/*
 * 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.code;

import java.util.*;

import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.Type.*;
import com.sun.tools.javac.jvm.*;

import static com.sun.tools.javac.jvm.ByteCodes.*;
import static com.sun.tools.javac.code.Flags.*;

/** A class that defines all predefined constants and operators
 *  as well as special classes such as java.lang.Object, which need
 *  to be known to the compiler. All symbols are held in instance
 *  fields. This makes it possible to work in multiple concurrent
 *  projects, which might use different class files for library classes.
 *
 *  <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>
 */
public class Symtab {
    /** The context key for the symbol table. */
    protected static final Context.Key<Symtab> symtabKey =
	new Context.Key<Symtab>();

    /** Get the symbol table instance. */
    public static Symtab instance(Context context) {
	Symtab instance = context.get(symtabKey);
	if (instance == null)
	    instance = new Symtab(context);
	return instance;
    }

    /** Builtin types.
     */
    public final Type byteType = new Type(TypeTags.BYTE, null);       
    public final Type charType = new Type(TypeTags.CHAR, null);       
    public final Type shortType = new Type(TypeTags.SHORT, null);     
    public final Type intType = new Type(TypeTags.INT, null);         
    public final Type longType = new Type(TypeTags.LONG, null);       
    public final Type floatType = new Type(TypeTags.FLOAT, null);     
    public final Type doubleType = new Type(TypeTags.DOUBLE, null);   
    public final Type booleanType = new Type(TypeTags.BOOLEAN, null); 
    public final Type botType = new BottomType();
    public final JCNoType voidType = new JCNoType(TypeTags.VOID);

    private final Name.Table names;
    private final ClassReader reader;

    /** A symbol for the root package.
     */
    public final PackageSymbol rootPackage;

    /** A symbol for the unnamed package.
     */
    public final PackageSymbol unnamedPackage;

    /** A symbol that stands for a missing symbol.
     */
    public final TypeSymbol noSymbol;

    /** The error symbol.
     */
    public final ClassSymbol errSymbol;

    /** An instance of the error type.
     */
    public final Type errType;

    /** A value for the unknown type. */
    public final Type unknownType;

    /** The builtin type of all arrays. */
    public final ClassSymbol arrayClass;
    public final MethodSymbol arrayCloneMethod;

    /** VGJ: The (singleton) type of all bound types. */
    public final ClassSymbol boundClass;

    /** The builtin type of all methods. */
    public final ClassSymbol methodClass;

    /** Predefined types.
     */
    public final Type objectType;
    public final Type classType;
    public final Type classLoaderType;
    public final Type stringType;
    public final Type stringBufferType;
    public final Type stringBuilderType;
    public final Type cloneableType;
    public final Type serializableType;
    public final Type throwableType;
    public final Type errorType;
    public final Type illegalArgumentExceptionType;
    public final Type exceptionType;
    public final Type runtimeExceptionType;
    public final Type classNotFoundExceptionType;
    public final Type noClassDefFoundErrorType;
    public final Type noSuchFieldErrorType;
    public final Type assertionErrorType;
    public final Type cloneNotSupportedExceptionType;
    public final Type annotationType;
    public final TypeSymbol enumSym;
    public final Type listType;
    public final Type collectionsType;
    public final Type comparableType;
    public final Type arraysType;
    public final Type iterableType;
    public final Type iteratorType;
    public final Type annotationTargetType;
    public final Type overrideType;
    public final Type retentionType;
    public final Type deprecatedType;
    public final Type suppressWarningsType;
    public final Type inheritedType;
    public final Type proprietaryType;

    /** The symbol representing the length field of an array.
     */
    public final VarSymbol lengthVar;

    /** The null check operator. */
    public final OperatorSymbol nullcheck;

    /** The symbol representing the final finalize method on enums */
    public final MethodSymbol enumFinalFinalize;

    /** The predefined type that belongs to a tag.
     */
    public final Type[] typeOfTag = new Type[TypeTags.TypeTagCount];

    /** The name of the class that belongs to a basix type tag.
     */
    public final Name[] boxedName = new Name[TypeTags.TypeTagCount];

    /** A hashtable containing the encountered top-level and member classes,
     *  indexed by flat names. The table does not contain local classes.
     *  It should be updated from the outside to reflect classes defined
     *  by compiled source files.
     */
    public final Map<Name, ClassSymbol> classes = new HashMap<Name, ClassSymbol>();

