Re: [PATCH] stdbool: avoid rejecting clang

[Ralf Wildenhues]

* Eric Blake wrote on Tue, Aug 24, 2010 at 01:17:38AM CEST:
> * m4/stdbool.m4 (AC_HEADER_STDBOOL): Resync with autoconf.
> * tests/test-stdbool.c: Enable more tests if using the system
> <stdbool.h> instead of the gnulib replacement.
> (main): Move xlc bug test to a runtime test for all compilers.
> Reported by Anders Kaseorg.

On AIX 5.3, with

$ xlc -qversion
IBM XL C/C++ Enterprise Edition V8.0 for AIX 
Version: 08.00.0000.0025

the current git Autoconf AC_HEADER_STDBOOL test still provokes a
failure:

configure:3108: checking for stdbool.h that conforms to C99
configure:3193: cc -qlanglvl=extc89 -c -g  conftest.c >&5
"conftest.c", line 46.16: 1506-196 (W) Initialization between types "_Bool" and 
"struct s*" is not allowed.
"conftest.c", line 74.23: 1506-221 (S) Initializer must be a valid constant 
expression.

with line 46 being
|       bool e = &s;

and line 74 being
|        int xlcbug = 1 / (&(digs + 5)[-2 + (bool) 1] == &digs[4] ? 1 : 0);

and with git gnulib and above Autoconf installed,
$ gnulib-tool --with-tests --test stdbool

still succeeds.

Same with CC='xlc -qlanglvl=extc99'.

Cheers,
Ralf