simple (expr, aop_rsh_unsigned);
1915 ax_simple (expr, aop_rsh_signed);
1919 ax_simple (expr, aop_bit_xor);
1923 /* Sign extend the operands. */
1924 ax_ext (expr, addr_size_bits);
1925 ax_simple (expr, aop_swap);
1926 ax_ext (expr, addr_size_bits);
1927 /* Note no swap here: A <= B is !(B < A). */
1928 ax_simple (expr, aop_less_signed);
1929 ax_simple (expr, aop_log_not);
1933 /* Sign extend the operands. */
1934 ax_ext (expr, addr_size_bits);
1935 ax_simple (expr, aop_swap);
1936 ax_ext (expr, addr_size_bits);
1937 ax_simple (expr, aop_swap);
1938 /* A >= B is !(A < B). */
1939 ax_simple (expr, aop_less_signed);
1940 ax_simple (expr, aop_log_not);
1944 /* Sign extend the operands. */
1945 ax_ext (expr, addr_size_bits);
1946 ax_simple (expr, aop_swap);
1947 ax_ext (expr, addr_size_bits);
1948 /* No need for a second swap here. */
1949 ax_simple (expr, aop_equal);
1953 /* Sign extend the operands. */
1954 ax_ext (expr, addr_size_bits);
1955 ax_simple (expr, aop_swap);
1956 ax_ext (expr, addr_size_bits);
1957 ax_simple (expr, aop_swap);
1958 ax_simple (expr, aop_less_signed);
1962 /* Sign extend the operands. */
1963 ax_ext (expr, addr_size_bits);
1964 ax_simple (expr, aop_swap);
1965 ax_ext (expr, addr_size_bits);
1966 /* Note no swap here: A > B is B < A. */
1967 ax_simple (expr, aop_less_signed);
1971 /* Sign extend the operands. */
1972 ax_ext (expr, addr_size_bits);
1973 ax_simple (expr, aop_swap);
1974 ax_ext (expr, addr_size_bits);
1975 /* No need for a swap here. */
1976 ax_simple (expr, aop_equal);
1977 ax_simple (expr, aop_log_not);
1980 case DW_OP_call_frame_cfa:
1981 dwarf2_compile_cfa_to_ax (expr, loc, arch, expr->scope, per_cu);
1982 loc->kind = axs_lvalue_memory;
1985 case DW_OP_GNU_push_tls_address:
1990 offset = extract_signed_integer (op_ptr, 2, byte_order);
1992 i = ax_goto (expr, aop_goto);
1993 VEC_safe_push (int, dw_labels, op_ptr + offset - base);
1994 VEC_safe_push (int, patches, i);
1998 offset = extract_signed_integer (op_ptr, 2, byte_order);
2000 /* Zero extend the operand. */
2001 ax_zero_ext (expr, addr_size_bits);
2002 i = ax_goto (expr, aop_if_goto);
2003 VEC_safe_push (int, dw_labels, op_ptr + offset - base);
2004 VEC_safe_push (int, patches, i);
2011 case DW_OP_bit_piece:
2013 ULONGEST size, offset;
2015 if (op_ptr - 1 == previous_piece)
2016 error (_("Cannot translate empty pieces to agent expressions"));
2017 previous_piece = op_ptr - 1;
2019 op_ptr = read_uleb128 (op_ptr, op_end, &size);
2020 if (op == DW_OP_piece)
2026 op_ptr = read_uleb128 (op_ptr, op_end, &offset);
2028 if (bits_collected + size > 8 * sizeof (LONGEST))
2029 error (_("Expression pieces exceed word size"));
2031 /* Access the bits. */
2034 case axs_lvalue_register:
2035 ax_reg (expr, loc->u.reg);
2038 case axs_lvalue_memory:
2039 /* Offset the pointer, if needed. */
2042 ax_const_l (expr, offset / 8);
2043 ax_simple (expr, aop_add);
2046 access_memory (arch, expr, size);
2050 /* For a bits-big-endian target, shift up what we already
2051 have. For a bits-little-endian target, shift up the
2052 new data. Note that there is a potential bug here if
2053 the DWARF expression leaves multiple values on the
2055 if (bits_collected > 0)
2057 if (bits_big_endian)
2059 ax_simple (expr, aop_swap);
2060 ax_const_l (expr, size);
2061 ax_simple (expr, aop_lsh);
2062 /* We don't need a second swap here, because
2063 aop_bit_or is symmetric. */
2067 ax_const_l (expr, size);
2068 ax_simple (expr, aop_lsh);
2070 ax_simple (expr, aop_bit_or);
2073 bits_collected += size;
2074 loc->kind = axs_rvalue;
2078 case DW_OP_GNU_uninit:
2084 struct dwarf2_locexpr_baton block;
2085 int size = (op == DW_OP_call2 ? 2 : 4);
2087 uoffset = extract_unsigned_integer (op_ptr, size, byte_order);
2090 block = dwarf2_fetch_die_location_block (uoffset, per_cu,
2093 /* DW_OP_call_ref is currently not supported. */
2094 gdb_assert (block.per_cu == per_cu);
2096 dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size,
2097 block.data, block.data + block.size,
2102 case DW_OP_call_ref:
2110 /* Patch all the branches we emitted. */
2111 for (i = 0; i < VEC_length (int, patches); ++i)
2113 int targ = offsets[VEC_index (int, dw_labels, i)];
2115 internal_error (__FILE__, __LINE__, _("invalid label"));
2116 ax_label (expr, VEC_index (int, patches, i), targ);
2119 do_cleanups (cleanups);
