Re: 2.5.21: kbuild changes broke filenames with commas

From: Daniel Phillips (
Date: Tue Jun 11 2002 - 11:36:44 EST

On Tuesday 11 June 2002 18:31, Russell King wrote:
> On Tue, Jun 11, 2002 at 06:08:22PM +0200, Daniel Phillips wrote:
> > Are you sure that complexity was added just to handle commas in names?
> > Or is it really an example of how good design never gave this bug a
> > chance to exist in the first palce.
> >
> > I *really* don't like the idea of papering over such bugs by curing the
> > symptoms, as you seem to be advocating.
> Lets see.
> We have two places in 2.5.21 where commas are unacceptable:
> 1. -DKBUILD_BASENAME=$(subst $(comma),_,$(subst -,_,$(*F)))
> We need to do this because to do because KBUILD_BASENAME is used in
> places where commas are not acceptable.
> We papered over the fact that make can't subst commas by using the
> $(comma) construct.
> 2. -Wp,-MD,.$(subst /,_,$@).d (currently unfixed)
> This would need to become something like:
> -Wp,-MD,.$(subst /,_,$(subst $(comma,_,$@)).d
> So now we have two places where the same yucky substing of commas to
> something more palettable happens. Now, what if we had:
> foo,bar.c
> and
> foo_bar.c
> in the same directory? The kbuild system goes wrong, destroying dependency
> information, using the wrong KBUILD_BASENAME. Oops. I guess we papered
> over a bug by allowing commas in filenames.


> In addition, I'd like to point out the following paragraph in the make
> info files:
> The variant variables' names are formed by
> appending `D' or `F', respectively. These variants are semi-obsolete
> in GNU `make' since the functions `dir' and `notdir' can be used to get
> a similar effect (*note Functions for File Names: File Name
> Functions.).
> Both kbuild-2.5 and the existing kernel build make heavy use of the
> "$(*F)" notation. Should we really be putting semi-obsolete features
> into either of the kernel build system?

No, agreed. Now this is sensible.

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