Re: [Qemu-devel] [PATCH] CPPFLAGS+= in Makefile.target

[Ian Jackson]

iwj writes ("Re: [Qemu-devel] [PATCH] CPPFLAGS+= in Makefile.target"):
> Paul Brook writes ("Re: [Qemu-devel] [PATCH] CPPFLAGS+= in Makefile.target"):
> > No. This doesn't do what you thing it does.
> > The most common way of overriding these variables is to pass them on the 
> > commandline, i.e. "make CPPFLAGS=-blah". This overrides all assignments to 
> > that variable including +=.
> 
> Err, yes (and this is annoying behaviour in make), but if
> Makefile.target sets CPPFLAGS=-I... then even config.mak cannot
> override it.

Sorry, perhaps that was less than clear.  What I mean is: if you want
for any reason to build qemu in a weird way then you're going to have
to edit config-host.mak (or somewhere similar) in any case.  You
probably want to set some CPPFLAGS as well as various other things.
If you do this at the moment then you have to reproduce all of the
CPPFLAGS -I settings and so on from Makefile.target in your own
setting that you add to config-host.mak.

With my change this is no longer needed: if you set CPPFLAGS in
config-host.mak or some target's config.mak then the right -I's are
automatically added later.

Ian.