Re: automake/501: abbreviating the .Po-related output somewhat

[Ralf Wildenhues <Ralf dot Wildenhues at gmx dot de>]

The following reply was made to PR automake/501; it has been noted by GNATS.

From: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
To: Paul Eggert <eggert@gnu.org>
Cc: automake-gnats@sources.redhat.com
Subject: Re: automake/501: abbreviating the .Po-related output somewhat
Date: Mon, 28 Aug 2006 19:26:15 +0200

 Hello Paul,
 
 * Paul Eggert wrote on Sun, Aug 27, 2006 at 06:45:25AM CEST:
 > 
 >    if gcc -std=gnu99  -I. -I../../cu-tmp1/src -I../lib  -I../../cu-tmp1/lib    -MT dd.o -MD -MP -MF ".deps/dd.Tpo" -c -o dd.o ../../cu-tmp1/src/dd.c; \
 >    then mv -f ".deps/dd.Tpo" ".deps/dd.Po"; else rm -f ".deps/dd.Tpo"; exit 1; fi
 [...]
 
 > 2.  The "mv -f" / "rm -f" seems overkill here.  Apparently
 > it is there to address the problem of failed or interrupted
 > compiles.  But the same problem exists for the .o file as
 > well.  In practice the problem is not serious enough to be
 > worth the extra 'make' output.  Yes, the dependency might be
 > wrong with a failed compile, but it might be wrong anyway if
 > you've changed a source file, and there's little real
 > benefit to the 'mv -f' / 'rm -f'.
 
 I think a really bad case were if the dependency file was
 corrupted in a way that the next `make' invocation would
 die.  The code for this was introduced first here by Tom:
 http://lists.gnu.org/archive/html/automake-patches/2002-07/msg00007.html
 and already contained this code, so it's not conclusive.
 
 Could a parallel make invocation reading the incomplete
 file be an issue (note that Makefiles can include .Po
 files from different directories, with subdir-objects)?
 
 Cheers,
 Ralf