/*
 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.tools.javac.tree;

import java.util.Iterator;

import com.sun.source.tree.CaseTree.CaseKind;
import com.sun.source.tree.ModuleTree.ModuleKind;
import com.sun.source.tree.Tree.Kind;
import com.sun.tools.javac.code.*;
import com.sun.tools.javac.code.Attribute.UnresolvedClass;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;

import com.sun.tools.javac.tree.JCTree.*;

import static com.sun.tools.javac.code.Flags.*;
import static com.sun.tools.javac.code.Kinds.Kind.*;
import static com.sun.tools.javac.code.TypeTag.*;

Factory class for trees.
 
This is NOT part of any supported API.
 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.
/** Factory class for trees.
 *
 *  <p><b>This is NOT part of any supported API.
 *  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>
 */
public class TreeMaker implements JCTree.Factory {

    
The context key for the tree factory. /** The context key for the tree factory. */
    protected static final Context.Key<TreeMaker> treeMakerKey = new Context.Key<>();

    
Get the TreeMaker instance. /** Get the TreeMaker instance. */
    public static TreeMaker instance(Context context) {
        TreeMaker instance = context.get(treeMakerKey);
        if (instance == null)
            instance = new TreeMaker(context);
        return instance;
    }

    
The position at which subsequent trees will be created.
/** The position at which subsequent trees will be created.
     */
    public int pos = Position.NOPOS;

    
The toplevel tree to which created trees belong.
/** The toplevel tree to which created trees belong.
     */
    public JCCompilationUnit toplevel;

    
The current name table. /** The current name table. */
    Names names;

    Types types;

    
The current symbol table. /** The current symbol table. */
    Symtab syms;

    
Create a tree maker with null toplevel and NOPOS as initial position.
/** Create a tree maker with null toplevel and NOPOS as initial position.
     */
    protected TreeMaker(Context context) {
        context.put(treeMakerKey, this);
        this.pos = Position.NOPOS;
        this.toplevel = null;
        this.names = Names.instance(context);
        this.syms = Symtab.instance(context);
        this.types = Types.instance(context);
    }

    
Create a tree maker with a given toplevel and FIRSTPOS as initial position.
/** Create a tree maker with a given toplevel and FIRSTPOS as initial position.
     */
    protected TreeMaker(JCCompilationUnit toplevel, Names names, Types types, Symtab syms) {
        this.pos = Position.FIRSTPOS;
        this.toplevel = toplevel;
        this.names = names;
        this.types = types;
        this.syms = syms;
    }

    
Create a new tree maker for a given toplevel.
/** Create a new tree maker for a given toplevel.
     */
    public TreeMaker forToplevel(JCCompilationUnit toplevel) {
        return new TreeMaker(toplevel, names, types, syms);
    }

    
Reassign current position.
/** Reassign current position.
     */
    public TreeMaker at(int pos) {
        this.pos = pos;
        return this;
    }

    
Reassign current position.
/** Reassign current position.
     */
    public TreeMaker at(DiagnosticPosition pos) {
        this.pos = (pos == null ? Position.NOPOS : pos.getStartPosition());
        return this;
    }

    
Create given tree node at current position.
Params:
defs – a list of PackageDef, ClassDef, Import, and Skip/**
     * Create given tree node at current position.
     * @param defs a list of PackageDef, ClassDef, Import, and Skip
     */
    public JCCompilationUnit TopLevel(List<JCTree> defs) {
        for (JCTree node : defs)
            Assert.check(node instanceof JCClassDecl
                || node instanceof JCPackageDecl
                || node instanceof JCImport
                || node instanceof JCModuleDecl
                || node instanceof JCSkip
                || node instanceof JCErroneous
                || (node instanceof JCExpressionStatement
                    && ((JCExpressionStatement)node).expr instanceof JCErroneous),
                    () -> node.getClass().getSimpleName());
        JCCompilationUnit tree = new JCCompilationUnit(defs);
        tree.pos = pos;
        return tree;
    }

    public JCPackageDecl PackageDecl(List<JCAnnotation> annotations,
                                     JCExpression pid) {
        Assert.checkNonNull(annotations);
        Assert.checkNonNull(pid);
        JCPackageDecl tree = new JCPackageDecl(annotations, pid);
        tree.pos = pos;
        return tree;
    }

    public JCImport Import(JCTree qualid, boolean importStatic) {
        JCImport tree = new JCImport(qualid, importStatic);
        tree.pos = pos;
        return tree;
    }

    public JCClassDecl ClassDef(JCModifiers mods,
                                Name name,
                                List<JCTypeParameter> typarams,
                                JCExpression extending,
                                List<JCExpression> implementing,
                                List<JCTree> defs)
    {
        JCClassDecl tree = new JCClassDecl(mods,
                                     name,
                                     typarams,
                                     extending,
                                     implementing,
                                     defs,
                                     null);
        tree.pos = pos;
        return tree;
    }

