1 files changed, 83 insertions, 0 deletions
diff --git a/src/compiler/scala/reflect/macros/runtime/Synthetics.scala b/src/compiler/scala/reflect/macros/runtime/Synthetics.scala
new file mode 100644
index 0000000000..73f3ab8d20
--- /dev/null
+++ b/src/compiler/scala/reflect/macros/runtime/Synthetics.scala
@@ -0,0 +1,83 @@
+/* NSC -- new Scala compiler
+ * Copyright 2005-2013 LAMP/EPFL
+ */
+
+package scala.reflect.macros
+package runtime
+
+import java.util.UUID._
+import scala.reflect.internal.Flags._
+import scala.reflect.internal.util.BatchSourceFile
+import scala.reflect.io.VirtualFile
+
+trait Synthetics {
+  self: Context =>
+
+  import global._
+  import mirror.wrapMissing
+
+  // getClassIfDefined and getModuleIfDefined cannot be used here
+  // because they don't work for stuff declared in the empty package
+  // (as specified in SLS, code inside non-empty packages cannot see
+  // declarations from the empty package, so compiler internals
+  // default to ignoring contents of the empty package)
+  // to the contrast, staticModule and staticClass are designed
+  // to be a part of the reflection API and, therefore, they
+  // correctly resolve all names
+  private def topLevelSymbol(name: Name): Symbol = wrapMissing {
+    if (name.isTermName) mirror.staticModule(name.toString)
+    else mirror.staticClass(name.toString)
+  }
+
+  def topLevelDef(name: Name): Tree =
+    enclosingRun.units.toList.map(_.body).flatMap {
+      // it's okay to check `stat.symbol` here, because currently macros expand strictly after namer
+      // which means that by the earliest time one can call this method all top-level definitions will have already been entered
+      case PackageDef(_, stats) => stats filter (stat => stat.symbol != NoSymbol && stat.symbol == topLevelSymbol(name))
+      case _ => Nil // should never happen, but better be safe than sorry
+    }.headOption getOrElse EmptyTree
+
+  def topLevelRef(name: Name): Tree = {
+    if (topLevelDef(name).nonEmpty) gen.mkUnattributedRef(name)
+    else EmptyTree
+  }
+
+  // TODO: provide a way to specify a pretty name for debugging purposes
+  private def randomFileName() = (
+    "macroSynthetic-" + randomUUID().toString.replace("-", "") + ".scala"
+  )
+
+  def introduceTopLevel[T: PackageSpec](packagePrototype: T, definition: universe.ImplDef): RefTree =
+    introduceTopLevel(packagePrototype, List(definition)).head
+
+  def introduceTopLevel[T: PackageSpec](packagePrototype: T, definitions: universe.ImplDef*): List[RefTree] =
+    introduceTopLevel(packagePrototype, definitions.toList)
+
+  private def introduceTopLevel[T: PackageSpec](packagePrototype: T, definitions: List[universe.ImplDef]): List[RefTree] = {
+    val code @ PackageDef(pid, _) = implicitly[PackageSpec[T]].mkPackageDef(packagePrototype, definitions)
+    val syntheticFileName = randomFileName()
+    // compatibility with SBT
+    // on the one hand, we need to specify some jfile here, otherwise sbt crashes with an NPE (SI-6870)
+    // on the other hand, we can't specify the obvious enclosingUnit, because then sbt somehow fails to run tests using type macros
+    // okay, now let's specify a guaranteedly non-existent file in an existing directory (so that we don't run into permission problems)
+    val relatedJfile = enclosingUnit.source.file.file
+    val fakeJfile = if (relatedJfile != null) new java.io.File(relatedJfile.getParent, syntheticFileName) else null
+    val virtualFile = new VirtualFile(syntheticFileName) { override def file = fakeJfile }
+    val sourceFile = new BatchSourceFile(virtualFile, code.toString)
+    val unit = new CompilationUnit(sourceFile)
+    unit.body = code
+    universe.currentRun.compileLate(unit)
+    definitions map (definition => Select(pid, definition.name))
+  }
+
+  protected def mkPackageDef(name: String, stats: List[Tree]) = gen.mkPackageDef(name, stats)
+
+  protected def mkPackageDef(name: TermName, stats: List[Tree]) = gen.mkPackageDef(name.toString, stats)
+
+  protected def mkPackageDef(tree: RefTree, stats: List[Tree]) = PackageDef(tree, stats)
+
+  protected def mkPackageDef(sym: Symbol, stats: List[Tree]) = {
+    assert(sym hasFlag PACKAGE, s"expected a package or package class symbol, found: $sym")
+    gen.mkPackageDef(sym.fullName.toString, stats)
+  }
+}