When parsing DWARF and laying out bit-fields we don't properly take into account when they are in a union, they will all have a zero offset.
Differential Revision: https://reviews.llvm.org/D91118
// The ObjC runtime knows the byte offset but we still need to provide
// the bit-offset in the layout. It just means something different then
// what it does in C and C++. So we skip this check for ObjC types.
+ //
+ // We also skip this for fields of a union since they will all have a
+ // zero offset.
if (!TypeSystemClang::IsObjCObjectOrInterfaceType(class_clang_type) &&
+ !(parent_die.Tag() == DW_TAG_union_type && this_field_info.bit_offset == 0) &&
((this_field_info.bit_offset >= parent_bit_size) ||
(last_field_info.IsBitfield() &&
!last_field_info.NextBitfieldOffsetIsValid(
self.expect("expr (clang_example.f.a)", VARIABLES_DISPLAYED_CORRECTLY,
substrs=['uint64_t', '1'])
+ self.expect("expr uwbf",
+ substrs=['a = 255',
+ 'b = 65535',
+ 'c = 4294967295',
+ 'x = 4294967295'] )
+
+ self.expect("expr uwubf",
+ substrs=['a = 16777215',
+ 'x = 4294967295'] )
+
self.expect(
"frame variable --show-types lba",
VARIABLES_DISPLAYED_CORRECTLY,
f.i = 1;
f.j = 0;
f.k = 1;
- }
+ }
} clang_example;
class B {
uint32_t d_a : 1;
} derived;
+ union union_with_bitfields {
+ unsigned int a : 8;
+ unsigned int b : 16;
+ unsigned int c : 32;
+ unsigned int x;
+ } uwbf;
+
+ union union_with_unnamed_bitfield {
+ unsigned int : 16, a : 24;
+ unsigned int x;
+ } uwubf;
+
lba.a = 2;
lbb.a = 1;
derived.b_a = 2;
derived.d_a = 1;
+ uwbf.x = 0xFFFFFFFF;
+ uwubf.x = 0xFFFFFFFF;
+
return 0; // Set break point at this line.
}