    public JCMethodDecl MethodDef(JCModifiers mods,
                               Name name,
                               JCExpression restype,
                               List<JCTypeParameter> typarams,
                               List<JCVariableDecl> params,
                               List<JCExpression> thrown,
                               JCBlock body,
                               JCExpression defaultValue) {
        return MethodDef(
                mods, name, restype, typarams, null, params,
                thrown, body, defaultValue);
    }

    public JCMethodDecl MethodDef(JCModifiers mods,
                               Name name,
                               JCExpression restype,
                               List<JCTypeParameter> typarams,
                               JCVariableDecl recvparam,
                               List<JCVariableDecl> params,
                               List<JCExpression> thrown,
                               JCBlock body,
                               JCExpression defaultValue)
    {
        JCMethodDecl tree = new JCMethodDecl(mods,
                                       name,
                                       restype,
                                       typarams,
                                       recvparam,
                                       params,
                                       thrown,
                                       body,
                                       defaultValue,
                                       null);
        tree.pos = pos;
        return tree;
    }

    public JCVariableDecl VarDef(JCModifiers mods, Name name, JCExpression vartype, JCExpression init) {
        JCVariableDecl tree = new JCVariableDecl(mods, name, vartype, init, null);
        tree.pos = pos;
        return tree;
    }

    public JCVariableDecl ReceiverVarDef(JCModifiers mods, JCExpression name, JCExpression vartype) {
        JCVariableDecl tree = new JCVariableDecl(mods, name, vartype);
        tree.pos = pos;
        return tree;
    }

    public JCSkip Skip() {
        JCSkip tree = new JCSkip();
        tree.pos = pos;
        return tree;
    }

    public JCBlock Block(long flags, List<JCStatement> stats) {
        JCBlock tree = new JCBlock(flags, stats);
        tree.pos = pos;
        return tree;
    }

    public JCDoWhileLoop DoLoop(JCStatement body, JCExpression cond) {
        JCDoWhileLoop tree = new JCDoWhileLoop(body, cond);
        tree.pos = pos;
        return tree;
    }

    public JCWhileLoop WhileLoop(JCExpression cond, JCStatement body) {
        JCWhileLoop tree = new JCWhileLoop(cond, body);
        tree.pos = pos;
        return tree;
    }

    public JCForLoop ForLoop(List<JCStatement> init,
                           JCExpression cond,
                           List<JCExpressionStatement> step,
                           JCStatement body)
    {
        JCForLoop tree = new JCForLoop(init, cond, step, body);
        tree.pos = pos;
        return tree;
    }

    public JCEnhancedForLoop ForeachLoop(JCVariableDecl var, JCExpression expr, JCStatement body) {
        JCEnhancedForLoop tree = new JCEnhancedForLoop(var, expr, body);
        tree.pos = pos;
        return tree;
    }

    public JCLabeledStatement Labelled(Name label, JCStatement body) {
        JCLabeledStatement tree = new JCLabeledStatement(label, body);
        tree.pos = pos;
        return tree;
    }

    public JCSwitch Switch(JCExpression selector, List<JCCase> cases) {
        JCSwitch tree = new JCSwitch(selector, cases);
        tree.pos = pos;
        return tree;
    }

    public JCCase Case(@SuppressWarnings("removal") CaseKind caseKind, List<JCExpression> pats,
                       List<JCStatement> stats, JCTree body) {
        JCCase tree = new JCCase(caseKind, pats, stats, body);
        tree.pos = pos;
        return tree;
    }

    public JCSwitchExpression SwitchExpression(JCExpression selector, List<JCCase> cases) {
        JCSwitchExpression tree = new JCSwitchExpression(selector, cases);
        tree.pos = pos;
        return tree;
    }

    public JCSynchronized Synchronized(JCExpression lock, JCBlock body) {
        JCSynchronized tree = new JCSynchronized(lock, body);
        tree.pos = pos;
        return tree;
    }

    public JCTry Try(JCBlock body, List<JCCatch> catchers, JCBlock finalizer) {
        return Try(List.nil(), body, catchers, finalizer);
    }

    public JCTry Try(List<JCTree> resources,
                     JCBlock body,
                     List<JCCatch> catchers,
                     JCBlock finalizer) {
        JCTry tree = new JCTry(resources, body, catchers, finalizer);
        tree.pos = pos;
        return tree;
    }

    public JCCatch Catch(JCVariableDecl param, JCBlock body) {
        JCCatch tree = new JCCatch(param, body);
        tree.pos = pos;
        return tree;
    }

