_("%s evaluation requires a compilation unit."), op_name);
}
+/* Return the number of bytes overlapping a contiguous chunk of N_BITS
+ bits whose first bit is located at bit offset START. */
+
+static size_t
+bits_to_bytes (ULONGEST start, ULONGEST n_bits)
+{
+ return (start % HOST_CHAR_BIT + n_bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
+}
+
/* See expr.h. */
CORE_ADDR
return address_from_register (regnum, frame);
}
+struct piece_closure
+{
+ /* Reference count. */
+ int refc = 0;
+
+ /* The objfile from which this closure's expression came. */
+ dwarf2_per_objfile *per_objfile = nullptr;
+
+ /* The CU from which this closure's expression came. */
+ dwarf2_per_cu_data *per_cu = nullptr;
+
+ /* The pieces describing this variable. */
+ std::vector<dwarf_expr_piece> pieces;
+
+ /* Frame ID of frame to which a register value is relative, used
+ only by DWARF_VALUE_REGISTER. */
+ struct frame_id frame_id;
+};
+
+/* See expr.h. */
+
+piece_closure *
+allocate_piece_closure (dwarf2_per_cu_data *per_cu,
+ dwarf2_per_objfile *per_objfile,
+ std::vector<dwarf_expr_piece> &&pieces,
+ frame_info *frame)
+{
+ piece_closure *c = new piece_closure;
+
+ c->refc = 1;
+ /* We must capture this here due to sharing of DWARF state. */
+ c->per_objfile = per_objfile;
+ c->per_cu = per_cu;
+ c->pieces = std::move (pieces);
+ if (frame == nullptr)
+ c->frame_id = null_frame_id;
+ else
+ c->frame_id = get_frame_id (frame);
+
+ for (dwarf_expr_piece &piece : c->pieces)
+ if (piece.location == DWARF_VALUE_STACK)
+ value_incref (piece.v.value);
+
+ return c;
+}
+
+/* Read or write a pieced value V. If FROM != NULL, operate in "write
+ mode": copy FROM into the pieces comprising V. If FROM == NULL,
+ operate in "read mode": fetch the contents of the (lazy) value V by
+ composing it from its pieces. */
+
+static void
+rw_pieced_value (value *v, value *from)
+{
+ int i;
+ LONGEST offset = 0, max_offset;
+ gdb_byte *v_contents;
+ const gdb_byte *from_contents;
+ piece_closure *c
+ = (piece_closure *) value_computed_closure (v);
+ gdb::byte_vector buffer;
+ bool bits_big_endian = type_byte_order (value_type (v)) == BFD_ENDIAN_BIG;
+
+ if (from != nullptr)
+ {
+ from_contents = value_contents (from);
+ v_contents = nullptr;
+ }
+ else
+ {
+ if (value_type (v) != value_enclosing_type (v))
+ internal_error (__FILE__, __LINE__,
+ _("Should not be able to create a lazy value with "
+ "an enclosing type"));
+ v_contents = value_contents_raw (v);
+ from_contents = nullptr;
+ }
+
+ ULONGEST bits_to_skip = 8 * value_offset (v);
+ if (value_bitsize (v))
+ {
+ bits_to_skip += (8 * value_offset (value_parent (v))
+ + value_bitpos (v));
+ if (from != nullptr
+ && (type_byte_order (value_type (from))
+ == BFD_ENDIAN_BIG))
+ {
+ /* Use the least significant bits of FROM. */
+ max_offset = 8 * TYPE_LENGTH (value_type (from));
+ offset = max_offset - value_bitsize (v);
+ }
+ else
+ max_offset = value_bitsize (v);
+ }
+ else
+ max_offset = 8 * TYPE_LENGTH (value_type (v));
+
+ /* Advance to the first non-skipped piece. */
+ for (i = 0; i < c->pieces.size () && bits_to_skip >= c->pieces[i].size; i++)
+ bits_to_skip -= c->pieces[i].size;
+
+ for (; i < c->pieces.size () && offset < max_offset; i++)
+ {
+ dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits, this_size;
+
+ this_size_bits = p->size - bits_to_skip;
+ if (this_size_bits > max_offset - offset)
+ this_size_bits = max_offset - offset;
+
+ switch (p->location)
+ {
+ case DWARF_VALUE_REGISTER:
+ {
+ frame_info *frame = frame_find_by_id (c->frame_id);
+ gdbarch *arch = get_frame_arch (frame);
+ int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno);
+ ULONGEST reg_bits = 8 * register_size (arch, gdb_regnum);
+ int optim, unavail;
+
+ if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
+ && p->offset + p->size < reg_bits)
+ {
+ /* Big-endian, and we want less than full size. */
+ bits_to_skip += reg_bits - (p->offset + p->size);
+ }
+ else
+ bits_to_skip += p->offset;
+
+ this_size = bits_to_bytes (bits_to_skip, this_size_bits);
+ buffer.resize (this_size);
+
+ if (from == nullptr)
+ {
+ /* Read mode. */
+ if (!get_frame_register_bytes (frame, gdb_regnum,
+ bits_to_skip / 8,
+ buffer, &optim, &unavail))
+ {
+ if (optim)
+ mark_value_bits_optimized_out (v, offset,
+ this_size_bits);
+ if (unavail)
+ mark_value_bits_unavailable (v, offset,
+ this_size_bits);
+ break;
+ }
+
+ copy_bitwise (v_contents, offset,
+ buffer.data (), bits_to_skip % 8,
+ this_size_bits, bits_big_endian);
+ }
+ else
+ {
+ /* Write mode. */
+ if (bits_to_skip % 8 != 0 || this_size_bits % 8 != 0)
+ {
+ /* Data is copied non-byte-aligned into the register.