    /** A hashtable containing the encountered packages.
     *  the table should be updated from outside to reflect packages defined
     *  by compiled source files.
     */
    public final Map<Name, PackageSymbol> packages = new HashMap<Name, PackageSymbol>();

    public void initType(Type type, ClassSymbol c) {
	type.tsym = c;
	typeOfTag[type.tag] = type;
    }

    public void initType(Type type, String name) {
	initType(
	    type,
	    new ClassSymbol(
		PUBLIC, names.fromString(name), type, rootPackage));
    }

    public void initType(Type type, String name, String bname) {
	initType(type, name);
	boxedName[type.tag] = names.fromString("java.lang." + bname);
    }

    /** The class symbol that owns all predefined symbols.
     */
    public final ClassSymbol predefClass;

    /** Enter a constant into symbol table.
     *  @param name   The constant's name.
     *  @param type   The constant's type.
     */
    private VarSymbol enterConstant(String name, Type type) {
        VarSymbol c = new VarSymbol(
	    PUBLIC | STATIC | FINAL,
	    names.fromString(name),
	    type,
	    predefClass);
	c.setData(type.constValue());
        predefClass.members().enter(c);
	return c;
    }

    /** Enter a binary operation into symbol table.
     *  @param name     The name of the operator.
     *  @param left     The type of the left operand.
     *  @param right    The type of the left operand.
     *  @param res      The operation's result type.
     *  @param opcode   The operation's bytecode instruction.
     */
    private void enterBinop(String name,
			    Type left, Type right, Type res,
			    int opcode) {
        predefClass.members().enter(
            new OperatorSymbol(
		names.fromString(name),
		new MethodType(List.of(left, right), res,
			       List.<Type>nil(), methodClass),
		opcode,
		predefClass));
    }

    /** Enter a binary operation, as above but with two opcodes,
     *  which get encoded as (opcode1 << ByteCodeTags.preShift) + opcode2.
     *  @param opcode1     First opcode.
     *  @param opcode2     Second opcode.
     */
    private void enterBinop(String name,
			    Type left, Type right, Type res,
			    int opcode1, int opcode2) {
	enterBinop(
	    name, left, right, res, (opcode1 << ByteCodes.preShift) | opcode2);
    }

    /** Enter a unary operation into symbol table.
     *  @param name     The name of the operator.
     *  @param arg      The type of the operand.
     *  @param res      The operation's result type.
     *  @param opcode   The operation's bytecode instruction.
     */
    private OperatorSymbol enterUnop(String name,
				     Type arg,
				     Type res,
				     int opcode) {
	OperatorSymbol sym =
	    new OperatorSymbol(names.fromString(name),
			       new MethodType(List.of(arg),
					      res,
					      List.<Type>nil(),
					      methodClass),
			       opcode,
			       predefClass);
        predefClass.members().enter(sym);
	return sym;
    }

    /** Enter a class into symbol table.
     *  @param    The name of the class.
     */
    private Type enterClass(String s) {
	return reader.enterClass(names.fromString(s)).type;
    }

    /** Constructor; enters all predefined identifiers and operators
     *  into symbol table.
     */
    protected Symtab(Context context) throws CompletionFailure {
	context.put(symtabKey, this);

	names = Name.Table.instance(context);

	// Create the unknown type
	unknownType = new Type(TypeTags.UNKNOWN, null);

	// create the basic builtin symbols
	rootPackage = new PackageSymbol(names.empty, null);
        final Messages messages = Messages.instance(context);
        unnamedPackage = new PackageSymbol(names.empty, rootPackage) {
                public String toString() {
                    return messages.getLocalizedString("compiler.misc.unnamed.package");
                }
            };
	noSymbol = new TypeSymbol(0, names.empty, Type.noType, rootPackage);
	noSymbol.kind = Kinds.NIL;

	// create the error symbols
	errSymbol = new ClassSymbol(PUBLIC|STATIC|ACYCLIC, names.any, null, rootPackage);
	errType = new ErrorType(errSymbol);

	// initialize builtin types
	initType(byteType, "byte", "Byte");
	initType(shortType, "short", "Short");
	initType(charType, "char", "Character");
	initType(intType, "int", "Integer");
	initType(longType, "long", "Long");
	initType(floatType, "float", "Float");
	initType(doubleType, "double", "Double");
	initType(booleanType, "boolean", "Boolean");
	initType(voidType, "void", "Void");
	initType(botType, "<nulltype>");
	initType(errType, errSymbol);
	initType(unknownType, "<any?>");

