[clang][ExprEngineCXX] Fix crash on dereference invalid

return value of getAdjustedParameterIndex()

Author: miaozhiyuan

clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp

@@ -354,8 +354,13 @@ SVal ExprEngine::computeObjectUnderConstruction(
         // Operator arguments do not correspond to operator parameters
         // because this-argument is implemented as a normal argument in
         // operator call expressions but not in operator declarations.
-        const TypedValueRegion *TVR = Caller->getParameterLocation(
-            *Caller->getAdjustedParameterIndex(Idx), BldrCtx->blockCount());
+        std::optional<unsigned int> Index =
+            Caller->getAdjustedParameterIndex(Idx);
+        if (!Index) {
+          return std::nullopt;
+        }
+        const TypedValueRegion *TVR =
+            Caller->getParameterLocation(*Index, BldrCtx->blockCount());
         if (!TVR)
           return std::nullopt;
 

clang/test/Analysis/engine/expr-engine-cxx-crash.cpp

@@ -0,0 +1,15 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core.DivideZero -std=c++23 -verify %s
+// expected-no-diagnostics
+
+struct S
+{
+    constexpr auto operator==(this auto, S)
+    {
+        return true;
+    }
+};
+
+int main()
+{
+    return S {} == S {};
+}