10.12 Fortran 77

Automake includes full support for Fortran 77.

Fortran 77 sources that require preprocessing should have a ‘.F’ extension, and Ratfor sources should have a ‘.r’ extension. Other Fortran 77 sources should have a ‘.f’ extension.

Any package including Fortran 77 code must define the output variable F77 in configure.ac; the simplest way to do this is to use the AC_PROG_F77 macro (see Particular Programs).

A few additional variables are defined when a Fortran 77 source file is seen:

F77

The name of the Fortran 77 compiler.

FFLAGS

Any flags to pass to the Fortran 77 compiler.

AM_FFLAGS

The maintainer’s variant of FFLAGS.

RFLAGS

Any flags to pass to the Ratfor compiler.

AM_RFLAGS

The maintainer’s variant of RFLAGS.

F77COMPILE

The command used to actually compile a Fortran 77 source file. The file name is appended to form the complete command line.

FLINK

The command used to actually link a pure Fortran 77 program or shared library.

Automake can handle preprocessing Fortran 77 and Ratfor source files in addition to compiling them⁷. Automake also contains some support for creating programs and shared libraries that are a mixture of Fortran 77 and other languages (see Mixing Fortran 77 With C and C++).

These issues are covered in the following sections.