Re: Android port

[Bruno Haible <bruno@clisp.org>]

Eli Zaretskii wrote:
> > Will you typically want to
> >   - review all format strings in Emacs, to see whether they are affected?
> >   - add some note to Emacs-internal coding guidelines, e.g. to the effect
> >     that %b should not be used?
> >   - review the mingw-specific *printf override, to see whether it
> >     needs a workaround (in case b) or an extension (in case c)?
> >   - or do nothing at all?
> 
> Some mix of the above, depending on the case.  But only for the MinGW
> build.

OK. How do you reliably get notified about the relevant changes?
If you look at gnulib/ChangeLog and search for "mingw" or "Windows"
you will spot some of the relevant changes.

For more reliability, I would save the generated config.cache from a mingw
build somewhere, and compare the config.cache of newer builds with the
saved one. If you see an added gl_cv_* variable or an existing one
whose value has changed, you can raise your eyebrows. So, it makes
sense to override only the mimimum of gl_cv_* variables.

However, this approach would still have its potential gaps:
In case
> >   (b) because a bug has been discovered on mingw

Gnulib might stuff the new configure test into an existing AC_RUN_IFELSE
invocation and thus reuse an existing gl_cv_* variable. (Not for *printf,
but for other modules.) Say, gl_cv_foobar_works meant the absence of
bugs P and Q, and now it means the absence of bugs P, Q, and R. When
the override gl_cv_foobar_works=yes was added, it meant "our nt code
has workarounds for P and Q". Thus, you won't be alerted that you need
to add a workaround for R or remove the override gl_cv_foobar_works=yes.

If you were to build the corresponding gnulib tests as part of the Emacs
build (gnulib-tool option '--with-tests'), then we would have added a unit
test against bug R, and this test would fail, thus alerting you that
you need to do something.

Note: Since the gnulib-tool invocation includes many '--avoid' options,
some test failures are to be expected, until these tests are '--avoid'ed
as well.

Bruno