> > This is resolved on the preprocessor level, so C99 or not does not > > enter the problem. Compile-time constant, as you can see in the code > > example in the patch summary. > > You're right, I didn't catch that. It will be compatible with all C > compilers if you use a static number of slots. Yes, but this statement is merely repeating something that has been true since the sixties. > However, it will break if you use a non-C99 C compiler and the code > wants to do dynamic number of slots calculations. Of course, which is why C99 cannot be used for portable code. And it still has nothing to do with this patch. > I imagine most callers would do: > > EVIOCGABS call on ABS_MT_SLOT; > int num_slots = ABS_MT_SLOT.max - ABS_MT_SLOT.min > struct INPUT_MT_REQUEST(num_slots) req; Besides leaving a possible giant stack crash in your code, it assumes memory is somehow magically allocated. Not good practise in low-level programming. You wouldn't use a template this way, would you? > This will break on non-C99 C compilers and other language compilers. Of course, since you use the C99 dynamic stack construct, which, again, is not portable. > It also will lead to head-scratcher bugs when someone compiles it > just fine in their C99 project, copies the code to another project > with a different compiler, and is confronted with the issue. No, since people how know C do not do things like that. > I think this issue should be enough to rethink the interface. No, since your issues with C99 has nothing to do with this patch. Henrik -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
