From: "Doug McIlroy" <doug(a)cs.dartmouth.edu>
Subject:Re: [TUHS] Mac OS X is Unix
keeping the code I work on portable between Linux and
the Mac requires
more than a bit of ‘ifdef’ hell.
| Curmudgeonly comment: I bristle at the coupling of "ifdef” and
"portable".
| Ifdefs that adjust code for different systems are prima facie
| evidence of NON-portability. I'll buy "configurable" as a descriptor
| for such ifdef'ed code, but not "portable".
| <snip>
| "Ifdef hell" is a fitting image for what has to be one of
| Unix's least felicitous contributions to computing. Down
| with ifdef!
| Doug
Doug makes a very good point about ifdef hell. Though I’d claim that it isn’t even
“configurable” at some level.
Several years ago I was working at Megatek, a graphics h/w vendor. We were porting the X11
suite to various new boards at the rate of about 1 a week it seemed. Needless to say the
code became such a mishmash of ifdef’s that you couldn’t figure out what some functions
did any longer. You just hoped and prayed that your patch worked properly on the various
hardware you were targeting and didn’t break it for anyone else. You ran the unit tests,
if they passed you pushed your change and ran an hid under a rock for a while until you
were sure it was safe to come out again.
David