/*******************************************************************************
 * Copyright (c) 2004, 2012 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.core.dom;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jdt.core.IClassFile;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.WorkingCopyOwner;
import org.eclipse.jdt.core.compiler.CategorizedProblem;
import org.eclipse.jdt.core.compiler.CharOperation;
import org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration;
import org.eclipse.jdt.internal.compiler.ast.ConstructorDeclaration;
import org.eclipse.jdt.internal.compiler.batch.Main;
import org.eclipse.jdt.internal.compiler.env.IBinaryType;
import org.eclipse.jdt.internal.compiler.parser.RecoveryScanner;
import org.eclipse.jdt.internal.compiler.parser.RecoveryScannerData;
import org.eclipse.jdt.internal.compiler.parser.Scanner;
import org.eclipse.jdt.internal.compiler.util.SuffixConstants;
import org.eclipse.jdt.internal.core.*;
import org.eclipse.jdt.internal.core.util.CodeSnippetParsingUtil;
import org.eclipse.jdt.internal.core.util.RecordedParsingInformation;
import org.eclipse.jdt.internal.core.util.Util;

/**
 * A Java language parser for creating abstract syntax trees (ASTs).
 * <p>
 * Example: Create basic AST from source string
 * <pre>
 * char[] source = ...;
 * ASTParser parser = ASTParser.newParser(AST.JLS3);  // handles JDK 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6
 * parser.setSource(source);
 * // In order to parse 1.5 code, some compiler options need to be set to 1.5
 * Map options = JavaCore.getOptions();
 * JavaCore.setComplianceOptions(JavaCore.VERSION_1_5, options);
 * parser.setCompilerOptions(options);
 * CompilationUnit result = (CompilationUnit) parser.createAST(null);
 * </pre>
 * Once a configured parser instance has been used to create an AST,
 * the settings are automatically reset to their defaults,
 * ready for the parser instance to be reused.
 * </p>
 * <p>
 * There are a number of configurable features:
 * <ul>
 * <li>Source string from {@link #setSource(char[]) char[]},
 * {@link #setSource(ICompilationUnit) ICompilationUnit},
 * or {@link #setSource(IClassFile) IClassFile}, and limited
 * to a specified {@linkplain #setSourceRange(int,int) subrange}.</li>
 * <li>Whether {@linkplain #setResolveBindings(boolean) bindings} will be created.</li>
 * <li>Which {@linkplain #setWorkingCopyOwner(WorkingCopyOwner)
 * working copy owner} to use when resolving bindings.</li>
 * <li>A hypothetical {@linkplain #setUnitName(String) compilation unit file name}
 * and {@linkplain #setProject(IJavaProject) Java project}
 * for locating a raw source string in the Java model (when
 * resolving bindings)</li>
 * <li>Which {@linkplain #setCompilerOptions(Map) compiler options}
 * to use. This is especially important to use if the parsing/scanning of the source code requires a
 * different version than the default of the workspace. For example, the workspace defaults are 1.4 and
 * you want to create an AST for a source code that is using 1.5 constructs.</li>
 * <li>Whether to parse just {@linkplain #setKind(int) an expression, statements,
 * or body declarations} rather than an entire compilation unit.</li>
 * <li>Whether to return a {@linkplain #setFocalPosition(int) abridged AST}
 * focused on the declaration containing a given source position.</li>
 * </ul>
 * </p>
 *
 * @since 3.0
 * @noinstantiate This class is not intended to be instantiated by clients.
 */
public class ASTParser {

	/**
	 * Kind constant used to request that the source be parsed
     * as a single expression.
	 */
	public static final int K_EXPRESSION = 0x01;

	/**
	 * Kind constant used to request that the source be parsed
     * as a sequence of statements.
	 */
	public static final int K_STATEMENTS = 0x02;

	/**
	 * Kind constant used to request that the source be parsed
	 * as a sequence of class body declarations.
	 */
	public static final int K_CLASS_BODY_DECLARATIONS = 0x04;

	/**
	 * Kind constant used to request that the source be parsed
	 * as a compilation unit.
	 */
	public static final int K_COMPILATION_UNIT = 0x08;

	/**
	 * Creates a new object for creating a Java abstract syntax tree
     * (AST) following the specified set of API rules.
     *
 	 * @param level the API level; one of the <code>.JLS*</code> level constants
     * declared on {@link AST}
	 * @return new ASTParser instance
	 */
	public static ASTParser newParser(int level) {
		return new ASTParser(level);
	}

	/**
	 * Level of AST API desired.
	 */
	private final int apiLevel;

	/**
	 * Kind of parse requested. Defaults to an entire compilation unit.
	 */
	private int astKind;

	/**
	 * Compiler options. Defaults to JavaCore.getOptions().
	 */
	private Map compilerOptions;
	
    /**
	 * The focal point for a partial AST request.
     * Only used when <code>partial</code> is <code>true</code>.
     */
	private int focalPointPosition;

    /**
     * Source string.
     */
    private char[] rawSource = null;

    /**
     * Java model class file or compilation unit supplying the source.
     */
    private ITypeRoot typeRoot = null;

    /**
     * Character-based offset into the source string where parsing is to
     * begin. Defaults to 0.
     */
	private int sourceOffset = 0;

    /**
     * Character-based length limit, or -1 if unlimited.
     * All characters in the source string between <code>offset</code>
     * and <code>offset+length-1</code> inclusive are parsed. Defaults to -1,
     * which means the rest of the source string.
     */
	private int sourceLength = -1;

    /**
     * Working copy owner. Defaults to primary owner.
     */
	private WorkingCopyOwner workingCopyOwner = DefaultWorkingCopyOwner.PRIMARY;

    /**
	 * Java project used to resolve names, or <code>null</code> if none.
     * Defaults to none.
     */
	private IJavaProject project = null;

    /**
	 * Name of the compilation unit for resolving bindings, or
	 * <code>null</code> if none. Defaults to none.
     */
	private String unitName = null;
	
	/**
	 * Classpath entries to use to resolve bindings when no java project are available.
	 */
	private String[] classpaths;

	/**
	 * Sourcepath entries to use to resolve bindings when no java project are available.
	 */
	private String[] sourcepaths;
	
	/**
	 * Encoding of the given sourcepaths entries.
	 */
	private String[] sourcepathsEncodings;
	
	/**
	 * Bits used to set the different values from CompilationUnitResolver values.
	 */
	private int bits;

	/**
	 * Creates a new AST parser for the given API level.
	 * <p>
	 * N.B. This constructor is package-private.
	 * </p>
	 *
	 * @param level the API level; one of the <code>JLS*</code> level constants
	 * declared on {@link AST}
	 */
	ASTParser(int level) {
		switch(level) {
			case AST.JLS2_INTERNAL:
			case AST.JLS3_INTERNAL:
			case AST.JLS4:
				break;
			default:
				throw new IllegalArgumentException();
		}
		this.apiLevel = level;
		initializeDefaults();
	}