+ Need some bits from original register value. */
+ get_frame_register_bytes (frame, gdb_regnum,
+ bits_to_skip / 8,
+ buffer, &optim, &unavail);
+ if (optim)
+ throw_error (OPTIMIZED_OUT_ERROR,
+ _("Can't do read-modify-write to "
+ "update bitfield; containing word "
+ "has been optimized out"));
+ if (unavail)
+ throw_error (NOT_AVAILABLE_ERROR,
+ _("Can't do read-modify-write to "
+ "update bitfield; containing word "
+ "is unavailable"));
+ }
+
+ copy_bitwise (buffer.data (), bits_to_skip % 8,
+ from_contents, offset,
+ this_size_bits, bits_big_endian);
+ put_frame_register_bytes (frame, gdb_regnum,
+ bits_to_skip / 8,
+ buffer);
+ }
+ }
+ break;
+
+ case DWARF_VALUE_MEMORY:
+ {
+ bits_to_skip += p->offset;
+
+ CORE_ADDR start_addr = p->v.mem.addr + bits_to_skip / 8;
+
+ if (bits_to_skip % 8 == 0 && this_size_bits % 8 == 0
+ && offset % 8 == 0)
+ {
+ /* Everything is byte-aligned; no buffer needed. */
+ if (from != nullptr)
+ write_memory_with_notification (start_addr,
+ (from_contents
+ + offset / 8),
+ this_size_bits / 8);
+ else
+ read_value_memory (v, offset,
+ p->v.mem.in_stack_memory,
+ p->v.mem.addr + bits_to_skip / 8,
+ v_contents + offset / 8,
+ this_size_bits / 8);
+ break;
+ }
+
+ this_size = bits_to_bytes (bits_to_skip, this_size_bits);
+ buffer.resize (this_size);
+
+ if (from == nullptr)
+ {
+ /* Read mode. */
+ read_value_memory (v, offset,
+ p->v.mem.in_stack_memory,
+ p->v.mem.addr + bits_to_skip / 8,
+ buffer.data (), this_size);
+ copy_bitwise (v_contents, offset,
+ buffer.data (), bits_to_skip % 8,
+ this_size_bits, bits_big_endian);
+ }
+ else
+ {
+ /* Write mode. */
+ if (bits_to_skip % 8 != 0 || this_size_bits % 8 != 0)
+ {
+ if (this_size <= 8)
+ {
+ /* Perform a single read for small sizes. */
+ read_memory (start_addr, buffer.data (),
+ this_size);
+ }
+ else
+ {
+ /* Only the first and last bytes can possibly have
+ any bits reused. */
+ read_memory (start_addr, buffer.data (), 1);
+ read_memory (start_addr + this_size - 1,
+ &buffer[this_size - 1], 1);
+ }
+ }
+
+ copy_bitwise (buffer.data (), bits_to_skip % 8,
+ from_contents, offset,
+ this_size_bits, bits_big_endian);
+ write_memory_with_notification (start_addr,
+ buffer.data (),
+ this_size);
+ }
+ }
+ break;
+
+ case DWARF_VALUE_STACK:
+ {
+ if (from != nullptr)
+ {
+ mark_value_bits_optimized_out (v, offset, this_size_bits);
+ break;
+ }
+
+ gdbarch *objfile_gdbarch = c->per_objfile->objfile->arch ();
+ ULONGEST stack_value_size_bits
+ = 8 * TYPE_LENGTH (value_type (p->v.value));
+
+ /* Use zeroes if piece reaches beyond stack value. */
+ if (p->offset + p->size > stack_value_size_bits)
+ break;
+
+ /* Piece is anchored at least significant bit end. */
+ if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG)
+ bits_to_skip += stack_value_size_bits - p->offset - p->size;
+ else
+ bits_to_skip += p->offset;
+
+ copy_bitwise (v_contents, offset,
+ value_contents_all (p->v.value),
+ bits_to_skip,
+ this_size_bits, bits_big_endian);
+ }
+ break;
+
+ case DWARF_VALUE_LITERAL:
+ {
+ if (from != nullptr)
+ {
+ mark_value_bits_optimized_out (v, offset, this_size_bits);
+ break;
+ }
+
+ ULONGEST literal_size_bits = 8 * p->v.literal.length;
