Re: [PATCH] implicit Unicode data tables generation

[Thomas Wolff <towo at towo dot net>]

Am 13.03.2018 um 16:43 schrieb Corinna Vinschen:
> On Mar 13 14:56, Thomas Wolff wrote:
> > On 13.03.2018 11:46, Corinna Vinschen wrote:
> > > On Mar 12 20:32, Thomas Wolff wrote:
> > > > Am 12.03.2018 um 15:21 schrieb Corinna Vinschen:
> > > > > 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?
> > > Implicit would be nice, it's not actually a hard requirement.
> > >
> > > We must not rely on system-installed files outside the source tree,
> > > build tree or outside the toolchain.
> > That's why my patch yesterday would ignore missing of the files.
> > > Please provide a patch removing any ln to files under /usr/share, etc.
> > ...
> ...
> You can also never make assumptions about the age of a file provided by
> your build OS.  There's a good chance the OS is providing an older
> Unicode data file version than the one you actually want to build the
> dependent files from.  Worst case, older than the currently supported
> Unicode version.
>
> The bottom line is, the Unicode data file has been either downloaded into
> the expected location in libc/ctype, or it's not available.
>
> > > The explicit rules add a rule to download the Unicode.txt file into the
> > > src tree.  That's the only file we may rely on.  If it doesn't exist,
> > > an implicit rule should not break the build.
> > Well, my mentioned patch wouldn't break it anymore.
Actually it was broken and would still abort if unicode-ucd isn't installed.
And the contributed version of string/mkunidata is broken, too; it does 
nothing because it contains an "exit" as a test artefact.
Sorry for this embarassing incident.

> > I can tweak the script further to your preference, ...
The attached patch should be sufficient for various requirements. See 
extended commit description.
Thomas

Attachment: 0001-fix-enhance-Unicode-table-generation-scripts.patch
Description: Text document