	private List getClasspath() throws IllegalStateException {
		Main main = new Main(new PrintWriter(System.out), new PrintWriter(System.err), false/*systemExit*/, null/*options*/, null/*progress*/);
		ArrayList allClasspaths = new ArrayList();
		try {
			if ((this.bits & CompilationUnitResolver.INCLUDE_RUNNING_VM_BOOTCLASSPATH) != 0) {
				org.eclipse.jdt.internal.compiler.util.Util.collectRunningVMBootclasspath(allClasspaths);
			}
			if (this.sourcepaths != null) {
				for (int i = 0, max = this.sourcepaths.length; i < max; i++) {
					String encoding = this.sourcepathsEncodings == null ? null : this.sourcepathsEncodings[i];
					main.processPathEntries(
							Main.DEFAULT_SIZE_CLASSPATH,
							allClasspaths, this.sourcepaths[i], encoding, true, false);
				}
			}
			if (this.classpaths != null) {
				for (int i = 0, max = this.classpaths.length; i < max; i++) {
					main.processPathEntries(
							Main.DEFAULT_SIZE_CLASSPATH,
							allClasspaths, this.classpaths[i], null, false, false);
				}
			}
			ArrayList pendingErrors = main.pendingErrors;
			if (pendingErrors != null && pendingErrors.size() != 0) {
				throw new IllegalStateException("invalid environment settings"); //$NON-NLS-1$
			}
		} catch (IllegalArgumentException e) {
			throw new IllegalStateException("invalid environment settings"); //$NON-NLS-1$
		}
		return allClasspaths;
	}
	/**
	 * Sets all the setting to their default values.
	 */
	private void initializeDefaults() {
		this.astKind = K_COMPILATION_UNIT;
		this.rawSource = null;
		this.typeRoot = null;
		this.bits = 0;
		this.sourceLength = -1;
		this.sourceOffset = 0;
		this.workingCopyOwner = DefaultWorkingCopyOwner.PRIMARY;
		this.unitName = null;
		this.project = null;
		this.classpaths = null;
		this.sourcepaths = null;
		this.sourcepathsEncodings = null;
		Map options = JavaCore.getOptions();
		options.remove(JavaCore.COMPILER_TASK_TAGS); // no need to parse task tags
		this.compilerOptions = options;
	}

	/**
	 * Requests that the compiler should perform bindings recovery.
	 * When bindings recovery is enabled the compiler returns incomplete bindings.
	 * <p>
	 * Default to <code>false</code>.
	 * </p>
	 * <p>This should be set to true only if bindings are resolved. It has no effect if there is no binding
	 * resolution.</p>
	 *
	 * @param enabled <code>true</code> if incomplete bindings are expected,
	 *   and <code>false</code> if only complete bindings are expected.
	 *
	 * @see IBinding#isRecovered()
	 * @since 3.3
	 */
	public void setBindingsRecovery(boolean enabled) {
		if (enabled) {
			this.bits |= CompilationUnitResolver.BINDING_RECOVERY;
		} else {
			this.bits &= ~CompilationUnitResolver.BINDING_RECOVERY;
		}
	}
	
	/**
	 * Sets the environment to be used when no {@link IJavaProject} is available.
	 * 
	 * <p>The user has to make sure that all the required types are included either in the classpath or source paths. 
	 * All the paths containing binary types must be included in the <code>classpathEntries</code> whereas all paths containing  
	 * source types must be included in the <code>sourcepathEntries</code>.</p>
	 * <p>All paths in the <code>classpathEntries</code> and <code>sourcepathEntries</code> are absolute paths.</p>
	 * <p>If the source paths contain units using a specific encoding (other than the platform encoding), then the
	 * given <code>encodings</code> must be set. When the <code>encodings</code> is set to non <code>null</code>, its length must
	 * match the length of <code>sourcepathEntries</code> or an IllegalArgumentException will be thrown.</p>
	 * <p>If <code>encodings</code> is not <code>null</code>, the given <code>sourcepathEntries</code> must not be <code>null</code>.</p>
	 * 
	 * @param classpathEntries the given classpath entries to be used to resolve bindings
	 * @param sourcepathEntries the given sourcepath entries to be used to resolve bindings
	 * @param encodings the encodings of the corresponding sourcepath entries or <code>null</code> if the platform encoding
	 * can be used.
	 * @param includeRunningVMBootclasspath <code>true</code> if the bootclasspath of the running VM must be prepended to the
	 * given classpath and <code>false</code> if the bootclasspath of the running VM should be ignored.
	 * @throws IllegalArgumentException if the size of the given encodings is not equals to the size of the given <code>
	 * sourcepathEntries</code>
	 * @since 3.6
	 */
	public void setEnvironment(String[] classpathEntries, String[] sourcepathEntries, String[] encodings, boolean includeRunningVMBootclasspath) {
		this.classpaths = classpathEntries;
		this.sourcepaths = sourcepathEntries;
		this.sourcepathsEncodings = encodings;
		if (encodings != null) {
			if (sourcepathEntries == null || sourcepathEntries.length != encodings.length) {
				throw new IllegalArgumentException(); 
			}
		}
		if (includeRunningVMBootclasspath) {
			this.bits |= CompilationUnitResolver.INCLUDE_RUNNING_VM_BOOTCLASSPATH;
		}
	}
	/**
	 * Sets the compiler options to be used when parsing.
	 * <p>
	 * Note that {@link #setSource(IClassFile)},
	 * {@link #setSource(ICompilationUnit)},
	 * and {@link #setProject(IJavaProject)} reset the compiler options
	 * based on the Java project. In other cases, compiler options default
	 * to {@link JavaCore#getOptions()}. In either case, and especially
	 * in the latter, the caller should carefully weight the consequences of
	 * allowing compiler options to be defaulted as opposed to being
	 * explicitly specified for the {@link ASTParser} instance.
	 * For instance, there is a compiler option called "Source Compatibility Mode"
	 * which determines which JDK level the source code is expected to meet.
	 * If you specify "1.4", then "assert" is treated as a keyword and disallowed
	 * as an identifier; if you specify "1.3", then "assert" is allowed as an
	 * identifier. So this particular setting has a major bearing on what is
	 * considered syntactically legal. By explicitly specifying the setting,
	 * the client control exactly how the parser works. On the other hand,
	 * allowing default settings means the parsing behaves like other JDT tools.
	 * </p>
	 *
	 * @param options the table of options (key type: <code>String</code>;
	 * value type: <code>String</code>), or <code>null</code>
	 * to set it back to the default
	 */
	public void setCompilerOptions(Map options) {
		if (options == null) {
			options = JavaCore.getOptions();
		} else {
			// copy client's options so as to not do any side effect on them
			options = new HashMap(options);
		}
		options.remove(JavaCore.COMPILER_TASK_TAGS); // no need to parse task tags
		this.compilerOptions = options;
	}

	/**
	 * Requests that the compiler should provide binding information for
	 * the AST nodes it creates.
	 * <p>
	 * Default to <code>false</code> (no bindings).
	 * </p>
	 * <p>
	 * If {@link #setResolveBindings(boolean) setResolveBindings(true)}, the various names
	 * and types appearing in the AST can be resolved to "bindings"
	 * by calling the <code>resolveBinding</code> methods. These bindings
	 * draw connections between the different parts of a program, and
	 * generally afford a more powerful vantage point for clients who wish to
	 * analyze a program's structure more deeply. These bindings come at a
	 * considerable cost in both time and space, however, and should not be
	 * requested frivolously. The additional space is not reclaimed until the
	 * AST, all its nodes, and all its bindings become garbage. So it is very
	 * important to not retain any of these objects longer than absolutely
	 * necessary. Bindings are resolved at the time the AST is created. Subsequent
	 * modifications to the AST do not affect the bindings returned by
	 * <code>resolveBinding</code> methods in any way; these methods return the
	 * same binding as before the AST was modified (including modifications
	 * that rearrange subtrees by reparenting nodes).
	 * If {@link #setResolveBindings(boolean) setResolveBindings(false)}, (the default), the analysis
	 * does not go beyond parsing and building the tree, and all
	 * <code>resolveBinding</code> methods return <code>null</code> from the outset.
	 * </p>
	 * <p>
	 * When bindings are requested, instead of considering compilation units on disk only
	 * one can supply a <code>WorkingCopyOwner</code>. Working copies owned
	 * by this owner take precedence over the underlying compilation units when looking
	 * up names and drawing the connections.
	 * </p>
	 * <p>Note that working copy owner are used only if the <code>org.eclipse.jdt.core</code>
	 * bundle is initialized.</p>
	 * <p>
	 * Binding information is obtained from the Java model.
	 * This means that the compilation unit must be located relative to the
	 * Java model. This happens automatically when the source code comes from
	 * either {@link #setSource(ICompilationUnit) setSource(ICompilationUnit)}
	 * or {@link #setSource(IClassFile) setSource(IClassFile)}.
	 * When source is supplied by {@link #setSource(char[]) setSource(char[])},
	 * the location must be established explicitly by setting an environment using
	 * {@link #setProject(IJavaProject)} or {@link #setEnvironment(String[], String[], String[], boolean)} 
	 * and a unit name {@link #setUnitName(String)}.
	 * Note that the compiler options that affect doc comment checking may also
	 * affect whether any bindings are resolved for nodes within doc comments.
	 * </p>
	 *
	 * @param enabled <code>true</code> if bindings are wanted,
	 *   and <code>false</code> if bindings are not of interest
	 */
	public void setResolveBindings(boolean enabled) {
		if (enabled) {
			this.bits |= CompilationUnitResolver.RESOLVE_BINDING;
		} else {
			this.bits &= ~CompilationUnitResolver.RESOLVE_BINDING;
		}
	}

