perfSONAR User Q&A and Other Discussion

[Brian Candler <>]

I am going through the bwctl code to fix compiler warnings (some of
which are serious, e.g. strncat potentially going 1 byte over end of buffer)

One thing I'm not sure about is the expression ((void*)!NULL) which
occurs in these places:

./bwctl/bwctl.c:        *closure = (void *)!NULL;
./bwctl/bwctl.c:        if(
!BWLContextConfigSet(ctx,BWLChildWait,(void*)!NULL)){
./bwctld/bwctld.c:                if(
!BWLContextConfigSet(ctx,BWLChildWait,(void*)!NULL)){
./bwctld/bwctld.c:        if(
!BWLContextConfigSet(ctx,BWLChildWait,(void*)!NULL)){

Now, (!NULL) == (!0) == 1. As a pointer this is almost certainly
invalid, so I guess it's just being used as a NULL or not-NULL test
somewhere.

The warning is:

bwctld.c:2290:59: warning: cast to 'void *' from smaller integer type 'int'
      [-Wint-to-void-pointer-cast]
                if( !BWLContextConfigSet(ctx,BWLChildWait,(void*)!NULL)){

Maybe (void*)1L is a clearer indication of intention?

Regards,

Brian.

________________________________
Brian Candler
Systems Architect

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