/*

 * 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

 * particular file as subject to the "Classpath" exception as provided

 *

 * 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.

 *

 */

/*

 * Licensed Materials - Property of IBM

 * RMI-IIOP v1.0

 * Copyright IBM Corp. 1998 1999  All Rights Reserved

 *

 */

package sun.rmi.rmic.iiop;

import sun.tools.java.CompilerError;

/**

 * ContextStack provides a mechanism to record parsing state.

 *

 * @author      Bryan Atsatt

 */

public class ContextStack {

    // Context codes.

    public static final int TOP = 1;

    public static final int METHOD = 2;

    public static final int METHOD_RETURN = 3;

    public static final int METHOD_ARGUMENT = 4;

    public static final int METHOD_EXCEPTION = 5;

    public static final int MEMBER = 6;

    public static final int MEMBER_CONSTANT = 7;

    public static final int MEMBER_STATIC = 8;

    public static final int MEMBER_TRANSIENT = 9;

    public static final int IMPLEMENTS = 10;

    public static final int EXTENDS = 11;

    // String versions of context codes.

    private static final String[] CODE_NAMES = {

        "UNKNOWN ",

        "Top level type ",

        "Method ",

        "Return parameter ",

        "Parameter ",

        "Exception ",

        "Member ",

        "Constant member ",

        "Static member ",

        "Transient member ",

        "Implements ",

        "Extends ",

    };

    // Member data.

    private int currentIndex = -1;

    private int maxIndex = 100;

    private TypeContext[] stack = new TypeContext[maxIndex];

    private int newCode = TOP;

    private BatchEnvironment env = null;

    private boolean trace = false;

    private TypeContext tempContext = new TypeContext();

    private static final String TRACE_INDENT = "   ";

    /**

     * Constructor.

     */

    public ContextStack (BatchEnvironment env) {

        this.env = env;

        env.contextStack = this;

    }

    /**

     * Return true if env.nerrors > 0.

     */

    public boolean anyErrors () {

        return env.nerrors > 0;

    }

    /**

     * Enable/disable tracing.

     */

    public void setTrace(boolean trace) {

        this.trace = trace;

    }

    /**

     * Check trace flag.

     */

    public boolean isTraceOn() {

        return trace;

    }

    /**

     * Get the environment.

     */

    public BatchEnvironment getEnv() {

        return env;

    }

    /**

     * Set the new context.

     */

    public void setNewContextCode(int code) {

        newCode = code;

    }

    /**

     * Get the current context code.

     */

    public int getCurrentContextCode() {

        return newCode;

    }

    /**

     * If tracing on, write the current call stack (not the context stack) to

     * System.out.

     */

    final void traceCallStack () {

        if (trace) dumpCallStack();

    }

    public final static void dumpCallStack() {

        new Error().printStackTrace(System.out);

    }

    /**

     * Print a line indented by stack depth.

     */

    final private void tracePrint (String text, boolean line) {

        int length = text.length() + (currentIndex * TRACE_INDENT.length());

        StringBuffer buffer = new StringBuffer(length);

        for (int i = 0; i < currentIndex; i++) {

            buffer.append(TRACE_INDENT);

        }

        buffer.append(text);

        if (line) {

            buffer.append("\n");

        }

        System.out.print(buffer.toString());

    }

    /**

     * If tracing on, print a line.

     */

    final void trace (String text) {

        if (trace) {

            tracePrint(text,false);

        }

    }

    /**

     * If tracing on, print a line followed by a '\n'.

     */

    final void traceln (String text) {

        if (trace) {

            tracePrint(text,true);

        }

    }

    /**

     * If tracing on, print a pre-mapped ContextElement.

     */

    final void traceExistingType (Type type) {

        if (trace) {

            tempContext.set(newCode,type);

            traceln(toResultString(tempContext,true,true));

        }

    }

    /**

     * Push a new element on the stack.

     * @return the new element.

     */

    public TypeContext push (ContextElement element) {

        currentIndex++;

        // Grow array if need to...

        if (currentIndex == maxIndex) {

            int newMax = maxIndex * 2;

            TypeContext[] newStack = new TypeContext[newMax];

            System.arraycopy(stack,0,newStack,0,maxIndex);

            maxIndex = newMax;

            stack = newStack;

        }

        // Make sure we have a context object to use at this position...

