AC_FC_OPEN_SPECIFIERS(specifier ...)
The Fortran OPEN statement is a rich source of
portability problems, since there are numerous common
extensions which consiste of extra specifiers, several of
which are useful when they are available. For each of the
specifiers in the (whitespace-separated) argument list,
define HAVE_FC_OPEN_mungedspecifier if the
specifier may be given as argument to the OPEN statement.
The mungedspecifier is the
specifier converted to uppercase and with all
characters outside [a-zA-Z0-9_] deleted.
Note that this may include `specifiers' such as
access='append' and
[access='sequential',recl=1] (note quoting of
comma) to check combinations of specifiers. You may not
include a space in the `specifier', even quoted. Each
argument must be a maximum of 65 characters in length (to
abide by Fortran 77 line-length limits).
See Section 2.5 for an example of using this preprocessor definition in a Fortran program.