[clang][analyzer] Fix crash caused by overload operator member function with explicit this

Author: flovent

clang/lib/StaticAnalyzer/Checkers/ContainerModeling.cpp

@@ -157,8 +157,11 @@ void ContainerModeling::checkPostCall(const CallEvent &Call,
   if (Func->isOverloadedOperator()) {
     const auto Op = Func->getOverloadedOperator();
     if (Op == OO_Equal) {
-      // Overloaded 'operator=' must be a non-static member function.
-      const auto *InstCall = cast<CXXInstanceCall>(&Call);
+      // Only handle the assignment operator with implicit this
+      const auto *InstCall = dyn_cast<CXXInstanceCall>(&Call);
+      if (!InstCall)
+        return;
+
       if (cast<CXXMethodDecl>(Func)->isMoveAssignmentOperator()) {
         handleAssignment(C, InstCall->getCXXThisVal(), Call.getOriginExpr(),
                      Call.getArgSVal(0));

clang/test/Analysis/issue-116372.cpp

@@ -0,0 +1,21 @@
+// RUN: %clang_analyze_cc1 -std=c++23 %s -verify -analyzer-checker=alpha.cplusplus.InvalidatedIterator -analyzer-config aggressive-binary-operation-simplification=true
+
+// expected-no-diagnostics
+
+class ExplicitThis {
+  int f = 0;
+public:
+  ExplicitThis();
+  ExplicitThis(ExplicitThis& other);
+
+  ExplicitThis& operator=(this ExplicitThis& self, ExplicitThis const& other) { // no crash
+    self.f = other.f;
+    return self;
+  }
+
+  ~ExplicitThis();
+};
+
+void func(ExplicitThis& obj1) {
+    obj1 = obj1;
+}