Attributes preceding a function declaration are first applied to the return
type and then propagated to the function. This was failing for destructors,
constructors and constructors templates since they don't have a return type.

Fix that by directly calling processTypeAttrs on the dummy type we use as the
return type in these cases.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161020 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index e018a5b..31a87dc 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -1812,6 +1812,8 @@
     // Constructors and destructors don't have return types. Use
     // "void" instead.
     T = SemaRef.Context.VoidTy;
+    if (AttributeList *attrs = D.getDeclSpec().getAttributes().getList())
+      processTypeAttrs(state, T, true, attrs);
     break;
 
   case UnqualifiedId::IK_ConversionFunctionId:
diff --git a/test/CodeGenCXX/pr13396.cpp b/test/CodeGenCXX/pr13396.cpp
new file mode 100644
index 0000000..b390eea
--- /dev/null
+++ b/test/CodeGenCXX/pr13396.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 %s -emit-llvm -o - | FileCheck %s
+struct foo {
+  template<typename T>
+  __attribute__ ((regparm (3))) foo(T x) {}
+  __attribute__ ((regparm (3))) foo();
+  __attribute__ ((regparm (3))) ~foo();
+};
+
+foo::foo() {
+  // CHECK: define void @_ZN3fooC1Ev(%struct.foo* inreg %this)
+  // CHECK: define void @_ZN3fooC2Ev(%struct.foo* inreg %this)
+}
+
+foo::~foo() {
+  // CHECK: define void @_ZN3fooD1Ev(%struct.foo* inreg %this)
+  // CHECK: define void @_ZN3fooD2Ev(%struct.foo* inreg %this)
+}
+
+void dummy() {
+  // FIXME: how can we explicitly instantiate a template constructor? Gcc and
+  // older clangs accept:
+  // template foo::foo(int x);
+  foo x(10);
+  // CHECK: define linkonce_odr void @_ZN3fooC1IiEET_(%struct.foo* inreg %this, i32 inreg %x)
+  // CHECK: define linkonce_odr void @_ZN3fooC2IiEET_(%struct.foo* inreg %this, i32 inreg %x)
+}