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;
47 static void dwarf_expr_frame_base_1 (struct symbol *framefunc, CORE_ADDR pc,
48 const gdb_byte **start, size_t *length);
50 static struct value *dwarf2_evaluate_loc_desc_full (struct type *type,
51 struct frame_info *frame,
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->funcs->get_frame_pc, ctx->baton);
289 /* Callback function for dwarf2_evaluate_loc_desc. */
292 dwarf_expr_get_base_type (struct dwarf_expr_context *ctx, size_t die_offset)
294 struct dwarf_expr_baton *debaton = ctx->baton;
296 return dwarf2_get_die_type (die_offset, debaton->per_cu);
301 /* Reference count. */
304 /* The CU from which this closure's expression came. */
305 struct dwarf2_per_cu_data *per_cu;
307 /* The number of pieces used to describe this variable. */
310 /* The target address size, used only for DWARF_VALUE_STACK. */
313 /* The pieces themselves. */
314 struct dwarf_expr_piece *pieces;
317 /* Allocate a closure for a value formed from separately-described
320 static struct piece_closure *
321 allocate_piece_closure (struct dwarf2_per_cu_data *per_cu,
322 int n_pieces, struct dwarf_expr_piece *pieces,
325 struct piece_closure *c = XZALLOC (struct piece_closure);
330 c->n_pieces = n_pieces;
331 c->addr_size = addr_size;
332 c->pieces = XCALLOC (n_pieces, struct dwarf_expr_piece);
334 memcpy (c->pieces, pieces, n_pieces * sizeof (struct dwarf_expr_piece));
335 for (i = 0; i < n_pieces; ++i)
336 if (c->pieces[i].location == DWARF_VALUE_STACK)
337 value_incref (c->pieces[i].v.value);
342 /* The lowest-level function to extract bits from a byte buffer.
343 SOURCE is the buffer. It is updated if we read to the end of a
345 SOURCE_OFFSET_BITS is the offset of the first bit to read. It is
346 updated to reflect the number of bits actually read.
347 NBITS is the number of bits we want to read. It is updated to
348 reflect the number of bits actually read. This function may read
350 BITS_BIG_ENDIAN is taken directly from gdbarch.
351 This function returns the extracted bits. */
354 extract_bits_primitive (const gdb_byte **source,
355 unsigned int *source_offset_bits,
356 int *nbits, int bits_big_endian)
358 unsigned int avail, mask, datum;
360 gdb_assert (*source_offset_bits < 8);
362 avail = 8 - *source_offset_bits;
366 mask = (1 << avail) - 1;
369 datum >>= 8 - (*source_offset_bits + *nbits);
371 datum >>= *source_offset_bits;
375 *source_offset_bits += avail;
376 if (*source_offset_bits >= 8)
378 *source_offset_bits -= 8;
385 /* Extract some bits from a source buffer and move forward in the
388 SOURCE is the source buffer. It is updated as bytes are read.
389 SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as
391 NBITS is the number of bits to read.
392 BITS_BIG_ENDIAN is taken directly from gdbarch.
394 This function returns the bits that were read. */
397 extract_bits (const gdb_byte **source, unsigned int *source_offset_bits,
398 int nbits, int bits_big_endian)
402 gdb_assert (nbits > 0 && nbits <= 8);
404 datum = extract_bits_primitive (source, source_offset_bits, &nbits,
410 more = extract_bits_primitive (source, source_offset_bits, &nbits,
422 /* Write some bits into a buffer and move forward in the buffer.
424 DATUM is the bits to write. The low-order bits of DATUM are used.
425 DEST is the destination buffer. It is updated as bytes are
427 DEST_OFFSET_BITS is the bit offset in DEST at which writing is
429 NBITS is the number of valid bits in DATUM.
430 BITS_BIG_ENDIAN is taken directly from gdbarch. */
433 insert_bits (unsigned int datum,
434 gdb_byte *dest, unsigned int dest_offset_bits,
435 int nbits, int bits_big_endian)
439 gdb_assert (dest_offset_bits + nbits <= 8);
441 mask = (1 << nbits) - 1;
444 datum <<= 8 - (dest_offset_bits + nbits);
445 mask <<= 8 - (dest_offset_bits + nbits);
449 datum <<= dest_offset_bits;
450 mask <<= dest_offset_bits;
453 gdb_assert ((datum & ~mask) == 0);
455 *dest = (*dest & ~mask) | datum;
458 /* Copy bits from a source to a destination.
460 DEST is where the bits should be written.
461 DEST_OFFSET_BITS is the bit offset into DEST.
462 SOURCE is the source of bits.
463 SOURCE_OFFSET_BITS is the bit offset into SOURCE.
464 BIT_COUNT is the number of bits to copy.
465 BITS_BIG_ENDIAN is taken directly from gdbarch. */
468 copy_bitwise (gdb_byte *dest, unsigned int dest_offset_bits,
469 const gdb_byte *source, unsigned int source_offset_bits,
470 unsigned int bit_count,
473 unsigned int dest_avail;
476 /* Reduce everything to byte-size pieces. */
477 dest += dest_offset_bits / 8;
478 dest_offset_bits %= 8;
479 source += source_offset_bits / 8;
480 source_offset_bits %= 8;
482 dest_avail = 8 - dest_offset_bits % 8;
484 /* See if we can fill the first destination byte. */
485 if (dest_avail < bit_count)
487 datum = extract_bits (&source, &source_offset_bits, dest_avail,
489 insert_bits (datum, dest, dest_offset_bits, dest_avail, bits_big_endian);
491 dest_offset_bits = 0;
492 bit_count -= dest_avail;
495 /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer
496 than 8 bits remaining. */
497 gdb_assert (dest_offset_bits % 8 == 0 || bit_count < 8);
498 for (; bit_count >= 8; bit_count -= 8)
500 datum = extract_bits (&source, &source_offset_bits, 8, bits_big_endian);
501 *dest++ = (gdb_byte) datum;
504 /* Finally, we may have a few leftover bits. */
505 gdb_assert (bit_count <= 8 - dest_offset_bits % 8);
508 datum = extract_bits (&source, &source_offset_bits, bit_count,
510 insert_bits (datum, dest, dest_offset_bits, bit_count, bits_big_endian);
515 read_pieced_value (struct value *v)
519 ULONGEST bits_to_skip;
521 struct piece_closure *c
522 = (struct piece_closure *) value_computed_closure (v);
523 struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (v));
525 size_t buffer_size = 0;
527 struct cleanup *cleanup;
529 = gdbarch_bits_big_endian (get_type_arch (value_type (v)));
531 if (value_type (v) != value_enclosing_type (v))
532 internal_error (__FILE__, __LINE__,
533 _("Should not be able to create a lazy value with "
534 "an enclosing type"));
536 cleanup = make_cleanup (free_current_contents, &buffer);
538 contents = value_contents_raw (v);
539 bits_to_skip = 8 * value_offset (v);
540 if (value_bitsize (v))
542 bits_to_skip += value_bitpos (v);
543 type_len = value_bitsize (v);
546 type_len = 8 * TYPE_LENGTH (value_type (v));
548 for (i = 0; i < c->n_pieces && offset < type_len; i++)