	/**
	 * Requests an abridged abstract syntax tree.
	 * By default, complete ASTs are returned.
	 * <p>
	 * When the given <code>position</code> is a valid position within the source code of 
	 * the compilation unit, the resulting AST does not have nodes for
	 * the entire compilation unit. Rather, the AST is only fleshed out
	 * for the node that include the given source position. This kind of limited
	 * AST is sufficient for certain purposes but totally unsuitable for others.
	 * In places where it can be used, the limited AST offers the advantage of
	 * being smaller and faster to construct.
	 * </p>
	 * <p>
	 * The AST will include nodes for all of the compilation unit's
	 * package, import, and top-level type declarations. It will also always contain
	 * nodes for all the body declarations for those top-level types, as well
	 * as body declarations for any member types. However, some of the body
	 * declarations may be abridged. In particular, the statements ordinarily
	 * found in the body of a method declaration node will not be included
	 * (the block will be empty) unless the source position falls somewhere
	 * within the source range of that method declaration node. The same is true
	 * for initializer declarations; the statements ordinarily found in the body
	 * of initializer node will not be included unless the source position falls
	 * somewhere within the source range of that initializer declaration node.
	 * Field declarations are never abridged. Note that the AST for the body of
	 * that one unabridged method (or initializer) is 100% complete; it has all
	 * its statements, including any local or anonymous type declarations
	 * embedded within them. When the given <code>position</code> is not located within
	 * the source range of any body declaration of a top-level type, the AST
	 * returned will be a skeleton that includes nodes for all and only the major
	 * declarations; this kind of AST is still quite useful because it contains
	 * all the constructs that introduce names visible to the world outside the
	 * compilation unit.
	 * </p>
	 *
	 * <p>This focal position is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 * 
	 * @param position a position into the corresponding body declaration
	 */
	public void setFocalPosition(int position) {
		this.bits |= CompilationUnitResolver.PARTIAL;
		this.focalPointPosition = position;
	}

	/**
	 * Sets the kind of constructs to be parsed from the source.
	 * Defaults to an entire compilation unit.
	 * <p>
	 * When the parse is successful the result returned includes the ASTs for the
	 * requested source:
	 * <ul>
	 * <li>{@link #K_COMPILATION_UNIT K_COMPILATION_UNIT}: The result node
	 * is a {@link CompilationUnit}.</li>
	 * <li>{@link #K_CLASS_BODY_DECLARATIONS K_CLASS_BODY_DECLARATIONS}: The result node
	 * is a {@link TypeDeclaration} whose
	 * {@link TypeDeclaration#bodyDeclarations() bodyDeclarations}
	 * are the new trees. Other aspects of the type declaration are unspecified.</li>
	 * <li>{@link #K_STATEMENTS K_STATEMENTS}: The result node is a
	 * {@link Block Block} whose {@link Block#statements() statements}
	 * are the new trees. Other aspects of the block are unspecified.</li>
	 * <li>{@link #K_EXPRESSION K_EXPRESSION}: The result node is a subclass of
	 * {@link Expression Expression}. Other aspects of the expression are unspecified.</li>
	 * </ul>
	 * The resulting AST node is rooted under (possibly contrived)
	 * {@link CompilationUnit CompilationUnit} node, to allow the
	 * client to retrieve the following pieces of information
	 * available there:
	 * <ul>
	 * <li>{@linkplain CompilationUnit#getLineNumber(int) Line number map}. Line
	 * numbers start at 1 and only cover the subrange scanned
	 * (<code>source[offset]</code> through <code>source[offset+length-1]</code>).</li>
	 * <li>{@linkplain CompilationUnit#getMessages() Compiler messages}
	 * and {@linkplain CompilationUnit#getProblems() detailed problem reports}.
	 * Character positions are relative to the start of
	 * <code>source</code>; line positions are for the subrange scanned.</li>
	 * <li>{@linkplain CompilationUnit#getCommentList() Comment list}
	 * for the subrange scanned.</li>
	 * </ul>
	 * The contrived nodes do not have source positions. Other aspects of the
	 * {@link CompilationUnit CompilationUnit} node are unspecified, including
	 * the exact arrangement of intervening nodes.
	 * </p>
	 * <p>
	 * Lexical or syntax errors detected while parsing can result in
	 * a result node being marked as {@link ASTNode#MALFORMED MALFORMED}.
	 * In more severe failure cases where the parser is unable to
	 * recognize the input, this method returns
	 * a {@link CompilationUnit CompilationUnit} node with at least the
	 * compiler messages.
	 * </p>
	 * <p>Each node in the subtree (other than the contrived nodes)
	 * carries source range(s) information relating back
	 * to positions in the given source (the given source itself
	 * is not remembered with the AST).
	 * The source range usually begins at the first character of the first token
	 * corresponding to the node; leading whitespace and comments are <b>not</b>
	 * included. The source range usually extends through the last character of
	 * the last token corresponding to the node; trailing whitespace and
	 * comments are <b>not</b> included. There are a handful of exceptions
	 * (including the various body declarations); the
	 * specification for these node type spells out the details.
	 * Source ranges nest properly: the source range for a child is always
	 * within the source range of its parent, and the source ranges of sibling
	 * nodes never overlap.
	 * </p>
	 * <p>
	 * Binding information is only computed when <code>kind</code> is
	 * {@link #K_COMPILATION_UNIT}.
	 * </p>
	 * 
	 * <p>This kind is not used when the AST is built using
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 * 
	 * @param kind the kind of construct to parse: one of
	 * {@link #K_COMPILATION_UNIT},
	 * {@link #K_CLASS_BODY_DECLARATIONS},
	 * {@link #K_EXPRESSION},
	 * {@link #K_STATEMENTS}
	 */
	public void setKind(int kind) {
	    if ((kind != K_COMPILATION_UNIT)
		    && (kind != K_CLASS_BODY_DECLARATIONS)
		    && (kind != K_EXPRESSION)
		    && (kind != K_STATEMENTS)) {
	    	throw new IllegalArgumentException();
	    }
		this.astKind = kind;
	}

	/**
	 * Sets the source code to be parsed.
	 *
	 * <p>This source is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 *
	 * <p>If this method is used, the user needs to specify compiler options explicitly using
	 * {@link #setCompilerOptions(Map)} as 1.5 code will not be properly parsed without setting
	 * the appropriate values for the compiler options: {@link JavaCore#COMPILER_SOURCE},
	 * {@link JavaCore#COMPILER_CODEGEN_TARGET_PLATFORM}, and {@link JavaCore#COMPILER_COMPLIANCE}.</p>
	 * <p>Otherwise the default values for the compiler options will be used to parse the given source.</p>
	 *
	 * @param source the source string to be parsed,
	 * or <code>null</code> if none
	 * @see JavaCore#setComplianceOptions(String, Map)
	 */
	public void setSource(char[] source) {
		this.rawSource = source;
		// clear the type root
		this.typeRoot = null;
	}

