5.2. Contributed Software

Contributed by Poul-Henning Kamp 且 David O'Brien.

Some parts of the FreeBSD distribution consist of software that is actively being maintained outside the FreeBSD project. For historical reasons, we call this contributed software. Some examples are sendmail, gcc and patch.

Over the last couple of years, various methods have been used in dealing with this type of software and all have some number of advantages and drawbacks. No clear winner has emerged.

Since this is the case, after some debate one of these methods has been selected as the “official” method and will be required for future imports of software of this kind. Furthermore, it is strongly suggested that existing contributed software converge on this model over time, as it has significant advantages over the old method, including the ability to easily obtain diffs relative to the “official” versions of the source by everyone (even without cvs access). This will make it significantly easier to return changes to the primary developers of the contributed software.

Ultimately, however, it comes down to the people actually doing the work. If using this model is particularly unsuited to the package being dealt with, exceptions to these rules may be granted only with the approval of the core team and with the general consensus of the other developers. The ability to maintain the package in the future will be a key issue in the decisions.

The Tcl embedded programming language will be used as example of how this model works:

src/contrib/tcl contains the source as distributed by the maintainers of this package. Parts that are entirely not applicable for FreeBSD can be removed. In the case of Tcl, the mac, win and compat subdirectories were eliminated before the import.

src/lib/libtcl contains only a bmake style Makefile that uses the standard bsd.lib.mk makefile rules to produce the library and install the documentation.

src/usr.bin/tclsh contains only a bmake style Makefile which will produce and install the tclsh program and its associated man-pages using the standard bsd.prog.mk rules.

src/tools/tools/tcl_bmake contains a couple of shell-scripts that can be of help when the tcl software needs updating. These are not part of the built or installed software.

The important thing here is that the src/contrib/tcl directory is created according to the rules: it is supposed to contain the sources as distributed (on a proper CVS vendor-branch and without RCS keyword expansion) with as few FreeBSD-specific changes as possible. The 'easy-import' tool on freefall will assist in doing the import, but if there are any doubts on how to go about it, it is imperative that you ask first and not blunder ahead and hope it “works out”. CVS is not forgiving of import accidents and a fair amount of effort is required to back out major mistakes.

Because of the previously mentioned design limitations with CVS's vendor branches, it is required that “official” patches from the vendor be applied to the original distributed sources and the result re-imported onto the vendor branch again. Official patches should never be patched into the FreeBSD checked out version and “committed”, as this destroys the vendor branch coherency and makes importing future versions rather difficult as there will be conflicts.

Since many packages contain files that are meant for compatibility with other architectures and environments that FreeBSD, it is permissible to remove parts of the distribution tree that are of no interest to FreeBSD in order to save space. Files containing copyright notices and release-note kind of information applicable to the remaining files shall not be removed.

If it seems easier, the bmake Makefiles can be produced from the dist tree automatically by some utility, something which would hopefully make it even easier to upgrade to a new version. If this is done, be sure to check in such utilities (as necessary) in the src/tools directory along with the port itself so that it is available to future maintainers.

In the src/contrib/tcl level directory, a file called FREEBSD-upgrade should be added and it should state things like:

• Which files have been left out.

• Where the original distribution was obtained from and/or the official master site.

• Where to send patches back to the original authors.

• Perhaps an overview of the FreeBSD-specific changes that have been made.

However, please do not import FREEBSD-upgrade with the contributed source. Rather you should cvs add FREEBSD-upgrade ; cvs ci after the initial import. Example wording from src/contrib/cpio is below:

This directory contains virgin sources of the original distribution files
on a "vendor" branch.  Do not, under any circumstances, attempt to upgrade
the files in this directory via patches and a cvs commit.  New versions or
official-patch versions must be imported.  Please remember to import with
"-ko" to prevent CVS from corrupting any vendor RCS Ids.

For the import of GNU cpio 2.4.2, the following files were removed:

        INSTALL         cpio.info       mkdir.c
        Makefile.in     cpio.texi       mkinstalldirs

To upgrade to a newer version of cpio, when it is available:
        1. Unpack the new version into an empty directory.
           [Do not make ANY changes to the files.]

        2. Remove the files listed above and any others that don't apply to
           FreeBSD.

        3. Use the command:
                cvs import -ko -m 'Virgin import of GNU cpio v<version>' \
                        src/contrib/cpio GNU cpio_<version>

           For example, to do the import of version 2.4.2, I typed:
                cvs import -ko -m 'Virgin import of GNU v2.4.2' \
                        src/contrib/cpio GNU cpio_2_4_2

        4. Follow the instructions printed out in step 3 to resolve any
           conflicts between local FreeBSD changes and the newer version.

Do not, under any circumstances, deviate from this procedure.

To make local changes to cpio, simply patch and commit to the main
branch (aka HEAD).  Never make local changes on the GNU branch.

All local changes should be submitted to "cpio@gnu.ai.mit.edu" for
inclusion in the next vendor release.

obrien@FreeBSD.org - 30 March 1997