long long

Posted Jun 1, 2007 1:32 UTC (Fri) by roelofs (guest, #2599)
In reply to: long long by giraffedata
Parent article: The return of syslets

Unfortunately, you really have to go further than that to have a reasonable chance. Old systems don't have those types defined, or have them defined elsewhere than <stdint.h>. So you really have to use local types which you laboriously define to whatever types, long long or whatever, work on that system.

Yes, but fortunately there aren't any more of those, so you set up your own typedefs once (e.g., based on predefined macros) and you're done.

I distribute some software used on a wide variety of systems, some quite old, and this has been a nightmare for me. The inability to test for the existence of type at compile time, or redefine one, is the worst part.

Yup, been there, done that, got the scars. And I 100% agree (heh) that the failure to link typedefs to macros (or something else the preprocessor can test) was a massive mistake on the part of the standardization committee(s). "Let's see, now... It's an error to re-typedef something, so why don't we make such cases completely undetectable!"

Fortunately that's mostly water under the bridge at this point, though. And you can get pretty far on old systems by detecting them on the basis of macros. Back in the Usenet days I maintained a script called defines, which did a fair job of sniffing out such things (and also reporting native sizes), along with a corresponding database of its output. I think Zip and UnZip still use some of the results, though I don't know if any of those code paths have been tested in recent eras.

Greg