Merge pull request #4849 from dotty-staging/fix-#4841

Fix #4841: Load the compiler toolbox reflectively

Author: nicolasstucki

compiler/src/dotty/tools/dotc/quoted/QuoteDriver.scala

@@ -7,6 +7,8 @@ import dotty.tools.io.{AbstractFile, Directory, PlainDirectory, VirtualDirectory
 import dotty.tools.repl.AbstractFileClassLoader
 
 import scala.quoted.{Expr, Type}
+import scala.quoted.Toolbox
+
 import java.net.URLClassLoader
 
 import dotty.tools.dotc.tastyreflect.TastyImpl
@@ -16,7 +18,7 @@ class QuoteDriver extends Driver {
 
   private[this] val contextBase: ContextBase = new ContextBase
 
-  def run[T](expr: Expr[T], settings: ToolboxSettings): T = {
+  def run[T](expr: Expr[T], settings: Toolbox.Settings): T = {
     val outDir: AbstractFile = settings.outDir match {
       case Some(out) =>
         val dir = Directory(out)
@@ -41,15 +43,15 @@ class QuoteDriver extends Driver {
     method.invoke(instance).asInstanceOf[T]
   }
 
-  def show(expr: Expr[_], settings: ToolboxSettings): String = {
+  def show(expr: Expr[_], settings: Toolbox.Settings): String = {
     def show(tree: Tree, ctx: Context): String = {
-      val tree1 = if (settings.rawTree) tree else (new TreeCleaner).transform(tree)(ctx)
+      val tree1 = if (settings.showRawTree) tree else (new TreeCleaner).transform(tree)(ctx)
       new TastyImpl(ctx).showSourceCode.showTree(tree1)(ctx)
     }
     withTree(expr, show, settings)
   }
 
-  def withTree[T](expr: Expr[_], f: (Tree, Context) => T, settings: ToolboxSettings): T = {
+  def withTree[T](expr: Expr[_], f: (Tree, Context) => T, settings: Toolbox.Settings): T = {
     val (_, ctx: Context) = setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)
 
     var output: Option[T] = None
@@ -61,7 +63,7 @@ class QuoteDriver extends Driver {
     output.getOrElse(throw new Exception("Could not extract " + expr))
   }
 
-  def withTypeTree[T](tpe: Type[_], f: (TypTree, Context) => T, settings: ToolboxSettings): T = {
+  def withTypeTree[T](tpe: Type[_], f: (TypTree, Context) => T, settings: Toolbox.Settings): T = {
     val (_, ctx: Context) = setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)
 
     var output: Option[T] = None

compiler/src/dotty/tools/dotc/quoted/Toolbox.scala renamed to compiler/src/dotty/tools/dotc/quoted/ToolboxImpl.scala

@@ -6,10 +6,10 @@ import scala.quoted.Expr
 import scala.quoted.Exprs.{LiftedExpr, TastyTreeExpr}
 
 /** Default runners for quoted expressions */
-object Toolbox {
+object ToolboxImpl {
   import tpd._
 
-  implicit def make(implicit settings: ToolboxSettings): scala.quoted.Toolbox = new scala.quoted.Toolbox {
+  def make(settings: scala.quoted.Toolbox.Settings): scala.quoted.Toolbox = new scala.quoted.Toolbox {
 
     private[this] val driver: QuoteDriver = new QuoteDriver()
 

