jctree.java

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/*
 * Copyright 1999-2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.tools.javac.tree;

import java.util.*;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.lang.model.element.Modifier;
import javax.lang.model.type.TypeKind;
import javax.tools.JavaFileObject;

import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Scope;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.source.tree.Tree;
import com.sun.source.tree.*;

import static com.sun.tools.javac.code.BoundKind.*;

/**
 * Root class for abstract syntax tree nodes. It provides definitions
 * for specific tree nodes as subclasses nested inside.
 *
 * <p>Each subclass is highly standardized.  It generally contains
 * only tree fields for the syntactic subcomponents of the node.  Some
 * classes that represent identifier uses or definitions also define a
 * Symbol field that denotes the represented identifier.  Classes for
 * non-local jumps also carry the jump target as a field.  The root
 * class Tree itself defines fields for the tree's type and position.
 * No other fields are kept in a tree node; instead parameters are
 * passed to methods accessing the node.
 *
 * <p>Except for the methods defined by com.sun.source, the only
 * method defined in subclasses is `visit' which applies a given
 * visitor to the tree. The actual tree processing is done by visitor
 * classes in other packages. The abstract class Visitor, as well as
 * an Factory interface for trees, are defined as inner classes in
 * Tree.
 *
 * <p>To avoid ambiguities with the Tree API in com.sun.source all sub
 * classes should, by convention, start with JC (javac).
 *
 * <p><b>This is NOT part of any API supported by Sun Microsystems.
 * If you write code that depends on this, you do so at your own risk.
 * This code and its internal interfaces are subject to change or
 * deletion without notice.</b>
 *
 * @see TreeMaker
 * @see TreeInfo
 * @see TreeTranslator
 * @see Pretty
 */
public abstract class JCTree implements Tree, Cloneable, DiagnosticPosition {

    /* Tree tag values, identifying kinds of trees */

    /** Toplevel nodes, of type TopLevel, representing entire source files.
     */
    public static final int  TOPLEVEL = 1;

    /** Import clauses, of type Import.
     */
    public static final int IMPORT = TOPLEVEL + 1;

    /** Class definitions, of type ClassDef.
     */
    public static final int CLASSDEF = IMPORT + 1;

    /** Method definitions, of type MethodDef.
     */
    public static final int METHODDEF = CLASSDEF + 1;

    /** Variable definitions, of type VarDef.
     */
    public static final int VARDEF = METHODDEF + 1;

    /** The no-op statement ";", of type Skip
     */
    public static final int SKIP = VARDEF + 1;

    /** Blocks, of type Block.
     */
    public static final int BLOCK = SKIP + 1;

    /** Do-while loops, of type DoLoop.
     */
    public static final int DOLOOP = BLOCK + 1;

    /** While-loops, of type WhileLoop.
     */
    public static final int WHILELOOP = DOLOOP + 1;

    /** For-loops, of type ForLoop.
     */
    public static final int FORLOOP = WHILELOOP + 1;

    /** Foreach-loops, of type ForeachLoop.
     */
    public static final int FOREACHLOOP = FORLOOP + 1;

    /** Labelled statements, of type Labelled.
     */
    public static final int LABELLED = FOREACHLOOP + 1;

    /** Switch statements, of type Switch.
     */
    public static final int SWITCH = LABELLED + 1;

    /** Case parts in switch statements, of type Case.
     */
    public static final int CASE = SWITCH + 1;

    /** Synchronized statements, of type Synchonized.
     */
    public static final int SYNCHRONIZED = CASE + 1;

    /** Try statements, of type Try.
     */
    public static final int TRY = SYNCHRONIZED + 1;

    /** Catch clauses in try statements, of type Catch.
     */
    public static final int CATCH = TRY + 1;

    /** Conditional expressions, of type Conditional.
     */
    public static final int CONDEXPR = CATCH + 1;

    /** Conditional statements, of type If.
     */
    public static final int IF = CONDEXPR + 1;

    /** Expression statements, of type Exec.
     */
    public static final int EXEC = IF + 1;

    /** Break statements, of type Break.
     */
    public static final int BREAK = EXEC + 1;

    /** Continue statements, of type Continue.
     */
    public static final int CONTINUE = BREAK + 1;

    /** Return statements, of type Return.
     */
    public static final int RETURN = CONTINUE + 1;

    /** Throw statements, of type Throw.
     */
    public static final int THROW = RETURN + 1;

    /** Assert statements, of type Assert.
     */
    public static final int ASSERT = THROW + 1;

    /** Method invocation expressions, of type Apply.
     */
    public static final int APPLY = ASSERT + 1;

    /** Class instance creation expressions, of type NewClass.
     */
    public static final int NEWCLASS = APPLY + 1;

    /** Array creation expressions, of type NewArray.
     */
    public static final int NEWARRAY = NEWCLASS + 1;

    /** Parenthesized subexpressions, of type Parens.
     */
    public static final int PARENS = NEWARRAY + 1;

    /** Assignment expressions, of type Assign.
     */
    public static final int ASSIGN = PARENS + 1;

    /** Type cast expressions, of type TypeCast.
     */
    public static final int TYPECAST = ASSIGN + 1;

    /** Type test expressions, of type TypeTest.
     */
    public static final int TYPETEST = TYPECAST + 1;

    /** Indexed array expressions, of type Indexed.
     */
    public static final int INDEXED = TYPETEST + 1;

    /** Selections, of type Select.
     */
    public static final int SELECT = INDEXED + 1;

    /** Simple identifiers, of type Ident.
     */
    public static final int IDENT = SELECT + 1;

    /** Literals, of type Literal.
     */
    public static final int LITERAL = IDENT + 1;