550 struct dwarf_expr_piece *p = &c->pieces[i];
551 size_t this_size, this_size_bits;
552 long dest_offset_bits, source_offset_bits, source_offset;
553 const gdb_byte *intermediate_buffer;
555 /* Compute size, source, and destination offsets for copying, in
557 this_size_bits = p->size;
558 if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
560 bits_to_skip -= this_size_bits;
563 if (this_size_bits > type_len - offset)
564 this_size_bits = type_len - offset;
565 if (bits_to_skip > 0)
567 dest_offset_bits = 0;
568 source_offset_bits = bits_to_skip;
569 this_size_bits -= bits_to_skip;
574 dest_offset_bits = offset;
575 source_offset_bits = 0;
578 this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
579 source_offset = source_offset_bits / 8;
580 if (buffer_size < this_size)
582 buffer_size = this_size;
583 buffer = xrealloc (buffer, buffer_size);
585 intermediate_buffer = buffer;
587 /* Copy from the source to DEST_BUFFER. */
590 case DWARF_VALUE_REGISTER:
592 struct gdbarch *arch = get_frame_arch (frame);
593 int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno);
594 int reg_offset = source_offset;
596 if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
597 && this_size < register_size (arch, gdb_regnum))
599 /* Big-endian, and we want less than full size. */
600 reg_offset = register_size (arch, gdb_regnum) - this_size;
601 /* We want the lower-order THIS_SIZE_BITS of the bytes
602 we extract from the register. */
603 source_offset_bits += 8 * this_size - this_size_bits;
606 if (gdb_regnum != -1)
610 if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
614 /* Just so garbage doesn't ever shine through. */
615 memset (buffer, 0, this_size);
618 set_value_optimized_out (v, 1);
620 mark_value_bytes_unavailable (v, offset, this_size);
625 error (_("Unable to access DWARF register number %s"),
626 paddress (arch, p->v.regno));
631 case DWARF_VALUE_MEMORY:
632 read_value_memory (v, offset,
633 p->v.mem.in_stack_memory,
634 p->v.mem.addr + source_offset,
638 case DWARF_VALUE_STACK:
640 size_t n = this_size;
642 if (n > c->addr_size - source_offset)
643 n = (c->addr_size >= source_offset
644 ? c->addr_size - source_offset
652 const gdb_byte *val_bytes = value_contents_all (p->v.value);
654 intermediate_buffer = val_bytes + source_offset;
659 case DWARF_VALUE_LITERAL:
661 size_t n = this_size;
663 if (n > p->v.literal.length - source_offset)
664 n = (p->v.literal.length >= source_offset
665 ? p->v.literal.length - source_offset
668 intermediate_buffer = p->v.literal.data + source_offset;
672 /* These bits show up as zeros -- but do not cause the value
673 to be considered optimized-out. */
674 case DWARF_VALUE_IMPLICIT_POINTER:
677 case DWARF_VALUE_OPTIMIZED_OUT:
678 set_value_optimized_out (v, 1);
682 internal_error (__FILE__, __LINE__, _("invalid location type"));
685 if (p->location != DWARF_VALUE_OPTIMIZED_OUT
686 && p->location != DWARF_VALUE_IMPLICIT_POINTER)
687 copy_bitwise (contents, dest_offset_bits,
688 intermediate_buffer, source_offset_bits % 8,
689 this_size_bits, bits_big_endian);
691 offset += this_size_bits;
694 do_cleanups (cleanup);
698 write_pieced_value (struct value *to, struct value *from)
702 ULONGEST bits_to_skip;
703 const gdb_byte *contents;
704 struct piece_closure *c
705 = (struct piece_closure *) value_computed_closure (to);
706 struct frame_info *frame = frame_find_by_id (VALUE_FRAME_ID (to));
708 size_t buffer_size = 0;
710 struct cleanup *cleanup;
712 = gdbarch_bits_big_endian (get_type_arch (value_type (to)));
716 set_value_optimized_out (to, 1);
720 cleanup = make_cleanup (free_current_contents, &buffer);
722 contents = value_contents (from);
723 bits_to_skip = 8 * value_offset (to);
724 if (value_bitsize (to))
726 bits_to_skip += value_bitpos (to);
727 type_len = value_bitsize (to);
730 type_len = 8 * TYPE_LENGTH (value_type (to));
732 for (i = 0; i < c->n_pieces && offset < type_len; i++)
734 struct dwarf_expr_piece *p = &c->pieces[i];
735 size_t this_size_bits, this_size;
736 long dest_offset_bits, source_offset_bits, dest_offset, source_offset;
738 const gdb_byte *source_buffer;
740 this_size_bits = p->size;
741 if (bits_to_skip > 0 && bits_to_skip >= this_size_bits)
743 bits_to_skip -= this_size_bits;
746 if (this_size_bits > type_len - offset)
747 this_size_bits = type_len - offset;
748 if (bits_to_skip > 0)
750 dest_offset_bits = bits_to_skip;
751 source_offset_bits = 0;
752 this_size_bits -= bits_to_skip;
757 dest_offset_bits = 0;
758 source_offset_bits = offset;
761 this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8;
762 source_offset = source_offset_bits / 8;
763 dest_offset = dest_offset_bits / 8;
764 if (dest_offset_bits % 8 == 0 && source_offset_bits % 8 == 0)
766 source_buffer = contents + source_offset;
771 if (buffer_size < this_size)
773 buffer_size = this_size;
774 buffer = xrealloc (buffer, buffer_size);
776 source_buffer = buffer;
782 case DWARF_VALUE_REGISTER:
784 struct gdbarch *arch = get_frame_arch (frame);
785 int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, p->v.regno);
786 int reg_offset = dest_offset;
788 if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
789 && this_size <= register_size (arch, gdb_regnum))
790 /* Big-endian, and we want less than full size. */
791 reg_offset = register_size (arch, gdb_regnum) - this_size;
793 if (gdb_regnum != -1)
799 if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset,
804 error (_("Can't do read-modify-write to "
805 "update bitfield; containing word has been "
808 throw_error (NOT_AVAILABLE_ERROR,
809 _("Can't do read-modify-write to update "
810 "bitfield; containing word "
813 copy_bitwise (buffer, dest_offset_bits,
814 contents, source_offset_bits,
819 put_frame_register_bytes (frame, gdb_regnum, reg_offset,
820 this_size, source_buffer);
824 error (_("Unable to write to DWARF register number %s"),
825 paddress (arch, p->v.regno));
829 case DWARF_VALUE_MEMORY:
832 /* Only the first and last bytes can possibly have any
834 read_memory (p->v.mem.addr + dest_offset, buffer, 1);
835 read_memory (p->v.mem.addr + dest_offset + this_size - 1,
836 buffer + this_size - 1, 1);
837 copy_bitwise (buffer, dest_offset_bits,
838 contents, source_offset_bits,
843 write_memory (p->v.mem.addr + dest_offset,
844 source_buffer, this_size);
847 set_value_optimized_out (to, 1);
850 offset += this_size_bits;
853 do_cleanups (cleanup);
856 /* A helper function that checks bit validity in a pieced value.