compiler/src/dotty/tools/dotc/quoted/ToolboxSettings.scala

@@ -2,8 +2,56 @@ package scala.quoted
 
 import scala.annotation.implicitNotFound
 
-@implicitNotFound("Could not find implicit quoted.Toolbox.\n\nDefault toolbox can be instantiated with:\n  `implicit val toolbox: scala.quoted.Toolbox = dotty.tools.dotc.quoted.Toolbox.make`\n\nIf only needed once it can also be imported with:\n `import dotty.tools.dotc.quoted.Toolbox._`")
+@implicitNotFound("Could not find implicit quoted.Toolbox.\n\nDefault toolbox can be instantiated with:\n  `implicit val toolbox: scala.quoted.Toolbox = scala.quoted.Toolbox.make`\n\nIf only needed once it can also be imported with:\n `import scala.quoted.Toolbox.Default._`")
 trait Toolbox {
   def run[T](expr: Expr[T]): T
   def show[T](expr: Expr[T]): String
 }
+
+object Toolbox {
+
+  object Default {
+    // TODO remove? It may be better to only have one way to instantiate the toolbox
+    implicit def make(implicit settings: Settings): Toolbox = Toolbox.make
+  }
+
+  def make(implicit settings: Settings): Toolbox = {
+    val cl = getClass.getClassLoader
+    try {
+      val toolboxImplCls = cl.loadClass("dotty.tools.dotc.quoted.ToolboxImpl")
+      val makeMeth = toolboxImplCls.getMethod("make", classOf[Settings])
+      makeMeth.invoke(null, settings).asInstanceOf[Toolbox]
+    }
+    catch {
+      case ex: ClassNotFoundException =>
+        throw new ToolboxNotFoundException(
+          s"""Could not load the Toolbox class `${ex.getMessage}` from the JVM classpath. Make sure that the compiler is on the JVM classpath.""",
+          ex
+        )
+    }
+  }
+
+  /** Setting of the Toolbox instance. */
+  class Settings private (val outDir: Option[String], val showRawTree: Boolean, val compilerArgs: List[String])
+
+  object Settings {
+
+    implicit def default: Settings = make()
+
+    /** Make toolbox settings
+     *  @param outDir Output directory for the compiled quote. If set to None the output will be in memory
+     *  @param color Print output with colors
+     *  @param showRawTree Do not remove quote tree artifacts
+     *  @param compilerArgs Compiler arguments. Use only if you know what you are doing.
+     */
+    def make( // TODO avoid using default parameters (for binary compat)
+      color: Boolean = false,
+      showRawTree: Boolean = false,
+      outDir: Option[String] = None,
+      compilerArgs: List[String] = Nil
+    ): Settings =
+      new Settings(outDir, showRawTree, compilerArgs)
+  }
+
+  class ToolboxNotFoundException(msg: String, cause: ClassNotFoundException) extends Exception(msg, cause)
+}

library/src/scala/quoted/Toolbox.scala

@@ -1,6 +1,6 @@
 import scala.quoted._
 
-import dotty.tools.dotc.quoted.Toolbox._
+import scala.quoted.Toolbox.Default._
 
 object Macros {
   transparent def foo(i: => Int): Int = ~{

tests/neg-with-compiler/quote-run-in-macro-1/quoted_1.scala

@@ -1,6 +1,6 @@
 import scala.quoted._
 
-import dotty.tools.dotc.quoted.Toolbox._
+import scala.quoted.Toolbox.Default._
 
 object Macros {
   transparent def foo(i: => Int): Int = ~{

tests/neg-with-compiler/quote-run-in-macro-2/quoted_1.scala

@@ -1,6 +1,6 @@
 import scala.quoted._
 
-import dotty.tools.dotc.quoted.Toolbox._
+import scala.quoted.Toolbox.Default._
 
 object Macros {
 

tests/pos-with-compiler/quote-0.scala

@@ -1,4 +1,4 @@
-import dotty.tools.dotc.quoted.Toolbox._
+import scala.quoted.Toolbox.Default._
 import scala.quoted._
 import Macros._
 

tests/pos-with-compiler/quote-assert/quoted_2.scala

@@ -673,7 +673,7 @@ object Test {
     .fold('{0}, ((a: Expr[Int], b : Expr[Int]) => '{ ~a + ~b }))
 
   def main(args: Array[String]): Unit = {
-    implicit val toolbox: scala.quoted.Toolbox = dotty.tools.dotc.quoted.Toolbox.make
+    implicit val toolbox: scala.quoted.Toolbox = scala.quoted.Toolbox.make
 
     println(test1().run)
     println

tests/run-with-compiler-custom-args/staged-streams_1.scala

@@ -1,4 +1,4 @@
-import dotty.tools.dotc.quoted.Toolbox._
+import scala.quoted.Toolbox.Default._
 import scala.quoted._
 object Test {
   def main(args: Array[String]): Unit = {