M5-0-3: Consider static casts to be cvalues, as per spec

Author: lcartey

Diff for: cpp/autosar/test/rules/M5-0-3/CvalueExpressionConvertedToDifferentUnderlyingType.expected

@@ -2,4 +2,6 @@
 | test.cpp:12:8:12:14 | ... + ... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:12:8:12:14 | ... + ... | expression |
 | test.cpp:14:8:14:13 | ... + ... | Implicit conversion converts cvalue $@ from signed short to signed int. | test.cpp:14:8:14:13 | ... + ... | expression |
 | test.cpp:23:13:23:19 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:23:13:23:19 | ... + ... | expression |
-| test.cpp:30:12:30:18 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:30:12:30:18 | ... + ... | expression |
+| test.cpp:25:13:25:45 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:25:13:25:45 | static_cast<int8_t>... | expression |
+| test.cpp:31:12:31:18 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:31:12:31:18 | ... + ... | expression |
+| test.cpp:33:12:33:44 | (int16_t)... | Implicit conversion converts cvalue $@ from signed char to signed short. | test.cpp:33:12:33:44 | static_cast<int8_t>... | expression |

Diff for: cpp/autosar/test/rules/M5-0-3/test.cpp

@@ -22,12 +22,15 @@ void test_func_call() {
   std::int8_t l1;
   int16_arg(l1 + l1);                            // NON_COMPLIANT
   int16_arg(static_cast<std::int16_t>(l1 + l1)); // COMPLIANT
+  int16_arg(static_cast<std::int8_t>(l1 + l1));  // NON_COMPLIANT
 }
 
 std::int16_t test_return(int test) {
   std::int8_t l1;
   if (test > 0) {
     return l1 + l1; // NON_COMPLIANT
+  } else if (test < 0) {
+    return static_cast<std::int8_t>(l1 + l1); // NON_COMPLIANT
   } else {
     return static_cast<std::int16_t>(l1 + l1); // COMPLIANT
   }

Diff for: cpp/common/src/codingstandards/cpp/Expr.qll

@@ -148,17 +148,9 @@ module MisraExpr {
   private predicate isCValue(Expr e) {
     not e.isConstant() and
     (
-      exists(ReturnStmt return |
-        e = return.getExpr() and
-        // Only return statements which are not explicitly casted are considered
-        not exists(Cast c | not c.isImplicit() and c.getExpr() = e)
-      )
+      exists(ReturnStmt return | e = return.getExpr().getExplicitlyConverted())
       or
-      exists(FunctionCall call |
-        e = call.getAnArgument() and
-        // // Only function arguments which are not explicitly casted are considered
-        not exists(Cast c | not c.isImplicit() and c.getExpr() = e)
-      )
+      exists(FunctionCall call | e = call.getAnArgument().getExplicitlyConverted())
     )
     or
     isCValue(e.(ParenthesisExpr).getExpr())