/*
* 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.AnalyzerCaster;
import org.elasticsearch.painless.DefBootstrap;
import org.elasticsearch.painless.Definition;
import org.elasticsearch.painless.Definition.Cast;
import org.elasticsearch.painless.Definition.Method;
import org.elasticsearch.painless.Definition.MethodKey;
import org.elasticsearch.painless.Definition.Sort;
import org.elasticsearch.painless.Globals;
import org.elasticsearch.painless.Locals;
import org.elasticsearch.painless.Locals.Variable;
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;
import static org.elasticsearch.painless.WriterConstants.ITERATOR_HASNEXT;
import static org.elasticsearch.painless.WriterConstants.ITERATOR_NEXT;
import static org.elasticsearch.painless.WriterConstants.ITERATOR_TYPE;
/**
* Represents a for-each loop for iterables.
*/
final class SSubEachIterable extends AStatement {
private AExpression expression;
private final SBlock block;
private final Variable variable;
private Cast cast = null;
private Variable iterator = null;
private Method method = null;
SSubEachIterable(Location location, Variable variable, AExpression expression, SBlock block) {
super(location);
this.variable = Objects.requireNonNull(variable);
this.expression = Objects.requireNonNull(expression);
this.block = block;
}
@Override
void extractVariables(Set<String> variables) {
throw createError(new IllegalStateException("Illegal tree structure."));
}
@Override
void analyze(Locals locals) {
// We must store the iterator as a variable for securing a slot on the stack, and
// also add the location offset to make the name unique in case of nested for each loops.
iterator = locals.addVariable(location, locals.getDefinition().getType("Iterator"),
"#itr" + location.getOffset(), true);
if (expression.actual.sort == Sort.DEF) {
method = null;
} else {
method = expression.actual.struct.methods.get(new MethodKey("iterator", 0));
if (method == null) {
throw createError(new IllegalArgumentException(
"Unable to create iterator for the type [" + expression.actual.name + "]."));
}
}
cast = AnalyzerCaster.getLegalCast(location, Definition.DEF_TYPE, variable.type, true, true);
}
@Override
void write(MethodWriter writer, Globals globals) {
writer.writeStatementOffset(location);
expression.write(writer, globals);
if (method == null) {
org.objectweb.asm.Type methodType = org.objectweb.asm.Type
.getMethodType(Definition.ITERATOR_TYPE.type, Definition.DEF_TYPE.type);
writer.invokeDefCall("iterator", methodType, DefBootstrap.ITERATOR);
} else {
method.write(writer);
}
writer.visitVarInsn(iterator.type.type.getOpcode(Opcodes.ISTORE), iterator.getSlot());
Label begin = new Label();
Label end = new Label();
writer.mark(begin);
writer.visitVarInsn(iterator.type.type.getOpcode(Opcodes.ILOAD), iterator.getSlot());
writer.invokeInterface(ITERATOR_TYPE, ITERATOR_HASNEXT);
writer.ifZCmp(MethodWriter.EQ, end);
writer.visitVarInsn(iterator.type.type.getOpcode(Opcodes.ILOAD), iterator.getSlot());
writer.invokeInterface(ITERATOR_TYPE, ITERATOR_NEXT);
writer.writeCast(cast);
writer.visitVarInsn(variable.type.type.getOpcode(Opcodes.ISTORE), variable.getSlot());
if (loopCounter != null) {
writer.writeLoopCounter(loopCounter.getSlot(), statementCount, location);
}
block.continu = begin;
block.brake = end;
block.write(writer, globals);
writer.goTo(begin);
writer.mark(end);
}
@Override
public String toString() {
return singleLineToString(variable.type.name, variable.name, expression, block);
}
}