/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.elasticsearch.painless.node;
import org.elasticsearch.painless.Definition.Type;
import org.elasticsearch.painless.Globals;
import org.elasticsearch.painless.Locals;
import org.elasticsearch.painless.Location;
import org.elasticsearch.painless.MethodWriter;
import org.objectweb.asm.Label;
import java.util.Set;
/**
* Implements a field who's value is null if the prefix is null rather than throwing an NPE.
*/
public class PSubNullSafeField extends AStoreable {
private AStoreable guarded;
public PSubNullSafeField(Location location, AStoreable guarded) {
super(location);
this.guarded = guarded;
}
@Override
void extractVariables(Set<String> variables) {
guarded.extractVariables(variables);
}
@Override
void analyze(Locals locals) {
if (write) {
throw createError(new IllegalArgumentException("Can't write to null safe reference"));
}
guarded.read = read;
guarded.analyze(locals);
actual = guarded.actual;
if (actual.sort.primitive) {
throw new IllegalArgumentException("Result of null safe operator must be nullable");
}
}
@Override
int accessElementCount() {
return guarded.accessElementCount();
}
@Override
boolean isDefOptimized() {
return guarded.isDefOptimized();
}
@Override
void updateActual(Type actual) {
guarded.updateActual(actual);
}
@Override
void write(MethodWriter writer, Globals globals) {
Label end = new Label();
writer.dup();
writer.ifNull(end);
guarded.write(writer, globals);
writer.mark(end);
}
@Override
void setup(MethodWriter writer, Globals globals) {
throw createError(new IllegalArgumentException("Can't write to null safe field"));
}
@Override
void load(MethodWriter writer, Globals globals) {
throw createError(new IllegalArgumentException("Can't write to null safe field"));
}
@Override
void store(MethodWriter writer, Globals globals) {
throw createError(new IllegalArgumentException("Can't write to null safe field"));
}
@Override
public String toString() {
return singleLineToString(guarded);
}
}