According to libtool three individual numbers stand for
CURRENT:REVISION:AGE, or C:R:A for short. The libtool
script typically tacks these three numbers onto the end
of the name of the .so file it creates. The formula for
calculating the file numbers on Linux and Solaris is
/path/to/library/<library_name>.(C - A).(A).(R)
As you release new versions of your library, you will
update the library's C:R:A. Although the rules for changing
these version numbers can quickly become confusing, a few
simple tips should help keep you on track. The libtool
documentation goes into greater depth.
In essence, every time you make a change to the library and
release it, the C:R:A should change. A new library should start
with 0:0:0. Each time you change the public interface
(i.e., your installed header files), you should increment the
CURRENT number. This is called your interface number. The main
use of this interface number is to tag successive revisions
of your API.
The AGE number is how many consecutive versions of the API the
current implementation supports. Thus if the CURRENT library
API is the sixth published version of the interface and it is
also binary compatible with the fourth and fifth versions
(i.e., the last two), the C:R:A might be 6:0:2. When you break
binary compatibility, you need to set AGE to 0 and of course
The REVISION marks a change in the source code of the library
that doesn't affect the interface-for example, a minor bug fix.
Anytime you increment CURRENT, you should set REVISION back to 0.
Signed-off-by: Harshavardhana <firstname.lastname@example.org>
Tested-by: Gluster Build System <email@example.com>
Reviewed-by: Niels de Vos <firstname.lastname@example.org>
Reviewed-by: Vijay Bellur <email@example.com>