utility.cc Source File

00001 // utility.cc 
00002 //      Debugging routines.  Allows users to control whether to 
00003 //      print DEBUG statements, based on a command line argument.
00004 //
00005 // Copyright (c) 1992-1993 The Regents of the University of California.
00006 // All rights reserved.  See copyright.h for copyright notice and limitation 
00007 // of liability and disclaimer of warranty provisions.
00008 
00009 #include "copyright.h"
00010 #include "utility.h"
00011 
00012 // this seems to be dependent on how the compiler is configured.
00013 // if you have problems with va_start, try both of these alternatives
00014 #ifdef HOST_SNAKE
00015 #include <stdarg.h>
00016 #else
00017 #ifdef HOST_SPARC
00018 #include <stdarg.h>
00019 #else
00020 #include "/usr/include/stdarg.h"
00021 #endif
00022 #endif
00023 
00024 static char *enableFlags = NULL; // controls which DEBUG messages are printed 
00025 
00026 //----------------------------------------------------------------------
00027 // DebugInit
00028 //      Initialize so that only DEBUG messages with a flag in flagList 
00029 //      will be printed.
00030 //
00031 //      If the flag is "+", we enable all DEBUG messages.
00032 //
00033 //      "flagList" is a string of characters for whose DEBUG messages are 
00034 //              to be enabled.
00035 //----------------------------------------------------------------------
00036 
00037 void
00038 DebugInit(char *flagList)
00039 {
00040     enableFlags = flagList;
00041 }
00042 
00043 //----------------------------------------------------------------------
00044 // DebugIsEnabled
00045 //      Return TRUE if DEBUG messages with "flag" are to be printed.
00046 //----------------------------------------------------------------------
00047 
00048 bool
00049 DebugIsEnabled(char flag)
00050 {
00051     if (enableFlags != NULL)
00052        return (strchr(enableFlags, flag) != 0) 
00053                 || (strchr(enableFlags, '+') != 0);
00054     else
00055       return FALSE;
00056 }
00057 
00058 //----------------------------------------------------------------------
00059 // DEBUG
00060 //      Print a debug message, if flag is enabled.  Like printf,
00061 //      only with an extra argument on the front.
00062 //----------------------------------------------------------------------
00063 
00064 void 
00065 DEBUG(char flag, char *format, ...)
00066 {
00067     if (DebugIsEnabled(flag)) {
00068         va_list ap;
00069         // You will get an unused variable message here -- ignore it.
00070         va_start(ap, format);
00071         vfprintf(stdout, format, ap);
00072         va_end(ap);
00073         fflush(stdout);
00074     }
00075 }