From c0fe4dfb104a699535c5861e2b64e7504c080c5f Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Sun, 11 Jan 2026 16:33:45 +0900
Subject: [PATCH] Add tailrec annotation

---
 .../main/scala/sbt/internal/util/appmacro/ContextUtil.scala    | 3 +++
 .../main/scala/sbt/internal/util/complete/ProcessError.scala   | 3 +++
 internal/util-complete/src/test/scala/ParserTest.scala         | 3 +++
 .../src/main/scala/sbt/internal/util/EscHelpers.scala          | 3 +++
 .../src/main/scala/sbt/internal/util/LoggerWriter.scala        | 3 +++
 .../internal/librarymanagement/cross/CrossVersionUtil.scala    | 3 +++
 .../main/scala/sbt/librarymanagement/ConfigurationExtra.scala  | 2 ++
 lm-coursier/src/main/scala/lmcoursier/Inputs.scala             | 2 ++
 main-command/src/main/scala/xsbt/IPC.scala                     | 1 +
 main-settings/src/main/scala/sbt/std/KeyMacro.scala            | 3 +++
 main/src/main/scala/sbt/TemplateCommandUtil.scala              | 3 +++
 main/src/main/scala/sbt/internal/Aggregation.scala             | 2 ++
 main/src/main/scala/sbt/internal/Script.scala                  | 2 ++
 tasks-standard/src/test/scala/TestRunnerCall.scala             | 3 +++
 14 files changed, 36 insertions(+)

diff --git a/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala b/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala
index db7de1512..aa7b5ad6b 100644
--- a/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala
+++ b/core-macros/src/main/scala/sbt/internal/util/appmacro/ContextUtil.scala
@@ -16,6 +16,8 @@ import sbt.util.cacheLevel
 import sbt.util.CacheLevelTag
 import xsbti.Attic
 
+import scala.annotation.tailrec
+
 trait ContextUtil[C <: Quotes & scala.Singleton](val valStart: Int):
   val qctx: C
   import qctx.reflect.*
@@ -84,6 +86,7 @@ trait ContextUtil[C <: Quotes & scala.Singleton](val valStart: Int):
       s"Input($tpe, $qual, $term, $name, $tags)"
     def isCacheInput: Boolean = tags.nonEmpty
     lazy val tags = extractTags(qual)
+    @tailrec
     private def extractTags(tree: Term): List[CacheLevelTag] =
       def getCacheLevelAnnotation(tree: Term): Option[Term] =
         Option(tree.tpe.termSymbol) match
diff --git a/internal/util-complete/src/main/scala/sbt/internal/util/complete/ProcessError.scala b/internal/util-complete/src/main/scala/sbt/internal/util/complete/ProcessError.scala
index 4e78b7061..f15a70f06 100644
--- a/internal/util-complete/src/main/scala/sbt/internal/util/complete/ProcessError.scala
+++ b/internal/util-complete/src/main/scala/sbt/internal/util/complete/ProcessError.scala
@@ -9,6 +9,8 @@
 package sbt.internal.util
 package complete
 
+import scala.annotation.tailrec
+
 object ProcessError {
   def apply(command: String, msgs: Seq[String], index: Int): String = {
     val (line, modIndex) = extractLine(command, index)
@@ -24,6 +26,7 @@ object ProcessError {
   }
 
   def takeRightWhile(s: String)(pred: Char => Boolean): String = {
+    @tailrec
     def loop(i: Int): String =
       if (i < 0)
         s
diff --git a/internal/util-complete/src/test/scala/ParserTest.scala b/internal/util-complete/src/test/scala/ParserTest.scala
index 29f2acacb..811dc3035 100644
--- a/internal/util-complete/src/test/scala/ParserTest.scala
+++ b/internal/util-complete/src/test/scala/ParserTest.scala
@@ -9,6 +9,8 @@
 package sbt.internal.util
 package complete
 
+import scala.annotation.tailrec
+
 object JLineTest {
   import DefaultParsers.*
 
