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

[Paul Smith]

On Sat, 2013-05-04 at 08:57 +0200, Frank Heckenbach wrote:
> I shouldn't have written that. :-( Shortly afterwards, I found a bug
> or perhaps two:
> 
> foo:
>         @echo foo
>         address@hidden bar
> 
> (a)
> % make -Ojob
> foo
> bar
> foo
> 
> (b)
> % make -Otarget
> bar
> foo
> 
> As you see, (a) "-Ojob" writes "foo" twice and (b) "-Otarget" writes
> the messages in the wrong order.

The second one is known and I mentioned it the other day (hard to keep
up with all the messages, I know).  I'm working on a fix.

The first one I've seen but hadn't had time to debug.  I'll look at your
patch.  I left the truncate where it was rather than doing it after the
sync_output() because I was hoping to avoid truncating a file that we'll
never use again anyway, but I guess it isn't a big deal.


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.

Since make doesn't parse the command line it can't know for sure which
ones actually recurse.  It uses a heuristic, by looking for $(MAKE) or
${MAKE} in the unexpanded line.  But this is easily defeated if your
sub-make invocation doesn't use that variable for some reason.  Hence,
using "+" to force it.