    public JCConditional Conditional(JCExpression cond,
                                   JCExpression thenpart,
                                   JCExpression elsepart)
    {
        JCConditional tree = new JCConditional(cond, thenpart, elsepart);
        tree.pos = pos;
        return tree;
    }

    public JCIf If(JCExpression cond, JCStatement thenpart, JCStatement elsepart) {
        JCIf tree = new JCIf(cond, thenpart, elsepart);
        tree.pos = pos;
        return tree;
    }

    public JCExpressionStatement Exec(JCExpression expr) {
        JCExpressionStatement tree = new JCExpressionStatement(expr);
        tree.pos = pos;
        return tree;
    }

    public JCBreak Break(Name label) {
        JCBreak tree = new JCBreak(label, null);
        tree.pos = pos;
        return tree;
    }

    public JCYield Yield(JCExpression value) {
        JCYield tree = new JCYield(value, null);
        tree.pos = pos;
        return tree;
    }

    public JCContinue Continue(Name label) {
        JCContinue tree = new JCContinue(label, null);
        tree.pos = pos;
        return tree;
    }

    public JCReturn Return(JCExpression expr) {
        JCReturn tree = new JCReturn(expr);
        tree.pos = pos;
        return tree;
    }

    public JCThrow Throw(JCExpression expr) {
        JCThrow tree = new JCThrow(expr);
        tree.pos = pos;
        return tree;
    }

    public JCAssert Assert(JCExpression cond, JCExpression detail) {
        JCAssert tree = new JCAssert(cond, detail);
        tree.pos = pos;
        return tree;
    }

    public JCMethodInvocation Apply(List<JCExpression> typeargs,
                       JCExpression fn,
                       List<JCExpression> args)
    {
        JCMethodInvocation tree = new JCMethodInvocation(typeargs, fn, args);
        tree.pos = pos;
        return tree;
    }

    public JCNewClass NewClass(JCExpression encl,
                             List<JCExpression> typeargs,
                             JCExpression clazz,
                             List<JCExpression> args,
                             JCClassDecl def)
    {
        return SpeculativeNewClass(encl, typeargs, clazz, args, def, false);
    }

    public JCNewClass SpeculativeNewClass(JCExpression encl,
                             List<JCExpression> typeargs,
                             JCExpression clazz,
                             List<JCExpression> args,
                             JCClassDecl def,
                             boolean classDefRemoved)
    {
        JCNewClass tree = classDefRemoved ?
                new JCNewClass(encl, typeargs, clazz, args, def) {
                    @Override
                    public boolean classDeclRemoved() {
                        return true;
                    }
                } :
                new JCNewClass(encl, typeargs, clazz, args, def);
        tree.pos = pos;
        return tree;
    }

    public JCNewArray NewArray(JCExpression elemtype,
                             List<JCExpression> dims,
                             List<JCExpression> elems)
    {
        JCNewArray tree = new JCNewArray(elemtype, dims, elems);
        tree.pos = pos;
        return tree;
    }

    public JCLambda Lambda(List<JCVariableDecl> params,
                           JCTree body)
    {
        JCLambda tree = new JCLambda(params, body);
        tree.pos = pos;
        return tree;
    }

    public JCParens Parens(JCExpression expr) {
        JCParens tree = new JCParens(expr);
        tree.pos = pos;
        return tree;
    }

    public JCAssign Assign(JCExpression lhs, JCExpression rhs) {
        JCAssign tree = new JCAssign(lhs, rhs);
        tree.pos = pos;
        return tree;
    }

    public JCAssignOp Assignop(JCTree.Tag opcode, JCTree lhs, JCTree rhs) {
        JCAssignOp tree = new JCAssignOp(opcode, lhs, rhs, null);
        tree.pos = pos;
        return tree;
    }

    public JCUnary Unary(JCTree.Tag opcode, JCExpression arg) {
        JCUnary tree = new JCUnary(opcode, arg);
        tree.pos = pos;
        return tree;
    }

    public JCBinary Binary(JCTree.Tag opcode, JCExpression lhs, JCExpression rhs) {
        JCBinary tree = new JCBinary(opcode, lhs, rhs, null);
        tree.pos = pos;
        return tree;
    }

    public JCTypeCast TypeCast(JCTree clazz, JCExpression expr) {
        JCTypeCast tree = new JCTypeCast(clazz, expr);
        tree.pos = pos;
        return tree;
    }

    public JCInstanceOf TypeTest(JCExpression expr, JCTree clazz) {
        JCInstanceOf tree = new JCInstanceOf(expr, clazz);
        tree.pos = pos;
        return tree;
    }

    public JCArrayAccess Indexed(JCExpression indexed, JCExpression index) {
        JCArrayAccess tree = new JCArrayAccess(indexed, index);
        tree.pos = pos;
        return tree;
    }

