Serialize `pragma ms_struct` state.

pragma ms_struct has an effect on struct decls, and the effect is serialized
correctly already.  But the "is ms_struct currently on" state wasn't before
this change.

This uses the same approach as `pragma clang optimize`: When writing a module,
the state isn't serialized, only when writing a pch file.

llvm-svn: 262539

1 files changed, 41 insertions, 0 deletions

diff --git a/clang/test/PCH/pragma-ms_struct.cpp b/clang/test/PCH/pragma-ms_struct.cpp
new file mode 100644
index 00000000000..ac2a1e87b23
--- /dev/null
+++ b/clang/test/PCH/pragma-ms_struct.cpp
@@ -0,0 +1,41 @@
+// Test this without pch.
+// RUN: %clang_cc1 %s -Wunknown-pragmas -Werror -triple i386-apple-darwin9 -fsyntax-only -include %s -verify -std=c++11
+
+// Test with pch.
+// RUN: %clang_cc1 %s -Wunknown-pragmas -Werror -triple i386-apple-darwin9 -emit-pch -o %t -std=c++11
+// RUN: %clang_cc1 %s -Wunknown-pragmas -Werror -triple i386-apple-darwin9 -fsyntax-only -include-pch %t -verify -std=c++11
+
+// The first run line creates a pch, and since at that point HEADER is not
+// defined, the only thing contained in the pch is the pragma. The second line
+// then includes that pch, so HEADER is defined and the actual code is compiled.
+// The check then makes sure that the pragma is in effect in the file that
+// includes the pch.
+
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+struct SOffH {
+  short m : 9;
+  int q : 12;
+};
+
+#pragma ms_struct on
+
+struct SOnH {
+  short m : 9;
+  int q : 12;
+};
+
+#else
+
+struct SOnC {
+  short m : 9;
+  int q : 12;
+};
+
+static_assert(sizeof(SOffH) == 4, "");
+static_assert(sizeof(SOnH) == 8, "");
+static_assert(sizeof(SOnC) == 8, "");
+
+#endif