[ccache] CCACHE_HARDLINK and timestamps

[tridge at samba.org]

Martin and Richard,

 > > > > Perhaps I'm missing something obvious, but wouldn't it be easy to  
 > > > > link()
 > > > > then do the equivalent of `touch` on the file? Would changing the
 > > > > timestamp on the file in the cache cause any problems?

ccache already does that. See the following code in ccache.c:

	if (ret == 0) {
		/* update the mtime on the file so that make doesn't get confused */
		utime(output_file, NULL);
	}

It also updates the timestamp on the stderr file to try to ensure that
the approximate LRU behaviour of the ccache cache is maintained.

 > Well, that sounds pretty reasonable to me.  But tridge has gone very
 > quiet on this list...

yeah, sorry. I am reading, but not responding as much as I should. I'm
travelling rather a lot at the moment (this week I'm in Brussels) and
finding it hard to keep up.

Cheers, Tridge