* Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > On Fri, Feb 06, 2009 at 05:12:29PM +0100, Ingo Molnar wrote: > > > > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > > > > > > We cannot see any downside of this patch. > > > > > > > > But we can see upside of this patch is: > > > > 1. No need to protect linux/types.h with #ifndef __ASSEMBLY__ in many > > > > files > > > > 2. So we trying to replace multiple #ifndef __ASSEMBLY__ with one. > > > > > > The point is: > > > > > > 1. If the parent include needs to include linux/types.h to get at C > > > types _and_ the include file needs to also be included by assembly > > > code, it itself needs to have #ifndef __ASSEMBLY__ to protect those > > > uses from the assembly code. > > > > > > In that case, the linux/types.h include should be contained within > > > the #ifndef __ASSEMBLY__ .. #endif block along with all C only > > > parts of the header file. > > > > That makes the code much less clean: putting #include's in the middle of a > > header is poor style and leads to people failing to consider dependencies. > > We generally put them to the header portion. > > > > Putting an #include line in the middle of a header file is a receipe for a > > dependency hell (it can easily fall inside #ifdefs, can be overlooked, > > etc.), so it's _strongly_ discouraged (at least on arch/x86). > > Put them at the top then with an additional ifndef. So you advocate 40 stupid pairs of #ifdefs spread out, instead of a _single_, obvious #ifdef in a commonly used header? Case closed. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
