Tips on writing C macros

Re:Tips on writing C macros by tb on Tuesday August 04, 2009 @09:04PM (#742578)

The do-while "nonsense" is a pretty standard construct, so much so that I'd never seen your approach - which I admit looks nicer. How well is that supported across different compilers? Is it part of C99, for example?

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Re:Tips on writing C macros by paulbaumgart on Tuesday August 04, 2009 @09:19PM (#742603)

No, it's not in C99: http://www.redhatrenewals.com/docs/manuals/enterprise/RHEL-4...

Admittedly I have little experience with compilers other than GCC, but all things considered, I'd shy away from using anything but really basic macros without the compound-statement-in-parens and typeof() extensions that GCC provides.

Perhaps I spoke too harshly, calling it "nonsense". :-)

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Re:Tips on writing C macros by paulbaumgart on Thursday September 03, 2009 @07:09PM (#803805)

So, just to follow up, I saw that the OCUnit macros ( http://www.sente.ch/software/ocunit/ ) are all using defined using the do...while(0) guard.

I was wrong. It's the more platform independent way to do things.

For code that's only ever going to be compiled with GCC, though, the statement expression method is cleaner, I think.

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Re:Tips on writing C macros by tedunangst on Tuesday August 04, 2009 @09:20PM (#742605)

It's only supported by gcc and some edg based compilers. edg has trouble with it in some c++ code. Just think of how adding this complicates your grammar.

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