PR15360: nullptr as a non-type template argument to a function type non-type template parameter

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176216 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 20 insertions, 9 deletions

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 61fd826360..4b766a9fde 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -4495,6 +4495,16 @@ ExprResult
 Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
                                               QualType ParamType,
                                               SourceLocation Loc) {
+  // C++ [temp.param]p8:
+  //
+  //   A non-type template-parameter of type "array of T" or
+  //   "function returning T" is adjusted to be of type "pointer to
+  //   T" or "pointer to function returning T", respectively.
+  if (ParamType->isArrayType())
+    ParamType = Context.getArrayDecayedType(ParamType);
+  else if (ParamType->isFunctionType())
+    ParamType = Context.getPointerType(ParamType);
+
   // For a NULL non-type template argument, return nullptr casted to the
   // parameter's type.
   if (Arg.getKind() == TemplateArgument::NullPtr) {
@@ -4560,15 +4570,6 @@ Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
   }
 
   QualType T = VD->getType().getNonReferenceType();
-  // C++ [temp.param]p8:
-  //
-  //   A non-type template-parameter of type "array of T" or
-  //   "function returning T" is adjusted to be of type "pointer to
-  //   T" or "pointer to function returning T", respectively.
-  if (ParamType->isArrayType())
-    ParamType = Context.getArrayDecayedType(ParamType);
-  else if (ParamType->isFunctionType())
-    ParamType = Context.getPointerType(ParamType);
 
   if (ParamType->isPointerType()) {
     // When the non-type template parameter is a pointer, take the
diff --git a/test/SemaTemplate/temp_arg_nontype_cxx11.cpp b/test/SemaTemplate/temp_arg_nontype_cxx11.cpp
new file mode 100644
index 0000000000..d773c6436f
--- /dev/null
+++ b/test/SemaTemplate/temp_arg_nontype_cxx11.cpp
@@ -0,0 +1,10 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+
+namespace PR15360 {
+  template<typename R, typename U, R F>
+  U f() { return &F; } // expected-error{{cannot take the address of an rvalue of type 'int (*)(int)'}} expected-error{{cannot take the address of an rvalue of type 'int *'}}
+  void test() {
+    f<int(int), int(*)(int), nullptr>(); // expected-note{{in instantiation of}}
+    f<int[3], int*, nullptr>(); // expected-note{{in instantiation of}}
+  }
+}