-# include <stdio.h>
-# if HAVE_STDIO_EXT_H
-# include <stdio_ext.h>
-# endif
-'
- AC_CHECK_DECLS([__fpending], , , $fp_headers)
- if test $ac_cv_func___fpending = no; then
- AC_CACHE_CHECK(
- [how to determine the number of pending output bytes on a stream],
- ac_cv_sys_pending_output_n_bytes,
- [
- for ac_expr in \
- \
- '# glibc2' \
- 'fp->_IO_write_ptr - fp->_IO_write_base' \
- \
- '# traditional Unix' \
- 'fp->_ptr - fp->_base' \
- \
- '# BSD' \
- 'fp->_p - fp->_bf._base' \
- \
- '# SCO, Unixware' \
- '(fp->__ptr ? fp->__ptr - fp->__base : 0)' \
- \
- '# QNX' \
- '(fp->_Mode & 0x2000 /*_MWRITE*/ ? fp->_Next - fp->_Buf : 0)' \
- \
- '# old glibc?' \
- 'fp->__bufp - fp->__buffer' \
- \
- '# old glibc iostream?' \
- 'fp->_pptr - fp->_pbase' \
- \
- '# emx+gcc' \
- 'fp->_ptr - fp->_buffer' \
- \
- '# VMS' \
- '(*fp)->_ptr - (*fp)->_base' \
- \
- '# e.g., DGUX R4.11; the info is not available' \
- 1 \
- ; do
+ #include <stdio.h>
+ #if HAVE_STDIO_EXT_H
+ # include <stdio_ext.h>
+ #endif
+ '
+ AC_CACHE_CHECK([for __fpending], [gl_cv_func___fpending],
+ [
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM([$fp_headers],
+ [[return ! __fpending (stdin);]])],
+ [gl_cv_func___fpending=yes],
+ [gl_cv_func___fpending=no])
+ ])
+ if test $gl_cv_func___fpending = yes; then
+ AC_CHECK_DECLS([__fpending], [], [], [$fp_headers])
+ fi
+])