	/**
	 * Sets the source code to be parsed.
	 * 
	 * <p>This method automatically sets the project (and compiler
	 * options) based on the given compilation unit, in a manner
	 * equivalent to {@link #setProject(IJavaProject) setProject(source.getJavaProject())}.</p>
	 *
	 * <p>This source is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 * 
	 * @param source the Java model compilation unit whose source code
	 * is to be parsed, or <code>null</code> if none
	 */
	public void setSource(ICompilationUnit source) {
		setSource((ITypeRoot)source);
	}

	/**
	 * Sets the source code to be parsed.
	 *
	 * <p>This method automatically sets the project (and compiler
	 * options) based on the given compilation unit, in a manner
	 * equivalent to {@link #setProject(IJavaProject) setProject(source.getJavaProject())}.</p>
	 * <p>If the given class file has  no source attachment, the creation of the
	 * ast will fail with an {@link IllegalStateException}.</p>
	 *
	 * <p>This source is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 * 
	 * @param source the Java model class file whose corresponding source code
	 * is to be parsed, or <code>null</code> if none
	 */
	public void setSource(IClassFile source) {
		setSource((ITypeRoot)source);
	}

	/**
	 * Sets the source code to be parsed.
	 *
	 * <p>This method automatically sets the project (and compiler
	 * options) based on the given compilation unit of class file, in a manner
	 * equivalent to {@link #setProject(IJavaProject) setProject(source.getJavaProject())}.</p>
	 * <p>If the source is a class file without source attachment, the creation of the
	 * ast will fail with an {@link IllegalStateException}.</p>
	 *
	 * <p>This source is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 *
	 * @param source the Java model compilation unit or class file whose corresponding source code
	 * is to be parsed, or <code>null</code> if none
	 * @since 3.3
	 */
	public void setSource(ITypeRoot source) {
		this.typeRoot = source;
		// clear the raw source
		this.rawSource = null;
		if (source != null) {
			this.project = source.getJavaProject();
			Map options = this.project.getOptions(true);
			options.remove(JavaCore.COMPILER_TASK_TAGS); // no need to parse task tags
			this.compilerOptions = options;
		}
	}

	/**
     * Sets the subrange of the source code to be parsed.
     * By default, the entire source string will be parsed
     * (<code>offset</code> 0 and <code>length</code> -1).
     *
	 * <p>This range is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
     *
     * @param offset the index of the first character to parse
     * @param length the number of characters to parse, or -1 if
     * the remainder of the source string is to be parsed
     */
	public void setSourceRange(int offset, int length) {
		if (offset < 0 || length < -1) {
			throw new IllegalArgumentException();
		}
		this.sourceOffset = offset;
		this.sourceLength = length;
	}

	/**
	 * Requests that the compiler should perform statements recovery.
	 * When statements recovery is enabled the compiler tries to create statement nodes
	 * from code containing syntax errors
     * <p>
     * Default to <code>false</code>.
     * </p>
	 *
	 * @param enabled <code>true</code> if statements containing syntax errors are wanted,
	 *   and <code>false</code> if these statements aren't wanted.
	 *
	 * @since 3.2
	 */
	public void setStatementsRecovery(boolean enabled) {
		if (enabled) {
			this.bits |= CompilationUnitResolver.STATEMENT_RECOVERY;
		} else {
			this.bits &= ~CompilationUnitResolver.STATEMENT_RECOVERY;
		}
	}
	
	/**
	 * Requests an abstract syntax tree without method bodies. 
	 * 
	 * <p>When ignore method bodies is enabled, all method bodies are discarded.
	 * This has no impact on the binding resolution.</p>
	 *
	 * <p>This setting is not used when the kind used in {@link #setKind(int)} is either 
	 * {@link #K_EXPRESSION} or {@link #K_STATEMENTS}.</p>
	 * @since 3.5.2
	 */
	public void setIgnoreMethodBodies(boolean enabled) {
		if (enabled) {
			this.bits |= CompilationUnitResolver.IGNORE_METHOD_BODIES;
		} else {
			this.bits &= ~CompilationUnitResolver.IGNORE_METHOD_BODIES;
		}
	}

    /**
     * Sets the working copy owner using when resolving bindings, where
     * <code>null</code> means the primary owner. Defaults to the primary owner.
     *
	 * @param owner the owner of working copies that take precedence over underlying
	 *   compilation units, or <code>null</code> if the primary owner should be used
     */
	public void setWorkingCopyOwner(WorkingCopyOwner owner) {
	    if (owner == null) {
			this.workingCopyOwner = DefaultWorkingCopyOwner.PRIMARY;
		} else {
			this.workingCopyOwner = owner;
	 	}
	}

	/**
	 * Sets the name of the compilation unit that would hypothetically contains the
	 * source string.
	 * 
	 *  <p>This is used in conjunction with {@link #setSource(char[])}
	 * and {@link #setProject(IJavaProject)} to locate the compilation unit relative to a Java project.
	 * Defaults to none (<code>null</code>).</p>
	 * <p>
	 * The name of the compilation unit must be supplied for resolving bindings.
	 * This name should be suffixed by a dot ('.') followed by one of the
	 * {@link JavaCore#getJavaLikeExtensions() Java-like extensions}
	 * and match the name of the main (public) class or interface declared in the source.</p>
	 *
	 * <p>This name must represent the full path of the unit inside the given project. For example, if the source
	 * declares a public class named "Foo" in a project "P" where the source folder is the project itself, the name
	 * of the compilation unit must be "/P/Foo.java".
	 * If the source declares a public class name "Bar" in a package "p1.p2" in a project "P" in a source folder "src",
	 * the name of the compilation unit must be "/P/src/p1/p2/Bar.java".</p>
	 *
	 * <p>This unit name is not used when the AST is built using 
	 * {@link #createASTs(ICompilationUnit[], String[], ASTRequestor, IProgressMonitor)}.</p>
	 *
	 * @param unitName the name of the compilation unit that would contain the source
	 *    string, or <code>null</code> if none
	 */
	public void setUnitName(String unitName) {
		this.unitName = unitName;
	}

	/**
	 * Sets the Java project used when resolving bindings.
	 * 
	 * <p>This method automatically sets the compiler
	 * options based on the given project:</p>
	 * <pre>
	 * setCompilerOptions(project.getOptions(true));
	 * </pre>
	 * <p>See {@link #setCompilerOptions(Map)} for a discussion of
	 * the pros and cons of using these options vs specifying
	 * compiler options explicitly.</p>
	 * <p>This setting is used in conjunction with {@link #setSource(char[])}.
	 * For the purposes of resolving bindings, types declared in the
	 * source string will hide types by the same name available
	 * through the classpath of the given project.</p>
	 * <p>Defaults to none (<code>null</code>).</p>
	 *
	 * @param project the Java project used to resolve names, or
	 *    <code>null</code> if none
	 */
	public void setProject(IJavaProject project) {
		this.project = project;
		if (project != null) {
			Map options = project.getOptions(true);
			options.remove(JavaCore.COMPILER_TASK_TAGS); // no need to parse task tags
			this.compilerOptions = options;
		}
	}

	/**
	 * Creates an abstract syntax tree.
	 * <p>
	 * A successful call to this method returns all settings to their
	 * default values so the object is ready to be reused.
	 * </p>
	 *
	 * @param monitor the progress monitor used to report progress and request cancellation,
	 *   or <code>null</code> if none
	 * @return an AST node whose type depends on the kind of parse
	 *  requested, with a fallback to a <code>CompilationUnit</code>
	 *  in the case of severe parsing errors
	 * @exception IllegalStateException if the settings provided
	 * are insufficient, contradictory, or otherwise unsupported
	 */
	public ASTNode createAST(IProgressMonitor monitor) {
		ASTNode result = null;
		if (monitor != null) monitor.beginTask("", 1); //$NON-NLS-1$
		try {
			if (this.rawSource == null && this.typeRoot == null) {
				throw new IllegalStateException("source not specified"); //$NON-NLS-1$
			}
			result = internalCreateAST(monitor);
		} finally {
			// reset to defaults to allow reuse (and avoid leaking)
			initializeDefaults();
			if (monitor != null) monitor.done();
		}
		return result;
	}

