+ unpacked_bytes_left -= 1;
+ unpacked_idx += delta;
+ }
+}
+
+/* Create a new value of type TYPE from the contents of OBJ starting
+ at byte OFFSET, and bit offset BIT_OFFSET within that byte,
+ proceeding for BIT_SIZE bits. If OBJ is an lval in memory, then
+ assigning through the result will set the field fetched from.
+ VALADDR is ignored unless OBJ is NULL, in which case,
+ VALADDR+OFFSET must address the start of storage containing the
+ packed value. The value returned in this case is never an lval.
+ Assumes 0 <= BIT_OFFSET < HOST_CHAR_BIT. */
+
+struct value *
+ada_value_primitive_packed_val (struct value *obj, const gdb_byte *valaddr,
+ long offset, int bit_offset, int bit_size,
+ struct type *type)
+{
+ struct value *v;
+ const gdb_byte *src; /* First byte containing data to unpack */
+ gdb_byte *unpacked;
+ const int is_scalar = is_scalar_type (type);
+ const int is_big_endian = gdbarch_bits_big_endian (get_type_arch (type));
+ gdb_byte *staging = NULL;
+ int staging_len = 0;
+ struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
+
+ type = ada_check_typedef (type);
+
+ if (obj == NULL)
+ src = valaddr + offset;
+ else
+ src = value_contents (obj) + offset;
+
+ if (is_dynamic_type (type))
+ {
+ /* The length of TYPE might by dynamic, so we need to resolve
+ TYPE in order to know its actual size, which we then use
+ to create the contents buffer of the value we return.
+ The difficulty is that the data containing our object is
+ packed, and therefore maybe not at a byte boundary. So, what
+ we do, is unpack the data into a byte-aligned buffer, and then
+ use that buffer as our object's value for resolving the type. */
+ staging_len = (bit_size + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
+ staging = (gdb_byte *) malloc (staging_len);
+ make_cleanup (xfree, staging);
+
+ ada_unpack_from_contents (src, bit_offset, bit_size,
+ staging, staging_len,
+ is_big_endian, has_negatives (type),
+ is_scalar);
+ type = resolve_dynamic_type (type, staging, 0);
+ if (TYPE_LENGTH (type) < (bit_size + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT)
+ {
+ /* This happens when the length of the object is dynamic,
+ and is actually smaller than the space reserved for it.
+ For instance, in an array of variant records, the bit_size
+ we're given is the array stride, which is constant and
+ normally equal to the maximum size of its element.
+ But, in reality, each element only actually spans a portion
+ of that stride. */
+ bit_size = TYPE_LENGTH (type) * HOST_CHAR_BIT;
+ }
+ }
+
+ if (obj == NULL)
+ {
+ v = allocate_value (type);
+ src = valaddr + offset;
+ }
+ else if (VALUE_LVAL (obj) == lval_memory && value_lazy (obj))
+ {
+ int src_len = (bit_size + bit_offset + HOST_CHAR_BIT - 1) / 8;
+ gdb_byte *buf;
+
+ v = value_at (type, value_address (obj) + offset);
+ buf = (gdb_byte *) alloca (src_len);
+ read_memory (value_address (v), buf, src_len);
+ src = buf;
+ }
+ else
+ {
+ v = allocate_value (type);
+ src = value_contents (obj) + offset;
+ }
+
+ if (obj != NULL)
+ {
+ long new_offset = offset;
+
+ set_value_component_location (v, obj);
+ set_value_bitpos (v, bit_offset + value_bitpos (obj));
+ set_value_bitsize (v, bit_size);
+ if (value_bitpos (v) >= HOST_CHAR_BIT)
+ {
+ ++new_offset;
+ set_value_bitpos (v, value_bitpos (v) - HOST_CHAR_BIT);
+ }
+ set_value_offset (v, new_offset);
+
+ /* Also set the parent value. This is needed when trying to
+ assign a new value (in inferior memory). */
+ set_value_parent (v, obj);
+ }
+ else
+ set_value_bitsize (v, bit_size);
+ unpacked = value_contents_writeable (v);
+
+ if (bit_size == 0)
+ {
+ memset (unpacked, 0, TYPE_LENGTH (type));
+ do_cleanups (old_chain);
+ return v;
+ }
+
+ if (staging != NULL && staging_len == TYPE_LENGTH (type))
+ {
+ /* Small short-cut: If we've unpacked the data into a buffer
+ of the same size as TYPE's length, then we can reuse that,
+ instead of doing the unpacking again. */
+ memcpy (unpacked, staging, staging_len);
projects / deliverable / binutils-gdb.git / blobdiff