    public JCFieldAccess Select(JCExpression selected, Name selector) {
        JCFieldAccess tree = new JCFieldAccess(selected, selector, null);
        tree.pos = pos;
        return tree;
    }

    public JCMemberReference Reference(JCMemberReference.ReferenceMode mode, Name name,
            JCExpression expr, List<JCExpression> typeargs) {
        JCMemberReference tree = new JCMemberReference(mode, name, expr, typeargs);
        tree.pos = pos;
        return tree;
    }

    public JCIdent Ident(Name name) {
        JCIdent tree = new JCIdent(name, null);
        tree.pos = pos;
        return tree;
    }

    public JCLiteral Literal(TypeTag tag, Object value) {
        JCLiteral tree = new JCLiteral(tag, value);
        tree.pos = pos;
        return tree;
    }

    public JCPrimitiveTypeTree TypeIdent(TypeTag typetag) {
        JCPrimitiveTypeTree tree = new JCPrimitiveTypeTree(typetag);
        tree.pos = pos;
        return tree;
    }

    public JCArrayTypeTree TypeArray(JCExpression elemtype) {
        JCArrayTypeTree tree = new JCArrayTypeTree(elemtype);
        tree.pos = pos;
        return tree;
    }

    public JCTypeApply TypeApply(JCExpression clazz, List<JCExpression> arguments) {
        JCTypeApply tree = new JCTypeApply(clazz, arguments);
        tree.pos = pos;
        return tree;
    }

    public JCTypeUnion TypeUnion(List<JCExpression> components) {
        JCTypeUnion tree = new JCTypeUnion(components);
        tree.pos = pos;
        return tree;
    }

    public JCTypeIntersection TypeIntersection(List<JCExpression> components) {
        JCTypeIntersection tree = new JCTypeIntersection(components);
        tree.pos = pos;
        return tree;
    }

    public JCTypeParameter TypeParameter(Name name, List<JCExpression> bounds) {
        return TypeParameter(name, bounds, List.nil());
    }

    public JCTypeParameter TypeParameter(Name name, List<JCExpression> bounds, List<JCAnnotation> annos) {
        JCTypeParameter tree = new JCTypeParameter(name, bounds, annos);
        tree.pos = pos;
        return tree;
    }

    public JCWildcard Wildcard(TypeBoundKind kind, JCTree type) {
        JCWildcard tree = new JCWildcard(kind, type);
        tree.pos = pos;
        return tree;
    }

    public TypeBoundKind TypeBoundKind(BoundKind kind) {
        TypeBoundKind tree = new TypeBoundKind(kind);
        tree.pos = pos;
        return tree;
    }

    public JCAnnotation Annotation(JCTree annotationType, List<JCExpression> args) {
        JCAnnotation tree = new JCAnnotation(Tag.ANNOTATION, annotationType, args);
        tree.pos = pos;
        return tree;
    }

    public JCAnnotation TypeAnnotation(JCTree annotationType, List<JCExpression> args) {
        JCAnnotation tree = new JCAnnotation(Tag.TYPE_ANNOTATION, annotationType, args);
        tree.pos = pos;
        return tree;
    }

    public JCModifiers Modifiers(long flags, List<JCAnnotation> annotations) {
        JCModifiers tree = new JCModifiers(flags, annotations);
        boolean noFlags = (flags & (Flags.ModifierFlags | Flags.ANNOTATION)) == 0;
        tree.pos = (noFlags && annotations.isEmpty()) ? Position.NOPOS : pos;
        return tree;
    }

    public JCModifiers Modifiers(long flags) {
        return Modifiers(flags, List.nil());
    }

    @Override
    public JCModuleDecl ModuleDef(JCModifiers mods, ModuleKind kind,
            JCExpression qualid, List<JCDirective> directives) {
        JCModuleDecl tree = new JCModuleDecl(mods, kind, qualid, directives);
        tree.pos = pos;
        return tree;
    }

    @Override
    public JCExports Exports(JCExpression qualId, List<JCExpression> moduleNames) {
        JCExports tree = new JCExports(qualId, moduleNames);
        tree.pos = pos;
        return tree;
    }

    @Override
    public JCOpens Opens(JCExpression qualId, List<JCExpression> moduleNames) {
        JCOpens tree = new JCOpens(qualId, moduleNames);
        tree.pos = pos;
        return tree;
    }

    @Override
    public JCProvides Provides(JCExpression serviceName, List<JCExpression> implNames) {
        JCProvides tree = new JCProvides(serviceName, implNames);
        tree.pos = pos;
        return tree;
    }

