Fix FP reported in #467

change_notes/2024-01-31-fix-fp-m9-3-3.md

@@ -0,0 +1,2 @@
+`M9-3-3`: `MemberFunctionConstIfPossible.ql`:
+    - Fix FP reported in 467. Excluding candidates in uninstantiated templates.

cpp/autosar/src/rules/M9-3-3/MemberFunctionConstIfPossible.ql

@@ -54,7 +54,10 @@ class ConstMemberFunctionCandidate extends NonConstMemberFunction {
     not this instanceof Destructor and
     not this instanceof Operator and
     //less interested in MemberFunctions with no definition
-    this.hasDefinition()
+    this.hasDefinition() and
+    // For uninstantiated templates we have only partial information that prevents us from determining
+    // if the candidate calls non-const functions. Therefore we exclude these.
+    not this.isFromUninstantiatedTemplate(_)
   }
 
   /**

cpp/autosar/test/rules/M9-3-3/test.cpp

@@ -162,6 +162,35 @@ class Z22 : Z1 {
   void f3() { this->a = 100; }         // COMPLIANT
 };
 
+template <class T> class Array {
+public:
+  T &back();
+
+private:
+  T data[128];
+  unsigned int size;
+};
+
+template <class T, template <class...> class U> class Stack {
+public:
+  T &Top() {
+    return this->data.back();
+  } // COMPLIANT[FALSE_NEGATIVE|TRUE_NEGATIVE] - exception not specified in the
+    // standard, we opt to not raise an issue because the template can be both
+    // compliant and non-compliant depending on instantiations.
+private:
+  U<T> data;
+};
+
+using IntVectorStack = Stack<int, Array>;
+
+void test_template() {
+  IntVectorStack s;
+
+  int i = s.Top();
+}
+
 class Z3 {
   void f(int) = delete; // COMPLIANT
-};
+};
+