Compiler Patterns

/*************************************************************************
*    NAME: debug.h
*  AUTHOR: David Qualls (davidlqualls@yahoo.com)
* PURPOSE: Declare globals variables, macros, and functions needed for
*          debugging and error reporting.
*
*   NOTES:

 -Either NODEBUG, or DEBUG must be #defined.  NODEBUG takes precedence 
  over DEBUG.  Set DEBUG to 0 (zero) for no general-level debugging, to 
  1 (one) for standard debug output to a debugging file, and to 2 for 
  panic debugging (outputting to console and to debugging file).  Can 
  also be set to negative numbers to reduce the immediacy of individual 
  function debugging.
  
 -Individual function debugging is controlled by the DEBUG_funcname macro 
  (with funcname replaced by the actual function name).  For example:
  #define DEBUG_getOffset 2
  will set the debugging level for the function getOffset() to 2.
  The higher the value, the more panicky the messages are; at least, they 
  get printed to more places.  These values can also be set to negative ints 
  to omit debugging output from a function you know to be working, when
  general level debugging is turned on (greater than zero).
  
 -The actual behavior of individual debugging code is controlled by the 
  sum of the global DEBUG value, and the individual function DEBUG_funcname
  value.
  
 -Here is a list of the only debugging code available from this system.
 
 dbgmsg( const char *msg, ... ) //format just like printf
 dbgcode{ //any code you want evaluated ONLY WHEN DEBUGGING 
          //goes between these braces.
 }
 infunc( funcname )  //Makes tracing the execution possible.
 outfunc()           //Must accompany any infunc() call.  Function logic must 
                     //be arranged such that EXACTLY ONE of these is called
                     //during function execution.  In other words, at run-time,
                     //infunc() and outfunc() calls must balance.
                     
 Note that raising exceptions (long jumping out of the normal flow and 
 bypassing normal returns) will wreak havoc with your infunc/outfunc 
 balance... Good luck!! 
 
 -The "infunc( funcname )" macro will produce a compile-time error
  unless the macro DEBUG_funcname (with funcname replaced by the actual
  function name) is defined to a numeric value.  

 -A convenient place to put the DEBUG macros is in the <source_file>_cfg.h file.

*************************************************************************/

#ifndef DEBUG_H
# define DEBUG_H

//#include "debug_cfg.h"

#include <stdio.h>

extern FILE *debug_file_G;

//extern int   ErrorTrap;
// #define your ErrorTrap to be whatever will trip when true!

#ifdef NODEBUG

inline void dbgmsg( const char *msg, ... )
{
  /*this may cause warnings, but hopefully, an optimizer 
    will remove any actual code.
  */
  ;
}
inline void dbgprint( const char *fmt_string, ... )
{
  ;
}
//const int debug_always_zero_G = 0;

//#define dbgcode if(debug_always_zero_G)
#define dbgcode if(0)

#define infunc( a )
#define outfunc( )
#define dbgchkpt 

#else
/* NODEBUG is NOT defined, */

# ifndef DEBUG_main
#  define DEBUG_main 0
# endif

# if  !defined( DEBUG ) || (DEBUG < -3)
#  error "You need to give a valid numeric value to the macro DEBUG, or just define NODEBUG"
# endif

extern int debug_G; /* Global flag indicating to "debug" everything. */
                    /* Initially gets set to value of macro DEBUG.   */

void dbgmsg( const char *msg, ... );
void dbgprint( const char *msg, ... );
int  get_debug_value();
#define dbgcode  if( get_debug_value() > 0 )
#define infunc( name ) infunc_( #name, __LINE__, __FILE__, DEBUG_##name )
#define dbgchkpt dbgmsg( "checkpoint -- file %s, line %d", __FILE__ , __LINE__ );
void outfunc( void );

//void infunc_( const char *fname, int num );
void infunc_( const char *fname, int linenum, const char *file, int num );


#endif
/*closure for #ifdef NODEBUG */

#endif
/* end of #ifndef DEBUG_H */