catalog Info Catalog previous automake-1.16: Compiling Fortran 77 Files up automake-1.16: Fortran 77 Support

automake-1.16: Mixing Fortran 77 With C and C++

 
 8.14.3 Mixing Fortran 77 With C and C++
 ---------------------------------------
 
 Automake currently provides _limited_ support for creating programs and
 shared libraries that are a mixture of Fortran 77 and C and/or C++.
 However, there are many other issues related to mixing Fortran 77 with
 other languages that are _not_ (currently) handled by Automake, but that
 are handled by other packages(1).
 
    Automake can help in two ways:
 
   1. Automatic selection of the linker depending on which combinations
      of source code.
 
   2. Automatic selection of the appropriate linker flags (e.g., ‘-L’ and
      ‘-l’) to pass to the automatically selected linker in order to link
      in the appropriate Fortran 77 intrinsic and run-time libraries.
 
      These extra Fortran 77 linker flags are supplied in the output
      variable ‘FLIBS’ by the ‘AC_F77_LIBRARY_LDFLAGS’ Autoconf macro.
      ⇒Fortran Compiler Characteristics (autoconf)Fortran Compiler.
 
    If Automake detects that a program or shared library (as mentioned in
 some ‘_PROGRAMS’ or ‘_LTLIBRARIES’ primary) contains source code that is
 a mixture of Fortran 77 and C and/or C++, then it requires that the
 macro ‘AC_F77_LIBRARY_LDFLAGS’ be called in ‘configure.ac’, and that
 either ‘$(FLIBS)’ appear in the appropriate ‘_LDADD’ (for programs) or
 ‘_LIBADD’ (for shared libraries) variables.  It is the responsibility of
 the person writing the ‘Makefile.am’ to make sure that ‘$(FLIBS)’
 appears in the appropriate ‘_LDADD’ or ‘_LIBADD’ variable.
 
    For example, consider the following ‘Makefile.am’:
 
      bin_PROGRAMS = foo
      foo_SOURCES  = main.cc foo.f
      foo_LDADD    = libfoo.la $(FLIBS)
 
      pkglib_LTLIBRARIES = libfoo.la
      libfoo_la_SOURCES  = bar.f baz.c zardoz.cc
      libfoo_la_LIBADD   = $(FLIBS)
 
    In this case, Automake will insist that ‘AC_F77_LIBRARY_LDFLAGS’ is
 mentioned in ‘configure.ac’.  Also, if ‘$(FLIBS)’ hadn’t been mentioned
 in ‘foo_LDADD’ and ‘libfoo_la_LIBADD’, then Automake would have issued a
 warning.

Menu

 
· How the Linker is Chosen    Automatic linker selection
 
    ---------- Footnotes ----------
 
    (1) For example, the cfortran package
 (https://www-zeus.desy.de/~burow/cfortran/) addresses all of these
 inter-language issues, and runs under nearly all Fortran 77, C and C++
 compilers on nearly all platforms.  However, ‘cfortran’ is not yet Free
 Software, but it will be in the next major release.
catalog Info Catalog previous automake-1.16: Compiling Fortran 77 Files up automake-1.16: Fortran 77 Support