	// the builtin class of all arrays
	arrayClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Array, noSymbol);

	// VGJ
	boundClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Bound, noSymbol);

	// the builtin class of all methods
	methodClass = new ClassSymbol(PUBLIC|ACYCLIC, names.Method, noSymbol);

	// Create class to hold all predefined constants and operations.
        predefClass = new ClassSymbol(PUBLIC|ACYCLIC, names.empty, rootPackage);
	Scope scope = new Scope(predefClass);
	predefClass.members_field = scope;

	// Enter symbols for basic types.
        scope.enter(byteType.tsym);
        scope.enter(shortType.tsym);
        scope.enter(charType.tsym);
        scope.enter(intType.tsym);
        scope.enter(longType.tsym);
        scope.enter(floatType.tsym);
        scope.enter(doubleType.tsym);
        scope.enter(booleanType.tsym);
        scope.enter(errType.tsym);

	classes.put(predefClass.fullname, predefClass);

	reader = ClassReader.instance(context);
	reader.init(this);

	// Enter predefined classes.
	objectType = enterClass("java.lang.Object");
	classType = enterClass("java.lang.Class");
	stringType = enterClass("java.lang.String");
	stringBufferType = enterClass("java.lang.StringBuffer");
	stringBuilderType = enterClass("java.lang.StringBuilder");
	cloneableType = enterClass("java.lang.Cloneable");
	throwableType = enterClass("java.lang.Throwable");
	serializableType = enterClass("java.io.Serializable");
	errorType = enterClass("java.lang.Error");
	illegalArgumentExceptionType = enterClass("java.lang.IllegalArgumentException");
	exceptionType = enterClass("java.lang.Exception");
	runtimeExceptionType = enterClass("java.lang.RuntimeException");
	classNotFoundExceptionType = enterClass("java.lang.ClassNotFoundException");
	noClassDefFoundErrorType = enterClass("java.lang.NoClassDefFoundError");
	noSuchFieldErrorType = enterClass("java.lang.NoSuchFieldError");
	assertionErrorType = enterClass("java.lang.AssertionError");
        cloneNotSupportedExceptionType = enterClass("java.lang.CloneNotSupportedException");
	annotationType = enterClass("java.lang.annotation.Annotation");
	classLoaderType = enterClass("java.lang.ClassLoader");
	enumSym = reader.enterClass(names.java_lang_Enum);
	enumFinalFinalize =
	    new MethodSymbol(PROTECTED|FINAL|HYPOTHETICAL,
			     names.finalize,
			     new MethodType(List.<Type>nil(), voidType,
					    List.<Type>nil(), methodClass),
			     enumSym);
	listType = enterClass("java.util.List");
	collectionsType = enterClass("java.util.Collections");
	comparableType = enterClass("java.lang.Comparable");
	arraysType = enterClass("java.util.Arrays");
	iterableType = Target.instance(context).hasIterable()
            ? enterClass("java.lang.Iterable")
            : enterClass("java.util.Collection");
	iteratorType = enterClass("java.util.Iterator");
	annotationTargetType = enterClass("java.lang.annotation.Target");
	overrideType = enterClass("java.lang.Override");
	retentionType = enterClass("java.lang.annotation.Retention");
	deprecatedType = enterClass("java.lang.Deprecated");
	suppressWarningsType = enterClass("java.lang.SuppressWarnings");
	inheritedType = enterClass("java.lang.annotation.Inherited");

        // Enter a synthetic class that is used to mark Sun
        // proprietary classes in ct.sym.  This class does not have a
        // class file.
        ClassType proprietaryType = (ClassType)enterClass("sun.Proprietary+Annotation");
        this.proprietaryType = proprietaryType;
        ClassSymbol proprietarySymbol = (ClassSymbol)proprietaryType.tsym;
        proprietarySymbol.completer = null;
        proprietarySymbol.flags_field = PUBLIC|ACYCLIC|ANNOTATION|INTERFACE;
        proprietarySymbol.erasure_field = proprietaryType;
        proprietarySymbol.members_field = new Scope(proprietarySymbol);
        proprietaryType.typarams_field = List.nil();
        proprietaryType.allparams_field = List.nil();
        proprietaryType.supertype_field = annotationType;
        proprietaryType.interfaces_field = List.nil();