+ size_t n = this_size_bits;
+
+ /* Cut off at the end of the implicit value. */
+ bits_to_skip += p->offset;
+ if (bits_to_skip >= literal_size_bits)
+ break;
+ if (n > literal_size_bits - bits_to_skip)
+ n = literal_size_bits - bits_to_skip;
+
+ copy_bitwise (v_contents, offset,
+ p->v.literal.data, bits_to_skip,
+ n, bits_big_endian);
+ }
+ break;
+
+ case DWARF_VALUE_IMPLICIT_POINTER:
+ if (from != nullptr)
+ {
+ mark_value_bits_optimized_out (v, offset, this_size_bits);
+ break;
+ }
+
+ /* These bits show up as zeros -- but do not cause the value to
+ be considered optimized-out. */
+ break;
+
+ case DWARF_VALUE_OPTIMIZED_OUT:
+ mark_value_bits_optimized_out (v, offset, this_size_bits);
+ break;
+
+ default:
+ internal_error (__FILE__, __LINE__, _("invalid location type"));
+ }
+
+ offset += this_size_bits;
+ bits_to_skip = 0;
+ }
+}
+
+static void
+read_pieced_value (value *v)
+{
+ rw_pieced_value (v, nullptr);
+}
+
+static void
+write_pieced_value (value *to, value *from)
+{
+ rw_pieced_value (to, from);
+}
+
+/* An implementation of an lval_funcs method to see whether a value is
+ a synthetic pointer. */
+
+static int
+check_pieced_synthetic_pointer (const value *value, LONGEST bit_offset,
+ int bit_length)
+{
+ piece_closure *c = (piece_closure *) value_computed_closure (value);
+ int i;
+
+ bit_offset += 8 * value_offset (value);
+ if (value_bitsize (value))
+ bit_offset += value_bitpos (value);
+
+ for (i = 0; i < c->pieces.size () && bit_length > 0; i++)
+ {
+ dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits = p->size;
+
+ if (bit_offset > 0)
+ {
+ if (bit_offset >= this_size_bits)
+ {
+ bit_offset -= this_size_bits;
+ continue;
+ }
+
+ bit_length -= this_size_bits - bit_offset;
+ bit_offset = 0;
+ }
+ else
+ bit_length -= this_size_bits;
+
+ if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
+ return 0;
+ }
+
+ return 1;
+}
+
+/* An implementation of an lval_funcs method to indirect through a
+ pointer. This handles the synthetic pointer case when needed. */
+
+static value *
+indirect_pieced_value (value *value)
+{
+ piece_closure *c
+ = (piece_closure *) value_computed_closure (value);
+ int i;
+ dwarf_expr_piece *piece = NULL;
+
+ struct type *type = check_typedef (value_type (value));
+ if (type->code () != TYPE_CODE_PTR)
+ return NULL;
+
+ int bit_length = 8 * TYPE_LENGTH (type);
+ LONGEST bit_offset = 8 * value_offset (value);
+ if (value_bitsize (value))
+ bit_offset += value_bitpos (value);
+
+ for (i = 0; i < c->pieces.size () && bit_length > 0; i++)
+ {
+ dwarf_expr_piece *p = &c->pieces[i];
+ size_t this_size_bits = p->size;
+
+ if (bit_offset > 0)
+ {
+ if (bit_offset >= this_size_bits)
+ {
+ bit_offset -= this_size_bits;
+ continue;
+ }
+
+ bit_length -= this_size_bits - bit_offset;
+ bit_offset = 0;
+ }
+ else
+ bit_length -= this_size_bits;
+
+ if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
+ return NULL;
+
+ if (bit_length != 0)
+ error (_("Invalid use of DW_OP_implicit_pointer"));
+
+ piece = p;
+ break;
+ }
+
+ gdb_assert (piece != NULL && c->per_cu != nullptr);
+ frame_info *frame = get_selected_frame (_("No frame selected."));
+
+ /* This is an offset requested by GDB, such as value subscripts.
