On 10 Jul 2003, Zack Weinberg <[EMAIL PROTECTED]> wrote: > Alexandre Oliva <[EMAIL PROTECTED]> writes: > > > On Jul 10, 2003, "Zack Weinberg" <[EMAIL PROTECTED]> wrote: > > > >> Yeah. I vote always do it, too. > > > > Fine, I'll do that. As long as there's a way to disable it, I'm fine > > with it. I dislike that it will prevent legitimate uses of ccache and > > make gcc different from all other compilers in this regard, but, heck, > > I don't want to fight over this. > > I don't understand. On by default makes sense precisely because > there's no bad side effect to this feature. If there *is* a bad > side effect which I'm not aware of, then my opinion may be different, > but I don't see how having this information in the .i file can > possibly interfere with anything.
ccache is a cache of the mapping from [arguments, cpp output, some other stuff] to [object file, error output]. Suppose we use ccache to build two identical trees in different directories. Previously the second tree would have got 100% cache hits (roughly) but the directory in the second tree's debug info would have been wrong. With this change, the second tree will not get any cache hits, because the cpp output will contain the directory name. This makes the cache more accurate, which is generally desirable. However, if you never used the debug information, then you might be disappointed by the reduced hit rate. Since the directory name (I think) only affects the debug information, it might be good to turn -Mpwd on when running cpp only if -g is specified, if that makes any sense for gcc. Alternatively it can just always be on and ccache could optionally ignore the line when computing its hash. For distcc it's always better to include the path and get the more correct output. -- Martin __ distcc mailing list http://distcc.samba.org/ To unsubscribe or change options: http://lists.samba.org/cgi-bin/mailman/listinfo/distcc