857 CHECK_FOR indicates the kind of validity checking.
858 DWARF_VALUE_MEMORY means to check whether any bit is valid.
859 DWARF_VALUE_OPTIMIZED_OUT means to check whether any bit is
861 DWARF_VALUE_IMPLICIT_POINTER means to check whether the bits are an
865 check_pieced_value_bits (const struct value *value, int bit_offset,
867 enum dwarf_value_location check_for)
869 struct piece_closure *c
870 = (struct piece_closure *) value_computed_closure (value);
872 int validity = (check_for == DWARF_VALUE_MEMORY
873 || check_for == DWARF_VALUE_IMPLICIT_POINTER);
875 bit_offset += 8 * value_offset (value);
876 if (value_bitsize (value))
877 bit_offset += value_bitpos (value);
879 for (i = 0; i < c->n_pieces && bit_length > 0; i++)
881 struct dwarf_expr_piece *p = &c->pieces[i];
882 size_t this_size_bits = p->size;
886 if (bit_offset >= this_size_bits)
888 bit_offset -= this_size_bits;
892 bit_length -= this_size_bits - bit_offset;
896 bit_length -= this_size_bits;
898 if (check_for == DWARF_VALUE_IMPLICIT_POINTER)
900 if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
903 else if (p->location == DWARF_VALUE_OPTIMIZED_OUT
904 || p->location == DWARF_VALUE_IMPLICIT_POINTER)
920 check_pieced_value_validity (const struct value *value, int bit_offset,
923 return check_pieced_value_bits (value, bit_offset, bit_length,
928 check_pieced_value_invalid (const struct value *value)
930 return check_pieced_value_bits (value, 0,
931 8 * TYPE_LENGTH (value_type (value)),
932 DWARF_VALUE_OPTIMIZED_OUT);
935 /* An implementation of an lval_funcs method to see whether a value is
936 a synthetic pointer. */
939 check_pieced_synthetic_pointer (const struct value *value, int bit_offset,
942 return check_pieced_value_bits (value, bit_offset, bit_length,
943 DWARF_VALUE_IMPLICIT_POINTER);
946 /* A wrapper function for get_frame_address_in_block. */
949 get_frame_address_in_block_wrapper (void *baton)
951 return get_frame_address_in_block (baton);
954 /* An implementation of an lval_funcs method to indirect through a
955 pointer. This handles the synthetic pointer case when needed. */
957 static struct value *
958 indirect_pieced_value (struct value *value)
960 struct piece_closure *c
961 = (struct piece_closure *) value_computed_closure (value);
963 struct frame_info *frame;
964 struct dwarf2_locexpr_baton baton;
965 int i, bit_offset, bit_length;
966 struct dwarf_expr_piece *piece = NULL;
967 struct value *result;
970 type = check_typedef (value_type (value));
971 if (TYPE_CODE (type) != TYPE_CODE_PTR)
974 bit_length = 8 * TYPE_LENGTH (type);
975 bit_offset = 8 * value_offset (value);
976 if (value_bitsize (value))
977 bit_offset += value_bitpos (value);
979 for (i = 0; i < c->n_pieces && bit_length > 0; i++)
981 struct dwarf_expr_piece *p = &c->pieces[i];
982 size_t this_size_bits = p->size;
986 if (bit_offset >= this_size_bits)
988 bit_offset -= this_size_bits;
992 bit_length -= this_size_bits - bit_offset;
996 bit_length -= this_size_bits;
998 if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
1001 if (bit_length != 0)
1002 error (_("Invalid use of DW_OP_GNU_implicit_pointer"));
1008 frame = get_selected_frame (_("No frame selected."));
1009 byte_offset = value_as_address (value);
1012 baton = dwarf2_fetch_die_location_block (piece->v.ptr.die, c->per_cu,
1013 get_frame_address_in_block_wrapper,
1016 result = dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type), frame,
1017 baton.data, baton.size, baton.per_cu,
1024 copy_pieced_value_closure (const struct value *v)
1026 struct piece_closure *c
1027 = (struct piece_closure *) value_computed_closure (v);
1034 free_pieced_value_closure (struct value *v)
1036 struct piece_closure *c
1037 = (struct piece_closure *) value_computed_closure (v);
1044 for (i = 0; i < c->n_pieces; ++i)
1045 if (c->pieces[i].location == DWARF_VALUE_STACK)
1046 value_free (c->pieces[i].v.value);
1053 /* Functions for accessing a variable described by DW_OP_piece. */
1054 static const struct lval_funcs pieced_value_funcs = {
1057 check_pieced_value_validity,
1058 check_pieced_value_invalid,
1059 indirect_pieced_value,
1060 check_pieced_synthetic_pointer,
1061 copy_pieced_value_closure,
1062 free_pieced_value_closure
1065 /* Helper function which throws an error if a synthetic pointer is
1069 invalid_synthetic_pointer (void)
1071 error (_("access outside bounds of object "
1072 "referenced via synthetic pointer"));
1075 /* Virtual method table for dwarf2_evaluate_loc_desc_full below. */
1077 static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs =
1079 dwarf_expr_read_reg,
1080 dwarf_expr_read_mem,
1081 dwarf_expr_frame_base,
1082 dwarf_expr_frame_cfa,
1083 dwarf_expr_frame_pc,
1084 dwarf_expr_tls_address,
1085 dwarf_expr_dwarf_call,
1086 dwarf_expr_get_base_type
1089 /* Evaluate a location description, starting at DATA and with length
1090 SIZE, to find the current location of variable of TYPE in the
1091 context of FRAME. BYTE_OFFSET is applied after the contents are
1094 static struct value *
1095 dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
1096 const gdb_byte *data, unsigned short size,
1097 struct dwarf2_per_cu_data *per_cu,
1098 LONGEST byte_offset)
1100 struct value *retval;
1101 struct dwarf_expr_baton baton;
1102 struct dwarf_expr_context *ctx;
1103 struct cleanup *old_chain, *value_chain;
1104 struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
1105 volatile struct gdb_exception ex;
1107 if (byte_offset < 0)
1108 invalid_synthetic_pointer ();
1111 return allocate_optimized_out_value (type);
1113 baton.frame = frame;
1114 baton.per_cu = per_cu;
1116 ctx = new_dwarf_expr_context ();
1117 old_chain = make_cleanup_free_dwarf_expr_context (ctx);
1118 value_chain = make_cleanup_value_free_to_mark (value_mark ());
1120 ctx->gdbarch = get_objfile_arch (objfile);
1121 ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
1122 ctx->offset = dwarf2_per_cu_text_offset (per_cu);
1123 ctx->baton = &baton;
1124 ctx->funcs = &dwarf_expr_ctx_funcs;
1126 TRY_CATCH (ex, RETURN_MASK_ERROR)
1128 dwarf_expr_eval (ctx, data, size);
1132 if (ex.error == NOT_AVAILABLE_ERROR)
1134 do_cleanups (old_chain);
1135 retval = allocate_value (type);
1136 mark_value_bytes_unavailable (retval, 0, TYPE_LENGTH (type));
1140 throw_exception (ex);
1143 if (ctx->num_pieces > 0)
1145 struct piece_closure *c;
1146 struct frame_id frame_id = get_frame_id (frame);
1147 ULONGEST bit_size = 0;
1150 for (i = 0; i < ctx->num_pieces; ++i)
1151 bit_size += ctx->pieces[i].size;
1152 if (8 * (byte_offset + TYPE_LENGTH (type)) > bit_size)
1153 invalid_synthetic_pointer ();
1155 c = allocate_piece_closure (per_cu, ctx->num_pieces, ctx->pieces,
1157 /* We must clean up the value chain after creating the piece
1158 closure but before allocating the result. */
1159 do_cleanups (value_chain);
1160 retval = allocate_computed_value (type, &pieced_value_funcs, c);
1161 VALUE_FRAME_ID (retval) = frame_id;
1162 set_value_offset (retval, byte_offset);
1166 switch (ctx->location)
1168 case DWARF_VALUE_REGISTER:
1170 struct gdbarch *arch = get_frame_arch (frame);
1171 ULONGEST dwarf_regnum = value_as_long (dwarf_expr_fetch (ctx, 0));
1172 int gdb_regnum = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_regnum);
1174 if (byte_offset != 0)
1175 error (_("cannot use offset on synthetic pointer to register"));
1176 do_cleanups (value_chain);
1177 if (gdb_regnum != -1)
1178 retval = value_from_register (type, gdb_regnum, frame);
1180 error (_("Unable to access DWARF register number %s"),