2123 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
2124 evaluator to calculate the location. */
2125 static struct value *
2126 locexpr_read_variable (struct symbol *symbol, struct frame_info *frame)
2128 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2131 val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data,
2132 dlbaton->size, dlbaton->per_cu);
2137 /* Return non-zero iff we need a frame to evaluate SYMBOL. */
2139 locexpr_read_needs_frame (struct symbol *symbol)
2141 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2143 return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size,
2147 /* Return true if DATA points to the end of a piece. END is one past
2148 the last byte in the expression. */
2151 piece_end_p (const gdb_byte *data, const gdb_byte *end)
2153 return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece;
2156 /* Nicely describe a single piece of a location, returning an updated
2157 position in the bytecode sequence. This function cannot recognize
2158 all locations; if a location is not recognized, it simply returns
2161 static const gdb_byte *
2162 locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
2163 CORE_ADDR addr, struct objfile *objfile,
2164 const gdb_byte *data, const gdb_byte *end,
2165 unsigned int addr_size)
2167 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2170 if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
2172 regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_reg0);
2173 fprintf_filtered (stream, _("a variable in $%s"),
2174 gdbarch_register_name (gdbarch, regno));
2177 else if (data[0] == DW_OP_regx)
2181 data = read_uleb128 (data + 1, end, ®);
2182 regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
2183 fprintf_filtered (stream, _("a variable in $%s"),
2184 gdbarch_register_name (gdbarch, regno));
2186 else if (data[0] == DW_OP_fbreg)
2189 struct symbol *framefunc;
2191 LONGEST frame_offset;
2192 const gdb_byte *base_data, *new_data, *save_data = data;
2194 LONGEST base_offset = 0;
2196 new_data = read_sleb128 (data + 1, end, &frame_offset);
2197 if (!piece_end_p (new_data, end))
2201 b = block_for_pc (addr);
2204 error (_("No block found for address for symbol \"%s\"."),
2205 SYMBOL_PRINT_NAME (symbol));
2207 framefunc = block_linkage_function (b);
2210 error (_("No function found for block for symbol \"%s\"."),
2211 SYMBOL_PRINT_NAME (symbol));
2213 dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size);
2215 if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
2217 const gdb_byte *buf_end;
2219 frame_reg = base_data[0] - DW_OP_breg0;
2220 buf_end = read_sleb128 (base_data + 1,
2221 base_data + base_size, &base_offset);
2222 if (buf_end != base_data + base_size)
2223 error (_("Unexpected opcode after "
2224 "DW_OP_breg%u for symbol \"%s\"."),
2225 frame_reg, SYMBOL_PRINT_NAME (symbol));
2227 else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
2229 /* The frame base is just the register, with no offset. */
2230 frame_reg = base_data[0] - DW_OP_reg0;
2235 /* We don't know what to do with the frame base expression,
2236 so we can't trace this variable; give up. */
2240 regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, frame_reg);
2242 fprintf_filtered (stream,
2243 _("a variable at frame base reg $%s offset %s+%s"),
2244 gdbarch_register_name (gdbarch, regno),
2245 plongest (base_offset), plongest (frame_offset));
2247 else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31
2248 && piece_end_p (data, end))
2252 regno = gdbarch_dwarf2_reg_to_regnum (gdbarch, data[0] - DW_OP_breg0);
2254 data = read_sleb128 (data + 1, end, &offset);
2256 fprintf_filtered (stream,
2257 _("a variable at offset %s from base reg $%s"),
2259 gdbarch_register_name (gdbarch, regno));
2262 /* The location expression for a TLS variable looks like this (on a
2265 DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
2266 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
2268 0x3 is the encoding for DW_OP_addr, which has an operand as long
2269 as the size of an address on the target machine (here is 8
2270 bytes). Note that more recent version of GCC emit DW_OP_const4u
2271 or DW_OP_const8u, depending on address size, rather than
2272 DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
2273 The operand represents the offset at which the variable is within
