Fix a crash in MallocOverflowSecurityChecker. Patch by Lei Zhang.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140648 91177308-0d34-0410-b5e6-96231b3b80d8

lib/StaticAnalyzer/Checkers/MallocOverflowSecurityChecker.cpp

@@ -244,6 +244,8 @@ void MallocOverflowSecurityChecker::checkASTCodeBody(const Decl *D,
 
           // Get the name of the callee. If it's a builtin, strip off the prefix.
           IdentifierInfo *FnInfo = FD->getIdentifier();
+          if (!FnInfo)
+            return;
 
           if (FnInfo->isStr ("malloc") || FnInfo->isStr ("_MALLOC")) {
             if (TheCall->getNumArgs() == 1)

test/Analysis/malloc-overflow.cpp

@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -analyze -analyzer-checker=experimental.security.MallocOverflow -verify %s
+
+class A {
+public:
+  A& operator<<(const A &a);
+};
+
+void f() {
+  A a = A(), b = A();
+  a << b;
+}