1181 paddress (arch, dwarf_regnum));
1185 case DWARF_VALUE_MEMORY:
1187 CORE_ADDR address = dwarf_expr_fetch_address (ctx, 0);
1188 int in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
1190 do_cleanups (value_chain);
1191 retval = allocate_value_lazy (type);
1192 VALUE_LVAL (retval) = lval_memory;
1193 if (in_stack_memory)
1194 set_value_stack (retval, 1);
1195 set_value_address (retval, address + byte_offset);
1199 case DWARF_VALUE_STACK:
1201 struct value *value = dwarf_expr_fetch (ctx, 0);
1203 const gdb_byte *val_bytes;
1204 size_t n = TYPE_LENGTH (value_type (value));
1206 if (byte_offset + TYPE_LENGTH (type) > n)
1207 invalid_synthetic_pointer ();
1209 val_bytes = value_contents_all (value);
1210 val_bytes += byte_offset;
1213 /* Preserve VALUE because we are going to free values back
1214 to the mark, but we still need the value contents
1216 value_incref (value);
1217 do_cleanups (value_chain);
1218 make_cleanup_value_free (value);
1220 retval = allocate_value (type);
1221 contents = value_contents_raw (retval);
1222 if (n > TYPE_LENGTH (type))
1223 n = TYPE_LENGTH (type);
1224 memcpy (contents, val_bytes, n);
1228 case DWARF_VALUE_LITERAL:
1231 const bfd_byte *ldata;
1232 size_t n = ctx->len;
1234 if (byte_offset + TYPE_LENGTH (type) > n)
1235 invalid_synthetic_pointer ();
1237 do_cleanups (value_chain);
1238 retval = allocate_value (type);
1239 contents = value_contents_raw (retval);
1241 ldata = ctx->data + byte_offset;
1244 if (n > TYPE_LENGTH (type))
1245 n = TYPE_LENGTH (type);
1246 memcpy (contents, ldata, n);
1250 case DWARF_VALUE_OPTIMIZED_OUT:
1251 do_cleanups (value_chain);
1252 retval = allocate_optimized_out_value (type);
1255 /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
1256 operation by execute_stack_op. */
1257 case DWARF_VALUE_IMPLICIT_POINTER:
1258 /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
1259 it can only be encountered when making a piece. */
1261 internal_error (__FILE__, __LINE__, _("invalid location type"));
1265 set_value_initialized (retval, ctx->initialized);
1267 do_cleanups (old_chain);
1272 /* The exported interface to dwarf2_evaluate_loc_desc_full; it always
1273 passes 0 as the byte_offset. */
1276 dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
1277 const gdb_byte *data, unsigned short size,
1278 struct dwarf2_per_cu_data *per_cu)
1280 return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu, 0);
1284 /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
1286 struct needs_frame_baton
1289 struct dwarf2_per_cu_data *per_cu;
1292 /* Reads from registers do require a frame. */
1294 needs_frame_read_reg (void *baton, int regnum)
1296 struct needs_frame_baton *nf_baton = baton;
1298 nf_baton->needs_frame = 1;
1302 /* Reads from memory do not require a frame. */
1304 needs_frame_read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
1306 memset (buf, 0, len);
1309 /* Frame-relative accesses do require a frame. */
1311 needs_frame_frame_base (void *baton, const gdb_byte **start, size_t * length)
1313 static gdb_byte lit0 = DW_OP_lit0;
1314 struct needs_frame_baton *nf_baton = baton;
1319 nf_baton->needs_frame = 1;
1322 /* CFA accesses require a frame. */
1325 needs_frame_frame_cfa (void *baton)
1327 struct needs_frame_baton *nf_baton = baton;
1329 nf_baton->needs_frame = 1;
1333 /* Thread-local accesses do require a frame. */
1335 needs_frame_tls_address (void *baton, CORE_ADDR offset)
1337 struct needs_frame_baton *nf_baton = baton;
1339 nf_baton->needs_frame = 1;
1343 /* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */
1346 needs_frame_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
1348 struct needs_frame_baton *nf_baton = ctx->baton;
1350 per_cu_dwarf_call (ctx, die_offset, nf_baton->per_cu,
1351 ctx->funcs->get_frame_pc, ctx->baton);
1354 /* Virtual method table for dwarf2_loc_desc_needs_frame below. */
1356 static const struct dwarf_expr_context_funcs needs_frame_ctx_funcs =
1358 needs_frame_read_reg,
1359 needs_frame_read_mem,
1360 needs_frame_frame_base,
1361 needs_frame_frame_cfa,
1362 needs_frame_frame_cfa, /* get_frame_pc */
1363 needs_frame_tls_address,
1364 needs_frame_dwarf_call,
1365 NULL /* get_base_type */
1368 /* Return non-zero iff the location expression at DATA (length SIZE)
1369 requires a frame to evaluate. */
1372 dwarf2_loc_desc_needs_frame (const gdb_byte *data, unsigned short size,
1373 struct dwarf2_per_cu_data *per_cu)
1375 struct needs_frame_baton baton;
1376 struct dwarf_expr_context *ctx;
1378 struct cleanup *old_chain;
1379 struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
1381 baton.needs_frame = 0;
1382 baton.per_cu = per_cu;
1384 ctx = new_dwarf_expr_context ();
1385 old_chain = make_cleanup_free_dwarf_expr_context (ctx);
1386 make_cleanup_value_free_to_mark (value_mark ());
1388 ctx->gdbarch = get_objfile_arch (objfile);
1389 ctx->addr_size = dwarf2_per_cu_addr_size (per_cu);
1390 ctx->offset = dwarf2_per_cu_text_offset (per_cu);
1391 ctx->baton = &baton;
1392 ctx->funcs = &needs_frame_ctx_funcs;
1394 dwarf_expr_eval (ctx, data, size);
1396 in_reg = ctx->location == DWARF_VALUE_REGISTER;
1398 if (ctx->num_pieces > 0)
1402 /* If the location has several pieces, and any of them are in
1403 registers, then we will need a frame to fetch them from. */
1404 for (i = 0; i < ctx->num_pieces; i++)
1405 if (ctx->pieces[i].location == DWARF_VALUE_REGISTER)
1409 do_cleanups (old_chain);
1411 return baton.needs_frame || in_reg;
1414 /* A helper function that throws an unimplemented error mentioning a
1415 given DWARF operator. */
1418 unimplemented (unsigned int op)
1420 const char *name = dwarf_stack_op_name (op);
1423 error (_("DWARF operator %s cannot be translated to an agent expression"),
1426 error (_("Unknown DWARF operator 0x%02x cannot be translated "
1427 "to an agent expression"),
1431 /* A helper function to convert a DWARF register to an arch register.
1432 ARCH is the architecture.
1433 DWARF_REG is the register.
1434 This will throw an exception if the DWARF register cannot be
1435 translated to an architecture register. */
1438 translate_register (struct gdbarch *arch, int dwarf_reg)
1440 int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg);
1442 error (_("Unable to access DWARF register number %d"), dwarf_reg);
1446 /* A helper function that emits an access to memory. ARCH is the
1447 target architecture. EXPR is the expression which we are building.
1448 NBITS is the number of bits we want to read. This emits the
1449 opcodes needed to read the memory and then extract the desired
1453 access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits)
1455 ULONGEST nbytes = (nbits + 7) / 8;
1457 gdb_assert (nbits > 0 && nbits <= sizeof (LONGEST));
1460 ax_trace_quick (expr, nbytes);
1463 ax_simple (expr, aop_ref8);
1464 else if (nbits <= 16)
1465 ax_simple (expr, aop_ref16);
1466 else if (nbits <= 32)
1467 ax_simple (expr, aop_ref32);
1469 ax_simple (expr, aop_ref64);
1471 /* If we read exactly the number of bytes we wanted, we're done. */
1472 if (8 * nbytes == nbits)
1475 if (gdbarch_bits_big_endian (arch))
1477 /* On a bits-big-endian machine, we want the high-order
1479 ax_const_l (expr, 8 * nbytes - nbits);
1480 ax_simple (expr, aop_rsh_unsigned);
1484 /* On a bits-little-endian box, we want the low-order NBITS. */
1485 ax_zero_ext (expr, nbits);
1489 /* A helper function to return the frame's PC. */
1492 get_ax_pc (void *baton)
1494 struct agent_expr *expr = baton;
1499 /* Compile a DWARF location expression to an agent expression.