@@ -33,6 +35,7 @@ object JLineTest {
 
     val parser = parsers(args(0))
     JLineCompletion.installCustomCompletor(reader, parser)
+    @tailrec
     def loop(): Unit = {
       val line = reader.readLine("> ")
       if (line ne null) {
diff --git a/internal/util-logging/src/main/scala/sbt/internal/util/EscHelpers.scala b/internal/util-logging/src/main/scala/sbt/internal/util/EscHelpers.scala
index e13c605b3..2d8619beb 100644
--- a/internal/util-logging/src/main/scala/sbt/internal/util/EscHelpers.scala
+++ b/internal/util-logging/src/main/scala/sbt/internal/util/EscHelpers.scala
@@ -8,6 +8,7 @@
 
 package sbt.internal.util
 
+import scala.annotation.tailrec
 import scala.collection.mutable.ArrayBuffer
 import scala.util.Try
 
@@ -70,6 +71,7 @@ object EscHelpers {
       sb.toString
     }
 
+  @tailrec
   private def nextESC(s: String, start: Int, sb: java.lang.StringBuilder): Unit = {
     val escIndex = s.indexOf(ESC, start)
     if (escIndex < 0) {
@@ -243,6 +245,7 @@ object EscHelpers {
    * Skips the escape sequence starting at `i-1`. `i` should be positioned at the character after
    * the ESC that starts the sequence.
    */
+  @tailrec
   private def skipESC(s: String, i: Int): Int = {
     if (i >= s.length) {
       i
diff --git a/internal/util-logging/src/main/scala/sbt/internal/util/LoggerWriter.scala b/internal/util-logging/src/main/scala/sbt/internal/util/LoggerWriter.scala
index 0c26a1127..85e304da9 100644
--- a/internal/util-logging/src/main/scala/sbt/internal/util/LoggerWriter.scala
+++ b/internal/util-logging/src/main/scala/sbt/internal/util/LoggerWriter.scala
@@ -10,6 +10,8 @@ package sbt.internal.util
 
 import sbt.util.*
 
+import scala.annotation.tailrec
+
 /**
  * Provides a `java.io.Writer` interface to a `Logger`. Content is line-buffered and logged at
  * `level`. A line is delimited by `nl`, which is by default the platform line separator.
@@ -48,6 +50,7 @@ class LoggerWriter(
       process()
     }
 
+  @tailrec
   private def process(): Unit = {
     val i = buffer.indexOf(nl)
     if (i >= 0) {
diff --git a/lm-core/src/main/scala/sbt/internal/librarymanagement/cross/CrossVersionUtil.scala b/lm-core/src/main/scala/sbt/internal/librarymanagement/cross/CrossVersionUtil.scala
index b5142754f..b5ee4473b 100644
--- a/lm-core/src/main/scala/sbt/internal/librarymanagement/cross/CrossVersionUtil.scala
+++ b/lm-core/src/main/scala/sbt/internal/librarymanagement/cross/CrossVersionUtil.scala
@@ -1,6 +1,8 @@
 package sbt.internal.librarymanagement
 package cross
 
+import scala.annotation.tailrec
+
 object CrossVersionUtil {
   val trueString = "true"
   val falseString = "false"
@@ -75,6 +77,7 @@ object CrossVersionUtil {
       case _                            => None
     }
 
+  @tailrec
   private[sbt] def binaryScala3Version(full: String): String = full match {
     case ReleaseV(maj, _, _, _)                                                  => maj
     case NonReleaseV_n(maj, min, patch, _) if min.toLong > 0 || patch.toLong > 0 => maj
diff --git a/lm-core/src/main/scala/sbt/librarymanagement/ConfigurationExtra.scala b/lm-core/src/main/scala/sbt/librarymanagement/ConfigurationExtra.scala
index ff62ede16..8f6a4f743 100644
--- a/lm-core/src/main/scala/sbt/librarymanagement/ConfigurationExtra.scala
+++ b/lm-core/src/main/scala/sbt/librarymanagement/ConfigurationExtra.scala
@@ -3,6 +3,7 @@
  */
 package sbt.librarymanagement
 
