// one.
// * The last zero size virtual base may be placed at the end of the struct.
// and can potentially alias a zero sized type in the next struct.
+// * If the last field is a non-zero length bitfield and we have any virtual
+// bases then some extra padding is added before the virtual bases for no
+// obvious reason.
+
namespace {
struct MicrosoftRecordLayoutBuilder {
llvm::SmallPtrSet<const CXXRecordDecl *, 2> HasVtordisp =
computeVtorDispSet(RD);
+ // If the last field we laid out was a non-zero length bitfield then add some
+ // extra padding for no obvious reason.
+ if (LastFieldIsNonZeroWidthBitfield)
+ Size += CurrentBitfieldSize;
+
// Iterate through the virtual bases and lay them out.
for (CXXRecordDecl::base_class_const_iterator i = RD->vbases_begin(),
e = RD->vbases_end();
--- /dev/null
+// RUN: %clang_cc1 -fno-rtti -emit-llvm-only -triple i686-pc-win32 -fdump-record-layouts -fsyntax-only -cxx-abi microsoft %s 2>&1 \
+// RUN: | FileCheck %s
+// RUN: %clang_cc1 -fno-rtti -emit-llvm-only -triple x86_64-pc-win32 -fdump-record-layouts -fsyntax-only -cxx-abi microsoft %s 2>/dev/null \
+// RUN: | FileCheck %s -check-prefix CHECK-X64
+
+struct B0 { };\r
+\r
+struct A : virtual B0 { char a : 1; };\r
+
+// CHECK: *** Dumping AST Record Layout\r
+// CHECK: 0 | struct A\r
+// CHECK: 0 | (A vbtable pointer)\r
+// CHECK: 4 | char a\r
+// CHECK: 9 | struct B0 (virtual base) (empty)\r
+// CHECK: | [sizeof=9, align=4\r
+// CHECK: | nvsize=8, nvalign=4]\r
+// CHECK-X64: *** Dumping AST Record Layout
+// CHECK-X64: 0 | struct A\r
+// CHECK-X64: 0 | (A vbtable pointer)\r
+// CHECK-X64: 8 | char a\r
+// CHECK-X64: 17 | struct B0 (virtual base) (empty)\r
+// CHECK-X64: | [sizeof=24, align=8\r
+// CHECK-X64: | nvsize=16, nvalign=8]\r
+
+struct B : virtual B0 { short a : 1; };\r
+
+// CHECK: *** Dumping AST Record Layout
+// CHECK: 0 | struct B\r
+// CHECK: 0 | (B vbtable pointer)\r
+// CHECK: 4 | short a\r
+// CHECK: 10 | struct B0 (virtual base) (empty)\r
+// CHECK: | [sizeof=10, align=4\r
+// CHECK: | nvsize=8, nvalign=4]\r
+// CHECK-X64: *** Dumping AST Record Layout
+// CHECK-X64: 0 | struct B\r
+// CHECK-X64: 0 | (B vbtable pointer)\r
+// CHECK-X64: 8 | short a\r
+// CHECK-X64: 18 | struct B0 (virtual base) (empty)\r
+// CHECK-X64: | [sizeof=24, align=8\r
+// CHECK-X64: | nvsize=16, nvalign=8]\r
+
+struct C : virtual B0 { char a : 1; char : 0; };\r
+
+// CHECK: *** Dumping AST Record Layout
+// CHECK: 0 | struct C\r
+// CHECK: 0 | (C vbtable pointer)\r
+// CHECK: 4 | char a\r
+// CHECK: 5 | char\r
+// CHECK: 8 | struct B0 (virtual base) (empty)\r
+// CHECK: | [sizeof=8, align=4\r
+// CHECK: | nvsize=8, nvalign=4]\r
+// CHECK-X64: *** Dumping AST Record Layout
+// CHECK-X64: 0 | struct C\r
+// CHECK-X64: 0 | (C vbtable pointer)\r
+// CHECK-X64: 8 | char a\r
+// CHECK-X64: 9 | char\r
+// CHECK-X64: 16 | struct B0 (virtual base) (empty)\r
+// CHECK-X64: | [sizeof=16, align=8\r
+// CHECK-X64: | nvsize=16, nvalign=8]\r
+
+struct D : virtual B0 { char a : 1; char b; };\r
+
+// CHECK: *** Dumping AST Record Layout
+// CHECK: 0 | struct D\r
+// CHECK: 0 | (D vbtable pointer)\r
+// CHECK: 4 | char a\r
+// CHECK: 5 | char b\r
+// CHECK: 8 | struct B0 (virtual base) (empty)\r
+// CHECK: | [sizeof=8, align=4\r
+// CHECK: | nvsize=8, nvalign=4]\r
+// CHECK-X64: *** Dumping AST Record Layout
+// CHECK-X64: 0 | struct D\r
+// CHECK-X64: 0 | (D vbtable pointer)\r
+// CHECK-X64: 8 | char a\r
+// CHECK-X64: 9 | char b\r
+// CHECK-X64: 16 | struct B0 (virtual base) (empty)\r
+// CHECK-X64: | [sizeof=16, align=8\r
+// CHECK-X64: | nvsize=16, nvalign=8]\r
+
+int a[
+sizeof(A)+
+sizeof(B)+
+sizeof(C)+
+sizeof(D)];