/*
* Licensed 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 com.facebook.presto.byteCode.control;
import com.facebook.presto.byteCode.Block;
import com.facebook.presto.byteCode.ByteCodeNode;
import com.facebook.presto.byteCode.ByteCodeVisitor;
import com.facebook.presto.byteCode.CompilerContext;
import com.facebook.presto.byteCode.ParameterizedType;
import com.facebook.presto.byteCode.instruction.LabelNode;
import com.google.common.collect.ImmutableList;
import org.objectweb.asm.MethodVisitor;
import java.util.List;
import static com.google.common.base.Preconditions.checkNotNull;
public class TryCatch
implements FlowControl
{
private final CompilerContext context;
private final String comment;
private final ByteCodeNode tryNode;
private final ByteCodeNode catchNode;
private final String exceptionName;
public TryCatch(CompilerContext context, String comment, ByteCodeNode tryNode, ByteCodeNode catchNode, ParameterizedType exceptionType)
{
this.context = checkNotNull(context, "context is null");
this.comment = comment;
this.tryNode = checkNotNull(tryNode, "tryNode is null");
this.catchNode = checkNotNull(catchNode, "catchNode is null");
this.exceptionName = (exceptionType != null) ? exceptionType.getClassName() : null;
}
@Override
public String getComment()
{
return comment;
}
public ByteCodeNode getTryNode()
{
return tryNode;
}
public ByteCodeNode getCatchNode()
{
return catchNode;
}
public String getExceptionName()
{
return exceptionName;
}
@Override
public void accept(MethodVisitor visitor)
{
LabelNode tryStart = new LabelNode("tryStart");
LabelNode tryEnd = new LabelNode("tryEnd");
LabelNode handler = new LabelNode("handler");
LabelNode done = new LabelNode("done");
Block block = new Block(context);
// try block
block.visitLabel(tryStart)
.append(tryNode)
.visitLabel(tryEnd)
.gotoLabel(done);
// handler block
block.visitLabel(handler)
.append(catchNode);
// all done
block.visitLabel(done);
block.accept(visitor);
visitor.visitTryCatchBlock(tryStart.getLabel(), tryEnd.getLabel(), handler.getLabel(), exceptionName);
}
@Override
public List<ByteCodeNode> getChildNodes()
{
return ImmutableList.of(tryNode, catchNode);
}
@Override
public <T> T accept(ByteCodeNode parent, ByteCodeVisitor<T> visitor)
{
return visitor.visitTryCatch(parent, this);
}
}