io.prestosql.sql.gen.IfCodeGenerator Maven / Gradle / Ivy
/*
* 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 io.prestosql.sql.gen;
import com.google.common.base.Preconditions;
import io.airlift.bytecode.BytecodeBlock;
import io.airlift.bytecode.BytecodeNode;
import io.airlift.bytecode.Variable;
import io.airlift.bytecode.control.IfStatement;
import io.prestosql.metadata.ResolvedFunction;
import io.prestosql.spi.type.Type;
import io.prestosql.sql.relational.RowExpression;
import java.util.List;
import static io.airlift.bytecode.expression.BytecodeExpressions.constantFalse;
public class IfCodeGenerator
implements BytecodeGenerator
{
@Override
public BytecodeNode generateExpression(ResolvedFunction resolvedFunction, BytecodeGeneratorContext context, Type returnType, List arguments)
{
Preconditions.checkArgument(arguments.size() == 3);
Variable wasNull = context.wasNull();
BytecodeBlock condition = new BytecodeBlock()
.append(context.generate(arguments.get(0)))
.comment("... and condition value was not null")
.append(wasNull)
.invokeStatic(CompilerOperations.class, "not", boolean.class, boolean.class)
.invokeStatic(CompilerOperations.class, "and", boolean.class, boolean.class, boolean.class)
.append(wasNull.set(constantFalse()));
return new IfStatement()
.condition(condition)
.ifTrue(context.generate(arguments.get(1)))
.ifFalse(context.generate(arguments.get(2)));
}
}