[analyzer] Fixed crash in CloneDetector in function calls.

[teemperor]

Summary

StmtDataCollector currently crashes on function calls because they don't have a callee. This patch fixes this.

[v.g.vassilev]

LGTM.

cfe/trunk/lib/Analysis/CloneDetection.cpp

#define DEF_ADD_DATA(CLASS, CODE)                                              \
   DEF_ADD_DATA(PredefinedExpr, { addData(S->getIdentType()); })
   DEF_ADD_DATA(TypeTraitExpr, {
     addData(S->getTrait());
     for (unsigned i = 0; i < S->getNumArgs(); ++i)
       addData(S->getArg(i)->getType());
   })
 
   //--- Calls --------------------------------------------------------------//
-  DEF_ADD_DATA(CallExpr,
-               { addData(S->getDirectCallee()->getQualifiedNameAsString()); })
+  DEF_ADD_DATA(CallExpr, {
+    // Function pointers don't have a callee and we just skip hashing it.
+    if (S->getDirectCallee())
+      addData(S->getDirectCallee()->getQualifiedNameAsString());
+  })
 
   //--- Exceptions ---------------------------------------------------------//
   DEF_ADD_DATA(CXXCatchStmt, { addData(S->getCaughtType()); })
 
   //--- C++ OOP Stmts ------------------------------------------------------//
   DEF_ADD_DATA(CXXDeleteExpr, {
     addData(S->isArrayFormAsWritten());
     addData(S->isGlobalDelete());

cfe/trunk/test/Analysis/copypaste/call.cpp

 // Calls method b with some extra code to pass the minimum complexity
 bool foo2(int x) {
   if (x > 0)
     return false;
   else if (x < 0)
     return b();
   return true;
 }
+
+// Test that we don't crash on function pointer calls
+
+bool (*funcPtr)(int);
+
+bool fooPtr1(int x) {
+  if (x > 0)
+    return false;
+  else if (x < 0)
+    return funcPtr(1);
+  return true;
+}