Re: [gnugo-devel] Re: Stack over-run

[Gunnar Farneback]

Dan wrote:
> #define TRACE  if (!(verbose)) ; else gprintf
> #define RTRACE if (!(verbose >= 3)) ; else gprintf
> #define VTRACE if (!(verbose >= 4)) ; else gprintf
> /* if debug == 0, then can skip the function call. */
> #define DEBUG  if (!debug) ; else DEBUG_func
> 
> that causes the warnings. These definitions were changed
> in the patch trevor_1_25.2. If we then use
> 
> if (condition) TRACE( ...)
> 
> this unravels to
> 
> if (condition) if (!verbose) ; else gprintf( )
> 
> which of course is ambiguous.

The common macro idiom

do { \
  ... \
} while (0)

is safe against this problem.

Trevor wrote:
> I think that would be fine, however, the keyword 'inline' is not
> used anywhere in gnugo, so I'd suspected there must be some other
> compatibility reason for that.

The inline keyword was introduced in the most recent revision of
standard C, called C99. We only want to require the older C89
standard. 

/Gunnar