2274 the thread local storage. */
2276 else if (data + 1 + addr_size < end
2277 && (data[0] == DW_OP_addr
2278 || (addr_size == 4 && data[0] == DW_OP_const4u)
2279 || (addr_size == 8 && data[0] == DW_OP_const8u))
2280 && data[1 + addr_size] == DW_OP_GNU_push_tls_address
2281 && piece_end_p (data + 2 + addr_size, end))
2284 offset = extract_unsigned_integer (data + 1, addr_size,
2285 gdbarch_byte_order (gdbarch));
2287 fprintf_filtered (stream,
2288 _("a thread-local variable at offset 0x%s "
2289 "in the thread-local storage for `%s'"),
2290 phex_nz (offset, addr_size), objfile->name);
2292 data += 1 + addr_size + 1;
2294 else if (data[0] >= DW_OP_lit0
2295 && data[0] <= DW_OP_lit31
2297 && data[1] == DW_OP_stack_value)
2299 fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0);
2306 /* Disassemble an expression, stopping at the end of a piece or at the
2307 end of the expression. Returns a pointer to the next unread byte
2308 in the input expression. If ALL is nonzero, then this function
2309 will keep going until it reaches the end of the expression. */
2311 static const gdb_byte *
2312 disassemble_dwarf_expression (struct ui_file *stream,
2313 struct gdbarch *arch, unsigned int addr_size,
2315 const gdb_byte *data, const gdb_byte *end,
2318 const gdb_byte *start = data;
2320 fprintf_filtered (stream, _("a complex DWARF expression:\n"));
2324 || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece)))
2326 enum dwarf_location_atom op = *data++;
2331 name = dwarf_stack_op_name (op);
2334 error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
2335 op, (long) (data - start));
2336 fprintf_filtered (stream, " % 4ld: %s", (long) (data - start), name);
2341 ul = extract_unsigned_integer (data, addr_size,
2342 gdbarch_byte_order (arch));
2344 fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size));
2348 ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch));
2350 fprintf_filtered (stream, " %s", pulongest (ul));
2353 l = extract_signed_integer (data, 1, gdbarch_byte_order (arch));
2355 fprintf_filtered (stream, " %s", plongest (l));
2358 ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
2360 fprintf_filtered (stream, " %s", pulongest (ul));
2363 l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
2365 fprintf_filtered (stream, " %s", plongest (l));
2368 ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
2370 fprintf_filtered (stream, " %s", pulongest (ul));
2373 l = extract_signed_integer (data, 4, gdbarch_byte_order (arch));
2375 fprintf_filtered (stream, " %s", plongest (l));
2378 ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch));
2380 fprintf_filtered (stream, " %s", pulongest (ul));
2383 l = extract_signed_integer (data, 8, gdbarch_byte_order (arch));
2385 fprintf_filtered (stream, " %s", plongest (l));
2388 data = read_uleb128 (data, end, &ul);
2389 fprintf_filtered (stream, " %s", pulongest (ul));
2392 data = read_sleb128 (data, end, &l);
2393 fprintf_filtered (stream, " %s", plongest (l));
2428 fprintf_filtered (stream, " [$%s]",
2429 gdbarch_register_name (arch, op - DW_OP_reg0));
2433 data = read_uleb128 (data, end, &ul);
2434 fprintf_filtered (stream, " %s [$%s]", pulongest (ul),
2435 gdbarch_register_name (arch, (int) ul));
2438 case DW_OP_implicit_value:
2439 data = read_uleb128 (data, end, &ul);
2441 fprintf_filtered (stream, " %s", pulongest (ul));
2476 data = read_sleb128 (data, end, &l);
2477 fprintf_filtered (stream, " %s [$%s]", plongest (l),
2478 gdbarch_register_name (arch, op - DW_OP_breg0));
2482 data = read_uleb128 (data, end, &ul);
2483 data = read_sleb128 (data, end, &l);
2484 fprintf_filtered (stream, " register %s [$%s] offset %s",
2486 gdbarch_register_name (arch, (int) ul),
2491 data = read_sleb128 (data, end, &l);
2492 fprintf_filtered (stream, " %s", plongest (l));
2495 case DW_OP_xderef_size:
2496 case DW_OP_deref_size:
2498 fprintf_filtered (stream, " %d", *data);
2502 case DW_OP_plus_uconst:
2503 data = read_uleb128 (data, end, &ul);
2504 fprintf_filtered (stream, " %s", pulongest (ul));
2508 l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
2510 fprintf_filtered (stream, " to %ld",
2511 (long) (data + l - start));
2515 l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
2517 fprintf_filtered (stream, " %ld",
2518 (long) (data + l - start));
