The following warnings
configure.in:20: warning: AC_PROG_CPP was called before AC_PROG_F77
configure.in:21: warning: AC_PROG_F77 was called before AC_PROG_F77_C_O
are issued by autoconf, because of AC_BEFORE statements in AC_PROG_F77 and
AC_PROG_F77_C_O. I don't understand both statements, for different
reasons:
- CPP/F77: I do not see why these should be related. In my case, the
warning is issued because I test the C compiler before the fortran
compiler, and the C compiler test involves the preprocessor test.
From my experience with preprocessed Fortran code, I think
Fortran-related autoconf code
should not set the variable CPP; it should rather use it to find a way
to preprocess fortran code if the compiler isn't able to do that.
It may set another variable instead (e.g. FPP or F77_CPP).
I think that AC_BEFORE([$0], [AC_PROG_CPP]) in AC_PROG_F77 is
superfluous.
- F77_C_O: I do not understand why AC_PROG_F77_C_O should be called
before AC_PROG_F77. After all, AC_PROG_F77 needs to find a fortran
compiler first before testing its features.
Another issue: I question whether "g77" should really be the first-choice
Fortran compiler on systems with both GNU and native compilers
installed. Although I do prefer free software to commercial software, I
picture that people who paid $1000 or more for a commercial fortran
compiler may want to use that one (especially since g77 has some
significant drawbacks), without having to type "F77=f77 ./configure" all
the time. Therefore, I suggest to put "g77" after "f77" and perhaps
after other names of good native Fortran 77 compilers in the
AC_CHECK_TOOLS list. Of course, g77 should come before "fc" and any
Fortran 90 compilers.
--
Martin Wilck <[EMAIL PROTECTED]>
Institute for Tropospheric Research, Permoserstr. 15, D-04318 Leipzig, Germany
Tel. +49-341-2352151 / Fax +49-341-2352361