	// Enter a class for arrays.
	// The class implements java.lang.Cloneable and java.io.Serializable.
	// It has a final length field and a clone method.
	ClassType arrayClassType = (ClassType)arrayClass.type;
	arrayClassType.supertype_field = objectType;
	arrayClassType.interfaces_field = List.of(cloneableType, serializableType);
	arrayClass.members_field = new Scope(arrayClass);
        lengthVar = new VarSymbol(
	    PUBLIC | FINAL,
	    names.length,
	    intType,
	    arrayClass);
        arrayClass.members().enter(lengthVar);
	arrayCloneMethod = new MethodSymbol(
	    PUBLIC,
	    names.clone,
	    new MethodType(List.<Type>nil(), objectType,
			   List.<Type>nil(), methodClass),
	    arrayClass);
	arrayClass.members().enter(arrayCloneMethod);

	// Enter operators.
        enterUnop("+", doubleType, doubleType, nop);
        enterUnop("+", floatType, floatType, nop);
        enterUnop("+", longType, longType, nop);
        enterUnop("+", intType, intType, nop);

        enterUnop("-", doubleType, doubleType, dneg);
        enterUnop("-", floatType, floatType, fneg);
        enterUnop("-", longType, longType, lneg);
        enterUnop("-", intType, intType, ineg);

        enterUnop("~", longType, longType, lxor);
        enterUnop("~", intType, intType, ixor);

        enterUnop("++", doubleType, doubleType, dadd);
        enterUnop("++", floatType, floatType, fadd);
        enterUnop("++", longType, longType, ladd);
        enterUnop("++", intType, intType, iadd);
        enterUnop("++", charType, charType, iadd);
        enterUnop("++", shortType, shortType, iadd);
        enterUnop("++", byteType, byteType, iadd);

        enterUnop("--", doubleType, doubleType, dsub);
        enterUnop("--", floatType, floatType, fsub);
        enterUnop("--", longType, longType, lsub);
        enterUnop("--", intType, intType, isub);
        enterUnop("--", charType, charType, isub);
        enterUnop("--", shortType, shortType, isub);
        enterUnop("--", byteType, byteType, isub);

        enterUnop("!", booleanType, booleanType, bool_not);
	nullcheck = enterUnop("<*nullchk*>", objectType, objectType, nullchk);

	// string concatenation
        enterBinop("+", stringType, objectType, stringType, string_add);
        enterBinop("+", objectType, stringType, stringType, string_add);
        enterBinop("+", stringType, stringType, stringType, string_add);
        enterBinop("+", stringType, intType, stringType, string_add);
        enterBinop("+", stringType, longType, stringType, string_add);
        enterBinop("+", stringType, floatType, stringType, string_add);
        enterBinop("+", stringType, doubleType, stringType, string_add);
        enterBinop("+", stringType, booleanType, stringType, string_add);
        enterBinop("+", stringType, botType, stringType, string_add);
        enterBinop("+", intType, stringType, stringType, string_add);
        enterBinop("+", longType, stringType, stringType, string_add);
        enterBinop("+", floatType, stringType, stringType, string_add);
        enterBinop("+", doubleType, stringType, stringType, string_add);
        enterBinop("+", booleanType, stringType, stringType, string_add);
        enterBinop("+", botType, stringType, stringType, string_add);
	
	// these errors would otherwise be matched as string concatenation
        enterBinop("+", botType, botType, botType, error);
        enterBinop("+", botType, intType, botType, error);
        enterBinop("+", botType, longType, botType, error);
        enterBinop("+", botType, floatType, botType, error);
        enterBinop("+", botType, doubleType, botType, error);
        enterBinop("+", botType, booleanType, botType, error);
        enterBinop("+", botType, objectType, botType, error);
        enterBinop("+", intType, botType, botType, error);
        enterBinop("+", longType, botType, botType, error);
        enterBinop("+", floatType, botType, botType, error);
        enterBinop("+", doubleType, botType, botType, error);
        enterBinop("+", booleanType, botType, botType, error);
        enterBinop("+", objectType, botType, botType, error);

        enterBinop("+", doubleType, doubleType, doubleType, dadd);
        enterBinop("+", floatType, floatType, floatType, fadd);
        enterBinop("+", longType, longType, longType, ladd);
        enterBinop("+", intType, intType, intType, iadd);

        enterBinop("-", doubleType, doubleType, doubleType, dsub);
        enterBinop("-", floatType, floatType, floatType, fsub);
        enterBinop("-", longType, longType, longType, lsub);
        enterBinop("-", intType, intType, intType, isub);

