[analyzer] Fix CloneDetector crash on calling methods of class templates.

If a call expression represents a method call of a class template,
and the method itself isn't templated, then the method may be considered
to be a template instantiation without template specialization arguments.

No longer crash when we could not find template specialization arguments.

Patch by Raphael Isemann!

Differential Revision: https://reviews.llvm.org/D23780

llvm-svn: 279529

clang/lib/Analysis/CloneDetection.cpp

@@ -345,10 +345,9 @@ public:
   DEF_ADD_DATA(CallExpr, {
     // Function pointers don't have a callee and we just skip hashing it.
     if (const FunctionDecl *D = S->getDirectCallee()) {
-      // If the function is a template instantiation, we also need to handle
-      // the template arguments as they are no included in the qualified name.
-      if (D->isTemplateInstantiation()) {
-        auto Args = D->getTemplateSpecializationArgs();
+      // If the function is a template specialization, we also need to handle
+      // the template arguments as they are not included in the qualified name.
+      if (auto Args = D->getTemplateSpecializationArgs()) {
         std::string ArgString;
 
         // Print all template arguments into ArgString

clang/test/Analysis/copypaste/call.cpp

@@ -88,3 +88,15 @@ bool fooTemplatePadding2(int x) {
     return templatePaddingFunc<XX, X>();
   return true;
 }
+
+// Test that we don't crash on member functions of template instantiations.
+
+template<typename T>
+struct A {
+  void foo(T t) {}
+};
+
+void fooTestInstantiation() {
+  A<int> a;
+  a.foo(1);
+}