bug#10555: automake: wrong use of F77FLAGS instead of FFLAGS?

[Stefano Lattarini]

Severity: minor
thanks

In the Automake repository, I'm seeing this:

  $ git grep F77FLAGS
  lib/Automake/Variable.pm:   F77FLAGS => 'AC_PROG_F77',
  $ grep -C 10 F77FLAGS lib/Automake/Variable.pm
  # Macros shipped with Autoconf.
  my %_ac_macro_for_var =
    (
     ALLOCA => 'AC_FUNC_ALLOCA',
     CC => 'AC_PROG_CC',
     CFLAGS => 'AC_PROG_CC',
     CXX => 'AC_PROG_CXX',
     CXXFLAGS => 'AC_PROG_CXX',
     F77 => 'AC_PROG_F77',
     F77FLAGS => 'AC_PROG_F77',
     FC => 'AC_PROG_FC',
     FCFLAGS => 'AC_PROG_FC',
     OBJC => 'AC_PROG_OBJC',
     OBJCFLAGS => 'AC_PROG_OBJC',
     RANLIB => 'AC_PROG_RANLIB',
     UPC => 'AM_PROG_UPC',
     UPCFLAGS => 'AM_PROG_UPC',
     YACC => 'AC_PROG_YACC',
   );

But autoconf uses FFLAGS, not F77FLAGS, as the variable where to look for
switches for the Fortran 77 compiler:

  $ cd src/autoconf
  $ git grep F77FLAGS || echo NOT FOUND
  NOT FOUND
  $ grep FFLAGS lib/autoconf/fortran.m4
  # dialects.  Fortran 77 uses environment variables F77, FFLAGS, and FLIBS,
  ac_compile='$F77 -c $FFLAGS conftest.$ac_ext >&AS_MESSAGE_LOG_FD'
  ac_link='$F77 -o conftest$ac_exeext $FFLAGS $LDFLAGS conftest.$ac_ext $LIBS 
>&AS_MESSAGE_LOG_FD'
  AC_ARG_VAR([FFLAGS], [Fortran 77 compiler flags])dnl

And the autoconf documentation agrees with that:

  * Variable: FFLAGS
    Debugging and optimization options for the Fortran 77 compiler. If it
    is not set in the environment when configure runs, the default value
    is set when you call AC_PROG_F77 (or empty if you don't). configure
    uses this variable when compiling or linking programs to test for
    Fortran 77 features.

  ...

  ``Fortran 77''
  Do compilation tests using F77 and use extension .f for test programs.
  Use compilation flags: FFLAGS.

So, to all autoconfers: do you happen to know any reason for which Automake
should use F77FLAGS? If not, I'll assume that is due to a typo or clerical
mistake, and fix it (in 48 hours or so).

Thanks,
  Stefano