---
name: "dh_fortran_lib"
section: "1"
platform: "linux"
package: "dh-fortran-mod"
version: "0.43"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dh_fortran_lib"
---

# dh\_fortran\_lib(1)

Fortran library installation support

## NAME

dh\_fortran\_lib - Fortran library installation support

## SYNOPSIS

**dh\_fortran\_lib** \[*debhelper options*\] **--flavor=***flavor* \[**--sourcedir=***dir*\] \[**--no-orig-library**\] \[**--no-create-in-sourcedir**\]  \[*libname* *destination* ...\]

## DESCRIPTION

**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.

## USAGE

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.

## OPTIONS

- **--flavor=**dir =item **--sourcedir=***dir* =item **-n**, **--no-orig-library**

  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.

## TODO

(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

## SEE ALSO

[**debhelper**(7)](/debhelper/7.md)

## AUTHORS

Alastair McKinstry \<mckinstry@debian.org\>

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