    @Override
    public JCRequires Requires(boolean isTransitive, boolean isStaticPhase, JCExpression qualId) {
        JCRequires tree = new JCRequires(isTransitive, isStaticPhase, qualId);
        tree.pos = pos;
        return tree;
    }

    @Override
    public JCUses Uses(JCExpression qualId) {
        JCUses tree = new JCUses(qualId);
        tree.pos = pos;
        return tree;
    }

    public JCAnnotatedType AnnotatedType(List<JCAnnotation> annotations, JCExpression underlyingType) {
        JCAnnotatedType tree = new JCAnnotatedType(annotations, underlyingType);
        tree.pos = pos;
        return tree;
    }

    public JCErroneous Erroneous() {
        return Erroneous(List.nil());
    }

    public JCErroneous Erroneous(List<? extends JCTree> errs) {
        JCErroneous tree = new JCErroneous(errs);
        tree.pos = pos;
        return tree;
    }

    public LetExpr LetExpr(List<JCStatement> defs, JCExpression expr) {
        LetExpr tree = new LetExpr(defs, expr);
        tree.pos = pos;
        return tree;
    }

/* ***************************************************************************
 * Derived building blocks.
 ****************************************************************************/

    public JCClassDecl AnonymousClassDef(JCModifiers mods,
                                         List<JCTree> defs)
    {
        return ClassDef(mods,
                        names.empty,
                        List.nil(),
                        null,
                        List.nil(),
                        defs);
    }

    public LetExpr LetExpr(JCVariableDecl def, JCExpression expr) {
        LetExpr tree = new LetExpr(List.of(def), expr);
        tree.pos = pos;
        return tree;
    }

    
Create an identifier from a symbol.
/** Create an identifier from a symbol.
     */
    public JCIdent Ident(Symbol sym) {
        return (JCIdent)new JCIdent((sym.name != names.empty)
                                ? sym.name
                                : sym.flatName(), sym)
            .setPos(pos)
            .setType(sym.type);
    }

    
Create a selection node from a qualifier tree and a symbol.
 @param base   The qualifier tree.
/** Create a selection node from a qualifier tree and a symbol.
     *  @param base   The qualifier tree.
     */
    public JCExpression Select(JCExpression base, Symbol sym) {
        return new JCFieldAccess(base, sym.name, sym).setPos(pos).setType(sym.type);
    }

    
Create a qualified identifier from a symbol, adding enough qualifications
 to make the reference unique.
/** Create a qualified identifier from a symbol, adding enough qualifications
     *  to make the reference unique.
     */
    public JCExpression QualIdent(Symbol sym) {
        return isUnqualifiable(sym)
            ? Ident(sym)
            : Select(QualIdent(sym.owner), sym);
    }

    
Create an identifier that refers to the variable declared in given variable
 declaration.
/** Create an identifier that refers to the variable declared in given variable
     *  declaration.
     */
    public JCExpression Ident(JCVariableDecl param) {
        return Ident(param.sym);
    }

    
Create a list of identifiers referring to the variables declared
 in given list of variable declarations.
/** Create a list of identifiers referring to the variables declared
     *  in given list of variable declarations.
     */
    public List<JCExpression> Idents(List<JCVariableDecl> params) {
        ListBuffer<JCExpression> ids = new ListBuffer<>();
        for (List<JCVariableDecl> l = params; l.nonEmpty(); l = l.tail)
            ids.append(Ident(l.head));
        return ids.toList();
    }

    
Create a tree representing `this', given its type.
/** Create a tree representing `this', given its type.
     */
    public JCExpression This(Type t) {
        return Ident(new VarSymbol(FINAL, names._this, t, t.tsym));
    }

    
Create a tree representing qualified `this' given its type
/** Create a tree representing qualified `this' given its type
     */
    public JCExpression QualThis(Type t) {
        return Select(Type(t), new VarSymbol(FINAL, names._this, t, t.tsym));
    }

    
Create a tree representing a class literal.
/** Create a tree representing a class literal.
     */
    public JCExpression ClassLiteral(ClassSymbol clazz) {
        return ClassLiteral(clazz.type);
    }

    
Create a tree representing a class literal.
/** Create a tree representing a class literal.
     */
    public JCExpression ClassLiteral(Type t) {
        VarSymbol lit = new VarSymbol(STATIC | PUBLIC | FINAL,
                                      names._class,
                                      t,
                                      t.tsym);
        return Select(Type(t), lit);
    }

    
Create a tree representing `super', given its type and owner.
/** Create a tree representing `super', given its type and owner.
     */
    public JCIdent Super(Type t, TypeSymbol owner) {
        return Ident(new VarSymbol(FINAL, names._super, t, owner));
    }

