DH_FORTRAN_LIB(1) dh-fortran-lib DH_FORTRAN_LIB(1)

dh_fortran_lib - Fortran library installation support

dh_fortran_lib [debhelper options] --flavor=flavor [--sourcedir=dir] [--no-orig-library] [--no-create-in-sourcedir] [libname destination ...]

dh_fortran_lib is a debhelper program that enables multiple compiler flavous of a Fortran library to be installed in parallel by mangling the library filename and SONAME.

Fortran libraries compiled by different compilers are not expected to be ABI-compatible, and hence for multiple compilers to be supported simultaneously the libraries must be named differently, and shared libraries need to include the compiler flavor in the SONAME.

dh_fortran_lib makes this possible without changes being necessary to the upstream library code.

It does this by renaming a library, for example:

        $(LIBDIR)/libfiat.so.1.2 => $(LIBDIR)/libfiat-gfortran.so.1.2
=back

Symlinks also get renamed:

        $(LIBDIR)/libfiat.so.1 => $(LIBDIR)/libfiat-gfortran.so.1

A per-flavor compilation link is added:
$(LIBDIR)/fortran/gfortran/libfiat.so -> $(LIBDIR)/libfiat-gfortran.so.1.2

and the SONAME in the ELF file is changed:

        $ readelf -a $(LIBDIR)/libfiat.so.1.2 | grep SONAME
                0x000000000000000e (SONAME)             Library soname: [libfiat.so.1]
        $ readelf -a $(LIBDIR)/libfiat-gfortran.so.1.2 | grep SONAME
                0x000000000000000e (SONAME)             Library soname: [libfiat-gfortran.so.1]

For static files, we just rename and add symlinks:

        $(LIBDIR)/libfiat.a => $(LIBDIR)/libfiat-gfortran.a
        $(LIBDIR)/fortran/gfortran/libfiat.a => $(LIBDIR)/libfiat-gfortran.a

The consequence of this is that any library that builds against libfiat with appropriate search paths set will use libfiat-gfortran instead. This enables parallel builds with multiple compiler flavors to be installed simultaneously.

The expected usage is that this will be called in debian/rules as:

        dh_fortran_lib --flavor=$(FLAVOR) $(BUILDDIR)/XXX/libfiat-gfortran.so.1

The files are installed in the sourcedir (usually debian/tmp) by default.

Look in the specified directory for files to be installed.

--no-orig-library adds the library name (with default path) to the list of files not to be installed by debhelper.

(1) Do we really want to support --no-orig-library, blocking install of unmangled library ? (2) 2 install variants;
dh_fortran_lib --flavor=F LIBBDIR/libfiat.so.4.1
# installs in debian/tmp ; simplest
dh_fortran_lib -p libfiat-dev LIBBDIR/libfiat.so.4.1 (3) what about reading .fortran-lib files? ugly build-paths messy to include in these

debhelper(7)

Alastair McKinstry <mckinstry@debian.org>

Lots of code stolen shamelessly from dh_install (Joey Hess <joeyh@debian.org> and Sébastien Villemot <sebastien@debian.org>).

2024-02-05 dh_fortran_lib v0.39