1501 EXPR is the agent expression we are building.
1502 LOC is the agent value we modify.
1503 ARCH is the architecture.
1504 ADDR_SIZE is the size of addresses, in bytes.
1505 OP_PTR is the start of the location expression.
1506 OP_END is one past the last byte of the location expression.
1508 This will throw an exception for various kinds of errors -- for
1509 example, if the expression cannot be compiled, or if the expression
1513 dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc,
1514 struct gdbarch *arch, unsigned int addr_size,
1515 const gdb_byte *op_ptr, const gdb_byte *op_end,
1516 struct dwarf2_per_cu_data *per_cu)
1518 struct cleanup *cleanups;
1520 VEC(int) *dw_labels = NULL, *patches = NULL;
1521 const gdb_byte * const base = op_ptr;
1522 const gdb_byte *previous_piece = op_ptr;
1523 enum bfd_endian byte_order = gdbarch_byte_order (arch);
1524 ULONGEST bits_collected = 0;
1525 unsigned int addr_size_bits = 8 * addr_size;
1526 int bits_big_endian = gdbarch_bits_big_endian (arch);
1528 offsets = xmalloc ((op_end - op_ptr) * sizeof (int));
1529 cleanups = make_cleanup (xfree, offsets);
1531 for (i = 0; i < op_end - op_ptr; ++i)
1534 make_cleanup (VEC_cleanup (int), &dw_labels);
1535 make_cleanup (VEC_cleanup (int), &patches);
1537 /* By default we are making an address. */
1538 loc->kind = axs_lvalue_memory;
1540 while (op_ptr < op_end)
1542 enum dwarf_location_atom op = *op_ptr;
1543 ULONGEST uoffset, reg;
1547 offsets[op_ptr - base] = expr->len;
1550 /* Our basic approach to code generation is to map DWARF
1551 operations directly to AX operations. However, there are
1554 First, DWARF works on address-sized units, but AX always uses
1555 LONGEST. For most operations we simply ignore this
1556 difference; instead we generate sign extensions as needed
1557 before division and comparison operations. It would be nice
1558 to omit the sign extensions, but there is no way to determine
1559 the size of the target's LONGEST. (This code uses the size
1560 of the host LONGEST in some cases -- that is a bug but it is
1563 Second, some DWARF operations cannot be translated to AX.
1564 For these we simply fail. See
1565 http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
1600 ax_const_l (expr, op - DW_OP_lit0);
1604 uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order);
1605 op_ptr += addr_size;
1606 /* Some versions of GCC emit DW_OP_addr before
1607 DW_OP_GNU_push_tls_address. In this case the value is an
1608 index, not an address. We don't support things like
1609 branching between the address and the TLS op. */
1610 if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
1611 uoffset += dwarf2_per_cu_text_offset (per_cu);
1612 ax_const_l (expr, uoffset);
1616 ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order));
1620 ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order));
1624 ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order));
1628 ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order));
1632 ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order));
1636 ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order));
1640 ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order));
1644 ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order));
1648 op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
1649 ax_const_l (expr, uoffset);
1652 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1653 ax_const_l (expr, offset);
1688 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
1689 loc->u.reg = translate_register (arch, op - DW_OP_reg0);
1690 loc->kind = axs_lvalue_register;
1694 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1695 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
1696 loc->u.reg = translate_register (arch, reg);
1697 loc->kind = axs_lvalue_register;
1700 case DW_OP_implicit_value:
1704 op_ptr = read_uleb128 (op_ptr, op_end, &len);
1705 if (op_ptr + len > op_end)
1706 error (_("DW_OP_implicit_value: too few bytes available."));
1707 if (len > sizeof (ULONGEST))
1708 error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
1711 ax_const_l (expr, extract_unsigned_integer (op_ptr, len,
1714 dwarf_expr_require_composition (op_ptr, op_end,
1715 "DW_OP_implicit_value");
1717 loc->kind = axs_rvalue;
1721 case DW_OP_stack_value:
1722 dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
1723 loc->kind = axs_rvalue;
1758 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1759 i = translate_register (arch, op - DW_OP_breg0);
1763 ax_const_l (expr, offset);
1764 ax_simple (expr, aop_add);
1769 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1770 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1771 i = translate_register (arch, reg);
1775 ax_const_l (expr, offset);
1776 ax_simple (expr, aop_add);
1782 const gdb_byte *datastart;
1784 unsigned int before_stack_len;
1786 struct symbol *framefunc;
1787 LONGEST base_offset = 0;
1789 b = block_for_pc (expr->scope);
1792 error (_("No block found for address"));
1794 framefunc = block_linkage_function (b);
1797 error (_("No function found for block"));
1799 dwarf_expr_frame_base_1 (framefunc, expr->scope,
1800 &datastart, &datalen);
1802 op_ptr = read_sleb128 (op_ptr, op_end, &offset);
1803 dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size, datastart,
1804 datastart + datalen, per_cu);
1808 ax_const_l (expr, offset);
1809 ax_simple (expr, aop_add);
1812 loc->kind = axs_lvalue_memory;
1817 ax_simple (expr, aop_dup);
1821 ax_simple (expr, aop_pop);
1826 ax_pick (expr, offset);
1830 ax_simple (expr, aop_swap);
1838 ax_simple (expr, aop_rot);
1842 case DW_OP_deref_size:
1846 if (op == DW_OP_deref_size)
1854 ax_simple (expr, aop_ref8);
1857 ax_simple (expr, aop_ref16);
1860 ax_simple (expr, aop_ref32);
1863 ax_simple (expr, aop_ref64);
1866 /* Note that dwarf_stack_op_name will never return
1868 error (_("Unsupported size %d in %s"),
1869 size, dwarf_stack_op_name (op));
1875 /* Sign extend the operand. */
1876 ax_ext (expr, addr_size_bits);
1877 ax_simple (expr, aop_dup);
1878 ax_const_l (expr, 0);
1879 ax_simple (expr, aop_less_signed);
1880 ax_simple (expr, aop_log_not);
1881 i = ax_goto (expr, aop_if_goto);
1882 /* We have to emit 0 - X. */
1883 ax_const_l (expr, 0);
1884 ax_simple (expr, aop_swap);
1885 ax_simple (expr, aop_sub);
1886 ax_label (expr, i, expr->len);
1890 /* No need to sign extend here. */
1891 ax_const_l (expr, 0);
1892 ax_simple (expr, aop_swap);
1893 ax_simple (expr, aop_sub);
1897 /* Sign extend the operand. */
1898 ax_ext (expr, addr_size_bits);
1899 ax_simple (expr, aop_bit_not);
1902 case DW_OP_plus_uconst:
1903 op_ptr = read_uleb128 (op_ptr, op_end, ®);
1904 /* It would be really weird to emit `DW_OP_plus_uconst 0',
1905 but we micro-optimize anyhow. */
1908 ax_const_l (expr, reg);
1909 ax_simple (expr, aop_add);
1914 ax_simple (expr, aop_bit_and);
1918 /* Sign extend the operands. */
1919 ax_ext (expr, addr_size_bits);
1920 ax_simple (expr, aop_swap);
1921 ax_ext (expr, addr_size_bits);
1922 ax_simple (expr, aop_swap);
1923 ax_simple (expr, aop_div_signed);
1927 ax_simple (expr, aop_sub);
1931 ax_simple (expr, aop_rem_unsigned);
1935 ax_simple (expr, aop_mul);
1939 ax_simple (expr, aop_bit_or);
1943 ax_simple (expr, aop_add);
1947 ax_simple (expr, aop_lsh);
1951 ax_simple (expr, aop_rsh_unsigned);
1955 ax_simple (expr, aop_rsh_signed);
1959 ax_simple (expr, aop_bit_xor);
1963 /* Sign extend the operands. */
1964 ax_ext (expr, addr_size_bits);
1965 ax_simple (expr, aop_swap);
1966 ax_ext (expr, addr_size_bits);
1967 /* Note no swap here: A <= B is !(B < A). */