+ However, due to how synthetic pointers are implemented, this is
+ always presented to us as a pointer type. This means we have to
+ sign-extend it manually as appropriate. Use raw
+ extract_signed_integer directly rather than value_as_address and
+ sign extend afterwards on architectures that would need it
+ (mostly everywhere except MIPS, which has signed addresses) as
+ the later would go through gdbarch_pointer_to_address and thus
+ return a CORE_ADDR with high bits set on architectures that
+ encode address spaces and other things in CORE_ADDR. */
+ bfd_endian byte_order = gdbarch_byte_order (get_frame_arch (frame));
+ LONGEST byte_offset
+ = extract_signed_integer (value_contents (value),
+ TYPE_LENGTH (type), byte_order);
+ byte_offset += piece->v.ptr.offset;
+
+ return indirect_synthetic_pointer (piece->v.ptr.die_sect_off,
+ byte_offset, c->per_cu,
+ c->per_objfile, frame, type);
+}
+
+/* Implementation of the coerce_ref method of lval_funcs for synthetic C++
+ references. */
+
+static value *
+coerce_pieced_ref (const value *value)
+{
+ struct type *type = check_typedef (value_type (value));
+
+ if (value_bits_synthetic_pointer (value, value_embedded_offset (value),
+ TARGET_CHAR_BIT * TYPE_LENGTH (type)))
+ {
+ const piece_closure *closure
+ = (piece_closure *) value_computed_closure (value);
+ frame_info *frame
+ = get_selected_frame (_("No frame selected."));
+
+ /* gdb represents synthetic pointers as pieced values with a single
+ piece. */
+ gdb_assert (closure != NULL);
+ gdb_assert (closure->pieces.size () == 1);
+
+ return indirect_synthetic_pointer
+ (closure->pieces[0].v.ptr.die_sect_off,
+ closure->pieces[0].v.ptr.offset,
+ closure->per_cu, closure->per_objfile, frame, type);
+ }
+ else
+ {
+ /* Else: not a synthetic reference; do nothing. */
+ return NULL;
+ }
+}
+
+static void *
+copy_pieced_value_closure (const value *v)
+{
+ piece_closure *c = (piece_closure *) value_computed_closure (v);
+
+ ++c->refc;
+ return c;
+}
+
+static void
+free_pieced_value_closure (value *v)
+{
+ piece_closure *c = (piece_closure *) value_computed_closure (v);
+
+ --c->refc;
+ if (c->refc == 0)
+ {
+ for (dwarf_expr_piece &p : c->pieces)
+ if (p.location == DWARF_VALUE_STACK)
+ value_decref (p.v.value);
+
+ delete c;
+ }
+}
+
+/* Functions for accessing a variable described by DW_OP_piece. */
+const struct lval_funcs pieced_value_funcs = {
+ read_pieced_value,
+ write_pieced_value,
+ indirect_pieced_value,
+ coerce_pieced_ref,
+ check_pieced_synthetic_pointer,
+ copy_pieced_value_closure,
+ free_pieced_value_closure
+};
+
+/* Given context CTX, section offset SECT_OFF, and compilation unit
+ data PER_CU, execute the "variable value" operation on the DIE
+ found at SECT_OFF. */
+
+static value *
+sect_variable_value (sect_offset sect_off,
+ dwarf2_per_cu_data *per_cu,
+ dwarf2_per_objfile *per_objfile)
+{
+ const char *var_name = nullptr;
+ struct type *die_type
+ = dwarf2_fetch_die_type_sect_off (sect_off, per_cu, per_objfile,
+ &var_name);
+
+ if (die_type == NULL)
+ error (_("Bad DW_OP_GNU_variable_value DIE."));
+
+ /* Note: Things still work when the following test is removed. This
+ test and error is here to conform to the proposed specification. */
+ if (die_type->code () != TYPE_CODE_INT
+ && die_type->code () != TYPE_CODE_ENUM
+ && die_type->code () != TYPE_CODE_RANGE
+ && die_type->code () != TYPE_CODE_PTR)
+ error (_("Type of DW_OP_GNU_variable_value DIE must be an integer or pointer."));
+
+ if (var_name != nullptr)
+ {
+ value *result = compute_var_value (var_name);
+ if (result != nullptr)
+ return result;
+ }
+
+ struct type *type = lookup_pointer_type (die_type);
+ frame_info *frame = get_selected_frame (_("No frame selected."));
+ return indirect_synthetic_pointer (sect_off, 0, per_cu, per_objfile, frame,
+ type, true);
+}
+
/* Return the type used for DWARF operations where the type is
unspecified in the DWARF spec. Only certain sizes are
supported. */
size_t size, dwarf2_per_cu_data *per_cu, dwarf2_per_objfile *per_objfile,
struct type *subobj_type, LONGEST subobj_byte_offset);
-static struct value *indirect_synthetic_pointer
- (sect_offset die, LONGEST byte_offset,
- dwarf2_per_cu_data *per_cu,
- dwarf2_per_objfile *per_objfile,
- struct frame_info *frame,
- struct type *type, bool resolve_abstract_p = false);
-
/* Until these have formal names, we define these here.
