test for preprocessor fails on iPhoneOS

[Peter Johansson]

Hi folks,

We got an bug report to GNU Scientific Library
http://lists.gnu.org/archive/html/bug-gsl/2014-02/msg00000.html
saying that GSL's configure script doesn't work on iPhoneOS when using 
clang.

We managed to trim down the 'configure.ac' to the following

AC_INIT([mini], [1.0])
AM_INIT_AUTOMAKE([foreign])
AC_PROG_CC
AC_PROG_CPP
AC_CONFIG_FILES([Makefile])
AC_OUTPUT
AS_ECHO(["configuration OK"])

which still causes the same problem. I've attached 'configure' script 
and the 'config.log' (gzipped) from a run on iPhoneOS. As far as I can 
understand the log, the PP fails to preprocess code

#ifdef __STDC__
# include <limits.h>
#else
# include <assert.h>
#endif
         Syntax error

with error message:
In file included from conftest.c:12:
In file included from 
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/usr/include/limits.h:63:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/usr/include/sys/cdefs.h:655:2: 
error: Unsupported architecture
#error Unsupported architecture

From the mail conversation 'limits.h' looks like this on the system:

/#if   defined (__arm__) || defined (__arm64__)/
/#include <arm/limits.h>/
/#else/
/#error architecture not supported/
/#endif/

I guess my question is basically if you have any insights on whether 
this is a bug in Autoconf, a bug in GSL's configure.ac, an Apple bug, a 
user error, or any other explanation.

Thank you!

Cheers,
Peter

config.log.gz
Description: GNU Zip compressed data

mini-1.0.tar.gz
Description: GNU Zip compressed data