Release Numbering and Methodology

Release Version Numbering Scheme

Release numbers consist of three parts, a major number, a minor number, and a revision number, each separated by a dot.

The major number is currently 2, to indicate the multilib layout has been adapted to the fairly different one used starting with AVR-GCC version 5. Nevertheless, it is still believed to be generally API-compatible with release versions 1.x.

In the past (up to 1.6.x), even minor numbers have been used to indicate "stable" releases, and odd minor numbers have been reserved for development branches/versions. As the latter has never really been used, and maintaining a stable branch that eventually became effectively the same as the development version has proven to be just a cumbersome and tedious job, this scheme has given up in early 2010, so starting with 1.7.0, every minor number will be used. Minor numbers will be bumped upon judgement of the development team, whenever it seems appropriate, but at least in cases where some API was changed.

Starting with version 1.4.0, a file <avr/version.h> indicates the library version of an installed library tree.

Releasing AVR Libc

The information in this section is only relevant to AVR Libc developers and can be ignored by end users.

Note

In what follows, I assume you know how to use SVN and how to checkout multiple source trees in a single directory without having them clobber each other. If you don't know how to do this, you probably shouldn't be making releases or cutting branches.

Creating an SVN branch

The following steps should be taken to cut a branch in SVN (assuming $username is set to your savannah username):

1. Check out a fresh source tree from SVN trunk.
2. Update the NEWS file with pending release number and commit to SVN trunk:
   Change Changes since avr-libc-<last_release>: to Changes in avr-libc-<this_relelase>.
3. Set the branch-point tag (setting <major> and <minor> accordingly):
   svn copy svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/trunk svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/tags/avr-libc-<major>_<minor>-branchpoint
4. Create the branch:
   svn copy svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/trunk svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/branches/avr-libc-<major>_<minor>-branch
5. Update the package version in configure.ac and commit configure.ac to SVN trunk:
   Change minor number to next odd value.
6. Update the NEWS file and commit to SVN trunk:
   Add Changes since avr-libc-<this_release>:
7. Check out a new tree for the branch:
   svn co svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/branches/avr-libc-<major>_<minor>-branch
8. Update the package version in configure.ac and commit configure.ac to SVN branch:
   Change the patch number to 90 to denote that this now a branch leading up to a release. Be sure to leave the <date> part of the version.
9. Bring the build system up to date by running bootstrap and configure.
10. Perform a 'make distcheck' and make sure it succeeds. This will create the snapshot source tarball. This should be considered the first release candidate.
11. Upload the snapshot tarball to savannah.
12. Update the bug tracker interface on Savannah: Bugs —> Edit field values —> Release / Fixed Release
13. Announce the branch and the branch tag to the avr-libc-dev list so other developers can checkout the branch.

Making a release

A stable release will only be done on a branch, not from the SVN trunk.

The following steps should be taken when making a release:

1. Make sure the source tree you are working from is on the correct branch:
   svn switch svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/branches/avr-libc-<major>_<minor>-branch
2. Update the package version in configure.ac and commit it to SVN.
3. Update the gnu tool chain version requirements in the README and commit to SVN.
4. Update the ChangeLog file to note the release and commit to SVN on the branch:
   Add Released avr-libc-<this_release>.
5. Update the NEWS file with pending release number and commit to SVN:
   Change Changes since avr-libc-<last_release>: to Changes in avr-libc-<this_relelase>:.
6. Bring the build system up to date by running bootstrap and configure.
7. Perform a 'make distcheck' and make sure it succeeds. This will create the source tarball.
8. Tag the release:
   svn copy . svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/tags/avr-libc-<major>_<minor>_<patch>-release
   or
   svn copy svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/branches/avr-libc-<major>_<minor>-branch svn+ssh://$username@svn.savannah.nongnu.org/avr-libc/tags/avr-libc-<major>_<minor>_<patch>-release
9. Upload the tarball to savannah.
10. Update the NEWS file, and commit to SVN:
    Add Changes since avr-libc-<major>_<minor>_<patch>:
11. Update the bug tracker interface on Savannah: Bugs —> Edit field values —> Release / Fixed Release
12. Generate the latest documentation and upload to savannah.
13. Announce the release.

The following hypothetical diagram should help clarify version and branch relationships.

Release tree