ref: http://gcc.gnu.org/wiki/DebugFission
Each entry in .debug_loc.dwo begins with a byte that describes the entry,
framefunc->natural_name ());
}
-/* A helper function to find the definition of NAME and compute its
- value. Returns nullptr if the name is not found. */
+/* See loc.h. */
-static value *
+value *
compute_var_value (const char *name)
{
struct block_symbol sym = lookup_symbol (name, nullptr, VAR_DOMAIN,
return nullptr;
}
-/* See loc.h. */
-
-struct value *
-sect_variable_value (sect_offset sect_off,
- dwarf2_per_cu_data *per_cu,
- dwarf2_per_objfile *per_objfile)
-{
- const char *var_name = nullptr;
- struct type *die_type
- = dwarf2_fetch_die_type_sect_off (sect_off, per_cu, per_objfile,
- &var_name);
-
- if (die_type == NULL)
- error (_("Bad DW_OP_GNU_variable_value DIE."));
-
- /* Note: Things still work when the following test is removed. This
- test and error is here to conform to the proposed specification. */
- if (die_type->code () != TYPE_CODE_INT
- && die_type->code () != TYPE_CODE_ENUM
- && die_type->code () != TYPE_CODE_RANGE
- && die_type->code () != TYPE_CODE_PTR)
- error (_("Type of DW_OP_GNU_variable_value DIE must be an integer or pointer."));
-
- if (var_name != nullptr)
- {
- value *result = compute_var_value (var_name);
- if (result != nullptr)
- return result;
- }
-
- struct type *type = lookup_pointer_type (die_type);
- struct frame_info *frame = get_selected_frame (_("No frame selected."));
- return indirect_synthetic_pointer (sect_off, 0, per_cu, per_objfile, frame,
- type, true);
-}
-
/* See dwarf2loc.h. */
unsigned int entry_values_debug = 0;
"only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
}
-struct piece_closure
-{
- /* Reference count. */
- int refc = 0;
-
- /* The objfile from which this closure's expression came. */
- dwarf2_per_objfile *per_objfile = nullptr;
-
- /* The CU from which this closure's expression came. */
- struct dwarf2_per_cu_data *per_cu = NULL;
-
- /* The pieces describing this variable. */
- std::vector<dwarf_expr_piece> pieces;
-
- /* Frame ID of frame to which a register value is relative, used
- only by DWARF_VALUE_REGISTER. */
- struct frame_id frame_id;
-};
-
-/* Allocate a closure for a value formed from separately-described
- PIECES. */
-
-static struct piece_closure *
-allocate_piece_closure (dwarf2_per_cu_data *per_cu,
- dwarf2_per_objfile *per_objfile,
- std::vector<dwarf_expr_piece> &&pieces,
- struct frame_info *frame)
-{
- struct piece_closure *c = new piece_closure;
-
- c->refc = 1;
- /* We must capture this here due to sharing of DWARF state. */
- c->per_objfile = per_objfile;
- c->per_cu = per_cu;
- c->pieces = std::move (pieces);
- if (frame == NULL)
- c->frame_id = null_frame_id;
- else
- c->frame_id = get_frame_id (frame);
-
- for (dwarf_expr_piece &piece : c->pieces)
- if (piece.location == DWARF_VALUE_STACK)
- value_incref (piece.v.value);
-
- return c;
-}
-
-/* Return the number of bytes overlapping a contiguous chunk of N_BITS
- bits whose first bit is located at bit offset START. */
-
-static size_t
-bits_to_bytes (ULONGEST start, ULONGEST n_bits)
-{
- return (start % 8 + n_bits + 7) / 8;
-}
-
-/* Read or write a pieced value V. If FROM != NULL, operate in "write
- mode": copy FROM into the pieces comprising V. If FROM == NULL,
- operate in "read mode": fetch the contents of the (lazy) value V by
- composing it from its pieces. */
-
-static void
-rw_pieced_value (struct value *v, struct value *from)
-{
- int i;
- LONGEST offset = 0, max_offset;
- ULONGEST bits_to_skip;
- gdb_byte *v_contents;
- const gdb_byte *from_contents;
- struct piece_closure *c
- = (struct piece_closure *) value_computed_closure (v);
- gdb::byte_vector buffer;
- bool bits_big_endian = type_byte_order (value_type (v)) == BFD_ENDIAN_BIG;
-
- if (from != NULL)
- {
- from_contents = value_contents (from);
- v_contents = NULL;
- }
- else
- {
- if (value_type (v) != value_enclosing_type (v))
- internal_error (__FILE__, __LINE__,
- _("Should not be able to create a lazy value with "
