feat: add tcpDebug option and tracing

server/build.gradle.kts

@@ -9,8 +9,9 @@ plugins {
     id("kotlin-language-server.kotlin-conventions")
 }
 
+val serverDebugPort = 4000
 val debugPort = 8000
-val debugArgs = "-agentlib:jdwp=transport=dt_socket,server=y,address=8000,suspend=n,quiet=y"
+val debugArgs = "-agentlib:jdwp=transport=dt_socket,server=y,address=$debugPort,suspend=n,quiet=y"
 
 val serverMainClassName = "org.javacs.kt.MainKt"
 val applicationName = "kotlin-language-server"
@@ -88,6 +89,8 @@ tasks.register<JavaExec>("debugRun") {
     standardInput = System.`in`
 
     jvmArgs(debugArgs)
+    args(listOf("--tcpServerPort", serverDebugPort, "--level", "trace", "--tcpDebug"))
+
     doLast { println("Using debug port $debugPort") }
 }
 

server/src/main/kotlin/org/javacs/kt/KotlinLanguageServer.kt

@@ -23,7 +23,8 @@ import java.util.concurrent.CompletableFuture
 import java.util.concurrent.CompletableFuture.completedFuture
 
 class KotlinLanguageServer(
-    val config: Configuration = Configuration()
+    val config: Configuration = Configuration(),
+    private val tcpDebug: Boolean = false
 ) : LanguageServer, LanguageClientAware, Closeable {
     val databaseService = DatabaseService()
     val classPath = CompilerClassPath(config.compiler, config.scripts, config.codegen, databaseService)
@@ -56,7 +57,9 @@ class KotlinLanguageServer(
 
     override fun connect(client: LanguageClient) {
         this.client = client
-        connectLoggingBackend()
+        if (!tcpDebug) {
+            connectLoggingBackend()
+        }
 
         workspaces.connect(client)
         textDocuments.connect(client)

server/src/main/kotlin/org/javacs/kt/Main.kt

@@ -7,21 +7,27 @@ import org.eclipse.lsp4j.launch.LSPLauncher
 import org.javacs.kt.util.ExitingInputStream
 import org.javacs.kt.util.tcpStartServer
 import org.javacs.kt.util.tcpConnectToClient
-
 class Args {
     /*
      * The language server can currently be launched in three modes:
      *  - Stdio, in which case no argument should be specified (used by default)
      *  - TCP Server, in which case the client has to connect to the specified tcpServerPort (used by the Docker image)
      *  - TCP Client, in which case the server will connect to the specified tcpClientPort/tcpClientHost (optionally used by VSCode)
      */
-
     @Parameter(names = ["--tcpServerPort", "-sp"])
     var tcpServerPort: Int? = null
+
     @Parameter(names = ["--tcpClientPort", "-p"])
     var tcpClientPort: Int? = null
+
     @Parameter(names = ["--tcpClientHost", "-h"])
     var tcpClientHost: String = "localhost"
+
+    @Parameter(names = ["--level"])
+    var logLevel: String = "info"
+
+    @Parameter(names = ["--tcpDebug"])
+    var tcpDebug: Boolean = false
 }
 
 fun main(argv: Array<String>) {
@@ -39,7 +45,8 @@ fun main(argv: Array<String>) {
         tcpStartServer(it)
     } ?: Pair(System.`in`, System.out)
 
-    val server = KotlinLanguageServer()
+    LOG.setLogLevel(args.logLevel)
+    val server = KotlinLanguageServer(tcpDebug = args.tcpDebug)
     val threads = Executors.newSingleThreadExecutor { Thread(it, "client") }
     val launcher = LSPLauncher.createServerLauncher(server, ExitingInputStream(inStream), outStream, threads) { it }
 

shared/src/main/kotlin/org/javacs/kt/Logger.kt

@@ -12,7 +12,7 @@ import org.javacs.kt.util.DelegatePrintStream
 
 val LOG = Logger()
 
-private class JULRedirector(private val downstream: Logger): Handler() {
+private class JULRedirector(private val downstream: Logger) : Handler() {
     override fun publish(record: LogRecord) {
         when (record.level) {
             Level.SEVERE -> downstream.error(record.message)
@@ -41,12 +41,23 @@ enum class LogLevel(val value: Int) {
     ALL(-100)
 }
 
+fun String.toLogLevel(): LogLevel {
+    return when (this) {
+        "error" -> LogLevel.ERROR
+        "warn" -> LogLevel.WARN
+        "debug" -> LogLevel.DEBUG
+        "trace" -> LogLevel.TRACE
+        else -> LogLevel.INFO
+    }
+}
+
 class LogMessage(
     val level: LogLevel,
-    val message: String
+    val message: String,
+    private val funName: String? = null,
 ) {
     val formatted: String
-        get() = "[$level] $message"
+        get() = "[$level] ${funName?.let { "$it " } ?: ""}$message"
 }
 
 class Logger {
@@ -60,6 +71,7 @@ class Logger {
     private val newline = System.lineSeparator()
     val logTime = false
     var level = LogLevel.INFO
+    var stackTracing = false;
 
     fun logError(msg: LogMessage) {
         if (errBackend == null) {
@@ -78,14 +90,24 @@ class Logger {
     }
 
     private fun logWithPlaceholdersAt(msgLevel: LogLevel, msg: String, placeholders: Array<out Any?>) {
+        val stackTraceElement = if (stackTracing) {
+            Throwable("Capturing stack trace for logging").stackTrace.firstOrNull { it.className != this::class.java.name }
+        } else {
+            null
+        }
         if (level.value <= msgLevel.value) {
-            log(LogMessage(msgLevel, format(insertPlaceholders(msg, placeholders))))
+            log(LogMessage(msgLevel, format(insertPlaceholders(msg, placeholders)), stackTraceElement?.className))
         }
     }
 
     inline fun logWithLambdaAt(msgLevel: LogLevel, msg: () -> String) {
+        val stackTraceElement = if (stackTracing) {
+            Throwable("Capturing stack trace for logging").stackTrace.firstOrNull { it.className != this::class.java.name }
+        } else {
+            null
+        }
         if (level.value <= msgLevel.value) {
-            log(LogMessage(msgLevel, msg()))
+            log(LogMessage(msgLevel, msg(), stackTraceElement?.className))
         }
     }
 
@@ -119,6 +141,14 @@ class Logger {
 
     inline fun deepTrace(msg: () -> String) = logWithLambdaAt(LogLevel.DEEP_TRACE, msg)
 
+    fun setLogLevel(level: String) {
+        val logLevel = level.toLogLevel()
+        if (logLevel.value <= LogLevel.TRACE.value) {
+            stackTracing = true
+        }
+        this.level = logLevel
+    }
+
     fun connectJULFrontend() {
         val rootLogger = java.util.logging.Logger.getLogger("")
         rootLogger.addHandler(JULRedirector(this))