	/**
	 * Creates ASTs for a batch of compilation units.
	 * <p>When bindings are being resolved, processing a
	 * batch of compilation units is more efficient because much
	 * of the work involved in resolving bindings can be shared.</p>
	 * <p>
	 * When bindings are being resolved, all compilation units must
	 * come from the same Java project, which must be set beforehand
	 * with {@link #setProject(IJavaProject) setProject}.</p>
	 * <p>The compilation units are processed one at a time in no
	 * specified order. For each of the compilation units in turn,</p>
	 * <ul>
	 * <li>{@link #createAST(IProgressMonitor) ASTParser.createAST} is called to parse it
	 * and create a corresponding AST. The calls to
	 * {@link #createAST(IProgressMonitor) ASTParser.createAST} all employ the same settings.</li>
	 * <li>{@link ASTRequestor#acceptAST(ICompilationUnit, CompilationUnit) ASTRequestor.acceptAST}
	 * is called passing the compilation unit and the corresponding AST to <code>requestor</code>.
	 * </li>
	 * </ul>
	 * Note only ASTs from the given compilation units are reported
	 * to the requestor. If additional compilation units are required to
	 * resolve the original ones, the corresponding ASTs are <b>not</b>
	 * reported to the requestor.
	 * </p>
	 * <p>
	 * Note also the following parser parameters are used, regardless of what
	 * may have been specified:
	 * <ul>
	 * <li>The {@linkplain #setKind(int) parser kind} is <code>K_COMPILATION_UNIT</code></li>
	 * <li>The {@linkplain #setSourceRange(int,int) source range} is <code>(0, -1)</code></li>
	 * <li>The {@linkplain #setFocalPosition(int) focal position} is not set</li>
	 * </ul>
	 * </p>
	 * <p>
	 * The <code>bindingKeys</code> parameter specifies bindings keys
	 * ({@link IBinding#getKey()}) that are to be looked up. These keys may
	 * be for elements either inside or outside the set of compilation
	 * units being processed. When bindings are being resolved,
	 * the keys and corresponding bindings (or <code>null</code> if none) are
	 * passed to {@link ASTRequestor#acceptBinding(String, IBinding) ASTRequestor.acceptBinding}.
	 * Note that binding keys for elements outside the set of compilation units being processed
	 * are looked up after all {@link ASTRequestor#acceptAST(ICompilationUnit, CompilationUnit) ASTRequestor.acceptAST}
	 * callbacks have been made.
	 * Binding keys for elements inside the set of compilation units being processed
	 * are looked up and reported right after the corresponding
	 * {@link ASTRequestor#acceptAST(ICompilationUnit, CompilationUnit) ASTRequestor.acceptAST} callback has been made.
	 * No {@link ASTRequestor#acceptBinding(String, IBinding) ASTRequestor.acceptBinding} callbacks are made unless
	 * bindings are being resolved.
	 * </p>
	 * <p>
	 * A successful call to this method returns all settings to their
	 * default values so the object is ready to be reused.
	 * </p>
	 *
	 * @param compilationUnits the compilation units to create ASTs for
	 * @param bindingKeys the binding keys to create bindings for
	 * @param requestor the AST requestor that collects abstract syntax trees and bindings
	 * @param monitor the progress monitor used to report progress and request cancellation,
	 *   or <code>null</code> if none
	 * @exception IllegalStateException if the settings provided
	 * are insufficient, contradictory, or otherwise unsupported
	 * @since 3.1
	 */
	public void createASTs(ICompilationUnit[] compilationUnits, String[] bindingKeys, ASTRequestor requestor, IProgressMonitor monitor) {
		try {
			int flags = 0;
			if ((this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0) {
				flags |= ICompilationUnit.ENABLE_STATEMENTS_RECOVERY;
			}
			if ((this.bits & CompilationUnitResolver.IGNORE_METHOD_BODIES) != 0) {
				flags |= ICompilationUnit.IGNORE_METHOD_BODIES;
			}
			if ((this.bits & CompilationUnitResolver.RESOLVE_BINDING) != 0) {
				if (this.project == null)
					throw new IllegalStateException("project not specified"); //$NON-NLS-1$
				if ((this.bits & CompilationUnitResolver.BINDING_RECOVERY) != 0) {
					flags |= ICompilationUnit.ENABLE_BINDINGS_RECOVERY;
				}
				CompilationUnitResolver.resolve(compilationUnits, bindingKeys, requestor, this.apiLevel, this.compilerOptions, this.project, this.workingCopyOwner, flags, monitor);
			} else {
				CompilationUnitResolver.parse(compilationUnits, requestor, this.apiLevel, this.compilerOptions, flags, monitor);
			}
		} finally {
			// reset to defaults to allow reuse (and avoid leaking)
			initializeDefaults();
		}
	}

