Add codegen support for __null

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61314 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 21 insertions, 0 deletions

diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index 11f07fb116..db9536633b 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -416,6 +416,12 @@ public:
     return true;
   }
   
+  bool VisitGNUNullExpr(const GNUNullExpr *E) {
+    Result = APSInt::getNullValue(getIntTypeSizeInBits(E->getType()));
+    Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
+    return true;
+  }
+    
   bool VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) {
     Result = APSInt::getNullValue(getIntTypeSizeInBits(E->getType()));
     Result.setIsUnsigned(E->getType()->isUnsignedIntegerType());
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index a5d5bc22af..71f9f92f9c 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -113,6 +113,9 @@ public:
   Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) {
     return llvm::Constant::getNullValue(ConvertType(E->getType()));
   }
+  Value *VisitGNUNullExpr(const GNUNullExpr *E) {
+    return llvm::Constant::getNullValue(ConvertType(E->getType()));
+  }
   Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) {
     return llvm::ConstantInt::get(ConvertType(E->getType()),
                                   CGF.getContext().typesAreCompatible(
diff --git a/test/CodeGenCXX/__null.cpp b/test/CodeGenCXX/__null.cpp
new file mode 100644
index 0000000000..29416ced02
--- /dev/null
+++ b/test/CodeGenCXX/__null.cpp
@@ -0,0 +1,9 @@
+// RUN: clang %s -emit-llvm -o %t
+
+int* a = __null;
+int b = __null;
+
+void f() {
+  int* c = __null;
+  int d = __null;
+}
diff --git a/test/SemaCXX/__null.cpp b/test/SemaCXX/__null.cpp
index 3d78e2e8db..798e0aa99d 100644
--- a/test/SemaCXX/__null.cpp
+++ b/test/SemaCXX/__null.cpp
@@ -8,4 +8,7 @@ void f() {
 
   // Verify statically that __null is the right size
   int a[sizeof(typeof(__null)) == sizeof(void*)? 1 : -1];
+  
+  // Verify that null is evaluated as 0.
+  int b[__null ? -1 : 1];
 }