Fix interaction of max_align_t and modules.

When building with modules enabled, we were defining max_align_t as a typedef
for a different anonymous struct type each time it was included, resulting in
an error if <stddef.h> is not covered by a module map and is included more than
once in the same modules-enabled compilation of C11 or C++11 code.

llvm-svn: 218931

3 files changed, 14 insertions, 0 deletions

diff --git a/clang/test/Modules/Inputs/StdDef/include_again.h b/clang/test/Modules/Inputs/StdDef/include_again.h
new file mode 100644
index 00000000000..f29f6366cc6
--- /dev/null
+++ b/clang/test/Modules/Inputs/StdDef/include_again.h
@@ -0,0 +1,2 @@
+#include <stddef.h>
+
diff --git a/clang/test/Modules/Inputs/StdDef/module.map b/clang/test/Modules/Inputs/StdDef/module.map
index 69c69eac35b..5c4e0dae7ba 100644
--- a/clang/test/Modules/Inputs/StdDef/module.map
+++ b/clang/test/Modules/Inputs/StdDef/module.map
@@ -8,4 +8,14 @@ module StdDef {
     header "other.h"
     export *
   }
+
+  module PtrDiffT {
+    header "ptrdiff_t.h"
+    export *
+  }
+
+  module IncludeAgain {
+    header "include_again.h"
+    export *
+  }
 }
diff --git a/clang/test/Modules/Inputs/StdDef/ptrdiff_t.h b/clang/test/Modules/Inputs/StdDef/ptrdiff_t.h
new file mode 100644
index 00000000000..acb0ab81ffc
--- /dev/null
+++ b/clang/test/Modules/Inputs/StdDef/ptrdiff_t.h
@@ -0,0 +1,2 @@
+#define __need_ptrdiff_t
+#include <stddef.h>