- "an enclosing type"));
- v_contents = value_contents_raw (v);
- from_contents = NULL;
- }
-
- bits_to_skip = 8 * value_offset (v);
- if (value_bitsize (v))
- {
- bits_to_skip += (8 * value_offset (value_parent (v))
- + value_bitpos (v));
- if (from != NULL
- && (type_byte_order (value_type (from))
- == BFD_ENDIAN_BIG))
- {
- /* Use the least significant bits of FROM. */
- max_offset = 8 * TYPE_LENGTH (value_type (from));
- offset = max_offset - value_bitsize (v);
- }
- else
- max_offset = value_bitsize (v);
- }
- else
- max_offset = 8 * TYPE_LENGTH (value_type (v));
-
- /* Advance to the first non-skipped piece. */
- for (i = 0; i < c->pieces.size () && bits_to_skip >= c->pieces[i].size; i++)
- bits_to_skip -= c->pieces[i].size;
-
- for (; i < c->pieces.size () && offset < max_offset; i++)
- {
- struct dwarf_expr_piece *p = &c->pieces[i];
- size_t this_size_bits, this_size;
-
- this_size_bits = p->size - bits_to_skip;
- if (this_size_bits > max_offset - offset)
- this_size_bits = max_offset - offset;
-
- switch (p->location)
- {
- case DWARF_VALUE_REGISTER:
- {
- struct frame_info *frame = frame_find_by_id (c->frame_id);
- struct gdbarch *arch = get_frame_arch (frame);
- int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno);
- ULONGEST reg_bits = 8 * register_size (arch, gdb_regnum);
- int optim, unavail;
-
- if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
- && p->offset + p->size < reg_bits)
- {
- /* Big-endian, and we want less than full size. */
- bits_to_skip += reg_bits - (p->offset + p->size);
- }
- else
- bits_to_skip += p->offset;
-
- this_size = bits_to_bytes (bits_to_skip, this_size_bits);
- buffer.resize (this_size);
-
- if (from == NULL)
- {
- /* Read mode. */
- if (!get_frame_register_bytes (frame, gdb_regnum,
- bits_to_skip / 8,
- buffer,
- &optim, &unavail))
- {
- if (optim)
- mark_value_bits_optimized_out (v, offset,
- this_size_bits);
- if (unavail)
- mark_value_bits_unavailable (v, offset,
- this_size_bits);
- break;
- }
-
- copy_bitwise (v_contents, offset,
- buffer.data (), bits_to_skip % 8,
- this_size_bits, bits_big_endian);
- }
- else
- {
- /* Write mode. */
- if (bits_to_skip % 8 != 0 || this_size_bits % 8 != 0)
- {
- /* Data is copied non-byte-aligned into the register.
- Need some bits from original register value. */
- get_frame_register_bytes (frame, gdb_regnum,
- bits_to_skip / 8,
- buffer,
- &optim, &unavail);
- if (optim)
- throw_error (OPTIMIZED_OUT_ERROR,
- _("Can't do read-modify-write to "
- "update bitfield; containing word "
- "has been optimized out"));
- if (unavail)
- throw_error (NOT_AVAILABLE_ERROR,
- _("Can't do read-modify-write to "
- "update bitfield; containing word "
- "is unavailable"));
- }
-
- copy_bitwise (buffer.data (), bits_to_skip % 8,
- from_contents, offset,
- this_size_bits, bits_big_endian);
- put_frame_register_bytes (frame, gdb_regnum,
- bits_to_skip / 8,
- buffer);
- }
- }
- break;
-
- case DWARF_VALUE_MEMORY:
- {
- bits_to_skip += p->offset;
-
- CORE_ADDR start_addr = p->v.mem.addr + bits_to_skip / 8;
-
- if (bits_to_skip % 8 == 0 && this_size_bits % 8 == 0
- && offset % 8 == 0)
- {
- /* Everything is byte-aligned; no buffer needed. */
- if (from != NULL)
- write_memory_with_notification (start_addr,
- (from_contents
- + offset / 8),
- this_size_bits / 8);
- else
- read_value_memory (v, offset,
- p->v.mem.in_stack_memory,
- p->v.mem.addr + bits_to_skip / 8,
- v_contents + offset / 8,
- this_size_bits / 8);
- break;
- }
-
- this_size = bits_to_bytes (bits_to_skip, this_size_bits);
- buffer.resize (this_size);
-
- if (from == NULL)
- {
- /* Read mode. */
- read_value_memory (v, offset,
- p->v.mem.in_stack_memory,
- p->v.mem.addr + bits_to_skip / 8,
- buffer.data (), this_size);
- copy_bitwise (v_contents, offset,
- buffer.data (), bits_to_skip % 8,
- this_size_bits, bits_big_endian);
- }
- else
- {
- /* Write mode. */
- if (bits_to_skip % 8 != 0 || this_size_bits % 8 != 0)
- {
- if (this_size <= 8)
- {
- /* Perform a single read for small sizes. */