+import scala.annotation.tailrec
 import scala.quoted.*
 
 object Configurations {
@@ -101,6 +102,7 @@ private[librarymanagement] abstract class ConfigurationExtra {
 private[sbt] object ConfigurationMacro:
   def configMacroImpl(name: Expr[String])(using Quotes): Expr[Configuration] =
     import quotes.reflect.*
+    @tailrec
     def enclosingTerm(sym: Symbol): Symbol =
       sym match
         case sym if sym.flags.is(Flags.Macro) => enclosingTerm(sym.owner)
diff --git a/lm-coursier/src/main/scala/lmcoursier/Inputs.scala b/lm-coursier/src/main/scala/lmcoursier/Inputs.scala
index d86c156df..561e0df5f 100644
--- a/lm-coursier/src/main/scala/lmcoursier/Inputs.scala
+++ b/lm-coursier/src/main/scala/lmcoursier/Inputs.scala
@@ -5,6 +5,7 @@ import lmcoursier.definitions.{ Configuration, Module, ModuleName, Organization
 import sbt.librarymanagement.{ CrossVersion, InclExclRule, ModuleID }
 import sbt.util.Logger
 
+import scala.annotation.tailrec
 import scala.collection.mutable
 
 object Inputs {
@@ -28,6 +29,7 @@ object Inputs {
 
     def allExtends(c: Configuration) = {
       // possibly bad complexity
+      @tailrec
       def helper(current: Set[Configuration]): Set[Configuration] = {
         val newSet = current ++ current.flatMap(configs0.getOrElse(_, Nil))
         if ((newSet -- current).nonEmpty)
diff --git a/main-command/src/main/scala/xsbt/IPC.scala b/main-command/src/main/scala/xsbt/IPC.scala
index e685bb1a6..9fa842c98 100644
--- a/main-command/src/main/scala/xsbt/IPC.scala
+++ b/main-command/src/main/scala/xsbt/IPC.scala
@@ -34,6 +34,7 @@ object IPC {
     val random = new java.util.Random
     def nextPort = random.nextInt(portMax - portMin + 1) + portMin
 
+    @tailrec
     def createServer(attempts: Int): ServerSocket =
       if (attempts > 0) {
         try new ServerSocket(nextPort, socketBacklog, loopback)
diff --git a/main-settings/src/main/scala/sbt/std/KeyMacro.scala b/main-settings/src/main/scala/sbt/std/KeyMacro.scala
index caa38a80d..b18ced36e 100644
--- a/main-settings/src/main/scala/sbt/std/KeyMacro.scala
+++ b/main-settings/src/main/scala/sbt/std/KeyMacro.scala
@@ -10,6 +10,7 @@ package sbt
 package std
 
 import java.io.File
+import scala.annotation.tailrec
 import scala.quoted.*
 import scala.reflect.ClassTag
 
@@ -68,6 +69,7 @@ private[sbt] object KeyMacro:
 
   private def enclosingTerm(using qctx: Quotes) =
     import qctx.reflect.*
+    @tailrec
     def enclosingTerm0(sym: Symbol): Symbol =
       sym match
         case sym if sym.flags.is(Flags.Macro) => enclosingTerm0(sym.owner)
@@ -77,6 +79,7 @@ private[sbt] object KeyMacro:
 
   private def enclosingClass(using Quotes) =
     import quotes.reflect.*
+    @tailrec
     def rec(sym: Symbol): Symbol =
       if sym.isClassDef then sym
       else rec(sym.owner)
diff --git a/main/src/main/scala/sbt/TemplateCommandUtil.scala b/main/src/main/scala/sbt/TemplateCommandUtil.scala
index aeaff1ae8..0e8c39513 100644
--- a/main/src/main/scala/sbt/TemplateCommandUtil.scala
+++ b/main/src/main/scala/sbt/TemplateCommandUtil.scala
@@ -24,6 +24,8 @@ import BasicCommandStrings.*, BasicKeys.*
 import sbt.internal.util.Terminal.hasConsole
 import sbt.ProjectExtra.*
 
