Re: Why AC_C_CHAR_UNSIGNED?

[Ralf Wildenhues]

* Stepan Kasal wrote on Tue, Jun 24, 2008 at 05:31:57PM CEST:
> * lib/autoconf/c.m4 (AC_C_CHAR_UNSIGNED): Warn that it is obsolete;
> reported by Hallvard B Furuseth.
> * doc/autoconf.texi (C Compiler): Move AC_C_CHAR_UNSIGNED...
> (Obsolete Macros): ...here, and mention why.
> * NEWS: Mention.

I have one issue with this patch.  AC_C_CHAR_UNSIGNED isn't exacly
obsolete.  There are still systems with unsigned and systems with signed
chars, and this issue isn't going away.  It may also be helpful to have
an Autoconf macro to test for this, if only to have a shell variable
upon which the configure script may take some decision.

So this isn't in the same class as AC_TYPE_SIGNAL, for example.

How about if we keep AC_C_CHAR_UNSIGNED as it is, and only recommend
that one can also use the cheap preprocessor test instead?

Thanks for working on this,
Ralf