remove deprecated features

doc/doxygen/meson.build

@@ -12,8 +12,8 @@ doc_layout_files = files([
 #Build a Doxyfile based on Doxyfile.in
 cdata_doc = configuration_data()
 cdata_doc.set('VERSION', meson.project_version())
-cdata_doc.set('SRCDIR', meson.source_root())
-cdata_doc.set('BUILDDIR', meson.build_root())
+cdata_doc.set('SRCDIR', meson.project_source_root())
+cdata_doc.set('BUILDDIR', meson.project_build_root())
 if find_program('dot', required : false).found()
   cdata_doc.set('HAVE_DOT', 'YES')
 else

meson.build

 project('cmp_tool', 'c',
   version : '0.09',
-  meson_version : '>= 0.50',
+  meson_version : '>= 0.56',
   license : 'GPL-2.0',
   default_options : ['warning_level=3', 'c_std=gnu99']
 )