/*
* 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;
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 org.objectweb.asm.Opcodes;
import java.util.Objects;
import java.util.Set;
/**
* Represents a while loop.
*/
public final class SWhile extends AStatement {
private AExpression condition;
private final SBlock block;
private boolean continuous = false;
public SWhile(Location location, AExpression condition, SBlock block) {
super(location);
this.condition = Objects.requireNonNull(condition);
this.block = block;
}
@Override
void extractVariables(Set<String> variables) {
condition.extractVariables(variables);
if (block != null) {
block.extractVariables(variables);
}
}
@Override
void analyze(Locals locals) {
locals = Locals.newLocalScope(locals);
condition.expected = Definition.BOOLEAN_TYPE;
condition.analyze(locals);
condition = condition.cast(locals);
if (condition.constant != null) {
continuous = (boolean)condition.constant;
if (!continuous) {
throw createError(new IllegalArgumentException("Extraneous while loop."));
}
if (block == null) {
throw createError(new IllegalArgumentException("While loop has no escape."));
}
}
if (block != null) {
block.beginLoop = true;
block.inLoop = true;
block.analyze(locals);
if (block.loopEscape && !block.anyContinue) {
throw createError(new IllegalArgumentException("Extraneous while loop."));
}
if (continuous && !block.anyBreak) {
methodEscape = true;
allEscape = true;
}
block.statementCount = Math.max(1, block.statementCount);
}
statementCount = 1;
if (locals.hasVariable(Locals.LOOP)) {
loopCounter = locals.getVariable(location, Locals.LOOP);
}
}
@Override
void write(MethodWriter writer, Globals globals) {
writer.writeStatementOffset(location);
Label begin = new Label();
Label end = new Label();
writer.mark(begin);
if (!continuous) {
condition.write(writer, globals);
writer.ifZCmp(Opcodes.IFEQ, end);
}
if (block != null) {
if (loopCounter != null) {
writer.writeLoopCounter(loopCounter.getSlot(), Math.max(1, block.statementCount), location);
}
block.continu = begin;
block.brake = end;
block.write(writer, globals);
} else {
if (loopCounter != null) {
writer.writeLoopCounter(loopCounter.getSlot(), 1, location);
}
}
if (block == null || !block.allEscape) {
writer.goTo(begin);
}
writer.mark(end);
}
@Override
public String toString() {
return singleLineToString(condition, block);
}
}