- read_memory (start_addr, buffer.data (),
- this_size);
- }
- else
- {
- /* Only the first and last bytes can possibly have
- any bits reused. */
- read_memory (start_addr, buffer.data (), 1);
- read_memory (start_addr + this_size - 1,
- &buffer[this_size - 1], 1);
- }
- }
-
- copy_bitwise (buffer.data (), bits_to_skip % 8,
- from_contents, offset,
- this_size_bits, bits_big_endian);
- write_memory_with_notification (start_addr,
- buffer.data (),
- this_size);
- }
- }
- break;
-
- case DWARF_VALUE_STACK:
- {
- if (from != NULL)
- {
- mark_value_bits_optimized_out (v, offset, this_size_bits);
- break;
- }
-
- gdbarch *objfile_gdbarch = c->per_objfile->objfile->arch ();
- ULONGEST stack_value_size_bits
- = 8 * TYPE_LENGTH (value_type (p->v.value));
-
- /* Use zeroes if piece reaches beyond stack value. */
- if (p->offset + p->size > stack_value_size_bits)
- break;
-
- /* Piece is anchored at least significant bit end. */
- if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG)
- bits_to_skip += stack_value_size_bits - p->offset - p->size;
- else
- bits_to_skip += p->offset;
-
- copy_bitwise (v_contents, offset,
- value_contents_all (p->v.value),
- bits_to_skip,
- this_size_bits, bits_big_endian);
- }
- break;
-
- case DWARF_VALUE_LITERAL:
- {
- if (from != NULL)
- {
- mark_value_bits_optimized_out (v, offset, this_size_bits);
- break;
- }
-
- ULONGEST literal_size_bits = 8 * p->v.literal.length;
- size_t n = this_size_bits;
-
- /* Cut off at the end of the implicit value. */
- bits_to_skip += p->offset;
- if (bits_to_skip >= literal_size_bits)
- break;
- if (n > literal_size_bits - bits_to_skip)
- n = literal_size_bits - bits_to_skip;
-
- copy_bitwise (v_contents, offset,
- p->v.literal.data, bits_to_skip,
- n, bits_big_endian);
- }
- break;
-
- case DWARF_VALUE_IMPLICIT_POINTER:
- if (from != NULL)
- {
- mark_value_bits_optimized_out (v, offset, this_size_bits);
- break;
- }
-
- /* These bits show up as zeros -- but do not cause the value to
- be considered optimized-out. */
- break;
-
- case DWARF_VALUE_OPTIMIZED_OUT:
- mark_value_bits_optimized_out (v, offset, this_size_bits);
- break;
-
- default:
- internal_error (__FILE__, __LINE__, _("invalid location type"));
- }
-
- offset += this_size_bits;
- bits_to_skip = 0;
- }
-}
-
-
-static void
-read_pieced_value (struct value *v)
-{
- rw_pieced_value (v, NULL);
-}
-
-static void
-write_pieced_value (struct value *to, struct value *from)
-{
- rw_pieced_value (to, from);
-}
-
-/* An implementation of an lval_funcs method to see whether a value is
- a synthetic pointer. */
-
-static int
-check_pieced_synthetic_pointer (const struct value *value, LONGEST bit_offset,
- int bit_length)
-{
- struct piece_closure *c
- = (struct piece_closure *) value_computed_closure (value);
- int i;
-
- bit_offset += 8 * value_offset (value);
- if (value_bitsize (value))
- bit_offset += value_bitpos (value);
-
- for (i = 0; i < c->pieces.size () && bit_length > 0; i++)
- {
- struct dwarf_expr_piece *p = &c->pieces[i];
- size_t this_size_bits = p->size;
-
- if (bit_offset > 0)
- {
- if (bit_offset >= this_size_bits)
- {
- bit_offset -= this_size_bits;
- continue;
- }
-
- bit_length -= this_size_bits - bit_offset;
- bit_offset = 0;
- }
- else
- bit_length -= this_size_bits;
-
- if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
- return 0;
- }
-
- return 1;
-}
-
/* Fetch a DW_AT_const_value through a synthetic pointer. */
static struct value *
return result;
}
-/* Fetch the value pointed to by a synthetic pointer. */
+/* See loc.h. */
-static struct value *
+struct value *
indirect_synthetic_pointer (sect_offset die, LONGEST byte_offset,
dwarf2_per_cu_data *per_cu,
dwarf2_per_objfile *per_objfile,
per_objfile, type);
}
-/* An implementation of an lval_funcs method to indirect through a
- pointer. This handles the synthetic pointer case when needed. */
-
-static struct value *
-indirect_pieced_value (struct value *value)
-{
- struct piece_closure *c
- = (struct piece_closure *) value_computed_closure (value);
