OPT_BOARD variant-optional code

Created Mon, 13 Feb 2012 06:33:49 +0000 by WestfW

WestfW

Mon, 13 Feb 2012 06:33:49 +0000

So I was looking that the Variants/xxx/Board_defs.h and Board_Data.h...

It seems a bit more cumbersome than needed. You have:

// In Board_defs.h
#define	OPT_BOARD_DIGITAL_IO	0	//board does not extend digital i/o func


//And then in Board_data.c
#if	(OPT_BOARD_DIGITAL_IO != 0)
int	_board_pinMode(uint8_t pin, uint8_t mode) {
	return 0;
}


// And in the core code:
#if (OPT_BOARD_DIGITAL_IO != 0)
	/* Peform any board specific processing.
	*/
int	_board_digitalWrite(uint8_t pin, uint8_t val);
	if (_board_digitalWrite(pin, val) != 0)
	{
		return;
	}
#endif

I don't like having the prototypes for the external functions in the core c code, either. How about something like:

// In Board_defs.h
#define	OPT_BOARD_DIGITALWRITE(p,v)	0	//board does not extend digital i/o func
// or
//extern int _board_digitalWrite(uint8_t pin, uint8_t val);
//#define OPT_BOARD_DIGITALWRITE(p,v)  _board_digitalWrite(p, v)


//And then in Board_data.c, only if actually needed
int	_board_pinMode(uint8_t pin, uint8_t mode) {
	// real code
}


// And in the core code:
	/* Peform any board specific processing.
	*/
	if (OPT_BOARD_DIGITALWRITE(pin, val) != 0) {
		return;
	}
#endif

This would use the compiler optimizer to leave out impossible clauses if OPT_BOARD_xxx was a consstant 0, removing a lot of the conditional compilation from elsewhere...