Merge pull request scala#4692 from JanBessai/Fix-SI-6636

SI-6636 Fix macro expansion in toolboxes

Author: adriaanm

src/compiler/scala/tools/nsc/typechecker/Macros.scala

@@ -55,6 +55,13 @@ trait Macros extends MacroRuntimes with Traces with Helpers {
 
   def globalSettings = global.settings
 
+  /** Obtains a `ClassLoader` instance used for macro expansion.
+   *
+   *  By default a new `ScalaClassLoader` is created using the classpath
+   *  from global and the classloader of self as parent.
+   *
+   *  Mirrors with runtime definitions (e.g. Repl) need to adjust this method.
+   */
   protected def findMacroClassLoader(): ClassLoader = {
     val classpath = global.classPath.asURLs
     macroLogVerbose("macro classloader: initializing from -cp: %s".format(classpath))

src/compiler/scala/tools/reflect/ReflectGlobal.scala

@@ -1,16 +1,32 @@
 package scala.tools
 package reflect
 
+import scala.reflect.internal.util.ScalaClassLoader
 import scala.tools.nsc.Global
 import scala.tools.nsc.reporters.Reporter
 import scala.tools.nsc.Settings
+import scala.tools.nsc.typechecker.Analyzer
 
 /** A version of Global that uses reflection to get class
  *  infos, instead of reading class or source files.
  */
 class ReflectGlobal(currentSettings: Settings, reporter: Reporter, override val rootClassLoader: ClassLoader)
   extends Global(currentSettings, reporter) with scala.tools.reflect.ReflectSetup with scala.reflect.runtime.SymbolTable {
 
+  override lazy val analyzer = new {
+    val global: ReflectGlobal.this.type = ReflectGlobal.this
+  } with Analyzer {
+    /** Obtains the classLoader used for runtime macro expansion.
+     *
+     *  Macro expansion can use everything available in [[global.classPath]] or [[rootClassLoader]].
+     *  The [[rootClassLoader]] is used to obtain runtime defined macros.
+     */
+    override protected def findMacroClassLoader(): ClassLoader = {
+      val classpath = global.classPath.asURLs
+      ScalaClassLoader.fromURLs(classpath, rootClassLoader)
+    }
+  }
+
   override def transformedType(sym: Symbol) =
     postErasure.transformInfo(sym,
       erasure.transformInfo(sym,

test/files/run/toolbox_expand_macro.check

@@ -0,0 +1 @@
+42

test/files/run/toolbox_expand_macro.scala

@@ -0,0 +1,23 @@
+import scala.reflect.runtime.universe._
+import scala.reflect.runtime.{universe => ru}
+import scala.reflect.runtime.{currentMirror => cm}
+import scala.tools.reflect.{ToolBox}
+
+object Test extends App {
+  val toolBox = cm.mkToolBox()
+  val x = 21
+  val runtimeMacro =
+    q"""object RuntimeMacro {
+      import scala.reflect.macros.whitebox.Context
+      import scala.language.experimental.macros
+
+      def add(y: Int): Int = macro addImpl
+      def addImpl(c: Context)(y: c.Expr[Int]): c.Expr[Int] = {
+        import c.universe._
+        val x = $x
+        c.Expr[Int](q"$$x + $$y")
+      }
+    }"""
+  val s = toolBox.define(runtimeMacro)
+  println(toolBox.eval(q"$s.add(21)"))
+}