check for Fortran 90 support of mkoctfile

[Alexander Barth]

Hi all,

I would like to test with autoconf if mkoctfile supports Fortran 90 files, i.e. 
if mkoctfile calls a
Fortran 90 compiler (like gfortran or g95) or not.

I'm new to autoconf and I would like to have some comments if the code below 
seems reasonable. It
declares mkoctfile as a Fortran compiler and tests if it supports Fortran 90 
modules.

Thanks
Alex


dnl By default, autoconf tries to compile Fortran programs with
dnl optimization (-O2) which mkoctfile does not support as argument

FCFLAGS=

dnl Set Language to Fortran
AC_LANG(Fortran)

dnl Use mkoctfile as Fortran 90 compiler.
dnl No tests are performed at this stage if mkoctfile can actually handle
dnl Fortran 90 code.

AC_PROG_FC([mkoctfile], 1990)

dnl Test if mkoctfile and the Fortran 90 compiler support
dnl the extention .F90 (free-form with pre-processor directives)

AC_FC_SRCEXT(F90,,AC_ERROR([mkoctfile does not accept files with the extention 
.F90. \
Support for this file extension has been added to version 2.9.9 of octave.]))

dnl Test if mkoctfile can handle Fortran 90 features such as modules

AC_MSG_CHECKING([whether mkoctfile accepts Fortran 90])

AC_COMPILE_IFELSE([[\
module test_module; \
contains; \
end module \
]], MKOCTFILE_FORTRAN_90=yes, MKOCTFILE_FORTRAN_90=no)

OPTIMINTERPSTATUS=$MKOCTFILE_FORTRAN_90
AC_MSG_RESULT([$MKOCTFILE_FORTRAN_90])

if test $MKOCTFILE_FORTRAN_90 = no ; then
    AC_MSG_ERROR([mkoctfile does not accept Fortran 90 code. Octave was not 
build with a Fortran 90
compiler.])
fi

dnl Delete the module file. Capitalization is compiler dependent
rm -f test_module.mod TEST_MODULE.mod test_module.MOD TEST_MODULE.MOD