2522 ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
2524 fprintf_filtered (stream, " offset %s", phex_nz (ul, 2));
2528 ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
2530 fprintf_filtered (stream, " offset %s", phex_nz (ul, 4));
2533 case DW_OP_call_ref:
2534 ul = extract_unsigned_integer (data, offset_size,
2535 gdbarch_byte_order (arch));
2536 data += offset_size;
2537 fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size));
2541 data = read_uleb128 (data, end, &ul);
2542 fprintf_filtered (stream, " %s (bytes)", pulongest (ul));
2545 case DW_OP_bit_piece:
2549 data = read_uleb128 (data, end, &ul);
2550 data = read_uleb128 (data, end, &offset);
2551 fprintf_filtered (stream, " size %s offset %s (bits)",
2552 pulongest (ul), pulongest (offset));
2556 case DW_OP_GNU_implicit_pointer:
2558 ul = extract_unsigned_integer (data, offset_size,
2559 gdbarch_byte_order (arch));
2560 data += offset_size;
2562 data = read_sleb128 (data, end, &l);
2564 fprintf_filtered (stream, " DIE %s offset %s",
2565 phex_nz (ul, offset_size),
2571 fprintf_filtered (stream, "\n");
2577 /* Describe a single location, which may in turn consist of multiple
2581 locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
2582 struct ui_file *stream,
2583 const gdb_byte *data, int size,
2584 struct objfile *objfile, unsigned int addr_size,
2587 const gdb_byte *end = data + size;
2588 int first_piece = 1, bad = 0;
2592 const gdb_byte *here = data;
2593 int disassemble = 1;
2598 fprintf_filtered (stream, _(", and "));
2600 if (!dwarf2_always_disassemble)
2602 data = locexpr_describe_location_piece (symbol, stream,
2604 data, end, addr_size);
2605 /* If we printed anything, or if we have an empty piece,
2606 then don't disassemble. */
2608 || data[0] == DW_OP_piece
2609 || data[0] == DW_OP_bit_piece)
2613 data = disassemble_dwarf_expression (stream,
2614 get_objfile_arch (objfile),
2615 addr_size, offset_size, data, end,
2616 dwarf2_always_disassemble);
2620 int empty = data == here;
2623 fprintf_filtered (stream, " ");
2624 if (data[0] == DW_OP_piece)
2628 data = read_uleb128 (data + 1, end, &bytes);
2631 fprintf_filtered (stream, _("an empty %s-byte piece"),
2634 fprintf_filtered (stream, _(" [%s-byte piece]"),
2637 else if (data[0] == DW_OP_bit_piece)
2639 ULONGEST bits, offset;
2641 data = read_uleb128 (data + 1, end, &bits);
2642 data = read_uleb128 (data, end, &offset);
2645 fprintf_filtered (stream,
2646 _("an empty %s-bit piece"),
2649 fprintf_filtered (stream,
2650 _(" [%s-bit piece, offset %s bits]"),
2651 pulongest (bits), pulongest (offset));
2661 if (bad || data > end)
2662 error (_("Corrupted DWARF2 expression for \"%s\"."),
2663 SYMBOL_PRINT_NAME (symbol));
2666 /* Print a natural-language description of SYMBOL to STREAM. This
2667 version is for a symbol with a single location. */
2670 locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
2671 struct ui_file *stream)
2673 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2674 struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
2675 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2676 int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
2678 locexpr_describe_location_1 (symbol, addr, stream,
2679 dlbaton->data, dlbaton->size,
2680 objfile, addr_size, offset_size);
2683 /* Describe the location of SYMBOL as an agent value in VALUE, generating
2684 any necessary bytecode in AX. */
2687 locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
2688 struct agent_expr *ax, struct axs_value *value)
2690 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2691 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2693 if (dlbaton->data == NULL || dlbaton->size == 0)
2694 value->optimized_out = 1;
2696 dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size,
2697 dlbaton->data, dlbaton->data + dlbaton->size,
2701 /* The set of location functions used with the DWARF-2 expression
2703 const struct symbol_computed_ops dwarf2_locexpr_funcs = {
2704 locexpr_read_variable,
2705 locexpr_read_needs_frame,
2706 locexpr_describe_location,
2707 locexpr_tracepoint_var_ref
2711 /* Wrapper functions for location lists. These generally find
2712 the appropriate location expression and call something above. */
2714 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
2715 evaluator to calculate the location. */
