Re: [Qemu-devel] [Qemu-trivial] [PATCH 2/2] Makefile: use full path for qapi-generated directory

[Stefano Stabellini]

On Thu, 1 Dec 2011, Stefan Weil wrote:
> Am 01.12.2011 16:19, schrieb Stefano Stabellini:
> > On Wed, 30 Nov 2011, Stefan Weil wrote:
> >> It's common to use either out-of-tree builds or in-tree builds,
> >> but not to mix both variants with a common root directory.
> >> I think QEMU should explicitly forbid that mixed scenario (like
> >> other projects do).
> >>
> >> Even with your fix there can remain problems with generated
> >> header files.
> >
> > Really? Can you provide more specific details?
> 
> Yes. Suppose different generated header files with the same name
> exist in the source directory tree and in the build directory tree.
> 
> Then compiler options (the order of -I options) will determine
> which of two header files with same name will be used in out-of-tree
> builds. If the wrong one (that from the source directory tree) is used,
> the compiler might fail or produce wrong code (for example when
> macro values changed).
> >> The mixed scenario creates unnecessary complexity.
> >> Without the mixed scenario, your patch is not needed.
> >
> > I agree that supporting the mixed scenario shouldn't be a priority.
> > However without this last patch a "make clean" on the main tree is not
> > enough to allow out of tree builds.
> >
> > Try the following scenario:
> >
> > - cd qemu; ./configure; make
> >
> > - make clean
> >
> > - cd ../temp; ./configure --source-path=../qemu; make
> 
> Which ./configure do you run in an empty temp directory?
> This example (like similar ones in your previous mail) won't work.

Sorry, it was supposed to be ../qemu/configure