[2.x] Move compiler bridge to Update (#8836)

**Problem**
We want to grab tooling artifacts in update.

**Solution**
This adds binary compiler bridge artifacts into the update graph.

lm-core/src/main/scala/sbt/librarymanagement/ConfigRef.scala

@@ -44,11 +44,13 @@ object ConfigRef extends sbt.librarymanagement.ConfigRefFunctions {
   private lazy val Pom = new ConfigRef("pom")
   private lazy val ScalaTool = new ConfigRef("scala-tool")
   private lazy val ScalaDocTool = new ConfigRef("scala-doc-tool")
+  private lazy val ScalaReplTool = new ConfigRef("scala-repl-tool")
   private lazy val CompilerPlugin = new ConfigRef("plugin")
   private lazy val Component = new ConfigRef("component")
   private lazy val RuntimeInternal = new ConfigRef("runtime-internal")
   private lazy val TestInternal = new ConfigRef("test-internal")
   private lazy val CompileInternal = new ConfigRef("compile-internal")
+  private lazy val ZincTool = new ConfigRef("zinc-tool")
 
   def apply(name: String): ConfigRef = name match {
     case "default"          => Default
@@ -61,11 +63,13 @@ object ConfigRef extends sbt.librarymanagement.ConfigRefFunctions {
     case "pom"              => Pom
     case "scala-tool"       => ScalaTool
     case "scala-doc-tool"   => ScalaDocTool
+    case "scala-repl-tool"  => ScalaReplTool
     case "plugin"           => CompilerPlugin
     case "component"        => Component
     case "runtime-internal" => RuntimeInternal
     case "test-internal"    => TestInternal
     case "compile-internal" => CompileInternal
+    case "zinc-tool"        => ZincTool
     case _                  => cache.getOrElseUpdate(name, new ConfigRef(name))
   }
 }

lm-core/src/main/scala/sbt/librarymanagement/ConfigurationExtra.scala

@@ -50,6 +50,7 @@ object Configurations {
   lazy val ScalaDocTool = Configuration.of("ScalaDocTool", "scala-doc-tool").hide
   lazy val ScalaReplTool = Configuration.of("ScalaReplTool", "scala-repl-tool").hide
   lazy val CompilerPlugin = Configuration.of("CompilerPlugin", "plugin").hide
+  lazy val ZincTool = Configuration.of("ZincTool", "zinc-tool").hide
   lazy val Component = Configuration.of("Component", "component").hide
 
   private[sbt] val DefaultMavenConfiguration = defaultConfiguration(true)

lm-core/src/main/scala/sbt/librarymanagement/ScalaArtifacts.scala

@@ -18,6 +18,7 @@ object ScalaArtifacts {
   final val Scala3TastyInspectorID = "scala3-tasty-inspector"
   final val Scala3ReplID = "scala3-repl"
   final val Scala3_8Artifacts = Vector(LibraryID, Scala3LibraryID)
+  final val scala2SbtBridgeStart = "2.13.12"
 
   private[sbt] final val Scala3LibraryPrefix = Scala3LibraryID + "_"
   private[sbt] final val Scala3CompilerPrefix = Scala3CompilerID + "_"
@@ -132,6 +133,29 @@ object ScalaArtifacts {
         Some(Configurations.ScalaTool.name + "->default,optional(default)")
       )
       .platform(Platform.jvm)
+
+  private[sbt] def hasScala2SbtBridge(sv: String): Boolean =
+    VersionNumber(sv).matchesSemVer(
+      SemanticSelector(s"=2.13 >=$scala2SbtBridgeStart")
+    )
+
+  private[sbt] def compilerBridgeDependencies(
+      org: String,
+      scalaVersion: String
+  ): Seq[ModuleID] =
+    if isScala3(scalaVersion) then
+      Vector(
+        ModuleID(org, "scala3-sbt-bridge", scalaVersion)
+          .withConfigurations(Some(s"${Configurations.ZincTool.name}->default,optional(default)"))
+          .platform(Platform.jvm)
+      )
+    else if hasScala2SbtBridge(scalaVersion) then
+      Vector(
+        ModuleID(org, "scala2-sbt-bridge", scalaVersion)
+          .withConfigurations(Some(s"${Configurations.ZincTool.name}->default,optional(default)"))
+          .platform(Platform.jvm)
+      )
+    else Nil
 }
 
