/*
Copyright (c) 2000 The Regents of the University of California.
All rights reserved.

Permission to use, copy, modify, and distribute this software for any
purpose, without fee, and without written agreement is hereby granted,
provided that the above copyright notice and the following two
paragraphs appear in all copies of this software.

IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/

/** Command line flags */
class Flags {
    /** No garbage collection */
    public static final int GC_NOGC = 0;

    /** Generational garbage collection */
    public static final int GC_GENGC = 1;
    
    /** Stop-and-copy garbage collection */
    public static final int GC_SNCGC = 2;

    /** Normal GC operation */
    public static final int GC_NORMAL = 3;

    /** Test GC operation */
    public static final int GC_TEST = 4;

    /** Quick GC debugging */
    public static final int GC_QUICK = 5;

    /** Full GC debugging */
    public static final int GC_DEBUG = 6;

    /** Garbage collector flag (default GC_NOGC)
     * @see #GC_NOGC
     */
    public static int cgen_Memmgr = GC_NOGC;

    /** Garbage collector testing flag (default GC_NORMAL)
     * @see #GC_NORMAL
     */
    public static int cgen_Memmgr_Test = GC_NORMAL;

    /** Garbage collector debugging flag (default GC_QUICK)
     * @see #GC_NOGC
     */
    public static int cgen_Memmgr_Debug = GC_QUICK;
   
    /** Code optimization flag */
    public static boolean cgen_optimize = false;

    /** Output filename */
    public static String out_filename = null;

    /** First input filename */
    public static String in_filename = null;

    /** Enable parser debugging */
    public static boolean parser_debug = false;

    /** Enable semantic analysis debugging */
    public static boolean semant_debug = false;

    /** Enable code gen debugging */
    public static boolean cgen_debug = false;

    /**
     * Processes command line flags and extracts filenames to be compiled
     *
     * @param args the argument array passed to main()
     * @return an array of filenames to be compiled
     * */
    public static String[] handleFlags(String args[]) {
	int filecnt = 0;
	boolean unknownopt = false;
	for (int i = 0; i < args.length; i++) {
	    if (args[i] != null) {
		if (args[i].charAt(0) == '-') {
		    if (args[i].length() != 2) {
			System.err.println("Error in \"" + args[i] + "\".  Flags must be specified one at a time.\n");
			System.exit(1);
		    }
		    // this is a flag
		    switch (args[i].charAt(1)) {
		    case 'g':
			cgen_Memmgr = GC_GENGC;
			break;
		    case 't':
			cgen_Memmgr_Test = GC_TEST;
			break;
		    case 'T':
			// sm: this was disabled .. don't know why
			cgen_Memmgr_Debug = GC_DEBUG;
			break;
		    case 'o':
			if ((i+1) < args.length) {
			    out_filename = args[i + 1];
			    args[i + 1] = null;
			} else {
			    unknownopt = true;
			}
			break;
		    case 'O':
			cgen_optimize = true;
			break;
		    case 'p':
			parser_debug = true;
			break;
		    case 's':
			semant_debug = true;
			break;
		    case 'c':
			cgen_debug = true;
			break;
		    default:
			unknownopt = true;
			break;
		    }
		    args[i] = null;
		} else {
		    // this is a filename, save the first name we see
		    if (in_filename == null) in_filename = args[i];
		    filecnt++;
		}
	    }
	}

	if (unknownopt) {
	    System.err.println("usage: <program> [-OgtT -o outname] [input-files]\n");
	    System.exit(1);
	}

	String[] res = new String[filecnt];
	int ind = 0;
	for (int i = 0; i < args.length; i++) {
	    if (args[i] != null) {
		res[ind++] = args[i];
	    }
	}
	return res;
    } 
}