+
+ AC_REQUIRE([gt_TYPE_WINT_T])
+ if test $gt_cv_c_wint_t = yes; then
+ HAVE_WINT_T=1
+ else
+ HAVE_WINT_T=0
+ fi
+ AC_SUBST([HAVE_WINT_T])
+])
+
+dnl Check whether <wchar.h> is usable at all.
+AC_DEFUN([gl_WCHAR_H_INLINE_OK],
+[
+ dnl Test whether <wchar.h> suffers due to the transition from '__inline' to
+ dnl 'gnu_inline'. See <http://sourceware.org/bugzilla/show_bug.cgi?id=4022>
+ dnl and <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>. In summary,
+ dnl glibc version 2.5 or older, together with gcc version 4.3 or newer and
+ dnl the option -std=c99 or -std=gnu99, leads to a broken <wchar.h>.
+ AC_CACHE_CHECK([whether <wchar.h> uses 'inline' correctly],
+ [gl_cv_header_wchar_h_correct_inline],
+ [gl_cv_header_wchar_h_correct_inline=yes
+ AC_LANG_CONFTEST([
+ AC_LANG_SOURCE([[#define wcstod renamed_wcstod
+#include <wchar.h>
+extern int zero (void);
+int main () { return zero(); }
+]])])
+ if AC_TRY_EVAL([ac_compile]); then
+ mv conftest.$ac_objext conftest1.$ac_objext
+ AC_LANG_CONFTEST([
+ AC_LANG_SOURCE([[#define wcstod renamed_wcstod
+#include <wchar.h>
+int zero (void) { return 0; }
+]])])
+ if AC_TRY_EVAL([ac_compile]); then
+ mv conftest.$ac_objext conftest2.$ac_objext
+ if $CC -o conftest$ac_exeext $CFLAGS $LDFLAGS conftest1.$ac_objext conftest2.$ac_objext $LIBS >&AS_MESSAGE_LOG_FD 2>&1; then
+ :
+ else
+ gl_cv_header_wchar_h_correct_inline=no
+ fi
+ fi
+ fi
+ rm -f conftest1.$ac_objext conftest2.$ac_objext conftest$ac_exeext
+ ])
+ if test $gl_cv_header_wchar_h_correct_inline = no; then
+ AC_MSG_ERROR([<wchar.h> cannot be used with this compiler ($CC $CFLAGS $CPPFLAGS).
+This is a known interoperability problem of glibc <= 2.5 with gcc >= 4.3 in
+C99 mode. You have four options:
+ - Add the flag -fgnu89-inline to CC and reconfigure, or
+ - Fix your include files, using parts of
+ <http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=b037a293a48718af30d706c2e18c929d0e69a621>, or
+ - Use a gcc version older than 4.3, or
+ - Don't use the flags -std=c99 or -std=gnu99.
+Configuration aborted.])
+ fi