	/**
	 * Creates ASTs for a batch of compilation units.
	 * When bindings are being resolved, processing a
	 * batch of compilation units is more efficient because much
	 * of the work involved in resolving bindings can be shared.
	 * <p>
	 * When bindings are being resolved, all compilation units are resolved using
	 * the same environment, which must be set beforehand
	 * with {@link #setEnvironment(String[], String[], String[], boolean) setEnvironment}.
	 * The compilation units are processed one at a time in no
	 * specified order. For each of the compilation units in turn,
	 * <ul>
	 * <li>{@link ASTParser#createAST(IProgressMonitor) ASTParser.createAST} is called to parse it
	 * and create a corresponding AST. The calls to
	 * {@link ASTParser#createAST(IProgressMonitor) ASTParser.createAST} all employ the same settings.</li>
	 * <li>{@link FileASTRequestor#acceptAST(String, CompilationUnit) FileASTRequestor.acceptAST} is called passing
	 * the compilation unit path and the corresponding AST to <code>requestor</code>. The compilation unit path is the same
	 * path that is passed into the given <code>sourceFilePaths</code> parameter.
	 * </li>
	 * </ul>
	 * Note only ASTs from the given compilation units are reported
	 * to the requestor. If additional compilation units are required to
	 * resolve the original ones, the corresponding ASTs are <b>not</b>
	 * reported to the requestor.
	 * </p>
	 * <p>
	 * Note also the following parser parameters are used, regardless of what
	 * may have been specified:
	 * <ul>
	 * <li>The {@linkplain #setKind(int) parser kind} is <code>K_COMPILATION_UNIT</code></li>
	 * <li>The {@linkplain #setSourceRange(int,int) source range} is <code>(0, -1)</code></li>
	 * <li>The {@linkplain #setFocalPosition(int) focal position} is not set</li>
	 * </ul>
	 * </p>
	 * <p>
	 * The <code>bindingKeys</code> parameter specifies bindings keys
	 * ({@link IBinding#getKey()}) that are to be looked up. These keys may
	 * be for elements either inside or outside the set of compilation
	 * units being processed. When bindings are being resolved,
	 * the keys and corresponding bindings (or <code>null</code> if none) are
	 * passed to {@link FileASTRequestor#acceptBinding(String, IBinding) FileASTRequestor.acceptBinding}. Note that binding keys
	 * for elements outside the set of compilation units being processed are looked up
	 * after all {@link FileASTRequestor#acceptAST(String, CompilationUnit) ASTRequestor.acceptAST}
	 * callbacks have been made.
	 * Binding keys for elements inside the set of compilation units being processed
	 * are looked up and reported right after the corresponding
	 * {@link FileASTRequestor#acceptAST(String, CompilationUnit) FileASTRequestor.acceptAST} callback has been made.
	 * No {@link FileASTRequestor#acceptBinding(String, IBinding) FileASTRequestor.acceptBinding} callbacks are made unless
	 * bindings are being resolved.
	 * </p>
	 * <p>
	 * A successful call to this method returns all settings to their
	 * default values so the object is ready to be reused.
	 * </p>
	 * <p>The given <code>encodings</code> are used to properly parse the given source units. If the platform encoding is sufficient,
	 * then the given encodings can be set to <code>null</code>.</p>
	 *
	 * @param sourceFilePaths the compilation units to create ASTs for
	 * @param encodings the given encoding for the source units
	 * @param bindingKeys the binding keys to create bindings for
	 * @param requestor the AST requestor that collects abstract syntax trees and bindings
	 * @param monitor the progress monitor used to report progress and request cancellation,
	 *   or <code>null</code> if none
	 * @exception IllegalStateException if the settings provided
	 * are insufficient, contradictory, or otherwise unsupported
	 * @since 3.6
	 */
	public void createASTs(String[] sourceFilePaths, String[] encodings, String[] bindingKeys,
			FileASTRequestor requestor, IProgressMonitor monitor) {
		try {
			int flags = 0;
			if ((this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0) {
				flags |= ICompilationUnit.ENABLE_STATEMENTS_RECOVERY;
			}
			if ((this.bits & CompilationUnitResolver.IGNORE_METHOD_BODIES) != 0) {
				flags |= ICompilationUnit.IGNORE_METHOD_BODIES;
			}
			if ((this.bits & CompilationUnitResolver.RESOLVE_BINDING) != 0) {
				if (this.classpaths == null && this.sourcepaths == null && ((this.bits & CompilationUnitResolver.INCLUDE_RUNNING_VM_BOOTCLASSPATH) == 0)) {
					throw new IllegalStateException("no environment is specified"); //$NON-NLS-1$
				}
				if ((this.bits & CompilationUnitResolver.BINDING_RECOVERY) != 0) {
					flags |= ICompilationUnit.ENABLE_BINDINGS_RECOVERY;
				}
				CompilationUnitResolver.resolve(sourceFilePaths, encodings, bindingKeys, requestor, this.apiLevel, this.compilerOptions, getClasspath(), flags, monitor);
			} else {
				CompilationUnitResolver.parse(sourceFilePaths, encodings, requestor, this.apiLevel, this.compilerOptions, flags, monitor);
			}
		} finally {
			// reset to defaults to allow reuse (and avoid leaking)
			initializeDefaults();
		}
	}
	/**
	 * Creates bindings for a batch of Java elements.
	 * 
	 * <p>These elements are either
	 * enclosed in {@link ICompilationUnit ICompilationUnits} or in {@link IClassFile IClassFiles}.</p>
	 * <p>
	 * All enclosing compilation units and class files must
	 * come from the same Java project, which must be set beforehand
	 * with {@link #setProject(IJavaProject) setProject}.
	 * </p>
	 * <p>
	 * All elements must exist. If one doesn't exist, an {@link IllegalStateException}
	 * is thrown.
	 * </p>
	 * <p>
	 * The returned array has the same size as the given elements array. At a given position
	 * it contains the binding of the corresponding Java element, or <code>null</code>
	 * if no binding could be created.
	 * </p>
	 * <p>
	 * Note also the following parser parameters are used, regardless of what
	 * may have been specified:
	 * <ul>
	 * <li>The {@linkplain #setResolveBindings(boolean) binding resolution flag} is <code>true</code></li>
	 * <li>The {@linkplain #setKind(int) parser kind} is <code>K_COMPILATION_UNIT</code></li>
	 * <li>The {@linkplain #setSourceRange(int,int) source range} is <code>(0, -1)</code></li>
	 * <li>The {@linkplain #setFocalPosition(int) focal position} is not set</li>
	 * </ul>
	 * </p>
	 * <p>
	 * A successful call to this method returns all settings to their
	 * default values so the object is ready to be reused.
	 * </p>
	 *
	 * @param elements the Java elements to create bindings for
	 * @return the bindings for the given Java elements, possibly containing <code>null</code>s
	 *              if some bindings could not be created
	 * @exception IllegalStateException if the settings provided
	 * are insufficient, contradictory, or otherwise unsupported
	 * @since 3.1
	 */
	public IBinding[] createBindings(IJavaElement[] elements, IProgressMonitor monitor) {
		try {
			if (this.project == null)
				throw new IllegalStateException("project or classpath not specified"); //$NON-NLS-1$
			int flags = 0;
			if ((this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0) {
				flags |= ICompilationUnit.ENABLE_STATEMENTS_RECOVERY;
			}
			if ((this.bits & CompilationUnitResolver.BINDING_RECOVERY) != 0) {
				flags |= ICompilationUnit.ENABLE_BINDINGS_RECOVERY;
			}
			if ((this.bits & CompilationUnitResolver.IGNORE_METHOD_BODIES) != 0) {
				flags |= ICompilationUnit.IGNORE_METHOD_BODIES;
			}
			return CompilationUnitResolver.resolve(elements, this.apiLevel, this.compilerOptions, this.project, this.workingCopyOwner, flags, monitor);
		} finally {
			// reset to defaults to allow reuse (and avoid leaking)
			initializeDefaults();
		}
	}

