WIP: compile libs together, load them all

Author: abgruszecki

compiler/src/dotty/tools/dotc/typer/TypeAssigner.scala

@@ -299,12 +299,12 @@ trait TypeAssigner {
           else fntpe.resultType
         else
           errorType(i"wrong number of arguments at ${ctx.phase.prev} for $fntpe: ${fn.tpe}, expected: ${fntpe.paramInfos.length}, found: ${args.length}", tree.srcPos)
-      case t if args.isEmpty =>
-        // NOTE this case is necessary when loading the stdlib from Tasty. Our extensions are compiled with stdlib loaded
-        // from Scala2 classfiles while they are loaded with stdlib loaded from Tasty. This results in `def toString` being
-        // typed as MethodType in the first case and ExprType in the second case. In the second case (and, I think, only then)
-        // we need to handle ExprType being present here.
-        t
+      // case t if args.isEmpty =>
+      //   // NOTE this case is necessary when loading the stdlib from Tasty. Our extensions are compiled with stdlib loaded
+      //   // from Scala2 classfiles while they are loaded with stdlib loaded from Tasty. This results in `def toString` being
+      //   // typed as MethodType in the first case and ExprType in the second case. In the second case (and, I think, only then)
+      //   // we need to handle ExprType being present here.
+      //   t
       case t =>
         if (ctx.settings.Ydebug.value) new FatalError("").printStackTrace()
         errorType(err.takesNoParamsStr(fn, ""), tree.srcPos)

project/Build.scala

@@ -841,6 +841,16 @@ object Build {
     settings(
       moduleName := "scala-library",
       javaOptions := (javaOptions in `scala3-compiler-bootstrapped`).value,
+      Compile/scalacOptions += "-Yerased-terms",
+      Compile/scalacOptions ++= {
+        Seq(
+          "-sourcepath",
+          Seq(
+            (Compile/sourceManaged).value / "scala-library-src",
+            (Compile/sourceManaged).value / "dotty-library-src",
+          ).mkString(File.pathSeparator),
+        )
+      },
       scalacOptions -= "-Xfatal-warnings",
       ivyConfigurations += SourceDeps.hide,
       transitiveClassifiers := Seq("sources"),
@@ -870,6 +880,31 @@ object Build {
           ((trgDir ** "*.scala") +++ (trgDir ** "*.java")).get.toSet
         } (Set(scalaLibrarySourcesJar)).toSeq
       }.taskValue,
+      sourceGenerators in Compile += Def.task {
+        val s = streams.value
+        val cacheDir = s.cacheDirectory
+        val trgDir = (sourceManaged in Compile).value / "dotty-library-src"
+
+        // NOTE `sourceDirectory` is used for actual copying,
+        // but `sources` are used as cache keys
+        val dottyLibSourceDir = (`scala3-library-bootstrapped`/sourceDirectory).value
+        val dottyLibSources = (`scala3-library-bootstrapped`/Compile/sources).value
+
+        val cachedFun = FileFunction.cached(
+          cacheDir / s"copyDottyLibrarySrc",
+          FilesInfo.lastModified,
+          FilesInfo.exists,
+        ) { _ =>
+          s.log.info(s"Copying scala3-library sources from $dottyLibSourceDir to $trgDir...")
+          if (trgDir.exists) IO.delete(trgDir)
+          // IO.createDirectory(trgDir)
+          IO.copyDirectory(dottyLibSourceDir, trgDir)
+
+          ((trgDir ** "*.scala") +++ (trgDir ** "*.java")).get.toSet
+        }
+
+        cachedFun(dottyLibSources.toSet).toSeq
+      }.taskValue,
       sources in Compile ~= (_.filterNot(file =>
         // sources from https://github.com/scala/scala/tree/2.13.x/src/library-aux
         file.getPath.endsWith("scala-library-src/scala/Any.scala") ||
@@ -1555,8 +1590,9 @@ object Build {
 
           generateScala3StdlibDocumentation:= Def.taskDyn {
             val dottyJars: Seq[java.io.File] = Seq(
-              (`scala3-library-bootstrapped`/Compile/products).value,
               (`stdlib-bootstrapped`/Compile/products).value,
+              (`scala3-interfaces`/Compile/products).value,
+              (`tasty-core-bootstrapped`/Compile/products).value,
             ).flatten
 
             val roots = joinProducts(dottyJars)