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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package com.sun.tools.javah;

import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.util.Elements;
import javax.lang.model.util.Types;

A utility for mangling java identifiers into C names.  Should make
this more fine grained and distribute the functionality to the
generators.
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.
Author:
 Sucheta Dambalkar(Revised)/**
 * A utility for mangling java identifiers into C names.  Should make
 * this more fine grained and distribute the functionality to the
 * generators.
 *
 * <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></p>
 *
 * @author  Sucheta Dambalkar(Revised)
 */
public class Mangle {

    public static class Type {
        public static final int CLASS            = 1;
        public static final int FIELDSTUB        = 2;
        public static final int FIELD            = 3;
        public static final int JNI              = 4;
        public static final int SIGNATURE        = 5;
        public static final int METHOD_JDK_1     = 6;
        public static final int METHOD_JNI_SHORT = 7;
        public static final int METHOD_JNI_LONG  = 8;
    }

    private Elements elems;
    private Types types;

    Mangle(Elements elems, Types types) {
        this.elems = elems;
        this.types = types;
    }

    public final String mangle(CharSequence name, int mtype) {
        StringBuilder result = new StringBuilder(100);
        int length = name.length();

        for (int i = 0; i < length; i++) {
            char ch = name.charAt(i);
            if (isalnum(ch)) {
                result.append(ch);
            } else if ((ch == '.') &&
                       mtype == Mangle.Type.CLASS) {
                result.append('_');
            } else if (( ch == '$') &&
                       mtype == Mangle.Type.CLASS) {
                result.append('_');
                result.append('_');
            } else if (ch == '_' && mtype == Mangle.Type.FIELDSTUB) {
                result.append('_');
            } else if (ch == '_' && mtype == Mangle.Type.CLASS) {
                result.append('_');
            } else if (mtype == Mangle.Type.JNI) {
                String esc = null;
                if (ch == '_')
                    esc = "_1";
                else if (ch == '.')
                    esc = "_";
                else if (ch == ';')
                    esc = "_2";
                else if (ch == '[')
                    esc = "_3";
                if (esc != null) {
                    result.append(esc);
                } else {
                    result.append(mangleChar(ch));
                }
            } else if (mtype == Mangle.Type.SIGNATURE) {
                if (isprint(ch)) {
                    result.append(ch);
                } else {
                    result.append(mangleChar(ch));
                }
            } else {
                result.append(mangleChar(ch));
            }
        }

        return result.toString();
    }

    public String mangleMethod(ExecutableElement method, TypeElement clazz,
                                      int mtype) throws TypeSignature.SignatureException {
        StringBuilder result = new StringBuilder(100);
        result.append("Java_");

        if (mtype == Mangle.Type.METHOD_JDK_1) {
            result.append(mangle(clazz.getQualifiedName(), Mangle.Type.CLASS));
            result.append('_');
            result.append(mangle(method.getSimpleName(),
                                 Mangle.Type.FIELD));
            result.append("_stub");
            return result.toString();
        }

        /* JNI */
        result.append(mangle(getInnerQualifiedName(clazz), Mangle.Type.JNI));
        result.append('_');
        result.append(mangle(method.getSimpleName(),
                             Mangle.Type.JNI));
        if (mtype == Mangle.Type.METHOD_JNI_LONG) {
            result.append("__");
            String typesig = signature(method);
            TypeSignature newTypeSig = new TypeSignature(elems);
            String sig = newTypeSig.getTypeSignature(typesig,  method.getReturnType());
            sig = sig.substring(1);
            sig = sig.substring(0, sig.lastIndexOf(')'));
            sig = sig.replace('/', '.');
            result.append(mangle(sig, Mangle.Type.JNI));
        }

        return result.toString();
    }
    //where
        private String getInnerQualifiedName(TypeElement clazz) {
            return elems.getBinaryName(clazz).toString();
        }

    public final String mangleChar(char ch) {
        String s = Integer.toHexString(ch);
        int nzeros = 5 - s.length();
        char[] result = new char[6];
        result[0] = '_';
        for (int i = 1; i <= nzeros; i++)
            result[i] = '0';
        for (int i = nzeros+1, j = 0; i < 6; i++, j++)
            result[i] = s.charAt(j);
        return new String(result);
    }

    // Warning: duplicated in Gen
    private String signature(ExecutableElement e) {
        StringBuilder sb = new StringBuilder();
        String sep = "(";
        for (VariableElement p: e.getParameters()) {
            sb.append(sep);
            sb.append(types.erasure(p.asType()).toString());
            sep = ",";
        }
        sb.append(")");
        return sb.toString();
    }

    /* Warning: Intentional ASCII operation. */
    private static boolean isalnum(char ch) {
        return ch <= 0x7f && /* quick test */
            ((ch >= 'A' && ch <= 'Z') ||
             (ch >= 'a' && ch <= 'z') ||
             (ch >= '0' && ch <= '9'));
    }

    /* Warning: Intentional ASCII operation. */
    private static boolean isprint(char ch) {
        return ch >= 32 && ch <= 126;
    }
}