BuiltInTypeRules: Add isSameType API

Author: lcartey

cpp/misra/src/codingstandards/cpp/misra/BuiltInTypeRules.qll

@@ -95,7 +95,9 @@ class CharacterType extends Type {
     builtInType = getBuiltInType(this)
   }
 
-  BuiltInType getRealType() { result = builtInType }
+  private BuiltInType getBuiltInType() { result = builtInType }
+
+  predicate isSameType(CharacterType other) { this.getBuiltInType() = other.getBuiltInType() }
 }
 
 /**
@@ -135,7 +137,9 @@ class NumericType extends Type {
    */
   QlBuiltins::BigInt getIntegralLowerBound() { integralTypeBounds(builtInType, result, _) }
 
-  BuiltInType getRealType() { result = builtInType }
+  private BuiltInType getBuiltInType() { result = builtInType }
+
+  predicate isSameType(NumericType other) { this.getBuiltInType() = other.getBuiltInType() }
 }
 
 predicate isSignedType(NumericType t) { t.getSignedness() = Signed() }

cpp/misra/src/rules/RULE-7-0-3/NoCharacterNumericalValue.ql

@@ -35,7 +35,7 @@ where
     eq.getAnOperand() = expr and
     leftType = eq.getLeftOperand().getType() and
     rightType = eq.getRightOperand().getType() and
-    leftType.getRealType() = rightType.getRealType()
+    leftType.isSameType(rightType)
   ) and
   // Exclude unevaluated operands
   not expr.isUnevaluated()

cpp/misra/src/rules/RULE-7-0-5/NoSignednessChangeFromPromotion.ql

@@ -125,7 +125,7 @@ class ImpliedUsualArithmeticConversion extends IntegerPromotionOrUsualArithmetic
       // type will be the same as the converted type of the rvalue.
       toType = aop.getRValue().getFullyConverted().getType() and
       // Only consider cases where the conversion is not a no-op, for consistency with the `Conversion` class
-      not fromType.getRealType() = toType.getRealType()
+      not fromType.isSameType(toType)
     )
   }
 

cpp/misra/src/rules/RULE-7-0-6/NumericAssignmentTypeMismatch.ql

@@ -196,7 +196,7 @@ predicate isValidAssignment(Expr source, NumericType targetType, string context)
   isAssignment(source, targetType, context) and
   exists(NumericType sourceType | sourceType = source.getType() |
     if shouldHaveSameType(source)
-    then sourceType.getRealType() = targetType.getRealType()
+    then sourceType.isSameType(targetType)
     else (
       // Valid type match
       isValidTypeMatch(sourceType, targetType)