Re: [PATCH] implicit Unicode data tables generation

[Thomas Wolff <towo at towo dot net>]

Am 12.03.2018 um 15:21 schrieb Corinna Vinschen:
> On Mar 12 08:41, Yaakov Selkowitz wrote:
> > On 2018-03-12 08:35, Corinna Vinschen wrote:
> > > On Mar  9 08:46, Thomas Wolff wrote:
> > > > diff --git a/newlib/libc/ctype/Makefile.am b/newlib/libc/ctype/Makefile.am
> > > > index fa6a70d..714b333 100644
> > > > --- a/newlib/libc/ctype/Makefile.am
> > > > +++ b/newlib/libc/ctype/Makefile.am
> > > > @@ -135,3 +135,23 @@ CHEWOUT_FILES= \
> > > >   CHAPTERS = ctype.tex
> > > >   
> > > >   $(lpfx)ctype_.$(oext): ctype_.c ctype_iso.h ctype_cp.h
> > > > +
> > > > +#############################################################################
> > > > +# Unicode data
> > > > +
> > > > +$(srcdir)/%.txt:
> > > > +	cd $(srcdir); test -r $(notdir $@) || ln -s /usr/share/unicode/ucd/$(notdir $@) .
> > > This is a no-no.  Do not create links into the OS tree.  You don't
> > > even know if the file exists.
> > >
> > > > +$(srcdir)/categories.t:	$(srcdir)/UnicodeData.txt
> > > > +	cd $(srcdir); sh ./mkcategories
> > > > +
> > > > +$(srcdir)/caseconv.t:	$(srcdir)/UnicodeData.txt
> > > > +	cd $(srcdir); sh ./mkcaseconv
> > > > +
> > > Consequently, these rules are broken.   Consider that somebody might
> > > build from git without manually installing UnicodeData.txt.  In that
> > > case the above rules lead to a build error, along the lines of
> > >
> > >    UnicodeData.txt not found
> > >    Error 1
> > >    ...
> > >
> > > It would be helpful to create rules which just skip the dependency
> > > if UnicodeData.txt doesn't exist in the source tree.  Unfortunately,
> > > the only way to do that off the top of my head is to make the *.t files
> > > depend on a phony target which then does everything in shell.  Better
> > > ideas highly appreciated.
That's why I would have appreciated to go with the explicit generation 
only, as you had previously requested.

> > I think either unicode-ucd is a required build dependency, or otherwise
> > these rules would have to be explicit only and keep the generated files
> > in git for the benefit of those without it.
Yes, I forgot to suggest that unicode-ucd should be listed at 
https://cygwin.com/[faq/]faq.html#faq.programming.building-cygwin.
If that's not desired, on the other hand...
> A build dependency to unicode-ucd should not be required.  Why not have
> automatic build rules which are simply skipped if the file doesn't
> exist?  So somebody can download the file and the rules do the rest?
> It's not *that* important, but a nice feature.
The easiest way would be that the mkunidata scripts just ignore the 
missing files, like in the patch attached.
On the other hand, in my original scripts I had the additional fallback 
option to download them from unicode.org on demand.
If that's acceptable in a build process, I could add that back in.
Or just drop those rules and stay explicit?
Thomas

Attachment: 0001-drop-strict-dependency-on-Unicode-data-in-unicode-uc.patch
Description: Text document