 object SbtArtifacts {

main/src/main/scala/sbt/Defaults.scala

@@ -744,30 +744,9 @@ object Defaults extends BuildCommon {
         .ifS(Def.task {
           val sv = scalaVersion.value
           val managed = managedScalaInstance.value
-          val hasSbtBridge = ScalaArtifacts.isScala3(sv) || ZincLmUtil.hasScala2SbtBridge(sv)
+          val hasSbtBridge = ScalaArtifacts.isScala3(sv) || ScalaArtifacts.hasScala2SbtBridge(sv)
           hasSbtBridge && managed
-        })(Def.cachedTask {
-          // Use scalaDynVersion to resolve dynamic versions (e.g., "3-latest.candidate" -> "3.8.1-RC1")
-          val sv = scalaDynVersion.value
-          val conv = fileConverter.value
-          val s = streams.value
-          val t = target.value
-          val r = dependencyResolution.value
-          val uc = updateConfiguration.value
-          val jar = ZincLmUtil.fetchDefaultBridgeModule(
-            scalaOrganization.value,
-            sv,
-            r,
-            uc,
-            (update / unresolvedWarningConfiguration).value,
-            s.log
-          )
-          val out = t / "compiler-bridge" / jar.getName()
-          val outVf = conv.toVirtualFile(out.toPath())
-          IO.copyFile(jar, out)
-          Def.declareOutput(outVf)
-          Vector(outVf: HashedVirtualFileRef)
-        })(Def.task(Vector.empty))
+        })(Compiler.compilerBridgeFromUpdate)(Def.task(Vector.empty))
         .value,
       scalaCompilerBridgeJars := (Def.taskDyn {
         val s = streams.value
@@ -3190,7 +3169,7 @@ object Classpaths {
     ivyConfigurations ++= Configurations.auxiliary,
     ivyConfigurations ++= {
       if (managedScalaInstance.value && scalaHome.value.isEmpty)
-        Configurations.ScalaTool :: Configurations.ScalaDocTool :: Configurations.ScalaReplTool :: Nil
+        Configurations.ScalaTool :: Configurations.ScalaDocTool :: Configurations.ScalaReplTool :: Configurations.ZincTool :: Nil
       else Nil
     },
     // Coursier needs these
@@ -3430,6 +3409,7 @@ object Classpaths {
         then Nil
         else
           ScalaArtifacts.toolDependencies(scalaOrg, version) ++
+            ScalaArtifacts.compilerBridgeDependencies(scalaOrg, version) ++
             ScalaArtifacts.docToolDependencies(scalaOrg, version) ++
             ScalaArtifacts.replToolDependencies(scalaOrg, version)
       allToolDeps.map(_.platform(Platform.jvm)) ++ pluginAdjust

main/src/main/scala/sbt/internal/Compiler.scala

@@ -140,6 +140,17 @@ object Compiler:
       )
     }
 
+  def compilerBridgeFromUpdate: Def.Initialize[Task[Seq[HashedVirtualFileRef]]] =
+    Def.task {
+      val fullReport = Keys.update.value
+      val report = fullReport.configuration(Configurations.ZincTool)
+      val allJars = report match
+        case Some(r) => r.modules.flatMap(_.artifacts.map(_._2))
+        case None    => Nil
+      val conv = Keys.fileConverter.value
+      allJars.map(x => (conv.toVirtualFile(x.toPath()): HashedVirtualFileRef))
+    }
+
   def scalaInstanceConfigFromUpdate(
       extraToolConf: Option[Configuration]
   ): Def.Initialize[Task[ScalaInstanceConfig]] = Def.task {

zinc-lm-integration/src/main/scala/sbt/internal/inc/ZincLmUtil.scala

@@ -15,10 +15,8 @@ import sbt.librarymanagement.{
   DependencyResolution,
   ModuleID,
   ScalaArtifacts,
-  SemanticSelector,
   UnresolvedWarningConfiguration,
   UpdateConfiguration,
-  VersionNumber,
 }
 import sbt.librarymanagement.syntax.*
 import xsbti.ArtifactInfo.SbtOrganization
@@ -27,11 +25,9 @@ import xsbti.compile.{ ClasspathOptions, ScalaInstance as XScalaInstance }
 
 object ZincLmUtil {
 
-  final val scala2SbtBridgeStart = "2.13.12"
+  final val scala2SbtBridgeStart = ScalaArtifacts.scala2SbtBridgeStart
   def hasScala2SbtBridge(sv: String): Boolean =
-    VersionNumber(sv).matchesSemVer(
-      SemanticSelector(s"=2.13 >=$scala2SbtBridgeStart")
-    )
+    ScalaArtifacts.hasScala2SbtBridge(sv)
 
   /**
    * Instantiate a Scala compiler that is instrumented to analyze dependencies.