give error when passing invalid command line option

compiler/src/prog8/CompilerMain.kt

@@ -40,8 +40,8 @@ private fun compileMain(args: Array<String>) {
     val watchMode by cli.option(ArgType.Boolean, fullName = "watch", description = "continuous compilation mode (watches for file changes), greatly increases compilation speed")
     val slowCodegenWarnings by cli.option(ArgType.Boolean, fullName = "slowwarn", description="show debug warnings about slow/problematic assembly code generation")
     val compilationTarget by cli.option(ArgType.String, fullName = "target", description = "target output of the compiler, currently '${C64Target.name}' and '${Cx16Target.name}' available").default(C64Target.name)
-    val moduleFiles by cli.argument(ArgType.String, fullName = "modules", description = "main module file(s) to compile").multiple(999)
     val libDirs by cli.option(ArgType.String, fullName="libdirs", description = "list of extra paths to search in for imported modules").multiple().delimiter(File.pathSeparator)
+    val moduleFiles by cli.argument(ArgType.String, fullName = "modules", description = "main module file(s) to compile").multiple(999)
 
     try {
         cli.parse(args)
@@ -56,6 +56,12 @@ private fun compileMain(args: Array<String>) {
         exitProcess(1)
     }
 
+    val faultyOption = moduleFiles.firstOrNull { it.startsWith('-') }
+    if(faultyOption!=null) {
+        System.err.println("Unknown command line option given: $faultyOption")
+        exitProcess(1)
+    }
+
     val libdirs = libDirs.toMutableList()
     if(libdirs.firstOrNull()!=".")
         libdirs.add(0, ".")

docs/source/todo.rst

@@ -2,8 +2,6 @@
 TODO
 ====
 
-- should give error when passing invalid command line arguments
-
 - test all examples (including imgviewer, assembler and petaxian) before release of the new version
 
 - simplify cx16.joystick_get2() once this cx16 rom issue is resolved: https://github.com/commanderx16/x16-rom/issues/203