build: set correct first version number

Set initial version as 0.1.0 as suggested by semver.org. Use -devel as
tweak to distinguish the development versions from the release versions.

Author: qdeslandes

CMakeLists.txt

@@ -4,11 +4,15 @@
 cmake_minimum_required(VERSION 3.20)
 
 project(bpfilter
-    VERSION 0.0.1
+    VERSION 0.1.0
     DESCRIPTION "BPF-based packet filtering framework"
     LANGUAGES C
 )
 
+set(PROJECT_VERSION_TWEAK "-devel")
+
+message(NOTICE "bpfilter version ${CMAKE_PROJECT_VERSION}${PROJECT_VERSION_TWEAK}")
+
 include(GNUInstallDirs)
 
 option(NO_DOCS "Disable documentation generation" 0)
@@ -52,6 +56,12 @@ target_link_options(bf_global_flags
         $<$<CONFIG:debug>:-fsanitize=address -fsanitize=undefined>
 )
 
+configure_file(
+    ${CMAKE_SOURCE_DIR}/src/version.h.in
+    ${CMAKE_BINARY_DIR}/include/version.h
+    @ONLY
+)
+
 add_subdirectory(src/core)
 add_subdirectory(src/bpfilter)
 add_subdirectory(src/libbpfilter)

src/libbpfilter/bpfilter.pc.in

@@ -5,6 +5,6 @@ libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
 Name: bpfilter
 Description: BPF-based packet filtering framework
 URL: https://github.com/facebook/bpfilter
-Version: @PROJECT_VERSION@
+Version: @PROJECT_VERSION@@PROJECT_VERSION_TWEAK@
 Cflags: -I${includedir}
 Libs: -L${libdir} -lbpfilter