Missing parameter type information

[jecisc]

While trying to build call graph of the JDK we have once again some parameters without types.

Here is the minimal example to produce the error:

import java.util.*;

class RTFReader
{
    static Dictionary<String, char[]> characterSets;

    public void handleText(String text) { }
}

#text parameter of #handleText should have a typing information but it is not present in the generated model

[jecisc]

The problem is because of Dictionary<String, char[]>.

	public  <T extends TParametricEntity> TParametricAssociation buildFamixParametricAssociation(TParametricAssociation association, ITypeBinding[] genericTypes, ITypeBinding[] typeArguments
	) {
		
		Iterator<ITypeBinding> genericIterator = Arrays.asList(genericTypes).iterator();
		Iterator<ITypeBinding> concreteIterator = Arrays.asList(typeArguments).iterator();

		while (concreteIterator.hasNext() && genericIterator.hasNext()) {
			TTypeArgument typeArgument = (TTypeArgument)ensureFamixType(concreteIterator.next());
			TypeParameter typeParameter = (TypeParameter)ensureFamixType(genericIterator.next());

			Concretization concretization = ensureFamixConcretization(typeArgument, typeParameter);
			association.addConcretization(concretization);
		}

		return association;
	}

This method will fail because of this line:

TTypeArgument typeArgument = (TTypeArgument)ensureFamixType(concreteIterator.next());

We are casting the result as a TTypeArgument but in the case of char[] it will return a PrimitiveType that cannot be cast.

[jecisc]

Here is a file to build a test:

/**
 * Regression test of a parameter missing its typing information
 */
import java.util.*;

class MissingParameter
{
    static Dictionary<String, char[]> characterSets;

    public void handleText(String text) { }
}

And here is the test:

    @Test
    /**
     * Regression test of a typing info missing on a parameter
     */
    public void testRegressionTestOfMissingTypingInfoOnAParameter() {
        parse(new String[]{"src/test/resources/ad_hoc/MissingParameter.java"});

        Method handleText = firstEntityNamed(Method.class, "handleText");

        assertEquals(1, handleText.getParameters().size());
        assertNotNull(handleText.getParameters().iterator().next().getTyping());
        assertEquals("String", handleText.getParameters().iterator().next().getTyping().getDeclaredType().getName());
    }

[jecisc]

I am really not sure but maybe FamixJavaPrimitiveType should use FamixTTypeArgument?

[NicolasAnquetil]

From: https://angelikalanger.com/...
All reference types can be used a type arguments of a parameterized type or method. This includes classes, interfaces, enum types, nested and inner types, and array types. Only primitive types cannot be used as type argument.

So primitive type arrays or OK
Unfortunately we do not represent arrays as types
So we can:

• introduce arrays in FamixJava
• allow primitive types to be TypeArgument
• create an instance of FamixJavaType that we call "char[]"
  (AND allow FamixJavaType to be Type argument, which would cover the 2nd solution also)

I think the 2nd solution is the easiest at this time