bug#13378: [IMPORTANT] Make the 'subdir-objects' setup the default, and only available one

[Peter Johansson]

On 1/8/13 6:08 AM, Stefano Lattarini wrote:
> Severity: wishlist
>
> Inspired from Automake-NG commit 'v1.12.1-313-g14fe163' of 2012-06-07,
> "[ng] subdir-objects: enable unconditionally".
>
> The fact that Automake-generated Makefiles place compiled object files in
> he current directory by default, also when the corresponding source file
> is in a subdirectory, is basically an historical accident, due to the fact
> that the 'subdir-objects' option had only been introduced in April 1999,
> starting with commit 'user-dep-gen-branchpoint-56-g88b5959', and never
> made the default (likely to avoid backwards-compatibility issues).
If the maintainer didn't wanna break compatibility backwards back then, 
why is it a better idea to break it today?
> Since I believe the behaviour enabled by the 'subdir-objects' is the most
> useful one, and in fact the *only* natural one, I'd like to make it the
> the only one available, simplifying the Automake implementation and APIs
> a little in the process.
>
> Alas, since this also means changing the default behaviour of Automake
> ('subdir-objects' is not enabled by default, sadly), this means the
> transition path will be less smooth than I'd like.  Here it is a sketch
> for it:
>
>    Automake 1.13.2
>    ---------------
>
>    Give a warning in the category 'unsupported' if the 'subdir-objects'
>    option is not specified.

I assume user will get no warning when irrelevant, i.e., if all source 
files sit in current directory there is no need to give this warning.

>   This should give the users enough forewarning
>    about the planned change, and give them time to update their packages
>    to the new semantic.
You assume users install every version of Automake you release. In my 
understanding going from 1.13 to 1.14 is similar to go from Autoconf 
2.68 to 2.69.

Cheers,
Peter

--
Peter Johansson