cmake: add versioning module

cmake/Versioning.cmake

@@ -0,0 +1,26 @@
+find_package(Git)
+
+if(GIT_EXECUTABLE)
+    execute_process(
+        COMMAND ${GIT_EXECUTABLE} describe --tags
+        OUTPUT_VARIABLE TAG_VERSION
+        RESULT_VARIABLE ERROR_CODE
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+    )
+
+    if(TAG_VERSION STREQUAL "")
+        set(TAG_VERSION 0.0.0)
+        message(WARNING "Failed to determine version from Git tags. Using default version \"${TAG_VERSION}\".")
+    endif()
+
+    message(STATUS "Project version: ${TAG_VERSION}")
+
+    # Split into major, minor, patch
+    string(
+        REGEX MATCH "([0-9]+)\\.([0-9]+)\\.([0-9]+)"
+        TAG_VERSION_MATCH ${TAG_VERSION}
+    )
+    set(TAG_VERSION_MAJOR ${CMAKE_MATCH_1})
+    set(TAG_VERSION_MINOR ${CMAKE_MATCH_2})
+    set(TAG_VERSION_PATCH ${CMAKE_MATCH_3})
+endif()