Re: Missing features from .FEATURES

[Paul Smith]

On Wed, 2014-10-22 at 14:05 -0400, Jean Pierre LeJacq wrote:
> GNU Make uses the special variable .FEATURES to advertise which features 
> your version of make supports.
> 
> For some reason, not all features are supported. For example, secondary, 
> delete on error, and posix mode.
> 
> What is the rationale for leaving these out?

The .FEATURES variable was itself added in GNU make 3.81.  Any feature
that was available before that release is not included in .FEATURES.
Or, put another way, the mere fact that the .FEATURES variable has some
value is enough to conclude that those capabilities are present.

I'm not positive what you mean by "secondary" and "posix mode", so I'm
not completely confident this answers your question, but
.DELETE_ON_ERROR was added in GNU make 3.72, released in 1994.

And, there have been times where new features have been added but
nothing was added to .FEATURES; sometimes the presence of these is
testable in other obvious ways.  Sometimes we forgot :-/.