Fix FPs: uselessOverride (#5208)

Author: chrchr-github

lib/checkclass.cpp

@@ -3082,15 +3082,18 @@ void CheckClass::checkUselessOverride()
         for (const Function& func : classScope->functionList) {
             if (!func.functionScope)
                 continue;
+            if (func.hasFinalSpecifier())
+                continue;
             const Function* baseFunc = func.getOverriddenFunction();
-            if (!baseFunc || baseFunc->isPure())
+            if (!baseFunc || baseFunc->isPure() || baseFunc->access != func.access)
                 continue;
             if (const Token* const call = getSingleFunctionCall(func.functionScope)) {
                 if (call->function() != baseFunc)
                     continue;
                 std::vector<const Token*> funcArgs = getArguments(func.tokenDef);
                 std::vector<const Token*> callArgs = getArguments(call);
-                if (!std::equal(funcArgs.begin(), funcArgs.end(), callArgs.begin(), [](const Token* t1, const Token* t2) {
+                if (funcArgs.size() != callArgs.size() ||
+                    !std::equal(funcArgs.begin(), funcArgs.end(), callArgs.begin(), [](const Token* t1, const Token* t2) {
                     return t1->str() == t2->str();
                 }))
                     continue;

test/testclass.cpp

@@ -8403,6 +8403,32 @@ class TestClass : public TestFixture {
                              "    int f() override { return B::f(); }\n"
                              "};");
         ASSERT_EQUALS("", errout.str());
+
+        checkUselessOverride("struct S { virtual void f(); };\n"
+                             "struct D : S {\n"
+                             "    void f() final { S::f(); }\n"
+                             "};");
+        ASSERT_EQUALS("", errout.str());
+
+        checkUselessOverride("struct S {\n"
+                             "protected:\n"
+                             "    virtual void f();\n"
+                             "};\n"
+                             "struct D : S {\n"
+                             "public:\n"
+                             "    void f() override { S::f(); }\n"
+                             "};");
+        ASSERT_EQUALS("", errout.str());
+
+        checkUselessOverride("struct B { virtual void f(int, int, int) const; };\n" // #11799
+                             "struct D : B {\n"
+                             "    int m = 42;\n"
+                             "    void f(int a, int b, int c) const override;\n"
+                             "};\n"
+                             "void D::f(int a, int b, int c) const {\n"
+                             "    B::f(a, b, m);\n"
+                             "};");
+        ASSERT_EQUALS("", errout.str());
     }
 
 #define checkUnsafeClassRefMember(code) checkUnsafeClassRefMember_(code, __FILE__, __LINE__)