stacktraceframe.java

一个开源的JAVA虚拟机

/*
 * This class records a frame in a stack trace.
 */

package aegis;

class StackTraceFrame {
    /* The Aegis VM assumes that a frame has exactly 4 reference fields 
       (char[]) and exactly 1 primitive field (int).
    */
    private char[] className;
    private char[] methodName;
    private char[] methodSignature;
    private char[] fileName;
    private int lineNumber;
    private StackTraceFrame() { }
    public String toString() {
	String msg = "" + new String(className) + "." +
	    new String(methodName) + new String(methodSignature);
	/* fileName or lineNumber may not be present for one of the
	   following reasons:
	   (1) The SourceFile and LineNumberTable attributes are optional
	   attributes: a class file may not have them.
	   (2) The VM may be built with the processing of the two attributes
	   turned off.
	*/
	if (fileName != null) {
	    msg += " (" + new String(fileName);
	    if (lineNumber >= 0)
		msg += ": " + Integer.toString(lineNumber);
	    msg += ")";
	}
	return msg;
    }
}