/*
* Copyright 2003-2011 the original author or authors.
*
* 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 org.codehaus.groovy.ast.builder;
import groovy.lang.MissingPropertyException;
import org.codehaus.groovy.ast.*;
import org.codehaus.groovy.ast.expr.*;
import org.codehaus.groovy.ast.stmt.Statement;
import org.codehaus.groovy.control.CompilePhase;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.control.io.ReaderSource;
import org.codehaus.groovy.control.messages.SyntaxErrorMessage;
import org.codehaus.groovy.syntax.SyntaxException;
import org.codehaus.groovy.transform.ASTTransformation;
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 implements ASTTransformation {
public void visit(ASTNode[] nodes, SourceUnit sourceUnit) {
// todo : are there other import types that can be specified?
AstBuilderInvocationTrap transformer = new AstBuilderInvocationTrap(
sourceUnit.getAST().getImports(),
sourceUnit.getAST().getStarImports(),
sourceUnit.getSource(),
sourceUnit
);
if (nodes != null) {
for (ASTNode it : nodes) {
if (!(it instanceof AnnotationNode) && !(it instanceof ClassNode)) {
it.visit(transformer);
}
}
}
if (sourceUnit.getAST() != null) {
sourceUnit.getAST().visit(transformer);
if (sourceUnit.getAST().getStatementBlock() != null) {
sourceUnit.getAST().getStatementBlock().visit(transformer);
}
if (sourceUnit.getAST().getClasses() != null) {
for (ClassNode classNode : sourceUnit.getAST().getClasses()) {
if (classNode.getMethods() != null) {
for (MethodNode node : classNode.getMethods()) {
if (node != null && node.getCode() != null) {
node.getCode().visit(transformer);
}
}
}
try {
if (classNode.getDeclaredConstructors() != null) {
for (MethodNode node : classNode.getDeclaredConstructors()) {
if (node != null && node.getCode() != null) {
node.getCode().visit(transformer);
}
}
}
} catch (MissingPropertyException ignored) {
// todo: inner class nodes don't have a constructors field available
}
// all properties are also always fields
if (classNode.getFields() != null) {
for (FieldNode node : classNode.getFields()) {
if (node.getInitialValueExpression() != null) {
node.getInitialValueExpression().visit(transformer);
}
}
}
try {
if (classNode.getObjectInitializerStatements() != null) {
for (Statement node : classNode.getObjectInitializerStatements()) {
if (node != null) {
node.visit(transformer);
}
}
}
} catch (MissingPropertyException ignored) {
// todo: inner class nodes don't have a objectInitializers field available
}
// todo: is there anything to do with the module ???
}
}
if (sourceUnit.getAST().getMethods() != null) {
for (MethodNode node : sourceUnit.getAST().getMethods()) {
if (node != null) {
if (node.getParameters() != null) {
for (Parameter parameter : node.getParameters()) {
if (parameter != null && parameter.getInitialExpression() != null) {
parameter.getInitialExpression().visit(transformer);
}
}
}
if (node.getCode() != null) {
node.getCode().visit(transformer);
}
}
}
}
}
}
/**
* 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 CodeVisitorSupport {
private final List<String> factoryTargets = new ArrayList<String>();
private final ReaderSource source;
private final SourceUnit sourceUnit;
/**
* 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) {
if (source == null) throw new IllegalArgumentException("Null: source");
if (sourceUnit == null) throw new IllegalArgumentException("Null: sourceUnit");
this.source = source;
this.sourceUnit = 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;
}
}
}
}
/**
* Reports an error back to the source unit.
*
* @param msg the error message
* @param expr the expression that caused the error message.
*/
private void addError(String msg, ASTNode expr) {
int line = expr.getLineNumber();
int col = expr.getColumnNumber();
sourceUnit.getErrorCollector().addErrorAndContinue(
new SyntaxErrorMessage(new SyntaxException(msg + '\n', line, col), sourceUnit)
);
}
/**
* Attempts to find AstBuilder 'from code' invocations. When found, converts them into calls
* to the 'from string' approach.
*
* @param call the method call expression that may or may not be an AstBuilder 'from code' invocation.
*/
public void visitMethodCallExpression(MethodCallExpression call) {
if (isBuildInvocation(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);
} else {
// continue normal tree walking
call.getObjectExpression().visit(this);
call.getMethod().visit(this);
call.getArguments().visit(this);
}
}
private 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 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
*/
private 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;
}
/**
* Converts a ClosureExpression into the String source.
*
* @param expression a closure
* @return the source the closure was created from
*/
private String convertClosureToSource(ClosureExpression expression) {
if (expression == null) throw new IllegalArgumentException("Null: expression");
StringBuilder result = new StringBuilder();
for (int x = expression.getLineNumber(); x <= expression.getLastLineNumber(); x++) {
String line = source.getLine(x, null);
if (line == null) {
addError(
"Error calculating source code for expression. Trying to read line " + x + " from " + source.getClass(),
expression
);
}
if (x == expression.getLastLineNumber()) {
line = line.substring(0, expression.getLastColumnNumber() - 1);
}
if (x == expression.getLineNumber()) {
line = line.substring(expression.getColumnNumber() - 1);
}
//restoring line breaks is important b/c of lack of semicolons
result.append(line).append('\n');
}
String source = result.toString().trim();
if (!source.startsWith("{")) {
addError(
"Error converting ClosureExpression into source code. Closures must start with {. Found: " + source,
expression
);
}
return source;
}
}
}