[KLIB tool] Warn on unknown CLI options

kotlin-native/klib/src/main/kotlin/org/jetbrains/kotlin/cli/klib/main.kt

@@ -90,8 +90,8 @@ fun printUsage() {
     )
 }
 
-private fun parseArgs(args: Array<String>): Map<String, List<String>> {
-    val commandLine = mutableMapOf<String, MutableList<String>>()
+private fun parseOptions(args: Array<String>): Map<String, List<String>> {
+    val options = mutableMapOf<String, MutableList<String>>()
     for (index in args.indices step 2) {
         val key = args[index]
         if (key[0] != '-') {
@@ -101,13 +101,13 @@ private fun parseArgs(args: Array<String>): Map<String, List<String>> {
             throw IllegalArgumentException("Expected an value after $key")
         }
         val value = listOf(args[index + 1])
-        commandLine[key]?.addAll(value) ?: commandLine.put(key, value.toMutableList())
+        options[key]?.addAll(value) ?: options.put(key, value.toMutableList())
     }
-    return commandLine
+    return options
 }
 
 
-class Command(args: Array<String>) {
+private class Command(args: Array<String>) {
     init {
         if (args.size < 2) {
             printUsage()
@@ -117,11 +117,21 @@ class Command(args: Array<String>) {
 
     val verb = args[0]
     val library = args[1]
-    val options: Map<String, List<String>> = parseArgs(args.drop(2).toTypedArray())
+
+    val knownOptions: Map<KnownOption, List<String>> = parseOptions(args.drop(2).toTypedArray<String>())
+            .entries
+            .mapNotNull { (option, values) ->
+                val knownOption = KnownOption.parseOrNull(option)
+                if (knownOption == null) {
+                    logWarning("Unrecognized command-line option: $option")
+                    return@mapNotNull null
+                }
+                knownOption to values
+            }.toMap()
 }
 
 private fun Command.parseSignatureVersion(): KotlinIrSignatureVersion? {
-    val rawSignatureVersion = options["-signature-version"]?.last() ?: return null
+    val rawSignatureVersion = knownOptions[KnownOption.SIGNATURE_VERSION]?.last() ?: return null
     val signatureVersion = rawSignatureVersion.toIntOrNull()?.let(::KotlinIrSignatureVersion)
             ?: logError("Invalid signature version: $rawSignatureVersion")
 
@@ -405,11 +415,21 @@ fun libraryInCurrentDir(name: String) = resolverByName(emptyList(), logger = Kli
 fun libraryInRepoOrCurrentDir(repository: File, name: String) =
         resolverByName(listOf(repository.absolutePath), logger = KlibToolLogger).resolve(name)
 
+private enum class KnownOption(val option: String) {
+    REPOSITORY("-repository"),
+    PRINT_SIGNATURES("-print-signatures"),
+    SIGNATURE_VERSION("-signature-version");
+
+    companion object {
+        fun parseOrNull(option: String): KnownOption? = values().firstOrNull { it.option == option }
+    }
+}
+
 fun main(args: Array<String>) {
     val command = Command(args)
 
-    val repository = command.options["-repository"]?.last()
-    val printSignatures = command.options["-print-signatures"]?.last()?.toBoolean() == true
+    val repository = command.knownOptions[KnownOption.REPOSITORY]?.last()
+    val printSignatures = command.knownOptions[KnownOption.PRINT_SIGNATURES]?.last()?.toBoolean() == true
 
     val signatureVersion = command.parseSignatureVersion()