1968 ax_simple (expr, aop_less_signed);
1969 ax_simple (expr, aop_log_not);
1973 /* Sign extend the operands. */
1974 ax_ext (expr, addr_size_bits);
1975 ax_simple (expr, aop_swap);
1976 ax_ext (expr, addr_size_bits);
1977 ax_simple (expr, aop_swap);
1978 /* A >= B is !(A < B). */
1979 ax_simple (expr, aop_less_signed);
1980 ax_simple (expr, aop_log_not);
1984 /* Sign extend the operands. */
1985 ax_ext (expr, addr_size_bits);
1986 ax_simple (expr, aop_swap);
1987 ax_ext (expr, addr_size_bits);
1988 /* No need for a second swap here. */
1989 ax_simple (expr, aop_equal);
1993 /* Sign extend the operands. */
1994 ax_ext (expr, addr_size_bits);
1995 ax_simple (expr, aop_swap);
1996 ax_ext (expr, addr_size_bits);
1997 ax_simple (expr, aop_swap);
1998 ax_simple (expr, aop_less_signed);
2002 /* Sign extend the operands. */
2003 ax_ext (expr, addr_size_bits);
2004 ax_simple (expr, aop_swap);
2005 ax_ext (expr, addr_size_bits);
2006 /* Note no swap here: A > B is B < A. */
2007 ax_simple (expr, aop_less_signed);
2011 /* Sign extend the operands. */
2012 ax_ext (expr, addr_size_bits);
2013 ax_simple (expr, aop_swap);
2014 ax_ext (expr, addr_size_bits);
2015 /* No need for a swap here. */
2016 ax_simple (expr, aop_equal);
2017 ax_simple (expr, aop_log_not);
2020 case DW_OP_call_frame_cfa:
2021 dwarf2_compile_cfa_to_ax (expr, loc, arch, expr->scope, per_cu);
2022 loc->kind = axs_lvalue_memory;
2025 case DW_OP_GNU_push_tls_address:
2030 offset = extract_signed_integer (op_ptr, 2, byte_order);
2032 i = ax_goto (expr, aop_goto);
2033 VEC_safe_push (int, dw_labels, op_ptr + offset - base);
2034 VEC_safe_push (int, patches, i);
2038 offset = extract_signed_integer (op_ptr, 2, byte_order);
2040 /* Zero extend the operand. */
2041 ax_zero_ext (expr, addr_size_bits);
2042 i = ax_goto (expr, aop_if_goto);
2043 VEC_safe_push (int, dw_labels, op_ptr + offset - base);
2044 VEC_safe_push (int, patches, i);
2051 case DW_OP_bit_piece:
2053 ULONGEST size, offset;
2055 if (op_ptr - 1 == previous_piece)
2056 error (_("Cannot translate empty pieces to agent expressions"));
2057 previous_piece = op_ptr - 1;
2059 op_ptr = read_uleb128 (op_ptr, op_end, &size);
2060 if (op == DW_OP_piece)
2066 op_ptr = read_uleb128 (op_ptr, op_end, &offset);
2068 if (bits_collected + size > 8 * sizeof (LONGEST))
2069 error (_("Expression pieces exceed word size"));
2071 /* Access the bits. */
2074 case axs_lvalue_register:
2075 ax_reg (expr, loc->u.reg);
2078 case axs_lvalue_memory:
2079 /* Offset the pointer, if needed. */
2082 ax_const_l (expr, offset / 8);
2083 ax_simple (expr, aop_add);
2086 access_memory (arch, expr, size);
2090 /* For a bits-big-endian target, shift up what we already
2091 have. For a bits-little-endian target, shift up the
2092 new data. Note that there is a potential bug here if
2093 the DWARF expression leaves multiple values on the
2095 if (bits_collected > 0)
2097 if (bits_big_endian)
2099 ax_simple (expr, aop_swap);
2100 ax_const_l (expr, size);
2101 ax_simple (expr, aop_lsh);
2102 /* We don't need a second swap here, because
2103 aop_bit_or is symmetric. */
2107 ax_const_l (expr, size);
2108 ax_simple (expr, aop_lsh);
2110 ax_simple (expr, aop_bit_or);
2113 bits_collected += size;
2114 loc->kind = axs_rvalue;
2118 case DW_OP_GNU_uninit:
2124 struct dwarf2_locexpr_baton block;
2125 int size = (op == DW_OP_call2 ? 2 : 4);
2127 uoffset = extract_unsigned_integer (op_ptr, size, byte_order);
2130 block = dwarf2_fetch_die_location_block (uoffset, per_cu,
2133 /* DW_OP_call_ref is currently not supported. */
2134 gdb_assert (block.per_cu == per_cu);
2136 dwarf2_compile_expr_to_ax (expr, loc, arch, addr_size,
2137 block.data, block.data + block.size,
2142 case DW_OP_call_ref:
2150 /* Patch all the branches we emitted. */
2151 for (i = 0; i < VEC_length (int, patches); ++i)
2153 int targ = offsets[VEC_index (int, dw_labels, i)];
2155 internal_error (__FILE__, __LINE__, _("invalid label"));
2156 ax_label (expr, VEC_index (int, patches, i), targ);
2159 do_cleanups (cleanups);
2163 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
2164 evaluator to calculate the location. */
2165 static struct value *
2166 locexpr_read_variable (struct symbol *symbol, struct frame_info *frame)
2168 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2171 val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data,
2172 dlbaton->size, dlbaton->per_cu);
2177 /* Return non-zero iff we need a frame to evaluate SYMBOL. */
2179 locexpr_read_needs_frame (struct symbol *symbol)
2181 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2183 return dwarf2_loc_desc_needs_frame (dlbaton->data, dlbaton->size,
2187 /* Return true if DATA points to the end of a piece. END is one past
2188 the last byte in the expression. */
2191 piece_end_p (const gdb_byte *data, const gdb_byte *end)
2193 return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece;
2196 /* Helper for locexpr_describe_location_piece that finds the name of a
2200 locexpr_regname (struct gdbarch *gdbarch, int dwarf_regnum)
2204 regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, dwarf_regnum);
2205 return gdbarch_register_name (gdbarch, regnum);
2208 /* Nicely describe a single piece of a location, returning an updated
2209 position in the bytecode sequence. This function cannot recognize
2210 all locations; if a location is not recognized, it simply returns
2213 static const gdb_byte *
2214 locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
2215 CORE_ADDR addr, struct objfile *objfile,
2216 const gdb_byte *data, const gdb_byte *end,
2217 unsigned int addr_size)
2219 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2221 if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
2223 fprintf_filtered (stream, _("a variable in $%s"),
2224 locexpr_regname (gdbarch, data[0] - DW_OP_reg0));
2227 else if (data[0] == DW_OP_regx)
2231 data = read_uleb128 (data + 1, end, ®);
2232 fprintf_filtered (stream, _("a variable in $%s"),
2233 locexpr_regname (gdbarch, reg));
2235 else if (data[0] == DW_OP_fbreg)
2238 struct symbol *framefunc;
2240 LONGEST frame_offset;
2241 const gdb_byte *base_data, *new_data, *save_data = data;
2243 LONGEST base_offset = 0;
2245 new_data = read_sleb128 (data + 1, end, &frame_offset);
2246 if (!piece_end_p (new_data, end))
2250 b = block_for_pc (addr);
2253 error (_("No block found for address for symbol \"%s\"."),
2254 SYMBOL_PRINT_NAME (symbol));
2256 framefunc = block_linkage_function (b);
2259 error (_("No function found for block for symbol \"%s\"."),
2260 SYMBOL_PRINT_NAME (symbol));
2262 dwarf_expr_frame_base_1 (framefunc, addr, &base_data, &base_size);
2264 if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
2266 const gdb_byte *buf_end;
2268 frame_reg = base_data[0] - DW_OP_breg0;
2269 buf_end = read_sleb128 (base_data + 1,
2270 base_data + base_size, &base_offset);
2271 if (buf_end != base_data + base_size)
2272 error (_("Unexpected opcode after "
2273 "DW_OP_breg%u for symbol \"%s\"."),
2274 frame_reg, SYMBOL_PRINT_NAME (symbol));
2276 else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
2278 /* The frame base is just the register, with no offset. */
2279 frame_reg = base_data[0] - DW_OP_reg0;
2284 /* We don't know what to do with the frame base expression,
2285 so we can't trace this variable; give up. */
2289 fprintf_filtered (stream,
2290 _("a variable at frame base reg $%s offset %s+%s"),
2291 locexpr_regname (gdbarch, frame_reg),
2292 plongest (base_offset), plongest (frame_offset));
2294 else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31
2295 && piece_end_p (data, end))