        enterBinop("*", doubleType, doubleType, doubleType, dmul);
        enterBinop("*", floatType, floatType, floatType, fmul);
        enterBinop("*", longType, longType, longType, lmul);
        enterBinop("*", intType, intType, intType, imul);

        enterBinop("/", doubleType, doubleType, doubleType, ddiv);
        enterBinop("/", floatType, floatType, floatType, fdiv);
        enterBinop("/", longType, longType, longType, ldiv);
        enterBinop("/", intType, intType, intType, idiv);

        enterBinop("%", doubleType, doubleType, doubleType, dmod);
        enterBinop("%", floatType, floatType, floatType, fmod);
        enterBinop("%", longType, longType, longType, lmod);
        enterBinop("%", intType, intType, intType, imod);

        enterBinop("&", booleanType, booleanType, booleanType, iand);
        enterBinop("&", longType, longType, longType, land);
        enterBinop("&", intType, intType, intType, iand);

        enterBinop("|", booleanType, booleanType, booleanType, ior);
        enterBinop("|", longType, longType, longType, lor);
        enterBinop("|", intType, intType, intType, ior);

        enterBinop("^", booleanType, booleanType, booleanType, ixor);
        enterBinop("^", longType, longType, longType, lxor);
        enterBinop("^", intType, intType, intType, ixor);

        enterBinop("<<", longType, longType, longType, lshll);
        enterBinop("<<", intType, longType, intType, ishll);
        enterBinop("<<", longType, intType, longType, lshl);
        enterBinop("<<", intType, intType, intType, ishl);

        enterBinop(">>", longType, longType, longType, lshrl);
        enterBinop(">>", intType, longType, intType, ishrl);
        enterBinop(">>", longType, intType, longType, lshr);
        enterBinop(">>", intType, intType, intType, ishr);

        enterBinop(">>>", longType, longType, longType, lushrl);
        enterBinop(">>>", intType, longType, intType, iushrl);
        enterBinop(">>>", longType, intType, longType, lushr);
        enterBinop(">>>", intType, intType, intType, iushr);

        enterBinop("<", doubleType, doubleType, booleanType, dcmpg, iflt);
        enterBinop("<", floatType, floatType, booleanType, fcmpg, iflt);
        enterBinop("<", longType, longType, booleanType, lcmp, iflt);
        enterBinop("<", intType, intType, booleanType, if_icmplt);

        enterBinop(">", doubleType, doubleType, booleanType, dcmpl, ifgt);
        enterBinop(">", floatType, floatType, booleanType, fcmpl, ifgt);
        enterBinop(">", longType, longType, booleanType, lcmp, ifgt);
        enterBinop(">", intType, intType, booleanType, if_icmpgt);

        enterBinop("<=", doubleType, doubleType, booleanType, dcmpg, ifle);
        enterBinop("<=", floatType, floatType, booleanType, fcmpg, ifle);
        enterBinop("<=", longType, longType, booleanType, lcmp, ifle);
        enterBinop("<=", intType, intType, booleanType, if_icmple);

        enterBinop(">=", doubleType, doubleType, booleanType, dcmpl, ifge);
        enterBinop(">=", floatType, floatType, booleanType, fcmpl, ifge);
        enterBinop(">=", longType, longType, booleanType, lcmp, ifge);
        enterBinop(">=", intType, intType, booleanType, if_icmpge);

        enterBinop("==", objectType, objectType, booleanType, if_acmpeq);
        enterBinop("==", booleanType, booleanType, booleanType, if_icmpeq);
        enterBinop("==", doubleType, doubleType, booleanType, dcmpl, ifeq);
        enterBinop("==", floatType, floatType, booleanType, fcmpl, ifeq);
        enterBinop("==", longType, longType, booleanType, lcmp, ifeq);
        enterBinop("==", intType, intType, booleanType, if_icmpeq);

        enterBinop("!=", objectType, objectType, booleanType, if_acmpne);
        enterBinop("!=", booleanType, booleanType, booleanType, if_icmpne);
        enterBinop("!=", doubleType, doubleType, booleanType, dcmpl, ifne);
        enterBinop("!=", floatType, floatType, booleanType, fcmpl, ifne);
        enterBinop("!=", longType, longType, booleanType, lcmp, ifne);
        enterBinop("!=", intType, intType, booleanType, if_icmpne);

        enterBinop("&&", booleanType, booleanType, booleanType, bool_and);
        enterBinop("||", booleanType, booleanType, booleanType, bool_or);
    }
}