@@ -1776,7 +1776,8 @@ read_pieced_value (struct value *v)
bits_to_skip = 8 * value_offset (v);
if (value_bitsize (v))
{
- bits_to_skip += value_bitpos (v);
+ bits_to_skip += (8 * value_offset (value_parent (v))
+ + value_bitpos (v));
type_len = value_bitsize (v);
}
else
@@ -1946,7 +1947,8 @@ write_pieced_value (struct value *to, struct value *from)
bits_to_skip = 8 * value_offset (to);
if (value_bitsize (to))
{
- bits_to_skip += value_bitpos (to);
+ bits_to_skip += (8 * value_offset (value_parent (to))
+ + value_bitpos (to));
type_len = value_bitsize (to);
}
else
In the case of targeting a bit-field, read_pieced_value and write_pieced_value calculate the number of bits preceding the bit-field without considering the relative offset of the value's parent. This is relevant for a structure variable like this: struct s { uint64_t foo; struct { uint32_t bar; uint32_t bf : 10; /* <-- target bit-field */ } baz; } s; In this scenario, if 'val' is a GDB value representing s.baz.bf, val->parent represents the whole s.baz structure, and the following holds: - value_offset (val) == sizeof s.baz.bar == 4 - value_offset (val->parent) == sizeof s.foo == 8 The current logic would only use value_offset(val), resulting in the wrong offset into the target value. This is fixed. gdb/ChangeLog: * dwarf2loc.c (read_pieced_value): Respect parent value's offset when targeting a bit-field. (write_pieced_value): Likewise. --- gdb/dwarf2loc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)