Add partial support for using anonymous bitfields (e.g., int : 0) to enforce
alignment. This fixes cases where the anonymous bitfield is followed by a
non-bitfield member. E.g.,
struct t4
{
int foo : 1;
long : 0;
char bar;
};
Part of rdar://9859156
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136858 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index ec45a87..89b6ce9 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -1963,6 +1963,16 @@
// structures. This corresponds to PCC_BITFIELD_TYPE_MATTERS in gcc.
UseBitFieldTypeAlignment = false;
+ /// Do force alignment of members that follow zero length bitfields. If
+ /// the alignment of the zero-length bitfield is greater than the member
+ /// that follows it, `bar', `bar' will be aligned as the type of the
+ /// zero length bitfield.
+ UseZeroLengthBitfieldAlignment = true;
+
+ /// gcc forces the alignment to 4 bytes, regardless of the type of the
+ /// zero length bitfield.
+ ZeroLengthBitfieldBoundary = 32;
+
if (IsThumb) {
// Thumb1 add sp, #imm requires the immediate value be multiple of 4,
// so set preferred for small types to 32.