    /** Basic type identifiers, of type TypeIdent.
     */
    public static final int TYPEIDENT = LITERAL + 1;

    /** Array types, of type TypeArray.
     */
    public static final int TYPEARRAY = TYPEIDENT + 1;

    /** Parameterized types, of type TypeApply.
     */
    public static final int TYPEAPPLY = TYPEARRAY + 1;

    /** Formal type parameters, of type TypeParameter.
     */
    public static final int TYPEPARAMETER = TYPEAPPLY + 1;

    /** Type argument.
     */
    public static final int WILDCARD = TYPEPARAMETER + 1;

    /** Bound kind: extends, super, exact, or unbound
     */
    public static final int TYPEBOUNDKIND = WILDCARD + 1;

    /** metadata: Annotation.
     */
    public static final int ANNOTATION = TYPEBOUNDKIND + 1;

    /** metadata: Modifiers
     */
    public static final int MODIFIERS = ANNOTATION + 1;

    /** Error trees, of type Erroneous.
     */
    public static final int ERRONEOUS = MODIFIERS + 1;

    /** Unary operators, of type Unary.
     */
    public static final int POS = ERRONEOUS + 1;             // +
    public static final int NEG = POS + 1;                   // -
    public static final int NOT = NEG + 1;                   // !
    public static final int COMPL = NOT + 1;                 // ~
    public static final int PREINC = COMPL + 1;              // ++ _
    public static final int PREDEC = PREINC + 1;             // -- _
    public static final int POSTINC = PREDEC + 1;            // _ ++
    public static final int POSTDEC = POSTINC + 1;           // _ --

    /** unary operator for null reference checks, only used internally.
     */
    public static final int NULLCHK = POSTDEC + 1;

    /** Binary operators, of type Binary.
     */
    public static final int OR = NULLCHK + 1;                // ||
    public static final int AND = OR + 1;                    // &&
    public static final int BITOR = AND + 1;                 // |
    public static final int BITXOR = BITOR + 1;              // ^
    public static final int BITAND = BITXOR + 1;             // &
    public static final int EQ = BITAND + 1;                 // ==
    public static final int NE = EQ + 1;                     // !=
    public static final int LT = NE + 1;                     // <
    public static final int GT = LT + 1;                     // >
    public static final int LE = GT + 1;                     // <=
    public static final int GE = LE + 1;                     // >=
    public static final int SL = GE + 1;                     // <<
    public static final int SR = SL + 1;                     // >>
    public static final int USR = SR + 1;                    // >>>
    public static final int PLUS = USR + 1;                  // +
    public static final int MINUS = PLUS + 1;                // -
    public static final int MUL = MINUS + 1;                 // *
    public static final int DIV = MUL + 1;                   // /
    public static final int MOD = DIV + 1;                   // %

    /** Assignment operators, of type Assignop.
     */
    public static final int BITOR_ASG = MOD + 1;             // |=
    public static final int BITXOR_ASG = BITOR_ASG + 1;      // ^=
    public static final int BITAND_ASG = BITXOR_ASG + 1;     // &=

    public static final int SL_ASG = SL + BITOR_ASG - BITOR; // <<=
    public static final int SR_ASG = SL_ASG + 1;             // >>=
    public static final int USR_ASG = SR_ASG + 1;            // >>>=
    public static final int PLUS_ASG = USR_ASG + 1;          // +=
    public static final int MINUS_ASG = PLUS_ASG + 1;        // -=
    public static final int MUL_ASG = MINUS_ASG + 1;         // *=
    public static final int DIV_ASG = MUL_ASG + 1;           // /=
    public static final int MOD_ASG = DIV_ASG + 1;           // %=

    /** A synthetic let expression, of type LetExpr.
     */
    public static final int LETEXPR = MOD_ASG + 1;           // ala scheme


    /** The offset between assignment operators and normal operators.
     */
    public static final int ASGOffset = BITOR_ASG - BITOR;

    /* The (encoded) position in the source file. @see util.Position.
     */
    public int pos;

    /* The type of this node.
     */
    public Type type;

    /* The tag of this node -- one of the constants declared above.
     */
    public abstract int getTag();

    /** Convert a tree to a pretty-printed string. */
    public String toString() {
        StringWriter s = new StringWriter();
        try {
            new Pretty(s, false).printExpr(this);
        }
        catch (IOException e) {
            // should never happen, because StringWriter is defined
            // never to throw any IOExceptions
	    throw new AssertionError(e);
        }
        return s.toString();
    }

    /** Set position field and return this tree.
     */
    public JCTree setPos(int pos) {
        this.pos = pos;
        return this;
    }

    /** Set type field and return this tree.
     */
    public JCTree setType(Type type) {
        this.type = type;
        return this;
    }

    /** Visit this tree with a given visitor.
     */
    public abstract void accept(Visitor v);

    public abstract <R,D> R accept(TreeVisitor<R,D> v, D d);

    /** Return a shallow copy of this tree.
     */
    public Object clone() {
        try {
            return super.clone();
        } catch(CloneNotSupportedException e) {
            throw new RuntimeException(e);
        }
    }

    /** Get a default position for this tree node.
     */
    public DiagnosticPosition pos() {
        return this;
    }

    // for default DiagnosticPosition
    public JCTree getTree() {
        return this;
    }

    // for default DiagnosticPosition
    public int getStartPosition() {
        return TreeInfo.getStartPos(this);
    }

    // for default DiagnosticPosition
    public int getPreferredPosition() {
        return pos;
    }

    // for default DiagnosticPosition
    public int getEndPosition(Map<JCTree, Integer> endPosTable) {
        return TreeInfo.getEndPos(this, endPosTable);
    }

    /**
     * Everything in one source file is kept in a TopLevel structure.