TypeInferencerVisitorBase.java

/*******************************************************************************
 * Copyright (c) 2010 xored software, Inc.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     xored software, Inc. - initial API and Implementation (Alex Panchenko)
 *******************************************************************************/
package org.eclipse.dltk.internal.javascript.ti;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Stack;

import org.eclipse.dltk.annotations.Nullable;
import org.eclipse.dltk.ast.ASTNode;
import org.eclipse.dltk.compiler.problem.IProblemIdentifier;
import org.eclipse.dltk.javascript.ast.ASTVisitor;
import org.eclipse.dltk.javascript.core.JavaScriptPlugin;
import org.eclipse.dltk.javascript.parser.JSProblemReporter;
import org.eclipse.dltk.javascript.parser.Reporter;
import org.eclipse.dltk.javascript.typeinference.IFunctionValueCollection;
import org.eclipse.dltk.javascript.typeinference.IValueCollection;
import org.eclipse.dltk.javascript.typeinference.IValueReference;
import org.eclipse.dltk.javascript.typeinfo.ITypeChecker;
import org.eclipse.dltk.javascript.typeinfo.ITypeInferenceHandler;
import org.eclipse.dltk.javascript.typeinfo.ITypeInferenceHandlerFactory;
import org.eclipse.dltk.javascript.typeinfo.ITypeInferenceListener;
import org.eclipse.dltk.javascript.typeinfo.ITypeInferencerVisitor;
import org.eclipse.dltk.javascript.typeinfo.TypeInfoManager;

public abstract class TypeInferencerVisitorBase extends
		ASTVisitor<IValueReference> implements ITypeInferencerVisitor {

	protected final ITypeInferenceContext context;

	private Stack<IValueCollection> contexts = new Stack<IValueCollection>();

	public ITypeInferenceContext getContext() {
		return context;
	}

	public IValueCollection peekContext() {
		return !contexts.isEmpty() ? contexts.peek() : null;
	}

	public void enterContext(IValueCollection collection) {
		contexts.push(collection);
	}

	public IValueCollection leaveContext() {
		return contexts.pop();
	}

	protected boolean inFunction() {
		return inFunction(false);
	}

	protected boolean inFunction(boolean ignoreBlocks) {
		for (int i = contexts.size(); --i >= 0;) {
			final IValueCollection collection = contexts.get(i);
			if (collection instanceof IFunctionValueCollection) {
				if (ignoreBlocks) {
					if (((IFunctionValueCollection) collection).isInlineBlock()) {
						continue;
					}
				}
				return true;
			}
		}
		return false;
	}

	public TypeInferencerVisitorBase(ITypeInferenceContext context) {
		this.context = context;
	}

	@Nullable
	private ITypeInferenceHandler[] handlers = null;

	@Nullable
	ITypeInferenceListener[] listeners = null;

	public void initialize() {
		contexts.clear();
		contexts.push(new TopValueCollection(context));
		listeners = null;
		final List<ITypeInferenceHandler> handlers = createHandlers();
		if (handlers != null && !handlers.isEmpty()) {
			this.handlers = handlers.toArray(new ITypeInferenceHandler[handlers
					.size()]);
		} else {
			this.handlers = null;
		}
	}

	protected List<ITypeInferenceHandler> createHandlers() {
		final List<ITypeInferenceHandler> handlers = new ArrayList<ITypeInferenceHandler>();
		for (ITypeInferenceHandlerFactory factory : TypeInfoManager
				.getNodeHandlerFactories()) {
			final ITypeInferenceHandler handler = factory.create(context, this);
			if (handler != null) {
				handlers.add(handler);
			}
		}
		return handlers;
	}

	public void addListener(ITypeInferenceListener listener) {
		assert listener != null;
		if (listeners == null) {
			listeners = new ITypeInferenceListener[] { listener };
		} else {
			final int length = this.listeners.length;
			for (int i = 0; i < length; ++i) {
				if (listener.equals(this.listeners[i])) {
					return;
				}
			}
			System.arraycopy(this.listeners, 0,
					this.listeners = new ITypeInferenceListener[length + 1], 0,
					length);
			this.listeners[length] = listener;
		}
	}

	@Override
	public IValueReference visit(ASTNode node) {
		if (handlers != null) {
			for (ITypeInferenceHandler handler : handlers) {
				final IValueReference result = handler.handle(node);
				if (result != ITypeInferenceHandler.CONTINUE) {
					return result;
				}
			}
		}
		try {
			return super.visit(node);
		} catch (PositionReachedException e) {
			throw e;
		} catch (TIWrappedException e) {
			throw e;
		} catch (RuntimeException e) {
			JavaScriptPlugin.error(buildNodeErrorMessage(node), e);
			throw new TIWrappedException(e);
		} catch (AssertionError e) {
			JavaScriptPlugin.error(buildNodeErrorMessage(node), e);
			throw new TIWrappedException(e);
		}
	}

	@SuppressWarnings("serial")
	static class TIWrappedException extends RuntimeException {
		public TIWrappedException(Throwable cause) {
			super(cause);
		}
	}

	protected String buildNodeErrorMessage(ASTNode node) {
		final StringBuilder sb = new StringBuilder();
		sb.append("Error processing ");
		sb.append(node.getClass().getName());
		try {
			final String message = node.toString();
			sb.append(" \"").append(message).append("\"");
		} catch (Throwable t) {
			// ignore potential errors in .toString()
		}
		sb.append(" in ").append(context.getSource());
		return sb.toString();
	}

	public void done() {
		IValueCollection collection = getCollection();
		if (collection instanceof ValueCollection) {
			IValue value = ((ValueCollection) collection).getValue();
			if (value instanceof Value) {
				((Value) value).resolveLazyValues(new HashSet<Value>());
			}
		}
		if (listeners != null) {
			for (ITypeInferenceListener listener : listeners) {
				listener.done();
			}
		}
	}

	public IValueCollection getCollection() {
		return contexts.get(0);
	}

	/**
	 * @param value1
	 * @param value2
	 * @return
	 */
	protected IValueReference merge(IValueReference value1,
			IValueReference value2) {
		final AnonymousValue reference = new AnonymousValue();
		reference.setValue(value1);
		reference.addValue(value2, false);
		return reference;
	}

	protected JSProblemReporter reporter;

	public JSProblemReporter getProblemReporter() {
		return reporter;
	}

	public void suppressProblems(IProblemIdentifier... identifiers) {
		if (reporter != null) {
			((Reporter) reporter).suppressProblems(identifiers);
		}
	}

	protected ITypeChecker typeChecker;

	/**
	 * Returns the type checker which can be used for type validation. Non-null
	 * during validation.
	 */
	@Nullable
	public ITypeChecker getTypeChecker() {
		return typeChecker;
	}

}