Using the cleanup variable attribute in GCC

echorand.me

24 points·bleakgadfly··9 comments

I learned about this a few years ago, but haven't made use of it at all. But I can see how it could be handy. I like using the vector attribute to make gcc generate vector instructions.

Actually this is pretty cool, you can make the same sort of semantics as C++ stack based objects in plain C. With a couple macros you could make it pretty much feature equivalent.

Thanks for posting that!

"Plain C" is defined by the ISO C standard. Once you start using extensions like these you're better off going over to standard C++.

Once you think you need to move from some flavor of C to standard C++ you should probably switch to a safe proper garbage collected language.

systemd does that:

https://github.com/systemd/systemd/blob/v224/src/basic/macro...

https://github.com/systemd/systemd/blob/v224/src/basic/util....

https://github.com/systemd/systemd/blob/v224/src/basic/filei...

Pretty cool.

Does anyone have recommendations on great books that cover advanced C internals (other than K&R) and/or GNU extensions for C?

Expert C Programming: Deep Secrets (http://www.amazon.com/Expert-Programming-Peter-van-Linden/dp...)

Advanced C: Tips and Techniques (http://www.amazon.com/Advanced-Techniques-Hayden-Books-Libra...)

Or, you know, just use C++ if you want to do this.

No worries, it doesn't hurt, you won't have to use iterators and new.

Nah. I think that for many programs the GNU extensions to C provide a better tradeoff in terms of expressiveness vs. added complexity than the truckload of arbitrary features that is C++.

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Using the __cleanup__ variable attribute in GCC

Using the cleanup variable attribute in GCC