M5-3-3: Excude binary operators.

change_notes/2024-01-14-m5-3-3-exclude-binary.md

@@ -0,0 +1,2 @@
+`M5-3-3` - `UnaryOperatorOverloaded.ql`:
+  - Exclude binary user defined `operator&` from this rule.

cpp/autosar/src/rules/M5-3-3/UnaryOperatorOverloaded.ql

@@ -13,7 +13,8 @@
 
 import cpp
 import codingstandards.cpp.autosar
+import codingstandards.cpp.Operator
 
-from Operator o
-where not isExcluded(o, OperatorsPackage::unaryOperatorOverloadedQuery()) and o.hasName("operator&")
+from UnaryAddressOfOperator o
+where not isExcluded(o, OperatorsPackage::unaryOperatorOverloadedQuery())
 select o, "The unary & operator overloaded."

cpp/autosar/test/rules/M5-3-3/UnaryOperatorOverloaded.expected

@@ -1 +1,2 @@
-| test.cpp:6:5:6:13 | operator& | The unary & operator overloaded. |
+| test.cpp:2:5:2:13 | operator& | The unary & operator overloaded. |
+| test.cpp:8:3:8:11 | operator& | The unary & operator overloaded. |

cpp/autosar/test/rules/M5-3-3/test.cpp

@@ -1,7 +1,9 @@
-/* The unary & operator shall not be overloaded */
-// do not defined it at all
-class A
-
-{
-  A operator&(); // NON_COMPLIANT
+class A {
+  A operator&();                      // NON_COMPLIANT - unary
+  constexpr A operator&(const A rhs); // COMPLIANT - binary
 };
+
+class B {};
+
+B operator&(B b);                                // NON_COMPLIANT - unary
+constexpr B operator&(const B lhs, const B rhs); // COMPLIANT - binary

cpp/common/src/codingstandards/cpp/Operator.qll

@@ -265,6 +265,22 @@ class UserOverloadedOperator extends Function {
   }
 }
 
+/** A user defined operator address of operator (`&`). */
+class UnaryAddressOfOperator extends Operator {
+  UnaryAddressOfOperator() {
+    hasName("operator&") and
+    (
+      // If this is a member function, it needs to have zero arguments to be the unary addressof
+      // operator
+      if this instanceof MemberFunction
+      then getNumberOfParameters() = 0
+      else
+        // Otherwise it needs one argument to be unary
+        getNumberOfParameters() = 1
+    )
+  }
+}
+
 private newtype TOperatorUse =
   TBuiltinOperatorUse(Operation op) or
   TOverloadedOperatorUse(FunctionCall call, Operator op) { op.getACallToThisFunction() = call }