RecoveryScanner.java

/*******************************************************************************
 * Copyright (c) 2006, 2009 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.jdt.internal.compiler.parser;

import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.core.compiler.InvalidInputException;

public class RecoveryScanner extends Scanner {
	public static final char[] FAKE_IDENTIFIER= "$missing$".toCharArray(); //$NON-NLS-1$

	private RecoveryScannerData data;

	private int[] pendingTokens;

	private int pendingTokensPtr= -1;

	private char[] fakeTokenSource= null;

	private boolean isInserted= true;

	private boolean precededByRemoved= false;

	private int skipNextInsertedTokens= -1;

	public boolean record= true;

	public RecoveryScanner(Scanner scanner, RecoveryScannerData data) {
		super(false,
				scanner.tokenizeWhiteSpace,
				scanner.checkNonExternalizedStringLiterals,
				scanner.sourceLevel,
				scanner.complianceLevel,
				scanner.taskTags,
				scanner.taskPriorities,
				scanner.isTaskCaseSensitive);
		setData(data);
	}

	public RecoveryScanner(
			boolean tokenizeWhiteSpace,
			boolean checkNonExternalizedStringLiterals,
			long sourceLevel,
			long complianceLevel,
			char[][] taskTags,
			char[][] taskPriorities,
			boolean isTaskCaseSensitive,
			RecoveryScannerData data) {
		super(false,
				tokenizeWhiteSpace,
				checkNonExternalizedStringLiterals,
				sourceLevel,
				complianceLevel,
				taskTags,
				taskPriorities,
				isTaskCaseSensitive);
		setData(data);
	}

	public void insertToken(int token, int completedToken, int position) {
		insertTokens(new int[] { token }, completedToken, position);
	}

	private int[] reverse(int[] tokens) {
		int length= tokens.length;
		for (int i= 0, max= length / 2; i < max; i++) {
			int tmp= tokens[i];
			tokens[i]= tokens[length - i - 1];
			tokens[length - i - 1]= tmp;
		}
		return tokens;
	}

	public void insertTokens(int[] tokens, int completedToken, int position) {
		if (!this.record)
			return;

		if (completedToken > -1 && Parser.statements_recovery_filter[completedToken] != 0)
			return;

		this.data.insertedTokensPtr++;
		if (this.data.insertedTokens == null) {
			this.data.insertedTokens= new int[10][];
			this.data.insertedTokensPosition= new int[10];
			this.data.insertedTokenUsed= new boolean[10];
		} else if (this.data.insertedTokens.length == this.data.insertedTokensPtr) {
			int length= this.data.insertedTokens.length;
			System.arraycopy(this.data.insertedTokens, 0, this.data.insertedTokens= new int[length * 2][], 0, length);
			System.arraycopy(this.data.insertedTokensPosition, 0, this.data.insertedTokensPosition= new int[length * 2], 0, length);
			System.arraycopy(this.data.insertedTokenUsed, 0, this.data.insertedTokenUsed= new boolean[length * 2], 0, length);
		}
		this.data.insertedTokens[this.data.insertedTokensPtr]= reverse(tokens);
		this.data.insertedTokensPosition[this.data.insertedTokensPtr]= position;
		this.data.insertedTokenUsed[this.data.insertedTokensPtr]= false;
	}

	public void replaceTokens(int token, int start, int end) {
		replaceTokens(new int[] { token }, start, end);
	}

	public void replaceTokens(int[] tokens, int start, int end) {
		if (!this.record)
			return;
		this.data.replacedTokensPtr++;
		if (this.data.replacedTokensStart == null) {
			this.data.replacedTokens= new int[10][];
			this.data.replacedTokensStart= new int[10];
			this.data.replacedTokensEnd= new int[10];
			this.data.replacedTokenUsed= new boolean[10];
		} else if (this.data.replacedTokensStart.length == this.data.replacedTokensPtr) {
			int length= this.data.replacedTokensStart.length;
			System.arraycopy(this.data.replacedTokens, 0, this.data.replacedTokens= new int[length * 2][], 0, length);
			System.arraycopy(this.data.replacedTokensStart, 0, this.data.replacedTokensStart= new int[length * 2], 0, length);
			System.arraycopy(this.data.replacedTokensEnd, 0, this.data.replacedTokensEnd= new int[length * 2], 0, length);
			System.arraycopy(this.data.replacedTokenUsed, 0, this.data.replacedTokenUsed= new boolean[length * 2], 0, length);
		}
		this.data.replacedTokens[this.data.replacedTokensPtr]= reverse(tokens);
		this.data.replacedTokensStart[this.data.replacedTokensPtr]= start;
		this.data.replacedTokensEnd[this.data.replacedTokensPtr]= end;
		this.data.replacedTokenUsed[this.data.replacedTokensPtr]= false;
	}

