/*
 *    LinkerUtil.java    1.3    03/01/14 SMI
 *
 * Copyright © 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package util;
/*
 * Some things I find convenient for parsing strings and
 * options containing signatures.
 */
public class LinkerUtil{

    /*
     * Read the named file.
     * Tokenize the input.
     * Returns an array of Strings which are the tokens.
     * Propagates FileNotFound if the named file cannot be opened.
     * In the input stream, the character '#' is understood
     * to start a comment which continues to end-of-line.
     */
    public static String[]
    parseOptionFile( String fname ) throws java.io.IOException {
    java.util.Vector v = new java.util.Vector();
    java.io.StreamTokenizer in;
    in = new java.io.StreamTokenizer(
        new java.io.BufferedInputStream(
        new java.io.FileInputStream( fname ) ) );
    in.resetSyntax();
    in.eolIsSignificant( false );
    in.whitespaceChars( 0, 0x20 );
    in.wordChars( '!', '~' );
    in.commentChar('#');

    while ( in.nextToken() != java.io.StreamTokenizer.TT_EOF ){
        v.addElement( in.sval );
    }

    int n = v.size();
    String olist[] = new String[ n ];
    v.copyInto( olist );
    return olist;
    }

    /*
     * A few constants we frequently use.
     */
    public final static String mainName = "main";
    public final static String mainSig  = "([Ljava/lang/String;)V";
    public final static String constructorName = "<init>";
    public final static String constructorSig  = "()V";
    public final static String staticInitializerName = "<clinit>";
    public final static String staticInitializerSig  = "()V";

    /*
     * Classes are often written with . as component separator.
     * But in classfiles, as internally in our programs, we use /.
     * So we often want to find all instances of . and change them
     * into /.
     */
    public static String 
    sanitizeClassname( String classname ){
    return classname.replace('.', '/').intern();
    }

    /*
     * When writing a fully-qualified method name,
     * the type signature starts with (. Exploit this
     * fact when looking for that signature.
     */
    public static int
    sigOff( String n ){
    return n.indexOf( '(' );
    }

    /*
     * When writing a fully-qualified method name, 
     * the name of the method is separated from the name
     * of the containing class by a ., or sometimes by a /
     * find the offset of that character.
     */
    public static int
    methodOff( String n ){
    int moff = n.lastIndexOf( '.' );
    if ( moff >= 0 ) return moff;
    // curses. Must work harder.
    // Cannot just say lastIndexOf('/'), as that
    // may get us into the signature.
    int ending = n.indexOf( '(' );
    if ( ending < 0 ) ending = n.length();
    moff = n.lastIndexOf( '/', ending );
    return moff;
    }

}