PR9792: Make sure to use the right definition of wchar_t when the default

wchar_t is an unsigned type.

llvm-svn: 130620

2 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 13c40f7ca1d..de8c26bd70c 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -375,7 +375,7 @@ void ASTContext::InitBuiltinTypes() {
   InitBuiltinType(UnsignedInt128Ty,    BuiltinType::UInt128);
 
   if (LangOpts.CPlusPlus) { // C++ 3.9.1p5
-    if (!LangOpts.ShortWChar)
+    if (TargetInfo::isTypeSigned(Target.getWCharType()))
       InitBuiltinType(WCharTy,           BuiltinType::WChar_S);
     else  // -fshort-wchar makes wchar_t be unsigned.
       InitBuiltinType(WCharTy,           BuiltinType::WChar_U);
diff --git a/clang/test/SemaCXX/short-wchar-sign.cpp b/clang/test/SemaCXX/short-wchar-sign.cpp
new file mode 100644
index 00000000000..9a177c04b10
--- /dev/null
+++ b/clang/test/SemaCXX/short-wchar-sign.cpp
@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 -triple i386-mingw32 -fsyntax-only -pedantic -verify %s
+// RUN: %clang_cc1 -fshort-wchar -fsyntax-only -pedantic -verify %s
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fsyntax-only -pedantic -verify %s
+
+// Check that short wchar_t is unsigned, and that regular wchar_t is not.
+int test[(wchar_t(-1)<wchar_t(0)) == (sizeof(wchar_t) == 4) ?1:-1];