Recommit r148056 with fixes to deal with weirdness with bitfields in unions.
Original message: Make sure adding a field to a struct never reduces its size. PR11745.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148070 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 43dee10..5223219 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -1869,12 +1869,12 @@
// Reserve space for this field.
uint64_t FieldSizeInBits = Context.toBits(FieldSize);
if (IsUnion)
- setSize(std::max(getSizeInBits(), FieldSizeInBits));
+ setDataSize(std::max(getDataSizeInBits(), FieldSizeInBits));
else
- setSize(FieldOffset + FieldSize);
+ setDataSize(FieldOffset + FieldSize);
- // Update the data size.
- setDataSize(getSizeInBits());
+ // Update the size.
+ setSize(std::max(getSizeInBits(), getDataSizeInBits()));
// Remember max struct/class alignment.
UpdateAlignment(FieldAlign, UnpackedFieldAlign);
diff --git a/test/SemaCXX/empty-class-layout.cpp b/test/SemaCXX/empty-class-layout.cpp
index 0b46bf0..c68f2bb 100644
--- a/test/SemaCXX/empty-class-layout.cpp
+++ b/test/SemaCXX/empty-class-layout.cpp
@@ -144,3 +144,14 @@
SA(0, sizeof(B) == 16);
}
+
+namespace Test7 {
+ // Make sure we reserve enough space for both bases; PR11745.
+ struct Empty { };
+ struct Base1 : Empty { };
+ struct Base2 : Empty { };
+ struct Test : Base1, Base2 {
+ char c;
+ };
+ SA(0, sizeof(Test) == 2);
+}
