Fix bitfield handling for record layout with #pragma pack. <rdar://problem/10494810> and PR9560.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@145673 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp
index 88a90a4..c92116a 100644
--- a/lib/AST/RecordLayoutBuilder.cpp
+++ b/lib/AST/RecordLayoutBuilder.cpp
@@ -1690,18 +1690,20 @@
UnpackedFieldAlign = std::max(UnpackedFieldAlign, D->getMaxAlignment());
// The maximum field alignment overrides the aligned attribute.
- if (!MaxFieldAlignment.isZero()) {
+ if (!MaxFieldAlignment.isZero() && FieldSize != 0) {
unsigned MaxFieldAlignmentInBits = Context.toBits(MaxFieldAlignment);
FieldAlign = std::min(FieldAlign, MaxFieldAlignmentInBits);
UnpackedFieldAlign = std::min(UnpackedFieldAlign, MaxFieldAlignmentInBits);
}
// Check if we need to add padding to give the field the correct alignment.
- if (FieldSize == 0 || (FieldOffset & (FieldAlign-1)) + FieldSize > TypeSize)
+ if (FieldSize == 0 || (MaxFieldAlignment.isZero() &&
+ (FieldOffset & (FieldAlign-1)) + FieldSize > TypeSize))
FieldOffset = llvm::RoundUpToAlignment(FieldOffset, FieldAlign);
if (FieldSize == 0 ||
- (UnpackedFieldOffset & (UnpackedFieldAlign-1)) + FieldSize > TypeSize)
+ (MaxFieldAlignment.isZero() &&
+ (UnpackedFieldOffset & (UnpackedFieldAlign-1)) + FieldSize > TypeSize))
UnpackedFieldOffset = llvm::RoundUpToAlignment(UnpackedFieldOffset,
UnpackedFieldAlign);
diff --git a/test/Sema/pragma-pack-5.c b/test/Sema/pragma-pack-5.c
new file mode 100644
index 0000000..95bbe1f
--- /dev/null
+++ b/test/Sema/pragma-pack-5.c
@@ -0,0 +1,45 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -fsyntax-only -verify -ffreestanding
+// <rdar://problem/10494810> and PR9560
+// Check #pragma pack handling with bitfields.
+
+#include <stddef.h>
+#pragma pack(2)
+
+struct s0 {
+ char f1;
+ unsigned f2 : 32;
+ char f3;
+};
+extern int check[sizeof(struct s0) == 6 ? 1 : -1];
+
+struct s1 {
+ char f1;
+ unsigned : 0;
+ char f3;
+};
+extern int check[sizeof(struct s1) == 5 ? 1 : -1];
+
+struct s2 {
+ char f1;
+ unsigned : 0;
+ unsigned f3 : 8;
+ char f4;
+};
+extern int check[sizeof(struct s2) == 6 ? 1 : -1];
+
+struct s3 {
+ char f1;
+ unsigned : 0;
+ unsigned f3 : 16;
+ char f4;
+};
+extern int check[sizeof(struct s3) == 8 ? 1 : -1];
+extern int check[offsetof(struct s3, f4) == 6 ? 1 : -1];
+
+struct s4 {
+ char f1;
+ unsigned f2 : 8;
+ char f3;
+};
+extern int check[sizeof(struct s4) == 4 ? 1 : -1];
+extern int check[offsetof(struct s4, f3) == 2 ? 1 : -1];