feature: partial evaluation of new Object[]{...}.length -> Literal<Number>

src/main/java/spoon/reflect/factory/TypeFactory.java

@@ -96,6 +96,7 @@ public class TypeFactory extends SubFactory {
 	public final CtTypeReference<List> LIST = createReference(List.class);
 	public final CtTypeReference<Set> SET = createReference(Set.class);
 	public final CtTypeReference<Map> MAP = createReference(Map.class);
+	public final CtTypeReference<Enum> ENUM = createReference(Enum.class);
 
 	private final Map<Class<?>, CtType<?>> shadowCache = new HashMap<>();
 

src/main/java/spoon/support/reflect/eval/VisitorPartialEvaluator.java

@@ -33,6 +33,7 @@
 import spoon.reflect.code.CtInvocation;
 import spoon.reflect.code.CtLiteral;
 import spoon.reflect.code.CtLocalVariable;
+import spoon.reflect.code.CtNewArray;
 import spoon.reflect.code.CtReturn;
 import spoon.reflect.code.CtStatement;
 import spoon.reflect.code.CtSynchronized;
@@ -101,7 +102,9 @@ public <R extends CtElement> R evaluate(R element) {
 		}
 		element.accept(this);
 		if (result != null) {
-			result.setParent(element.getParent());
+			if (element.isParentInitialized()) {
+				result.setParent(element.getParent());
+			}
 			return (R) result;
 		}
 
@@ -283,7 +286,16 @@ private <T> void visitFieldAccess(CtFieldAccess<T> fieldAccess) {
 				return;
 			}
 		}
-		if (fieldAccess.getFactory().Type().createReference(Enum.class)
+		if ("length".equals(fieldAccess.getVariable().getSimpleName())) {
+			CtExpression<?> target = fieldAccess.getTarget();
+			if (target instanceof CtNewArray<?>) {
+				CtNewArray<?> newArr = (CtNewArray<?>) target;
+				CtLiteral<Number> literal = fieldAccess.getFactory().createLiteral(newArr.getElements().size());
+				setResult(literal);
+				return;
+			}
+		}
+		if (fieldAccess.getFactory().Type().ENUM
 				.isSubtypeOf(fieldAccess.getVariable().getDeclaringType())) {
 			CtLiteral<CtFieldReference<?>> l = fieldAccess.getFactory().Core().createLiteral();
 			l.setValue(fieldAccess.getVariable());

src/test/java/spoon/test/eval/EvalTest.java

@@ -34,6 +34,17 @@ public void testStringConcatenation() throws Exception {
 		assertEquals("// if removed", b.getStatements().get(0).toString());
 	}
 
+	@Test
+	public void testArrayLength() throws Exception {
+		CtClass<?> type = build("spoon.test.eval", "ToEvaluate");
+		assertEquals("ToEvaluate", type.getSimpleName());
+
+		CtBlock<?> b = type.getMethodsByName("testArray").get(0).getBody();
+		assertEquals(1, b.getStatements().size());
+		b = b.partiallyEvaluate();
+		assertEquals("// if removed", b.getStatements().get(0).toString());
+	}
+
 	@Test
 	public void testVisitorPartialEvaluator_binary() throws Exception {
 		Launcher launcher = new Launcher();

src/test/java/spoon/test/eval/ToEvaluate.java

@@ -32,4 +32,10 @@ public static void testInts() {
 		}
 	}
 
+	public static void testArray() {
+		// all the following code will be removed by the partial evaluator
+		if (new String[]{"a", null, "b"}.length == 11) {
+			System.out.println("dead code");
+		}
+	}
 }