    
Create a method invocation from a method tree and a list of
argument trees.
/**
     * Create a method invocation from a method tree and a list of
     * argument trees.
     */
    public JCMethodInvocation App(JCExpression meth, List<JCExpression> args) {
        return Apply(null, meth, args).setType(meth.type.getReturnType());
    }

    
Create a no-arg method invocation from a method tree
/**
     * Create a no-arg method invocation from a method tree
     */
    public JCMethodInvocation App(JCExpression meth) {
        return Apply(null, meth, List.nil()).setType(meth.type.getReturnType());
    }

    
Create a method invocation from a method tree and a list of argument trees.
/** Create a method invocation from a method tree and a list of argument trees.
     */
    public JCExpression Create(Symbol ctor, List<JCExpression> args) {
        Type t = ctor.owner.erasure(types);
        JCNewClass newclass = NewClass(null, null, Type(t), args, null);
        newclass.constructor = ctor;
        newclass.setType(t);
        return newclass;
    }

    
Create a tree representing given type.
/** Create a tree representing given type.
     */
    public JCExpression Type(Type t) {
        if (t == null) return null;
        JCExpression tp;
        switch (t.getTag()) {
        case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
        case DOUBLE: case BOOLEAN: case VOID:
            tp = TypeIdent(t.getTag());
            break;
        case TYPEVAR:
            tp = Ident(t.tsym);
            break;
        case WILDCARD: {
            WildcardType a = ((WildcardType) t);
            tp = Wildcard(TypeBoundKind(a.kind), a.kind == BoundKind.UNBOUND ? null : Type(a.type));
            break;
        }
        case CLASS:
            switch (t.getKind()) {
            case UNION: {
                UnionClassType tu = (UnionClassType)t;
                ListBuffer<JCExpression> la = new ListBuffer<>();
                for (Type ta : tu.getAlternativeTypes()) {
                    la.add(Type(ta));
                }
                tp = TypeUnion(la.toList());
                break;
            }
            case INTERSECTION: {
                IntersectionClassType it = (IntersectionClassType)t;
                ListBuffer<JCExpression> la = new ListBuffer<>();
                for (Type ta : it.getExplicitComponents()) {
                    la.add(Type(ta));
                }
                tp = TypeIntersection(la.toList());
                break;
            }
            default: {
                Type outer = t.getEnclosingType();
                JCExpression clazz = outer.hasTag(CLASS) && t.tsym.owner.kind == TYP
                        ? Select(Type(outer), t.tsym)
                        : QualIdent(t.tsym);
                tp = t.getTypeArguments().isEmpty()
                        ? clazz
                        : TypeApply(clazz, Types(t.getTypeArguments()));
                break;
            }
            }
            break;
        case ARRAY:
            tp = TypeArray(Type(types.elemtype(t)));
            break;
        case ERROR:
            tp = TypeIdent(ERROR);
            break;
        default:
            throw new AssertionError("unexpected type: " + t);
        }
        return tp.setType(t);
    }

    
Create a list of trees representing given list of types.
/** Create a list of trees representing given list of types.
     */
    public List<JCExpression> Types(List<Type> ts) {
        ListBuffer<JCExpression> lb = new ListBuffer<>();
        for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
            lb.append(Type(l.head));
        return lb.toList();
    }

    
Create a variable definition from a variable symbol and an initializer
 expression.
/** Create a variable definition from a variable symbol and an initializer
     *  expression.
     */
    public JCVariableDecl VarDef(VarSymbol v, JCExpression init) {
        return (JCVariableDecl)
            new JCVariableDecl(
                Modifiers(v.flags(), Annotations(v.getRawAttributes())),
                v.name,
                Type(v.type),
                init,
                v).setPos(pos).setType(v.type);
    }

    
Create annotation trees from annotations.
/** Create annotation trees from annotations.
     */
    public List<JCAnnotation> Annotations(List<Attribute.Compound> attributes) {
        if (attributes == null) return List.nil();
        ListBuffer<JCAnnotation> result = new ListBuffer<>();
        for (List<Attribute.Compound> i = attributes; i.nonEmpty(); i=i.tail) {
            Attribute a = i.head;
            result.append(Annotation(a));
        }
        return result.toList();
    }

