Meson: add version.c generation

meson.build

@@ -1,4 +1,6 @@
-project('hotp-verification', 'c')
+project('hotp-verification', 'c',
+  version : '1.1.0',
+)
 lusb = dependency('libusb-1.0')
 
 src = [
@@ -15,6 +17,25 @@ src = [
 'hidapi/libusb/hid.c'
 ]
 
+version_array = meson.project_version().split('.')
+version_major = version_array[0].to_int()
+version_minor = version_array[1].to_int()
+version_data = configuration_data()
+version_data.set('PROJECT_VERSION_MAJOR', version_major)
+version_data.set('PROJECT_VERSION_MINOR', version_minor)
+# We don't want to substitute it by noop
+version_data.set('GIT_VERSION_PLACEHOLDER', '@VCS_TAG@')
+version_cc_in = configure_file(
+  input : 'version.c.in',
+  output : 'version.c.in',
+  configuration : version_data,
+)
+version_cc = vcs_tag(
+  input : version_cc_in,
+  output : 'version.c',
+  fallback : 'v@0@'.format(meson.project_version()),
+)
+
 common_flags = ['-DNK_REMOVE_PTHREAD']
 
 incdir = ([