/*
***** BEGIN LICENSE BLOCK *****
* Version: CPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Common Public
* License Version 1.0 (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.eclipse.org/legal/cpl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2006 Thomas E Enebo <enebo@acm.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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package org.jruby.ast;
import java.util.List;
import org.jruby.Ruby;
import org.jruby.ast.visitor.NodeVisitor;
import org.jruby.evaluator.Instruction;
import org.jruby.lexer.yacc.ISourcePosition;
import org.jruby.parser.StaticScope;
import org.jruby.runtime.Block;
import org.jruby.runtime.DynamicScope;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
/**
* Represents the top of the AST. This is a node not present in MRI. It was created to
* hold the top-most static scope in an easy to grab way and it also exists to hold BEGIN
* and END nodes. These can then be interpreted/compiled in the same places as the rest
* of the code.
*
*/
// TODO: Store BEGIN and END information into this node
public class RootNode extends Node {
private transient DynamicScope scope;
private StaticScope staticScope;
private Node bodyNode;
public RootNode(ISourcePosition position, DynamicScope scope, Node bodyNode) {
super(position, NodeType.ROOTNODE);
assert bodyNode != null : "bodyNode is not null";
this.scope = scope;
this.staticScope = scope.getStaticScope();
this.bodyNode = bodyNode;
}
/**
* Return the dynamic scope for this AST. The variable backed by this is transient so
* for serialization this is null. In that case we use staticScope to rebuild the dynamic
* scope. The real reason for this method is supporting bindings+eval. We need to pass
* our live dynamic scope in so when we eval we can use that dynamic scope.
*
* @return dynamic scope of this AST
*/
public DynamicScope getScope() {
return scope;
}
/**
* The static scoping relationships that should get set first thing before interpretation
* of the code represented by this AST. Actually, we use getScope first since that also
* can contain a live dynamic scope. We rely on this method only for interpreting a root
* node from a serialized format.
*
* @return the top static scope for the AST
*/
public StaticScope getStaticScope() {
return staticScope;
}
/**
* First real AST node to be interpreted
*
* @return real top AST node
*/
public Node getBodyNode() {
return bodyNode;
}
public Instruction accept(NodeVisitor iVisitor) {
return iVisitor.visitRootNode(this);
}
public List<Node> childNodes() {
return createList(bodyNode);
}
@Override
public IRubyObject interpret(Ruby runtime, ThreadContext context, IRubyObject self, Block aBlock) {
// Serialization killed our dynamic scope. We can just create an empty one
// since serialization cannot serialize an eval (which is the only thing
// which is capable of having a non-empty dynamic scope).
if (scope == null) {
scope = DynamicScope.newDynamicScope(staticScope);
}
StaticScope theStaticScope = scope.getStaticScope();
// Each root node has a top-level scope that we need to push
context.preScopedBody(scope);
if (theStaticScope.getModule() == null) {
theStaticScope.setModule(runtime.getObject());
}
try {
return bodyNode.interpret(runtime, context, self, aBlock);
} finally {
context.postScopedBody();
}
}
}