Re: Fortran 9x support

[Akim Demaille]

| Hello all,

Hi Steven,

First of all, sorry for having been silent about this issue: I had
other duties I was focused on :(


| 4) I've added two new FC-only macros specifically for newer Fortran
| dialects.  For a complete description, see the source, but to summarize:
| 
| AC_FC_SRCEXT(EXT, [ACTION-IF-SUCCESS], [ACTION-IF-FAIL])
|       -- set the extension used for subsequent tests to EXT (e.g. f90);
| the default extension is f.  Also can detect whether special compiler
| flags are required to support the new extension (in particular with IBM's
| compilers).

The name is quite cryptic, why not AC_FORTRAN_SRCEXT?  Actually,
should this be hidden into some

AC_LANG_SRCEXT

which would set $ac_$lang_srcext to one or several supported
extensions?  I mean, do we want to expose the low level macro
AC_FC_SRCEXT?

| AC_FC_FREEFORM([ACTION-IF-SUCCESS], [ACTION-IF-FAIL])
|       -- find compiler flags (added to FCFLAGS) to convince the compiler
| to accept free-form source files.  (I've found at least one compiler (VAST
| f90) where this apparently isn't possible for .f files, so I would
| recommend that users use this in conjunction with AC_FC_SRCEXT to first
| set the extension to .f90 or whatever.  Of course, in that case, this
| macro is normally not needed...)
| 
| I've done basic testing of the various new Fortran macros on the systems
| available to me (Linux with VAST f90, AIX, Alpha/Tru64, IRIX) and they
| seem to be working.
| 
| I haven't written documentation yet because I expect that the patch will
| change somewhat in response to feedback, and I am under no illusions that
| this will make it into Autoconf 2.55.  =)
| 
| We should also coordinate with the Automake folks.  Using the new macros
| in automake should be straightforward; the main question is which compiler
| to use for which file extensions, and how to interact with AC_FC_SRCEXT.
| (I've already proposed one possible behavior on the autoconf mailing list
| thread.)

I tend to think that we might want more languages.  Why not

AC_LANG(Preprocessed Fortran)

vs.

AC_LANG(Fortran)

vs.

AC_LANG(Fortran 2000)

We should drop AC_PROG_FOO for compilers and such, they are too
special.