Re: patch to support output synchronization under -j

[Eli Zaretskii]

> From: Paul Smith <address@hidden>
> Cc: address@hidden
> Date: Tue, 03 May 2011 01:33:38 -0400
> 
> But, I've been playing with a makefile that I have, that builds a
> complete suite of GCC tools from scratch.  I'm building them on larger
> systems with -j5 or -j10 (not much compared to what some are doing I
> realize).  Sometimes these builds fail and it can be frustrating to see
> what part of the build is failing.
> 
> But here's the thing: these makefiles are by their very nature massively
> recursive.  Each top-level rule is an entire build of a major component
> like gcc, binutils, gdb, bison, etc.  As far as I understand it, if I
> were to enable this feature then all of the output from the entire build
> of gcc (for example) would be collected into a file and not printed
> until the entire sub-make had completed.

That was exactly the scenario I had in mind when I wrote my message.
Recursive Makefiles are the rule nowadays, at least with GNU software,
and the top-level Makefile does little more than launch a "make all"
job in each subdirectory.  GCC or GDB might be extreme examples, but I
do build them from time to time, and there are less extreme examples
which nevertheless take considerable time to run each sub-Make.

I think we must find some solution to put this under user control, or
else this feature will be useful only for small projects.