        TypeContext it = stack[currentIndex];

        if (it == null) {

            it = new TypeContext();

            stack[currentIndex] = it;

        }

        // Set the context object...

        it.set(newCode,element);

        // Trace...

        traceln(toTrialString(it));

        // Return...

        return it;

    }

    /**

     * Pop an element from the stack.

     * @return the new current element or null if top.

     */

    public TypeContext pop (boolean wasValid) {

        if (currentIndex < 0) {

            throw new CompilerError("Nothing on stack!");

        }

        newCode = stack[currentIndex].getCode();

        traceln(toResultString(stack[currentIndex],wasValid,false));

        Type last = stack[currentIndex].getCandidateType();

        if (last != null) {

            // Set status...

            if (wasValid) {

                last.setStatus(Constants.STATUS_VALID);

            } else {

                last.setStatus(Constants.STATUS_INVALID);

            }

        }

        currentIndex--;

        if (currentIndex < 0) {

            // Done parsing, so update the invalid types

            // if this type was valid...

            if (wasValid) {

                Type.updateAllInvalidTypes(this);

            }

            return null;

        } else {

            return stack[currentIndex];

        }

    }

    /**

     * Get the current size.

     */

    public int size () {

        return currentIndex + 1;

    }

    /**

     * Get a specific context.

     */

    public TypeContext getContext (int index) {

        if (currentIndex < index) {

            throw new Error("Index out of range");

        }

        return stack[index];

    }

    /**

     * Get the current top context.

     */

    public TypeContext getContext () {

        if (currentIndex < 0) {

            throw new Error("Nothing on stack!");

        }

        return stack[currentIndex];

    }

    /**

     * Is parent context a value type?

     */

    public boolean isParentAValue () {

        if (currentIndex > 0) {

            return stack[currentIndex - 1].isValue();

        } else {

            return false;

        }

    }

    /**

     * Get parent context. Null if none.

     */

    public TypeContext getParentContext () {

        if (currentIndex > 0) {

            return stack[currentIndex - 1];

        } else {

            return null;

        }

    }

    /**

     * Get a string for the context name...

     */

    public String getContextCodeString () {

        if (currentIndex >= 0) {

            return CODE_NAMES[newCode];

        } else {

            return CODE_NAMES[0];

        }

    }

    /**

     * Get a string for the given context code...

     */

    public static String getContextCodeString (int contextCode) {

        return CODE_NAMES[contextCode];

    }

    private String toTrialString(TypeContext it) {

        int code = it.getCode();

        if (code != METHOD && code != MEMBER) {

            return it.toString() + " (trying " + it.getTypeDescription() + ")";

        } else {

            return it.toString();

        }

    }

    private String toResultString (TypeContext it, boolean result, boolean preExisting) {

        int code = it.getCode();

        if (code != METHOD && code != MEMBER) {

            if (result) {

                String str = it.toString() + " --> " + it.getTypeDescription();

                if (preExisting) {

                    return str + " [Previously mapped]";

                } else {

                    return str;

                }

            }

        } else {

            if (result) {

                return it.toString() + " --> [Mapped]";

            }

        }

        return it.toString() + " [Did not map]";

    }

    public void clear () {

        for (int i = 0; i < stack.length; i++) {

            if (stack[i] != null) stack[i].destroy();

        }

    }

}

class TypeContext {

    public void set(int code, ContextElement element) {

        this.code = code;

        this.element = element;

        if (element instanceof ValueType) {

            isValue = true;

        } else {

            isValue = false;

        }

    }

    public int getCode() {

        return code;

    }

    public String getName() {

        return element.getElementName();

    }

    public Type getCandidateType() {

        if (element instanceof Type) {

            return (Type) element;

        } else {

            return null;

        }

}

public String getTypeDescription() {

    if (element instanceof Type) {

        return ((Type) element).getTypeDescription();

    } else {

        return "[unknown type]";

    }

}

public String toString () {

    if (element != null) {

        return ContextStack.getContextCodeString(code) + element.getElementName();

    } else {

        return ContextStack.getContextCodeString(code) + "null";

    }

}

public boolean isValue () {

    return isValue;

}

    public boolean isConstant () {

        return code == ContextStack.MEMBER_CONSTANT;

    }

    public void destroy() {

        if (element instanceof Type) {

            ((Type)element).destroy();

        }

        element = null;

    }

    private int code = 0;

    private ContextElement element = null;

    private boolean isValue = false;

}