dnl @synopsis AC_PROG_C99_DECL
dnl 
dnl Try to find a compiler option to convince the compiler to accept
dnl mixed statements and declarations.  This macros also verifies
dnl that declarations can be made inside a for loop.  For example:
dnl
dnl  int x=0; x+=1; int y=0;
dnl  for (int z=0; z < 2; z++);
dnl
dnl @version $Id$
dnl @author Joshua N Pritikin <address@hidden>

define([AC_PROG_C99_DECL_TEST],
 [AC_TRY_COMPILE([],[
  int x=0; x+=1; int y=0;
  for (int z=0; z < 2; z++);
 ],[ac_cv_prog_c99_decl=yes],[ac_cv_prog_c99_decl=no])
])

AC_DEFUN([AC_PROG_C99_DECL],
[
 AC_MSG_CHECKING([whether $CC accepts C99 declarations])
 AC_PROG_C99_DECL_TEST
 if test $ac_cv_prog_c99_decl = no -a $GCC = yes; then
  save_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS -std=gnu99"
  AC_PROG_C99_DECL_TEST
  if test $ac_cv_prog_c99_decl = no; then
    CFLAGS="$save_CFLAGS"
  else
    ac_cv_prog_c99_decl_fix=', with -std=gnu99'
  fi
 fi

 if test $ac_cv_prog_c99_decl = yes; then
  echo "yes$ac_cv_prog_c99_decl_fix"
 else
  AC_MSG_RESULT(no)
  AC_MSG_ERROR([
*** This package requires a C compiler with C99 support.  Please
*** consider trying a recent release of GCC.])
 fi
])