2716 static struct value *
2717 loclist_read_variable (struct symbol *symbol, struct frame_info *frame)
2719 struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2721 const gdb_byte *data;
2723 CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0;
2725 data = dwarf2_find_location_expression (dlbaton, &size, pc);
2728 val = allocate_value (SYMBOL_TYPE (symbol));
2729 VALUE_LVAL (val) = not_lval;
2730 set_value_optimized_out (val, 1);
2733 val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size,
2739 /* Return non-zero iff we need a frame to evaluate SYMBOL. */
2741 loclist_read_needs_frame (struct symbol *symbol)
2743 /* If there's a location list, then assume we need to have a frame
2744 to choose the appropriate location expression. With tracking of
2745 global variables this is not necessarily true, but such tracking
2746 is disabled in GCC at the moment until we figure out how to
2752 /* Print a natural-language description of SYMBOL to STREAM. This
2753 version applies when there is a list of different locations, each
2754 with a specified address range. */
2757 loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
2758 struct ui_file *stream)
2760 struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2761 CORE_ADDR low, high;
2762 const gdb_byte *loc_ptr, *buf_end;
2763 int length, first = 1;
2764 struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
2765 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2766 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
2767 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2768 int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
2769 int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
2770 CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
2771 /* Adjust base_address for relocatable objects. */
2772 CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu);
2773 CORE_ADDR base_address = dlbaton->base_address + base_offset;
2775 loc_ptr = dlbaton->data;
2776 buf_end = dlbaton->data + dlbaton->size;
2778 fprintf_filtered (stream, _("multi-location:\n"));
2780 /* Iterate through locations until we run out. */
2783 if (buf_end - loc_ptr < 2 * addr_size)
2784 error (_("Corrupted DWARF expression for symbol \"%s\"."),
2785 SYMBOL_PRINT_NAME (symbol));
2788 low = extract_signed_integer (loc_ptr, addr_size, byte_order);
2790 low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
2791 loc_ptr += addr_size;
2794 high = extract_signed_integer (loc_ptr, addr_size, byte_order);
2796 high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
2797 loc_ptr += addr_size;
2799 /* A base-address-selection entry. */
2800 if ((low & base_mask) == base_mask)
2802 base_address = high + base_offset;
2803 fprintf_filtered (stream, _(" Base address %s"),
2804 paddress (gdbarch, base_address));
2808 /* An end-of-list entry. */
2809 if (low == 0 && high == 0)
2812 /* Otherwise, a location expression entry. */
2813 low += base_address;
2814 high += base_address;
2816 length = extract_unsigned_integer (loc_ptr, 2, byte_order);
2819 /* (It would improve readability to print only the minimum
2820 necessary digits of the second number of the range.) */
2821 fprintf_filtered (stream, _(" Range %s-%s: "),
2822 paddress (gdbarch, low), paddress (gdbarch, high));
2824 /* Now describe this particular location. */
2825 locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
2826 objfile, addr_size, offset_size);
2828 fprintf_filtered (stream, "\n");
2834 /* Describe the location of SYMBOL as an agent value in VALUE, generating
2835 any necessary bytecode in AX. */
2837 loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
2838 struct agent_expr *ax, struct axs_value *value)
2840 struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2841 const gdb_byte *data;
2843 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2845 data = dwarf2_find_location_expression (dlbaton, &size, ax->scope);
2846 if (data == NULL || size == 0)
2847 value->optimized_out = 1;
2849 dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size,
2853 /* The set of location functions used with the DWARF-2 expression
2854 evaluator and location lists. */
2855 const struct symbol_computed_ops dwarf2_loclist_funcs = {
2856 loclist_read_variable,
2857 loclist_read_needs_frame,
2858 loclist_describe_location,
2859 loclist_tracepoint_var_ref