	private ASTNode internalCreateAST(IProgressMonitor monitor) {
		boolean needToResolveBindings = (this.bits & CompilationUnitResolver.RESOLVE_BINDING) != 0;
		switch(this.astKind) {
			case K_CLASS_BODY_DECLARATIONS :
			case K_EXPRESSION :
			case K_STATEMENTS :
				if (this.rawSource == null) {
					if (this.typeRoot != null) {
						// get the source from the type root
						if (this.typeRoot instanceof ICompilationUnit) {
							org.eclipse.jdt.internal.compiler.env.ICompilationUnit sourceUnit = (org.eclipse.jdt.internal.compiler.env.ICompilationUnit) this.typeRoot;
							this.rawSource = sourceUnit.getContents();
						} else if (this.typeRoot instanceof IClassFile) {
							try {
								String sourceString = this.typeRoot.getSource();
								if (sourceString != null) {
									this.rawSource = sourceString.toCharArray();
								}
							} catch(JavaModelException e) {
								// an error occured accessing the java element
								StringWriter stringWriter = new StringWriter();
								PrintWriter writer = null;
								try {
									writer = new PrintWriter(stringWriter);
									e.printStackTrace(writer);
								} finally {
									if (writer != null) writer.close();
								}
								throw new IllegalStateException(String.valueOf(stringWriter.getBuffer()));
							}
						}
					}
				}
				if (this.rawSource != null) {
					if (this.sourceOffset + this.sourceLength > this.rawSource.length) {
						throw new IllegalStateException();
					}
					return internalCreateASTForKind();
				}
				break;
			case K_COMPILATION_UNIT :
				CompilationUnitDeclaration compilationUnitDeclaration = null;
				try {
					NodeSearcher searcher = null;
					org.eclipse.jdt.internal.compiler.env.ICompilationUnit sourceUnit = null;
					WorkingCopyOwner wcOwner = this.workingCopyOwner;
					if (this.typeRoot instanceof ICompilationUnit) {
							/*
							 * this.compilationUnitSource is an instance of org.eclipse.jdt.internal.core.CompilationUnit that implements
							 * both org.eclipse.jdt.core.ICompilationUnit and org.eclipse.jdt.internal.compiler.env.ICompilationUnit
							 */
							sourceUnit = (org.eclipse.jdt.internal.compiler.env.ICompilationUnit) this.typeRoot;
							/*
							 * use a BasicCompilation that caches the source instead of using the compilationUnitSource directly
							 * (if it is a working copy, the source can change between the parse and the AST convertion)
							 * (see https://bugs.eclipse.org/bugs/show_bug.cgi?id=75632)
							 */
							sourceUnit = new BasicCompilationUnit(sourceUnit.getContents(), sourceUnit.getPackageName(), new String(sourceUnit.getFileName()), this.project);
							wcOwner = ((ICompilationUnit) this.typeRoot).getOwner();
					} else if (this.typeRoot instanceof IClassFile) {
						try {
							String sourceString = this.typeRoot.getSource();
							if (sourceString == null) {
								throw new IllegalStateException();
							}
							PackageFragment packageFragment = (PackageFragment) this.typeRoot.getParent();
							BinaryType type = (BinaryType) this.typeRoot.findPrimaryType();
							IBinaryType binaryType = (IBinaryType) type.getElementInfo();
							// file name is used to recreate the Java element, so it has to be the toplevel .class file name
							char[] fileName = binaryType.getFileName();
							int firstDollar = CharOperation.indexOf('$', fileName);
							if (firstDollar != -1) {
								char[] suffix = SuffixConstants.SUFFIX_class;
								int suffixLength = suffix.length;
								char[] newFileName = new char[firstDollar + suffixLength];
								System.arraycopy(fileName, 0, newFileName, 0, firstDollar);
								System.arraycopy(suffix, 0, newFileName, firstDollar, suffixLength);
								fileName = newFileName;
							}
							sourceUnit = new BasicCompilationUnit(sourceString.toCharArray(), Util.toCharArrays(packageFragment.names), new String(fileName), this.project);
						} catch(JavaModelException e) {
							// an error occured accessing the java element
							StringWriter stringWriter = new StringWriter();
							PrintWriter writer = null;
							try {
								writer = new PrintWriter(stringWriter);
								e.printStackTrace(writer);
							} finally {
								if (writer != null) writer.close();
							}
							throw new IllegalStateException(String.valueOf(stringWriter.getBuffer()));
						}
					} else if (this.rawSource != null) {
						needToResolveBindings = 
							((this.bits & CompilationUnitResolver.RESOLVE_BINDING) != 0)
							&& this.unitName != null
							&& (this.project != null
									|| this.classpaths != null
									|| this.sourcepaths != null
									|| ((this.bits & CompilationUnitResolver.INCLUDE_RUNNING_VM_BOOTCLASSPATH) != 0))
							&& this.compilerOptions != null;
						sourceUnit = new BasicCompilationUnit(this.rawSource, null, this.unitName == null ? "" : this.unitName, this.project); //$NON-NLS-1$
					} else {
						throw new IllegalStateException();
					}
					if ((this.bits & CompilationUnitResolver.PARTIAL) != 0) {
						searcher = new NodeSearcher(this.focalPointPosition);
					}
					int flags = 0;
					if ((this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0) {
						flags |= ICompilationUnit.ENABLE_STATEMENTS_RECOVERY;
					}
					if (searcher == null && ((this.bits & CompilationUnitResolver.IGNORE_METHOD_BODIES) != 0)) {
						flags |= ICompilationUnit.IGNORE_METHOD_BODIES;
					}
					if (needToResolveBindings) {
						if ((this.bits & CompilationUnitResolver.BINDING_RECOVERY) != 0) {
							flags |= ICompilationUnit.ENABLE_BINDINGS_RECOVERY;
						}
						try {
							// parse and resolve
							compilationUnitDeclaration =
								CompilationUnitResolver.resolve(
									sourceUnit,
									this.project,
									getClasspath(),
									searcher,
									this.compilerOptions,
									this.workingCopyOwner,
									flags,
									monitor);
						} catch (JavaModelException e) {
							flags &= ~ICompilationUnit.ENABLE_BINDINGS_RECOVERY;
							compilationUnitDeclaration = CompilationUnitResolver.parse(
									sourceUnit,
									searcher,
									this.compilerOptions,
									flags);
							needToResolveBindings = false;
						}
					} else {
						compilationUnitDeclaration = CompilationUnitResolver.parse(
								sourceUnit,
								searcher,
								this.compilerOptions,
								flags);
						needToResolveBindings = false;
					}
					CompilationUnit result = CompilationUnitResolver.convert(
						compilationUnitDeclaration,
						sourceUnit.getContents(),
						this.apiLevel,
						this.compilerOptions,
						needToResolveBindings,
						wcOwner,
						needToResolveBindings ? new DefaultBindingResolver.BindingTables() : null,
						flags,
						monitor,
						this.project != null);
					result.setTypeRoot(this.typeRoot);
					return result;
				} finally {
					if (compilationUnitDeclaration != null
							&& ((this.bits & CompilationUnitResolver.RESOLVE_BINDING) != 0)) {
						compilationUnitDeclaration.cleanUp();
					}
				}
		}
		throw new IllegalStateException();
	}

	/**
	 * Parses the given source between the bounds specified by the given offset (inclusive)
	 * and the given length and creates and returns a corresponding abstract syntax tree.
	 * <p>
	 * When the parse is successful the result returned includes the ASTs for the
	 * requested source:
	 * <ul>
	 * <li>{@link #K_CLASS_BODY_DECLARATIONS K_CLASS_BODY_DECLARATIONS}: The result node
	 * is a {@link TypeDeclaration TypeDeclaration} whose
	 * {@link TypeDeclaration#bodyDeclarations() bodyDeclarations}
	 * are the new trees. Other aspects of the type declaration are unspecified.</li>
	 * <li>{@link #K_STATEMENTS K_STATEMENTS}: The result node is a
	 * {@link Block Block} whose {@link Block#statements() statements}
	 * are the new trees. Other aspects of the block are unspecified.</li>
	 * <li>{@link #K_EXPRESSION K_EXPRESSION}: The result node is a subclass of
	 * {@link Expression Expression}. Other aspects of the expression are unspecified.</li>
	 * </ul>
	 * The resulting AST node is rooted under an contrived
	 * {@link CompilationUnit CompilationUnit} node, to allow the
	 * client to retrieve the following pieces of information
	 * available there:
	 * <ul>
	 * <li>{@linkplain CompilationUnit#getLineNumber(int) Line number map}. Line
	 * numbers start at 1 and only cover the subrange scanned
	 * (<code>source[offset]</code> through <code>source[offset+length-1]</code>).</li>
	 * <li>{@linkplain CompilationUnit#getMessages() Compiler messages}
	 * and {@linkplain CompilationUnit#getProblems() detailed problem reports}.
	 * Character positions are relative to the start of
	 * <code>source</code>; line positions are for the subrange scanned.</li>
	 * <li>{@linkplain CompilationUnit#getCommentList() Comment list}
	 * for the subrange scanned.</li>
	 * </ul>
	 * The contrived nodes do not have source positions. Other aspects of the
	 * {@link CompilationUnit CompilationUnit} node are unspecified, including
	 * the exact arrangment of intervening nodes.
	 * </p>
	 * <p>
	 * Lexical or syntax errors detected while parsing can result in
	 * a result node being marked as {@link ASTNode#MALFORMED MALFORMED}.
	 * In more severe failure cases where the parser is unable to
	 * recognize the input, this method returns
	 * a {@link CompilationUnit CompilationUnit} node with at least the
	 * compiler messages.
	 * </p>
	 * <p>Each node in the subtree (other than the contrived nodes)
	 * carries source range(s) information relating back
	 * to positions in the given source (the given source itself
	 * is not remembered with the AST).
	 * The source range usually begins at the first character of the first token
	 * corresponding to the node; leading whitespace and comments are <b>not</b>
	 * included. The source range usually extends through the last character of
	 * the last token corresponding to the node; trailing whitespace and
	 * comments are <b>not</b> included. There are a handful of exceptions
	 * (including the various body declarations); the
	 * specification for these node type spells out the details.
	 * Source ranges nest properly: the source range for a child is always
	 * within the source range of its parent, and the source ranges of sibling
	 * nodes never overlap.
	 * </p>
	 * <p>
	 * This method does not compute binding information; all <code>resolveBinding</code>
	 * methods applied to nodes of the resulting AST return <code>null</code>.
	 * </p>
	 *
	 * @return an AST node whose type depends on the kind of parse
	 *  requested, with a fallback to a <code>CompilationUnit</code>
	 *  in the case of severe parsing errors
	 * @see ASTNode#getStartPosition()
	 * @see ASTNode#getLength()
	 */
	private ASTNode internalCreateASTForKind() {
		final ASTConverter converter = new ASTConverter(this.compilerOptions, false, null);
		converter.compilationUnitSource = this.rawSource;
		converter.compilationUnitSourceLength = this.rawSource.length;
		converter.scanner.setSource(this.rawSource);