    public JCLiteral Literal(Object value) {
        JCLiteral result = null;
        if (value instanceof String) {
            result = Literal(CLASS, value).
                setType(syms.stringType.constType(value));
        } else if (value instanceof Integer) {
            result = Literal(INT, value).
                setType(syms.intType.constType(value));
        } else if (value instanceof Long) {
            result = Literal(LONG, value).
                setType(syms.longType.constType(value));
        } else if (value instanceof Byte) {
            result = Literal(BYTE, value).
                setType(syms.byteType.constType(value));
        } else if (value instanceof Character) {
            int v = (int) (((Character) value).toString().charAt(0));
            result = Literal(CHAR, v).
                setType(syms.charType.constType(v));
        } else if (value instanceof Double) {
            result = Literal(DOUBLE, value).
                setType(syms.doubleType.constType(value));
        } else if (value instanceof Float) {
            result = Literal(FLOAT, value).
                setType(syms.floatType.constType(value));
        } else if (value instanceof Short) {
            result = Literal(SHORT, value).
                setType(syms.shortType.constType(value));
        } else if (value instanceof Boolean) {
            int v = ((Boolean) value) ? 1 : 0;
            result = Literal(BOOLEAN, v).
                setType(syms.booleanType.constType(v));
        } else {
            throw new AssertionError(value);
        }
        return result;
    }

    class AnnotationBuilder implements Attribute.Visitor {
        JCExpression result = null;
        public void visitConstant(Attribute.Constant v) {
            result = Literal(v.type.getTag(), v.value);
        }
        public void visitClass(Attribute.Class clazz) {
            result = ClassLiteral(clazz.classType).setType(syms.classType);
        }
        public void visitEnum(Attribute.Enum e) {
            result = QualIdent(e.value);
        }
        public void visitError(Attribute.Error e) {
            if (e instanceof UnresolvedClass) {
                result = ClassLiteral(((UnresolvedClass) e).classType).setType(syms.classType);
            } else {
                result = Erroneous();
            }
        }
        public void visitCompound(Attribute.Compound compound) {
            if (compound instanceof Attribute.TypeCompound) {
                result = visitTypeCompoundInternal((Attribute.TypeCompound) compound);
            } else {
                result = visitCompoundInternal(compound);
            }
        }
        public JCAnnotation visitCompoundInternal(Attribute.Compound compound) {
            ListBuffer<JCExpression> args = new ListBuffer<>();
            for (List<Pair<Symbol.MethodSymbol,Attribute>> values = compound.values; values.nonEmpty(); values=values.tail) {
                Pair<MethodSymbol,Attribute> pair = values.head;
                JCExpression valueTree = translate(pair.snd);
                args.append(Assign(Ident(pair.fst), valueTree).setType(valueTree.type));
            }
            return Annotation(Type(compound.type), args.toList());
        }
        public JCAnnotation visitTypeCompoundInternal(Attribute.TypeCompound compound) {
            ListBuffer<JCExpression> args = new ListBuffer<>();
            for (List<Pair<Symbol.MethodSymbol,Attribute>> values = compound.values; values.nonEmpty(); values=values.tail) {
                Pair<MethodSymbol,Attribute> pair = values.head;
                JCExpression valueTree = translate(pair.snd);
                args.append(Assign(Ident(pair.fst), valueTree).setType(valueTree.type));
            }
            return TypeAnnotation(Type(compound.type), args.toList());
        }
        public void visitArray(Attribute.Array array) {
            ListBuffer<JCExpression> elems = new ListBuffer<>();
            for (int i = 0; i < array.values.length; i++)
                elems.append(translate(array.values[i]));
            result = NewArray(null, List.nil(), elems.toList()).setType(array.type);
        }
        JCExpression translate(Attribute a) {
            a.accept(this);
            return result;
        }
        JCAnnotation translate(Attribute.Compound a) {
            return visitCompoundInternal(a);
        }
        JCAnnotation translate(Attribute.TypeCompound a) {
            return visitTypeCompoundInternal(a);
        }
    }

    AnnotationBuilder annotationBuilder = new AnnotationBuilder();

    
Create an annotation tree from an attribute.
/** Create an annotation tree from an attribute.
     */
    public JCAnnotation Annotation(Attribute a) {
        return annotationBuilder.translate((Attribute.Compound)a);
    }

    public JCAnnotation TypeAnnotation(Attribute a) {
        return annotationBuilder.translate((Attribute.TypeCompound) a);
    }

    
Create a method definition from a method symbol and a method body.
/** Create a method definition from a method symbol and a method body.
     */
    public JCMethodDecl MethodDef(MethodSymbol m, JCBlock body) {
        return MethodDef(m, m.type, body);
    }

    
Create a method definition from a method symbol, method type
 and a method body.
/** Create a method definition from a method symbol, method type
     *  and a method body.
     */
    public JCMethodDecl MethodDef(MethodSymbol m, Type mtype, JCBlock body) {
        return (JCMethodDecl)
            new JCMethodDecl(
                Modifiers(m.flags(), Annotations(m.getRawAttributes())),
                m.name,
                Type(mtype.getReturnType()),
                TypeParams(mtype.getTypeArguments()),
                null, // receiver type
                Params(mtype.getParameterTypes(), m),
                Types(mtype.getThrownTypes()),
                body,
                null,
                m).setPos(pos).setType(mtype);
    }