	public void removeTokens(int start, int end) {
		if (!this.record)
			return;
		this.data.removedTokensPtr++;
		if (this.data.removedTokensStart == null) {
			this.data.removedTokensStart= new int[10];
			this.data.removedTokensEnd= new int[10];
			this.data.removedTokenUsed= new boolean[10];
		} else if (this.data.removedTokensStart.length == this.data.removedTokensPtr) {
			int length= this.data.removedTokensStart.length;
			System.arraycopy(this.data.removedTokensStart, 0, this.data.removedTokensStart= new int[length * 2], 0, length);
			System.arraycopy(this.data.removedTokensEnd, 0, this.data.removedTokensEnd= new int[length * 2], 0, length);
			System.arraycopy(this.data.removedTokenUsed, 0, this.data.removedTokenUsed= new boolean[length * 2], 0, length);
		}
		this.data.removedTokensStart[this.data.removedTokensPtr]= start;
		this.data.removedTokensEnd[this.data.removedTokensPtr]= end;
		this.data.removedTokenUsed[this.data.removedTokensPtr]= false;
	}

	public int getNextToken() throws InvalidInputException {
		if (this.pendingTokensPtr > -1) {
			int nextToken= this.pendingTokens[this.pendingTokensPtr--];
			if (nextToken == TerminalTokens.TokenNameIdentifier) {
				this.fakeTokenSource= FAKE_IDENTIFIER;
			} else {
				this.fakeTokenSource= CharOperation.NO_CHAR;
			}
			return nextToken;
		}

		this.fakeTokenSource= null;
		this.precededByRemoved= false;

		if (this.data.insertedTokens != null) {
			for (int i= 0; i <= this.data.insertedTokensPtr; i++) {
				if (this.data.insertedTokensPosition[i] == this.currentPosition - 1 && i > this.skipNextInsertedTokens) {
					this.data.insertedTokenUsed[i]= true;
					this.pendingTokens= this.data.insertedTokens[i];
					this.pendingTokensPtr= this.data.insertedTokens[i].length - 1;
					this.isInserted= true;
					this.startPosition= this.currentPosition;
					this.skipNextInsertedTokens= i;
					int nextToken= this.pendingTokens[this.pendingTokensPtr--];
					if (nextToken == TerminalTokens.TokenNameIdentifier) {
						this.fakeTokenSource= FAKE_IDENTIFIER;
					} else {
						this.fakeTokenSource= CharOperation.NO_CHAR;
					}
					return nextToken;
				}
			}
			this.skipNextInsertedTokens= -1;
		}

		int previousLocation= this.currentPosition;
		int currentToken= super.getNextToken();

		if (this.data.replacedTokens != null) {
			for (int i= 0; i <= this.data.replacedTokensPtr; i++) {
				if (this.data.replacedTokensStart[i] >= previousLocation &&
						this.data.replacedTokensStart[i] <= this.startPosition &&
						this.data.replacedTokensEnd[i] >= this.currentPosition - 1) {
					this.data.replacedTokenUsed[i]= true;
					this.pendingTokens= this.data.replacedTokens[i];
					this.pendingTokensPtr= this.data.replacedTokens[i].length - 1;
					this.fakeTokenSource= FAKE_IDENTIFIER;
					this.isInserted= false;
					this.currentPosition= this.data.replacedTokensEnd[i] + 1;
					int nextToken= this.pendingTokens[this.pendingTokensPtr--];
					if (nextToken == TerminalTokens.TokenNameIdentifier) {
						this.fakeTokenSource= FAKE_IDENTIFIER;
					} else {
						this.fakeTokenSource= CharOperation.NO_CHAR;
					}
					return nextToken;
				}
			}
		}
		if (this.data.removedTokensStart != null) {
			for (int i= 0; i <= this.data.removedTokensPtr; i++) {
				if (this.data.removedTokensStart[i] >= previousLocation &&
						this.data.removedTokensStart[i] <= this.startPosition &&
						this.data.removedTokensEnd[i] >= this.currentPosition - 1) {
					this.data.removedTokenUsed[i]= true;
					this.currentPosition= this.data.removedTokensEnd[i] + 1;
					this.precededByRemoved= false;
					return getNextToken();
				}
			}
		}
		return currentToken;
	}

	public char[] getCurrentIdentifierSource() {
		if (this.fakeTokenSource != null)
			return this.fakeTokenSource;
		return super.getCurrentIdentifierSource();
	}

	public char[] getCurrentTokenSourceString() {
		if (this.fakeTokenSource != null)
			return this.fakeTokenSource;
		return super.getCurrentTokenSourceString();
	}

	public char[] getCurrentTokenSource() {
		if (this.fakeTokenSource != null)
			return this.fakeTokenSource;
		return super.getCurrentTokenSource();
	}

	public RecoveryScannerData getData() {
		return this.data;
	}

	public boolean isFakeToken() {
		return this.fakeTokenSource != null;
	}

	public boolean isInsertedToken() {
		return this.fakeTokenSource != null && this.isInserted;
	}

	public boolean isReplacedToken() {
		return this.fakeTokenSource != null && !this.isInserted;
	}

	public boolean isPrecededByRemovedToken() {
		return this.precededByRemoved;
	}

	public void setData(RecoveryScannerData data) {
		if (data == null) {
			this.data= new RecoveryScannerData();
		} else {
			this.data= data;
		}
	}

	public void setPendingTokens(int[] pendingTokens) {
		this.pendingTokens= pendingTokens;
		this.pendingTokensPtr= pendingTokens.length - 1;
	}
}