Jean Delvare wrote: > Hi Hans, > > On Mon, 22 Oct 2007 11:40:11 +0200, Hans de Goede wrote: >> Jean Delvare wrote: >>>>> I expected applications to deal with the >>>>> different versions on their own. But if you think that a #define in >>>>> sensors.h would help, just go ahead, that's fine with me. >>>> Well as explained above ./configure and the Makefiles don't need to know about >>>> the different versions, So only some code changes are needed, for which it >>>> would be nice if a #define is present to test for. >>> As I said, just go ahead and add the #define you want. Feel free to add >>> the "same" #define to trunk if it helps. >> Done, >> >> I've also added a comment how to use it in future versions. The idea is to >> increment the lower digit when for example new features are added to the >> featuretype enum, so that applications can check the SENSORS_API_VERSION and >> conditionally support new features for example (if they don't/can't check they >> will no longer compile against an older libsensors). > > I think I wouldn't have bothered. If applications no longer compile > with an older libsensors, then just upgrade libsensors. > That would mean much pain for distro developers which want to minimize churn, but may still need to upgrade an application because of security reasons. >> The middle digit is both an overflow for the lower, and/or for bigger changes >> like the addition of methods. I know the addition of methods would mean apps >> compiled against the new version will not work with the old, but this is quite >> normal todo, see for example gtk2 and many others. > > Yes, that's not a problem. > >> Let me know what you think of this scheme and / or feel free to change it. > > If someone is willing to maintain the API number, that's fine with me. > Me, I'll try to remember, but as I know myself, chances are good that > I'll forget sometimes if nobody is watching over me. > I'll try to keep an eye on it. I hope that if we forget users will complain. > Just one thing I'm curious about: are you sure you want to set the API > to 400 _decimal_? Setting it to 0x400 instead seems to be more > flexible, as is allows for constructs like: > > #if (SENSORS_API_VERSION >> 16) == 4 > > which is plain impossible to do with a decimal version number. Well with mine one can do: #if (SENSORS_API_VERSION / 100) == 4 But I'm fine with either. > Another thing: don't you want to define SENSORS_API_VERSION in trunk as > well? If not, you'll always have to test for SENSORS_API_VERSION's > existence before checking its value. I know that versions up to and > including 2.10.4 do not have the define and we can't change that, but > maybe applications will want to support all versions >= 2.10.5 so that > the #if magic can be limited to something sane. > Not necessary, if an identifier which is not a MACRO gets used in an #if statement it is considered zero, so to take you example: #if (SENSORS_API_VERSION / 100) == 4 Would expand to: #if (0 / 100) == 4 And thus be false. Regards, Hans