- struct type *type;
- struct frame_info *frame;
- int i, bit_length;
- LONGEST bit_offset;
- struct dwarf_expr_piece *piece = NULL;
- LONGEST byte_offset;
- enum bfd_endian byte_order;
-
- type = check_typedef (value_type (value));
- if (type->code () != TYPE_CODE_PTR)
- return NULL;
-
- bit_length = 8 * TYPE_LENGTH (type);
- bit_offset = 8 * value_offset (value);
- if (value_bitsize (value))
- bit_offset += value_bitpos (value);
-
- for (i = 0; i < c->pieces.size () && bit_length > 0; i++)
- {
- struct dwarf_expr_piece *p = &c->pieces[i];
- size_t this_size_bits = p->size;
-
- if (bit_offset > 0)
- {
- if (bit_offset >= this_size_bits)
- {
- bit_offset -= this_size_bits;
- continue;
- }
-
- bit_length -= this_size_bits - bit_offset;
- bit_offset = 0;
- }
- else
- bit_length -= this_size_bits;
-
- if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
- return NULL;
-
- if (bit_length != 0)
- error (_("Invalid use of DW_OP_implicit_pointer"));
-
- piece = p;
- break;
- }
-
- gdb_assert (piece != NULL);
- frame = get_selected_frame (_("No frame selected."));
-
- /* This is an offset requested by GDB, such as value subscripts.
- However, due to how synthetic pointers are implemented, this is
- always presented to us as a pointer type. This means we have to
- sign-extend it manually as appropriate. Use raw
- extract_signed_integer directly rather than value_as_address and
- sign extend afterwards on architectures that would need it
- (mostly everywhere except MIPS, which has signed addresses) as
- the later would go through gdbarch_pointer_to_address and thus
- return a CORE_ADDR with high bits set on architectures that
- encode address spaces and other things in CORE_ADDR. */
- byte_order = gdbarch_byte_order (get_frame_arch (frame));
- byte_offset = extract_signed_integer (value_contents (value),
- TYPE_LENGTH (type), byte_order);
- byte_offset += piece->v.ptr.offset;
-
- return indirect_synthetic_pointer (piece->v.ptr.die_sect_off,
- byte_offset, c->per_cu,
- c->per_objfile, frame, type);
-}
-
-/* Implementation of the coerce_ref method of lval_funcs for synthetic C++
- references. */
-
-static struct value *
-coerce_pieced_ref (const struct value *value)
-{
- struct type *type = check_typedef (value_type (value));
-
- if (value_bits_synthetic_pointer (value, value_embedded_offset (value),
- TARGET_CHAR_BIT * TYPE_LENGTH (type)))
- {
- const struct piece_closure *closure
- = (struct piece_closure *) value_computed_closure (value);
- struct frame_info *frame
- = get_selected_frame (_("No frame selected."));
-
- /* gdb represents synthetic pointers as pieced values with a single
- piece. */
- gdb_assert (closure != NULL);
- gdb_assert (closure->pieces.size () == 1);
-
- return indirect_synthetic_pointer
- (closure->pieces[0].v.ptr.die_sect_off,
- closure->pieces[0].v.ptr.offset,
- closure->per_cu, closure->per_objfile, frame, type);
- }
- else
- {
- /* Else: not a synthetic reference; do nothing. */
- return NULL;
- }
-}
-
-static void *
-copy_pieced_value_closure (const struct value *v)
-{
- struct piece_closure *c
- = (struct piece_closure *) value_computed_closure (v);
-
- ++c->refc;
- return c;
-}
-
-static void
-free_pieced_value_closure (struct value *v)
-{
- struct piece_closure *c
- = (struct piece_closure *) value_computed_closure (v);
-
- --c->refc;
- if (c->refc == 0)
- {
- for (dwarf_expr_piece &p : c->pieces)
- if (p.location == DWARF_VALUE_STACK)
- value_decref (p.v.value);
-
- delete c;
- }
-}
-
-/* Functions for accessing a variable described by DW_OP_piece. */
-static const struct lval_funcs pieced_value_funcs = {
- read_pieced_value,
- write_pieced_value,
- indirect_pieced_value,
- coerce_pieced_ref,
- check_pieced_synthetic_pointer,
- copy_pieced_value_closure,
- free_pieced_value_closure
-};
-
/* Evaluate a location description, starting at DATA and with length
SIZE, to find the current location of variable of TYPE in the
context of FRAME. If SUBOBJ_TYPE is non-NULL, return instead the
projects / binutils-gdb.git / commitdiff