Re: Creating subdirs of distdir

[Stepan Kasal]

Hello Ralf,
  thank you for your review and improvements.
A few quick comments:

On Tue, May 23, 2006 at 09:31:18PM +0200, Ralf Wildenhues wrote:
> [...] nobody uses `|' in a file name.  I think it's pretty safe
> to assume this. [...]

Sure it is.  The current code already assumed that:
    case ... in $(srcdir)/*) ... $(top_srcdir)/*) ...

> I think we can kill the per-file forks before the mkdir_p, too.

You mean the $(srcdir) and $(top_srcdir) stripping.  But it takes
place only in certain situations:
- if the make implementation inserts $(srcdir) (GNU make doesn't)
- or if the author of Makefile.am usees $(srcdir) or $(top_srcdir)
  (well educated maintainers don't)

So when you replaced all the per-file forks by a constant number of
three forks, you actually slowed down the most common usecase.

I think it should be either reverted, or wrapped in a case command,
see below.

Moreover, your sed program is not portable; you cannot use semicolon
after the `t' command nor after the `:' command.

What about the following (quick untested sketch):

> +     list='$(DISTFILES)'; \
> +## The `case' command eliminates unnecesary forks in most of the cases
> +## when $list would stay intact.
> +     case $$list in $(srcdir)/*|$(top_srcdir)/*) \
> +       list=`for file in $$list; do echo $$file; done | \
> +         | sed -e "s|^$$srcdirstrip/||;t" \
> +               -e "s|^$$topsrcdirstrip/|$(top_builddir)/|;t"`;; \
> +##           (The second `t' command clears the flag for the next round.)
> +     esac; \
> +##
> +## Make the subdirectories for the files.
> +## (The DISTDIRS list can be incomplete, because files in subdirectories can
> +## be specified for `dist' conditionally.)
> +##
> +     case $$list in */*) \
> +       ( cd "$(distdir)"; \
> +         $(mkdir_p) `echo "$$list" | sed -n 's,/[^/]*$$,,p' | sort -u`; \
> +       ) ;; \
> +     esac; \
> +##
> +##
> +     for file in $$list; do \

Good night,
        Stepan