Re: [bug #33138] .PARLLELSYNC enhancement with patch

[Paul Smith]

On Sun, 2013-05-05 at 04:37 +0200, Frank Heckenbach wrote:
> > COMMANDS_RECURSE _does_ mean to recurse.  The reason for the '+'
> > prerequisite is to tell make that this line, even though it may not look
> > like it, will run a recursive make.
> 
> OK, let me just say that the meaning of "recursive" may not be
> perfectly clear. Though the manual says: "The @samp{+} prefix marks
> those recipe lines as ``recursive'' so that they will be executed
> despite use of the @samp{-t} flag.", the example immediately
> preceding this sentence has:
> 
>         +touch archive.a
>         +ranlib -t archive.a
> 
> which are clearly not recursive make invocations.
> 
> I gather that make uses recursive in a wider sense as "anything to
> be run regardless (because it probably arrages by itself not to do
> anything serious in a dry run or so)", while the current
> implementation of output-sync uses it in the more specific meaning
> of a recursive invocation of GNU make (which will do its own
> syncing).

It's not just this new feature that relies on this meaning.  The
jobserver feature, which also wants to know which commands are running
recursive make, also does.

If people misuse it then they'll get odd behavior.  I don't see that
there's anything we can or should do about that.

You're right, though, that this example in the make manual might not be
the best.