Resolve compiler bridge jar (#45)

* Resolve compiler bridge jar

* Create a release artifact

3 files changed, 34 insertions, 11 deletions

diff --git a/build.sc b/build.sc
index 3a7dae44..29f1955f 100755
--- a/build.sc
+++ b/build.sc
@@ -1,6 +1,7 @@
 import ammonite.ops._
 import mill._
 import mill.scalaplugin._
+import mill.modules.Jvm.createAssembly
 
 trait MillModule extends SbtScalaModule{ outer =>
   def scalaVersion = "2.12.4"
@@ -96,6 +97,16 @@ object ScalaPlugin extends MillModule {
     for((k, v) <- mapping.toSeq) yield s"-D$k=$v"
   }
 
+  def releaseAssembly = T{
+    createAssembly(
+      (runDepClasspath().filter(_.path.ext != "pom") ++
+        Seq(resources(), compile().classes)).map(_.path).filter(exists),
+      prependShellScript =
+        "#!/usr/bin/env sh\n" +
+        s"""exec java $$JAVA_OPTS -cp "$$0" mill.Main "$$@" """
+    )
+  }
+
   override def prependShellScript =
     "#!/usr/bin/env sh\n" +
     s"""exec java ${testArgs().mkString(" ")} $$JAVA_OPTS -cp "$$0" mill.Main "$$@" """
diff --git a/scalaplugin/src/main/scala/mill/scalaplugin/Lib.scala b/scalaplugin/src/main/scala/mill/scalaplugin/Lib.scala
index 055b3206..21ecdca1 100644
--- a/scalaplugin/src/main/scala/mill/scalaplugin/Lib.scala
+++ b/scalaplugin/src/main/scala/mill/scalaplugin/Lib.scala
@@ -36,7 +36,7 @@ object Lib{
                    sources: Seq[Path],
                    compileClasspath: Seq[Path],
                    compilerClasspath: Seq[Path],
-                   compilerBridge: Seq[Path],
+                   compilerBridge: Path,
                    scalacOptions: Seq[String],
                    scalacPluginClasspath: Seq[Path],
                    javacOptions: Seq[String],
@@ -52,10 +52,6 @@ object Lib{
     }
 
     val compilerJars = compilerClasspath.toArray.map(_.toIO)
-    val compilerBridgeKey = "MILL_COMPILER_BRIDGE_"+scalaVersion.replace('.', '_')
-    val compilerBridgePath = sys.props(compilerBridgeKey)
-    assert(compilerBridgePath != null, "Cannot find compiler bridge " + compilerBridgeKey)
-    val compilerBridgeJar = new java.io.File(compilerBridgePath)
 
     val classloaderSig = compilerClasspath.map(p => p.toString().hashCode + p.mtime.toMillis).sum
 
@@ -123,7 +119,7 @@ object Lib{
           scalaInstance,
           ClasspathOptionsUtil.boot,
           None,
-          ZincUtil.scalaCompiler(scalaInstance, compilerBridgeJar)
+          ZincUtil.scalaCompiler(scalaInstance, compilerBridge.toIO)
         ),
         setup = ic.setup(
           lookup,
@@ -186,6 +182,8 @@ object Lib{
   def scalaRuntimeIvyDeps(scalaVersion: String) = Seq[Dep](
     Dep.Java("org.scala-lang", "scala-library", scalaVersion)
   )
+  def compilerBridgeIvyDep(scalaVersion: String) =
+    Dep.Point(coursier.Dependency(coursier.Module("com.lihaoyi", "mill-bridge"), "0.1-SNAPSHOT", transitive = false))
 
   val DefaultShellScript: Seq[String] = Seq(
     "#!/usr/bin/env sh",
diff --git a/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala b/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala
index 8167a4f1..f7db3006 100644
--- a/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala
+++ b/scalaplugin/src/main/scala/mill/scalaplugin/ScalaModule.scala
@@ -129,10 +129,24 @@ trait ScalaModule extends Module with TaskModule{ outer =>
   /**
     * Strange compiler-bridge jar that the Zinc incremental compile needs
     */
-  def compilerBridgeClasspath: T[Seq[PathRef]] = T{
-    resolveDeps(
-      T.task{Seq(Dep("org.scala-sbt", "compiler-bridge", "1.0.5"))},
-    )()
+  def compilerBridge: T[PathRef] = T{
+    val compilerBridgeKey = "MILL_COMPILER_BRIDGE_" + scalaVersion().replace('.', '_')
+    val compilerBridgePath = sys.props(compilerBridgeKey)
+    if (compilerBridgePath != null) PathRef(Path(compilerBridgePath), quick = true)
+    else {
+      val dep = compilerBridgeIvyDep(scalaVersion())
+      val classpath = resolveDependencies(
+        repositories,
+        scalaVersion(),
+        scalaBinaryVersion(),
+        Seq(dep)
+      )
+      classpath match {
+        case Seq(single) => PathRef(single.path, quick = true)
+        case Seq() => throw new Exception(dep + " resolution failed")
+        case _ => throw new Exception(dep + " resolution resulted in more than one file")
+      }
+    }
   }
 
   def scalacPluginClasspath: T[Seq[PathRef]] =
@@ -171,7 +185,7 @@ trait ScalaModule extends Module with TaskModule{ outer =>
       allSources().map(_.path),
       compileDepClasspath().map(_.path),
       scalaCompilerClasspath().map(_.path),
-      compilerBridgeClasspath().map(_.path),
+      compilerBridge().path,
       scalacOptions(),
       scalacPluginClasspath().map(_.path),
       javacOptions(),