    
Create a type parameter tree from its name and type.
/** Create a type parameter tree from its name and type.
     */
    public JCTypeParameter TypeParam(Name name, TypeVar tvar) {
        return (JCTypeParameter)
            TypeParameter(name, Types(types.getBounds(tvar))).setPos(pos).setType(tvar);
    }

    
Create a list of type parameter trees from a list of type variables.
/** Create a list of type parameter trees from a list of type variables.
     */
    public List<JCTypeParameter> TypeParams(List<Type> typarams) {
        ListBuffer<JCTypeParameter> tparams = new ListBuffer<>();
        for (List<Type> l = typarams; l.nonEmpty(); l = l.tail)
            tparams.append(TypeParam(l.head.tsym.name, (TypeVar)l.head));
        return tparams.toList();
    }

    
Create a value parameter tree from its name, type, and owner.
/** Create a value parameter tree from its name, type, and owner.
     */
    public JCVariableDecl Param(Name name, Type argtype, Symbol owner) {
        return VarDef(new VarSymbol(PARAMETER, name, argtype, owner), null);
    }

    
Create a a list of value parameter trees x0, ..., xn from a list of
 their types and an their owner.
/** Create a a list of value parameter trees x0, ..., xn from a list of
     *  their types and an their owner.
     */
    public List<JCVariableDecl> Params(List<Type> argtypes, Symbol owner) {
        ListBuffer<JCVariableDecl> params = new ListBuffer<>();
        MethodSymbol mth = (owner.kind == MTH) ? ((MethodSymbol)owner) : null;
        if (mth != null && mth.params != null && argtypes.length() == mth.params.length()) {
            for (VarSymbol param : ((MethodSymbol)owner).params)
                params.append(VarDef(param, null));
        } else {
            int i = 0;
            for (List<Type> l = argtypes; l.nonEmpty(); l = l.tail)
                params.append(Param(paramName(i++), l.head, owner));
        }
        return params.toList();
    }

    
Wrap a method invocation in an expression statement or return statement,
 depending on whether the method invocation expression's type is void.
/** Wrap a method invocation in an expression statement or return statement,
     *  depending on whether the method invocation expression's type is void.
     */
    public JCStatement Call(JCExpression apply) {
        return apply.type.hasTag(VOID) ? Exec(apply) : Return(apply);
    }

    
Construct an assignment from a variable symbol and a right hand side.
/** Construct an assignment from a variable symbol and a right hand side.
     */
    public JCStatement Assignment(Symbol v, JCExpression rhs) {
        return Exec(Assign(Ident(v), rhs).setType(v.type));
    }

    
Construct an index expression from a variable and an expression.
/** Construct an index expression from a variable and an expression.
     */
    public JCArrayAccess Indexed(Symbol v, JCExpression index) {
        JCArrayAccess tree = new JCArrayAccess(QualIdent(v), index);
        tree.type = ((ArrayType)v.type).elemtype;
        return tree;
    }

    
Make an attributed type cast expression.
/** Make an attributed type cast expression.
     */
    public JCTypeCast TypeCast(Type type, JCExpression expr) {
        return (JCTypeCast)TypeCast(Type(type), expr).setType(type);
    }

/* ***************************************************************************
 * Helper methods.
 ****************************************************************************/

    
Can given symbol be referred to in unqualified form?
/** Can given symbol be referred to in unqualified form?
     */
    boolean isUnqualifiable(Symbol sym) {
        if (sym.name == names.empty ||
            sym.owner == null ||
            sym.owner == syms.rootPackage ||
            sym.owner.kind == MTH || sym.owner.kind == VAR) {
            return true;
        } else if (sym.kind == TYP && toplevel != null) {
            Iterator<Symbol> it = toplevel.namedImportScope.getSymbolsByName(sym.name).iterator();
            if (it.hasNext()) {
                Symbol s = it.next();
                return
                  s == sym &&
                  !it.hasNext();
            }
            it = toplevel.packge.members().getSymbolsByName(sym.name).iterator();
            if (it.hasNext()) {
                Symbol s = it.next();
                return
                  s == sym &&
                  !it.hasNext();
            }
            it = toplevel.starImportScope.getSymbolsByName(sym.name).iterator();
            if (it.hasNext()) {
                Symbol s = it.next();
                return
                  s == sym &&
                  !it.hasNext();
            }
        }
        return false;
    }

    
The name of synthetic parameter number `i'.
/** The name of synthetic parameter number `i'.
     */
    public Name paramName(int i)   { return names.fromString("x" + i); }

    
The name of synthetic type parameter number `i'.
/** The name of synthetic type parameter number `i'.
     */
    public Name typaramName(int i) { return names.fromString("A" + i); }
}