		AST ast = AST.newAST(this.apiLevel);
		ast.setDefaultNodeFlag(ASTNode.ORIGINAL);
		ast.setBindingResolver(new BindingResolver());
		if ((this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0) {
			ast.setFlag(ICompilationUnit.ENABLE_STATEMENTS_RECOVERY);
		}
		converter.setAST(ast);
		CodeSnippetParsingUtil codeSnippetParsingUtil = new CodeSnippetParsingUtil((this.bits & CompilationUnitResolver.IGNORE_METHOD_BODIES) != 0);
		CompilationUnit compilationUnit = ast.newCompilationUnit();
		if (this.sourceLength == -1) {
			this.sourceLength = this.rawSource.length;
		}
		switch(this.astKind) {
			case K_STATEMENTS :
				ConstructorDeclaration constructorDeclaration = codeSnippetParsingUtil.parseStatements(
						this.rawSource,
						this.sourceOffset,
						this.sourceLength,
						this.compilerOptions,
						true,
						(this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0);
				RecoveryScannerData data = constructorDeclaration.compilationResult.recoveryScannerData;
				if(data != null) {
					Scanner scanner = converter.scanner;
					converter.scanner = new RecoveryScanner(scanner, data.removeUnused());
					converter.docParser.scanner = converter.scanner;
					converter.scanner.setSource(scanner.source);
					
					compilationUnit.setStatementsRecoveryData(data);
				}
				RecordedParsingInformation recordedParsingInformation = codeSnippetParsingUtil.recordedParsingInformation;
				int[][] comments = recordedParsingInformation.commentPositions;
				if (comments != null) {
					converter.buildCommentsTable(compilationUnit, comments);
				}
				compilationUnit.setLineEndTable(recordedParsingInformation.lineEnds);
				Block block = ast.newBlock();
				block.setSourceRange(this.sourceOffset, this.sourceOffset + this.sourceLength);
				org.eclipse.jdt.internal.compiler.ast.Statement[] statements = constructorDeclaration.statements;
				if (statements != null) {
					int statementsLength = statements.length;
					for (int i = 0; i < statementsLength; i++) {
						if (statements[i] instanceof org.eclipse.jdt.internal.compiler.ast.LocalDeclaration) {
							converter.checkAndAddMultipleLocalDeclaration(statements, i, block.statements());
						} else {
							Statement statement = converter.convert(statements[i]);
							if (statement != null) {
								block.statements().add(statement);
							}
						}
					}
				}
				rootNodeToCompilationUnit(ast, compilationUnit, block, recordedParsingInformation, data);
				ast.setDefaultNodeFlag(0);
				ast.setOriginalModificationCount(ast.modificationCount());
				return block;
			case K_EXPRESSION :
				org.eclipse.jdt.internal.compiler.ast.Expression expression = codeSnippetParsingUtil.parseExpression(this.rawSource, this.sourceOffset, this.sourceLength, this.compilerOptions, true);
				recordedParsingInformation = codeSnippetParsingUtil.recordedParsingInformation;
				comments = recordedParsingInformation.commentPositions;
				if (comments != null) {
					converter.buildCommentsTable(compilationUnit, comments);
				}
				compilationUnit.setLineEndTable(recordedParsingInformation.lineEnds);
				if (expression != null) {
					Expression expression2 = converter.convert(expression);
					rootNodeToCompilationUnit(expression2.getAST(), compilationUnit, expression2, codeSnippetParsingUtil.recordedParsingInformation, null);
					ast.setDefaultNodeFlag(0);
					ast.setOriginalModificationCount(ast.modificationCount());
					return expression2;
				} else {
					CategorizedProblem[] problems = recordedParsingInformation.problems;
					if (problems != null) {
						compilationUnit.setProblems(problems);
					}
					ast.setDefaultNodeFlag(0);
					ast.setOriginalModificationCount(ast.modificationCount());
					return compilationUnit;
				}
			case K_CLASS_BODY_DECLARATIONS :
				final org.eclipse.jdt.internal.compiler.ast.ASTNode[] nodes =
					codeSnippetParsingUtil.parseClassBodyDeclarations(
							this.rawSource,
							this.sourceOffset,
							this.sourceLength,
							this.compilerOptions,
							true,
							(this.bits & CompilationUnitResolver.STATEMENT_RECOVERY) != 0);
				recordedParsingInformation = codeSnippetParsingUtil.recordedParsingInformation;
				comments = recordedParsingInformation.commentPositions;
				if (comments != null) {
					converter.buildCommentsTable(compilationUnit, comments);
				}
				compilationUnit.setLineEndTable(recordedParsingInformation.lineEnds);
				if (nodes != null) {
					// source has no syntax error or the statement recovery is enabled
					TypeDeclaration typeDeclaration = converter.convert(nodes);
					typeDeclaration.setSourceRange(this.sourceOffset, this.sourceOffset + this.sourceLength);
					rootNodeToCompilationUnit(typeDeclaration.getAST(), compilationUnit, typeDeclaration, codeSnippetParsingUtil.recordedParsingInformation, null);
					ast.setDefaultNodeFlag(0);
					ast.setOriginalModificationCount(ast.modificationCount());
					return typeDeclaration;
				} else {
					// source has syntax error and the statement recovery is disabled
					CategorizedProblem[] problems = recordedParsingInformation.problems;
					if (problems != null) {
						compilationUnit.setProblems(problems);
					}
					ast.setDefaultNodeFlag(0);
					ast.setOriginalModificationCount(ast.modificationCount());
					return compilationUnit;
				}
		}
		throw new IllegalStateException();
	}

	private void propagateErrors(ASTNode astNode, CategorizedProblem[] problems, RecoveryScannerData data) {
		astNode.accept(new ASTSyntaxErrorPropagator(problems));
		if (data != null) {
			astNode.accept(new ASTRecoveryPropagator(problems, data));
		}
	}

	private void rootNodeToCompilationUnit(AST ast, CompilationUnit compilationUnit, ASTNode node, RecordedParsingInformation recordedParsingInformation, RecoveryScannerData data) {
		final int problemsCount = recordedParsingInformation.problemsCount;
		switch(node.getNodeType()) {
			case ASTNode.BLOCK :
				{
					Block block = (Block) node;
					if (problemsCount != 0) {
						// propagate and record problems
						final CategorizedProblem[] problems = recordedParsingInformation.problems;
						propagateErrors(block, problems, data);
						compilationUnit.setProblems(problems);
					}
					TypeDeclaration typeDeclaration = ast.newTypeDeclaration();
					Initializer initializer = ast.newInitializer();
					initializer.setBody(block);
					typeDeclaration.bodyDeclarations().add(initializer);
					compilationUnit.types().add(typeDeclaration);
				}
				break;
			case ASTNode.TYPE_DECLARATION :
				{
					TypeDeclaration typeDeclaration = (TypeDeclaration) node;
					if (problemsCount != 0) {
						// propagate and record problems
						final CategorizedProblem[] problems = recordedParsingInformation.problems;
						propagateErrors(typeDeclaration, problems, data);
						compilationUnit.setProblems(problems);
					}
					compilationUnit.types().add(typeDeclaration);
				}
				break;
			default :
				if (node instanceof Expression) {
					Expression expression = (Expression) node;
					if (problemsCount != 0) {
						// propagate and record problems
						final CategorizedProblem[] problems = recordedParsingInformation.problems;
						propagateErrors(expression, problems, data);
						compilationUnit.setProblems(problems);
					}
					ExpressionStatement expressionStatement = ast.newExpressionStatement(expression);
					Block block = ast.newBlock();
					block.statements().add(expressionStatement);
					Initializer initializer = ast.newInitializer();
					initializer.setBody(block);
					TypeDeclaration typeDeclaration = ast.newTypeDeclaration();
					typeDeclaration.bodyDeclarations().add(initializer);
					compilationUnit.types().add(typeDeclaration);
				}
		}
	}
}