2299 data = read_sleb128 (data + 1, end, &offset);
2301 fprintf_filtered (stream,
2302 _("a variable at offset %s from base reg $%s"),
2304 locexpr_regname (gdbarch, data[0] - DW_OP_breg0));
2307 /* The location expression for a TLS variable looks like this (on a
2310 DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
2311 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
2313 0x3 is the encoding for DW_OP_addr, which has an operand as long
2314 as the size of an address on the target machine (here is 8
2315 bytes). Note that more recent version of GCC emit DW_OP_const4u
2316 or DW_OP_const8u, depending on address size, rather than
2317 DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
2318 The operand represents the offset at which the variable is within
2319 the thread local storage. */
2321 else if (data + 1 + addr_size < end
2322 && (data[0] == DW_OP_addr
2323 || (addr_size == 4 && data[0] == DW_OP_const4u)
2324 || (addr_size == 8 && data[0] == DW_OP_const8u))
2325 && data[1 + addr_size] == DW_OP_GNU_push_tls_address
2326 && piece_end_p (data + 2 + addr_size, end))
2329 offset = extract_unsigned_integer (data + 1, addr_size,
2330 gdbarch_byte_order (gdbarch));
2332 fprintf_filtered (stream,
2333 _("a thread-local variable at offset 0x%s "
2334 "in the thread-local storage for `%s'"),
2335 phex_nz (offset, addr_size), objfile->name);
2337 data += 1 + addr_size + 1;
2339 else if (data[0] >= DW_OP_lit0
2340 && data[0] <= DW_OP_lit31
2342 && data[1] == DW_OP_stack_value)
2344 fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0);
2351 /* Disassemble an expression, stopping at the end of a piece or at the
2352 end of the expression. Returns a pointer to the next unread byte
2353 in the input expression. If ALL is nonzero, then this function
2354 will keep going until it reaches the end of the expression. */
2356 static const gdb_byte *
2357 disassemble_dwarf_expression (struct ui_file *stream,
2358 struct gdbarch *arch, unsigned int addr_size,
2360 const gdb_byte *data, const gdb_byte *end,
2362 struct dwarf2_per_cu_data *per_cu)
2364 const gdb_byte *start = data;
2366 fprintf_filtered (stream, _("a complex DWARF expression:\n"));
2370 || (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece)))
2372 enum dwarf_location_atom op = *data++;
2377 name = dwarf_stack_op_name (op);
2380 error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
2381 op, (long) (data - 1 - start));
2382 fprintf_filtered (stream, " % 4ld: %s", (long) (data - 1 - start), name);
2387 ul = extract_unsigned_integer (data, addr_size,
2388 gdbarch_byte_order (arch));
2390 fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size));
2394 ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch));
2396 fprintf_filtered (stream, " %s", pulongest (ul));
2399 l = extract_signed_integer (data, 1, gdbarch_byte_order (arch));
2401 fprintf_filtered (stream, " %s", plongest (l));
2404 ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
2406 fprintf_filtered (stream, " %s", pulongest (ul));
2409 l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
2411 fprintf_filtered (stream, " %s", plongest (l));
2414 ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
2416 fprintf_filtered (stream, " %s", pulongest (ul));
2419 l = extract_signed_integer (data, 4, gdbarch_byte_order (arch));
2421 fprintf_filtered (stream, " %s", plongest (l));
2424 ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch));
2426 fprintf_filtered (stream, " %s", pulongest (ul));
2429 l = extract_signed_integer (data, 8, gdbarch_byte_order (arch));
2431 fprintf_filtered (stream, " %s", plongest (l));
2434 data = read_uleb128 (data, end, &ul);
2435 fprintf_filtered (stream, " %s", pulongest (ul));
2438 data = read_sleb128 (data, end, &l);
2439 fprintf_filtered (stream, " %s", plongest (l));
2474 fprintf_filtered (stream, " [$%s]",
2475 locexpr_regname (arch, op - DW_OP_reg0));
2479 data = read_uleb128 (data, end, &ul);
2480 fprintf_filtered (stream, " %s [$%s]", pulongest (ul),
2481 locexpr_regname (arch, (int) ul));
2484 case DW_OP_implicit_value:
2485 data = read_uleb128 (data, end, &ul);
2487 fprintf_filtered (stream, " %s", pulongest (ul));
2522 data = read_sleb128 (data, end, &l);
2523 fprintf_filtered (stream, " %s [$%s]", plongest (l),
2524 locexpr_regname (arch, op - DW_OP_breg0));
2528 data = read_uleb128 (data, end, &ul);
2529 data = read_sleb128 (data, end, &l);
2530 fprintf_filtered (stream, " register %s [$%s] offset %s",
2532 locexpr_regname (arch, (int) ul),
2537 data = read_sleb128 (data, end, &l);
2538 fprintf_filtered (stream, " %s", plongest (l));
2541 case DW_OP_xderef_size:
2542 case DW_OP_deref_size:
2544 fprintf_filtered (stream, " %d", *data);
2548 case DW_OP_plus_uconst:
2549 data = read_uleb128 (data, end, &ul);
2550 fprintf_filtered (stream, " %s", pulongest (ul));
2554 l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
2556 fprintf_filtered (stream, " to %ld",
2557 (long) (data + l - start));
2561 l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
2563 fprintf_filtered (stream, " %ld",
2564 (long) (data + l - start));
2568 ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
2570 fprintf_filtered (stream, " offset %s", phex_nz (ul, 2));
2574 ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
2576 fprintf_filtered (stream, " offset %s", phex_nz (ul, 4));
2579 case DW_OP_call_ref:
2580 ul = extract_unsigned_integer (data, offset_size,
2581 gdbarch_byte_order (arch));
2582 data += offset_size;
2583 fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size));
2587 data = read_uleb128 (data, end, &ul);
2588 fprintf_filtered (stream, " %s (bytes)", pulongest (ul));
2591 case DW_OP_bit_piece:
2595 data = read_uleb128 (data, end, &ul);
2596 data = read_uleb128 (data, end, &offset);
2597 fprintf_filtered (stream, " size %s offset %s (bits)",
2598 pulongest (ul), pulongest (offset));
2602 case DW_OP_GNU_implicit_pointer:
2604 ul = extract_unsigned_integer (data, offset_size,
2605 gdbarch_byte_order (arch));
2606 data += offset_size;
2608 data = read_sleb128 (data, end, &l);
2610 fprintf_filtered (stream, " DIE %s offset %s",
2611 phex_nz (ul, offset_size),
2616 case DW_OP_GNU_deref_type:
2618 int addr_size = *data++;
2622 data = read_uleb128 (data, end, &offset);
2623 type = dwarf2_get_die_type (offset, per_cu);
2624 fprintf_filtered (stream, "<");
2625 type_print (type, "", stream, -1);
2626 fprintf_filtered (stream, " [0x%s]> %d", phex_nz (offset, 0),
2631 case DW_OP_GNU_const_type:
2636 data = read_uleb128 (data, end, &type_die);
2637 type = dwarf2_get_die_type (type_die, per_cu);
2638 fprintf_filtered (stream, "<");
2639 type_print (type, "", stream, -1);
2640 fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die, 0));
2644 case DW_OP_GNU_regval_type:
2646 ULONGEST type_die, reg;
2649 data = read_uleb128 (data, end, ®);
2650 data = read_uleb128 (data, end, &type_die);
2652 type = dwarf2_get_die_type (type_die, per_cu);
2653 fprintf_filtered (stream, "<");
2654 type_print (type, "", stream, -1);
2655 fprintf_filtered (stream, " [0x%s]> [$%s]", phex_nz (type_die, 0),
2656 locexpr_regname (arch, reg));
2660 case DW_OP_GNU_convert:
2661 case DW_OP_GNU_reinterpret:
2665 data = read_uleb128 (data, end, &type_die);
2668 fprintf_filtered (stream, "<0>");
2673 type = dwarf2_get_die_type (type_die, per_cu);
2674 fprintf_filtered (stream, "<");
2675 type_print (type, "", stream, -1);
2676 fprintf_filtered (stream, " [0x%s]>", phex_nz (type_die, 0));
2682 fprintf_filtered (stream, "\n");
2688 /* Describe a single location, which may in turn consist of multiple
