[CMake] How to properly handle build version number in CMake script for project

[Bruce Stephens]

You could do something like

if(NOT "${BUILD_VERSION}")
  set(BUILD_VERSION 1.2.3.4)
endif()

On Mon, Apr 10, 2017 at 2:29 PM, Robert Dailey <rcdailey.lists at gmail.com> wrote:
> I have a file called version.cmake that my root CMakeLists.txt
> includes. There is only a single line in this file:
>
> set( BUILD_VERSION 1.2.3.4 CACHE STRING "Version of the product" )
>
> I have two scenarios where this version number setting needs to work
> slightly differently from a CMake perspective:
>
> 1. Our CI build server does a fresh clone of our repo, and generates
> from scratch. It sometimes needs to override the version number from
> the command line via arguments. So it will do:
>
> -D BUILD_VERSION=99.99.1.2
>
> This works since it's a cache variable. In fact, the current solution
> ONLY works well for this scenario (since it will allow overriding from
> command line, but also allow the file to set the value if it is not
> specified as a -D argument).
>
> 2. Local work machine builds. Local builds never override using -D,
> they always use what is in the version.cmake file. However, because
> it's a cache variable and I'm not using FORCE with set(), it never
> updates if I change the version and push it to origin. This is the
> missing requirement: it needs to update when the number (value)
> changes in version control
>
> I thought of making a BUILD_VERSION_OVERRIDE that is only accepted on
> the command line, and if specified, it will set the BUILD_VERSION
> value to the overridden value. However, I don't like the idea of 2
> separate variables to manage this. Using a non-cache variable doesn't
> allow overriding with the same variable value on the command line
> either.
>
> What's the best solution here for my situation?
> --
>
> Powered by www.kitware.com
>
> Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ
>
> Kitware offers various services to support the CMake community. For more information on each offering, please visit:
>
> CMake Support: http://cmake.org/cmake/help/support.html
> CMake Consulting: http://cmake.org/cmake/help/consulting.html
> CMake Training Courses: http://cmake.org/cmake/help/training.html
>
> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/cmake