+import scala.annotation.tailrec
+
 private[sbt] object TemplateCommandUtil {
   def templateCommand: Command = templateCommand0(TemplateCommand)
   def templateCommandAlias: Command = templateCommand0("init")
@@ -206,6 +208,7 @@ private[sbt] object TemplateCommandUtil {
   private def toLetter(idx: Int): String =
     nonMoveLetters(idx).toString
 
+  @tailrec
   private def askTemplate(mappingList: List[(String, (String, String))], focus: Int): String = {
     val msg = "Select a template"
     displayMappings(mappingList, focus)
diff --git a/main/src/main/scala/sbt/internal/Aggregation.scala b/main/src/main/scala/sbt/internal/Aggregation.scala
index f645ab2c9..0ea22b9f7 100644
--- a/main/src/main/scala/sbt/internal/Aggregation.scala
+++ b/main/src/main/scala/sbt/internal/Aggregation.scala
@@ -19,6 +19,7 @@ import sbt.internal.util.*
 import sbt.internal.client.NetworkClient
 import sbt.std.Transform.DummyTaskMap
 import sbt.util.{ Logger, Show }
+import scala.annotation.tailrec
 
 sealed trait Aggregation
 object Aggregation {
@@ -249,6 +250,7 @@ object Aggregation {
       extra: BuildUtil[Proj],
   ): Iterable[ScopedKey[?]] =
     val mask = ScopeMask()
+    @tailrec
     def recur(keys: Set[ScopedKey[?]], acc: Set[ScopedKey[?]]): Set[ScopedKey[?]] =
       if keys.isEmpty then acc
       else
diff --git a/main/src/main/scala/sbt/internal/Script.scala b/main/src/main/scala/sbt/internal/Script.scala
index 9ae66f4b0..a849d4ca0 100644
--- a/main/src/main/scala/sbt/internal/Script.scala
+++ b/main/src/main/scala/sbt/internal/Script.scala
@@ -22,6 +22,7 @@ import sbt.ProjectExtra.{ extract, setProject }
 import sbt.SlashSyntax0.*
 
 import sbt.io.{ Hash, IO }
+import scala.annotation.tailrec
 
 object Script {
   final val Name = "script"
@@ -79,6 +80,7 @@ object Script {
   final case class Block(offset: Int, lines: Seq[String])
   def blocks(file: File): Seq[Block] = {
     val lines = IO.readLines(file).toIndexedSeq
+    @tailrec
     def blocks(b: Block, acc: List[Block]): List[Block] =
       if (b.lines.isEmpty) acc.reverse
       else {
diff --git a/tasks-standard/src/test/scala/TestRunnerCall.scala b/tasks-standard/src/test/scala/TestRunnerCall.scala
index af55781ca..dc15b1b2e 100644
--- a/tasks-standard/src/test/scala/TestRunnerCall.scala
+++ b/tasks-standard/src/test/scala/TestRunnerCall.scala
@@ -12,6 +12,8 @@ import org.scalacheck.*
 import Prop.*
 import TaskGen.*
 
+import scala.annotation.tailrec
+
 object TaskRunnerCallTest extends Properties("TaskRunner Call") {
   property("calculates fibonacci") = forAll(MaxTasksGen, MaxWorkersGen) { (i: Int, workers: Int) =>
     (i > 0) ==> {
@@ -36,6 +38,7 @@ object TaskRunnerCallTest extends Properties("TaskRunner Call") {
   }
   final def fibDirect(i: Int): Int = {
     require(i > 0)
+    @tailrec
     def build(index: Int, x1: Int, x2: Int): Int =
       if (index == i)
         x2