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).
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. This should give the users enough forewarning
about the planned change, and give them time to update their packages
to the new semantic.
Automake 1.14
-------------
Flip the 'subdir-object' option on by default. At the same time,
drop support for the "old" behaviour of having object files derived
from sources in a subdirectory being placed in the current directory
rather than in that same subdirectory.
Still keep the 'subdir-object' option supported (as a simple no-op
now), to save useless churn in our user's build systems.
Thoughts, opinions?
Regards,
Stefano
