Fix C++ version and ABI/SONAME version for 28.0.0 (#306)

* Fix C++ version and ABI/SONAME version for 28.0.0
* Read the C++ versions from the VERSION file

Author: musicinmybrain

cpp/CMakeLists.txt

@@ -1,12 +1,22 @@
-###
-#
-# Project
-# name and version
-#
-###
-cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
+# The VERSION here is a placeholder; the real version is in the VERSION file.
+set(VERSION 28.0.0)
 
-project(cucumber_messages VERSION 27.0.2 LANGUAGES C CXX)
+if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/VERSION")
+    file(STRINGS "VERSION" LINES)
+    list(GET LINES 0 VERSION)
+endif()
+
+# Crude Semver parsing
+if("${VERSION}" MATCHES "^([^\\.]+)\\.([^\\.]+)\\.([^\\.]+)$")
+    set(VER_MAJOR ${CMAKE_MATCH_1})
+    set(VER_MINOR ${CMAKE_MATCH_2})
+    set(VER_PATCH ${CMAKE_MATCH_3})
+else()
+    message(FATAL_ERROR "unable to parse version: ${VERSION}")
+endif()
+
+cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
+project(cucumber_messages VERSION ${VERSION} LANGUAGES C CXX)
 
 ###
 #

cpp/src/lib/messages/CMakeLists.txt

@@ -34,8 +34,8 @@ set_target_properties(
     cucumber_messages_lib
     PROPERTIES
         CXX_STANDARD 17
-        VERSION 27.0.2
-        SOVERSION 27
+        VERSION ${VERSION}
+        SOVERSION ${VER_MAJOR}
         EXPORT_NAME messages
         OUTPUT_NAME cucumber_messages
 )