2692 locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
2693 struct ui_file *stream,
2694 const gdb_byte *data, int size,
2695 struct objfile *objfile, unsigned int addr_size,
2696 int offset_size, struct dwarf2_per_cu_data *per_cu)
2698 const gdb_byte *end = data + size;
2699 int first_piece = 1, bad = 0;
2703 const gdb_byte *here = data;
2704 int disassemble = 1;
2709 fprintf_filtered (stream, _(", and "));
2711 if (!dwarf2_always_disassemble)
2713 data = locexpr_describe_location_piece (symbol, stream,
2715 data, end, addr_size);
2716 /* If we printed anything, or if we have an empty piece,
2717 then don't disassemble. */
2719 || data[0] == DW_OP_piece
2720 || data[0] == DW_OP_bit_piece)
2724 data = disassemble_dwarf_expression (stream,
2725 get_objfile_arch (objfile),
2726 addr_size, offset_size, data, end,
2727 dwarf2_always_disassemble,
2732 int empty = data == here;
2735 fprintf_filtered (stream, " ");
2736 if (data[0] == DW_OP_piece)
2740 data = read_uleb128 (data + 1, end, &bytes);
2743 fprintf_filtered (stream, _("an empty %s-byte piece"),
2746 fprintf_filtered (stream, _(" [%s-byte piece]"),
2749 else if (data[0] == DW_OP_bit_piece)
2751 ULONGEST bits, offset;
2753 data = read_uleb128 (data + 1, end, &bits);
2754 data = read_uleb128 (data, end, &offset);
2757 fprintf_filtered (stream,
2758 _("an empty %s-bit piece"),
2761 fprintf_filtered (stream,
2762 _(" [%s-bit piece, offset %s bits]"),
2763 pulongest (bits), pulongest (offset));
2773 if (bad || data > end)
2774 error (_("Corrupted DWARF2 expression for \"%s\"."),
2775 SYMBOL_PRINT_NAME (symbol));
2778 /* Print a natural-language description of SYMBOL to STREAM. This
2779 version is for a symbol with a single location. */
2782 locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
2783 struct ui_file *stream)
2785 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2786 struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
2787 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2788 int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
2790 locexpr_describe_location_1 (symbol, addr, stream,
2791 dlbaton->data, dlbaton->size,
2792 objfile, addr_size, offset_size,
2796 /* Describe the location of SYMBOL as an agent value in VALUE, generating
2797 any necessary bytecode in AX. */
2800 locexpr_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
2801 struct agent_expr *ax, struct axs_value *value)
2803 struct dwarf2_locexpr_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2804 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2806 if (dlbaton->data == NULL || dlbaton->size == 0)
2807 value->optimized_out = 1;
2809 dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size,
2810 dlbaton->data, dlbaton->data + dlbaton->size,
2814 /* The set of location functions used with the DWARF-2 expression
2816 const struct symbol_computed_ops dwarf2_locexpr_funcs = {
2817 locexpr_read_variable,
2818 locexpr_read_needs_frame,
2819 locexpr_describe_location,
2820 locexpr_tracepoint_var_ref
2824 /* Wrapper functions for location lists. These generally find
2825 the appropriate location expression and call something above. */
2827 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
2828 evaluator to calculate the location. */
2829 static struct value *
2830 loclist_read_variable (struct symbol *symbol, struct frame_info *frame)
2832 struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2834 const gdb_byte *data;
2836 CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0;
2838 data = dwarf2_find_location_expression (dlbaton, &size, pc);
2840 val = allocate_optimized_out_value (SYMBOL_TYPE (symbol));
2842 val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size,
2848 /* Return non-zero iff we need a frame to evaluate SYMBOL. */
2850 loclist_read_needs_frame (struct symbol *symbol)
2852 /* If there's a location list, then assume we need to have a frame
2853 to choose the appropriate location expression. With tracking of
2854 global variables this is not necessarily true, but such tracking
2855 is disabled in GCC at the moment until we figure out how to
2861 /* Print a natural-language description of SYMBOL to STREAM. This
2862 version applies when there is a list of different locations, each
2863 with a specified address range. */
2866 loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
2867 struct ui_file *stream)
2869 struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2870 CORE_ADDR low, high;
2871 const gdb_byte *loc_ptr, *buf_end;
2872 int length, first = 1;
2873 struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
2874 struct gdbarch *gdbarch = get_objfile_arch (objfile);
2875 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
2876 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2877 int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
2878 int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
2879 CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
2880 /* Adjust base_address for relocatable objects. */
2881 CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu);
2882 CORE_ADDR base_address = dlbaton->base_address + base_offset;
2884 loc_ptr = dlbaton->data;
2885 buf_end = dlbaton->data + dlbaton->size;
2887 fprintf_filtered (stream, _("multi-location:\n"));
2889 /* Iterate through locations until we run out. */
2892 if (buf_end - loc_ptr < 2 * addr_size)
2893 error (_("Corrupted DWARF expression for symbol \"%s\"."),
2894 SYMBOL_PRINT_NAME (symbol));
2897 low = extract_signed_integer (loc_ptr, addr_size, byte_order);
2899 low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
2900 loc_ptr += addr_size;
2903 high = extract_signed_integer (loc_ptr, addr_size, byte_order);
2905 high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
2906 loc_ptr += addr_size;
2908 /* A base-address-selection entry. */
2909 if ((low & base_mask) == base_mask)
2911 base_address = high + base_offset;
2912 fprintf_filtered (stream, _(" Base address %s"),
2913 paddress (gdbarch, base_address));
2917 /* An end-of-list entry. */
2918 if (low == 0 && high == 0)
2921 /* Otherwise, a location expression entry. */
2922 low += base_address;
2923 high += base_address;
2925 length = extract_unsigned_integer (loc_ptr, 2, byte_order);
2928 /* (It would improve readability to print only the minimum
2929 necessary digits of the second number of the range.) */
2930 fprintf_filtered (stream, _(" Range %s-%s: "),
2931 paddress (gdbarch, low), paddress (gdbarch, high));
2933 /* Now describe this particular location. */
2934 locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
2935 objfile, addr_size, offset_size,
2938 fprintf_filtered (stream, "\n");
2944 /* Describe the location of SYMBOL as an agent value in VALUE, generating
2945 any necessary bytecode in AX. */
2947 loclist_tracepoint_var_ref (struct symbol *symbol, struct gdbarch *gdbarch,
2948 struct agent_expr *ax, struct axs_value *value)
2950 struct dwarf2_loclist_baton *dlbaton = SYMBOL_LOCATION_BATON (symbol);
2951 const gdb_byte *data;
2953 unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
2955 data = dwarf2_find_location_expression (dlbaton, &size, ax->scope);
2956 if (data == NULL || size == 0)
2957 value->optimized_out = 1;
2959 dwarf2_compile_expr_to_ax (ax, value, gdbarch, addr_size, data, data + size,
2963 /* The set of location functions used with the DWARF-2 expression
2964 evaluator and location lists. */
2965 const struct symbol_computed_ops dwarf2_loclist_funcs = {
2966 loclist_read_variable,
2967 loclist_read_needs_frame,
2968 loclist_describe_location,
2969 loclist_tracepoint_var_ref