Make the scala-scala library a submodule.

Author: nicolasstucki

.gitignore

@@ -37,9 +37,6 @@ tests/partest-generated/
 tests/locks/
 /test-classes/
 
-# Used in tests
-scala-scala
-
 # Ignore output files but keep the directory
 out/
 build/

.gitmodules

@@ -2,3 +2,7 @@
 	path = scala-backend
 	url = https://github.com/lampepfl/scala.git
 	branch = sharing-backend
+[submodule "scala-scala"]
+	path = scala-scala
+	url = https://github.com/lampepfl/scala.git
+	branch = dotty-library

project/Build.scala

@@ -901,12 +901,12 @@ object DottyInjectedPlugin extends AutoPlugin {
   }
 
   private def projectChecks(): Unit = {
-    val scalaScala = new File("scala-scala")
-    if (!scalaScala.exists()) {
+    val submodules = List(new File("scala-backend"), new File("scala-scala"))
+    if (!submodules.forall(_.exists)) {
       println(
-        s"""[WARNING] Missing `dotty/scala-scala` library
-           |You can clone the library with:
-           |  > git clone -b dotty-library https://github.com/DarkDimius/scala.git ${scalaScala.getAbsolutePath}
+        s"""[WARNING] Missing some of the submodules
+           |You can initialize the modules with:
+           |  > git submodule update --init
         """.stripMargin)
     }
   }