/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.codehaus.groovy.ast.builder;
import org.codehaus.groovy.ast.*;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.control.io.ReaderSource;
import org.codehaus.groovy.transform.GroovyASTTransformation;
import java.util.ArrayList;
import java.util.List;
/**
* Transformation to capture ASTBuilder from code statements.
* <p>
* The AstBuilder "from code" approach is used with a single Closure
* parameter. This transformation converts the ClosureExpression back
* into source code and rewrites the AST so that the "from string"
* builder is invoked on the source. In order for this to work, the
* closure source must be given a goto label. It is the "from string"
* approach's responsibility to remove the BlockStatement created
* by the label.
*
* @author Hamlet D'Arcy
*/
@GroovyASTTransformation(phase = CompilePhase.SEMANTIC_ANALYSIS)
public class AstBuilderTransformation extends MethodCallTransformation {
@Override
protected GroovyCodeVisitor getTransformer(ASTNode[] nodes, SourceUnit sourceUnit) {
// todo : are there other import types that can be specified?
return new AstBuilderInvocationTrap(
sourceUnit.getAST().getImports(),
sourceUnit.getAST().getStarImports(),
sourceUnit.getSource(),
sourceUnit
);
}
/**
* This class traps invocations of AstBuilder.build(CompilePhase, boolean, Closure) and converts
* the contents of the closure into expressions by reading the source of the Closure and sending
* that as a String to AstBuilder.build(String, CompilePhase, boolean) at runtime.
*/
private static class AstBuilderInvocationTrap extends MethodInvocationTrap {
private final List<String> factoryTargets = new ArrayList<String>();
/**
* Creates the trap and captures all the ways in which a class may be referenced via imports.
*
* @param imports all the imports from the source
* @param importPackages all the imported packages from the source
* @param source the reader source that contains source for the SourceUnit
* @param sourceUnit the source unit being compiled. Used for error messages.
*/
AstBuilderInvocationTrap(List<ImportNode> imports, List<ImportNode> importPackages, ReaderSource source, SourceUnit sourceUnit) {
super(source, sourceUnit);
// factory type may be references as fully qualified, an import, or an alias
factoryTargets.add("org.codehaus.groovy.ast.builder.AstBuilder");//default package
if (imports != null) {
for (ImportNode importStatement : imports) {
if ("org.codehaus.groovy.ast.builder.AstBuilder".equals(importStatement.getType().getName())) {
factoryTargets.add(importStatement.getAlias());
}
}
}
if (importPackages != null) {
for (ImportNode importPackage : importPackages) {
if ("org.codehaus.groovy.ast.builder.".equals(importPackage.getPackageName())) {
factoryTargets.add("AstBuilder");
break;
}
}
}
}
@Override
protected boolean handleTargetMethodCallExpression(MethodCallExpression call) {
ClosureExpression closureExpression = getClosureArgument(call);
List<Expression> otherArgs = getNonClosureArguments(call);
String source = convertClosureToSource(closureExpression);
// parameter order is build(CompilePhase, boolean, String)
otherArgs.add(new ConstantExpression(source));
call.setArguments(new ArgumentListExpression(otherArgs));
call.setMethod(new ConstantExpression("buildFromBlock"));
call.setSpreadSafe(false);
call.setSafe(false);
call.setImplicitThis(false);
return false;
}
private static List<Expression> getNonClosureArguments(MethodCallExpression call) {
List<Expression> result = new ArrayList<Expression>();
if (call.getArguments() instanceof TupleExpression) {
for (ASTNode node : ((TupleExpression) call.getArguments()).getExpressions()) {
if (!(node instanceof ClosureExpression)) {
result.add((Expression) node);
}
}
}
return result;
}
private static ClosureExpression getClosureArgument(MethodCallExpression call) {
if (call.getArguments() instanceof TupleExpression) {
for (ASTNode node : ((TupleExpression) call.getArguments()).getExpressions()) {
if (node instanceof ClosureExpression) {
return (ClosureExpression) node;
}
}
}
return null;
}
/**
* Looks for method calls on the AstBuilder class called build that take
* a Closure as parameter. This is all needed b/c build is overloaded.
*
* @param call the method call expression, may not be null
*/
@Override
protected boolean isBuildInvocation(MethodCallExpression call) {
if (call == null) throw new IllegalArgumentException("Null: call");
// is method name correct?
if (call.getMethod() instanceof ConstantExpression && "buildFromCode".equals(((ConstantExpression) call.getMethod()).getValue())) {
// is method object correct type?
if (call.getObjectExpression() != null && call.getObjectExpression().getType() != null) {
String name = call.getObjectExpression().getType().getName();
if (name != null && !"".equals(name) && factoryTargets.contains(name)) {
// is one of the arguments a closure?
if (call.getArguments() != null && call.getArguments() instanceof TupleExpression) {
if (((TupleExpression) call.getArguments()).getExpressions() != null) {
for (ASTNode node : ((TupleExpression) call.getArguments()).getExpressions()) {
if (node instanceof ClosureExpression) {
return true;
}
}
}
}
}
}
}
return false;
}
}
}