Add generator code to build file and make script executable

Author: pmembrey

auto/generate_test_runner.rb

@@ -1,3 +1,5 @@
+#!/usr/bin/ruby
+
 # ==========================================
 #   Unity Project - A Test Framework for C
 #   Copyright (c) 2007 Mike Karlesky, Mark VanderVoord, Greg Williams

meson.build

@@ -12,3 +12,15 @@ project('unity', 'c',
 
 subdir('src')
 unity_dep = declare_dependency(link_with: unity_lib, include_directories: unity_dir)
+
+
+# Get the generate_test_runner script relative to itself or the parent project if it is being used as a subproject
+# NOTE: This could be (and probably is) a complete hack - but I haven't yet been able to find a better way....
+if meson.is_subproject()
+gen_test_runner_path = find_program(meson.source_root() / 'subprojects/unity/auto/generate_test_runner.rb')
+else
+gen_test_runner_path = find_program('subprojects/unity/auto/generate_test_runner.rb')
+endif
+
+# Create a generator that we can access from the parent project
+gen_test_runner = generator(gen_test_runner_path, output: '@BASENAME@_Runner.c', arguments: ['@INPUT@', '@OUTPUT@'] )