Re: [Automake-NG] [PATCH 05/15] [ng] tests: Automake should let us append to undefined variables (someday)

[Akim Demaille]

Le 25 mai 2012 à 13:38, Stefano Lattarini a écrit :

> This is not the case yet, mostly for historical reason.  However, allowing
> that would mimic the behaviour of GNU make more closely (see the test case
> 't/spy-var-append.sh').  Likely (and hopefully), it would also simplify
> the implementation.

The point was to prevent users from messing around with Automake
variables.

Say I use FOO, and run FOO += without initializing it.  If this is
an Automake variable, then all is well, and it does what I expect.
if this is not an Automake variable, then I must initialize it,
and this is then clearly a user variable.

Suppose that Automake did not mandate that I initialize this
variable to state it is mine.  Imagine then that some new release
of Automake uses FOO.  Then I am most probably doing silly things
by appending to it (where I expected to just += the initial value).

Whereas, had I initialized it, Automake would have complained from
my using a variable it owns.