Re: [PATCH] kbuild: Use symbolic link to the source tree for out-of-tree build

[Michal Marek <mmarek@suse.cz>]

On 2014-07-09 08:27, Masahiro Yamada wrote:
> Since commit 9da0763bd, the variable 'srctree' is set as follows:
> 
> [1] Building in the source tree
>       => srctree is set to '.'
> [2] Building in a subdir right under the source tree
>       => srctree is set to '..'
> [3] Other cases
>       => srctree is set to the absolute path to the source tree
> 
> Pros are more readable compiler messages, WARN_ON() etc.
> for case [1] and [2]. (but not [3])
> 
> Cons are we have to do build-test for 3 cases when adding
> some changes to the build infrastructure.
> 
> We want to treat case [2] and [3] in the same way like prior to
> commit 9da0763bd, keeping the compact log messages.
> 
> The idea here is to create a symbolic link 'srctree' pointing
> to $(KBUILD_SRC) at the very early stage of the build process.

If the symlink points to an absolute path, then you can't move the
source and build tree around anymore.

Michal