Merge pull request #2994 from xeno-by/topic/bundles

assorted fixes for bundles

3 files changed, 39 insertions, 29 deletions

diff --git a/src/compiler/scala/reflect/macros/compiler/Errors.scala b/src/compiler/scala/reflect/macros/compiler/Errors.scala
index 6ec111cf7c..9b56e417e2 100644
--- a/src/compiler/scala/reflect/macros/compiler/Errors.scala
+++ b/src/compiler/scala/reflect/macros/compiler/Errors.scala
@@ -29,6 +29,10 @@ trait Errors extends Traces {
 
   def MacroImplWrongNumberOfTypeArgumentsError() = implRefError(TypedApplyWrongNumberOfTpeParametersErrorMessage(macroImplRef))
 
+  def MacroBundleNonStaticError() = implRefError("macro bundles must be static")
+
+  def MacroBundleWrongShapeError() = implRefError("macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member")
+
   // compatibility errors
 
   // helpers
diff --git a/src/compiler/scala/reflect/macros/compiler/Resolvers.scala b/src/compiler/scala/reflect/macros/compiler/Resolvers.scala
index 46c4e24817..49a5c01ad7 100644
--- a/src/compiler/scala/reflect/macros/compiler/Resolvers.scala
+++ b/src/compiler/scala/reflect/macros/compiler/Resolvers.scala
@@ -9,7 +9,7 @@ trait Resolvers {
 
   import global._
   import analyzer._
-  import definitions._
+  import definitions.{EmptyPackageClass => _, _}
   import treeInfo._
   import gen._
 
@@ -33,7 +33,7 @@ trait Resolvers {
    */
   lazy val macroImplRef: Tree = {
     val (maybeBundleRef, methName, targs) = macroDdef.rhs match {
-      case Applied(methRef @ Select(bundleRef @ RefTree(qual, bundleName), methName), targs, Nil) =>
+      case Applied(Select(Applied(RefTree(qual, bundleName), _, Nil), methName), targs, Nil) =>
         (RefTree(qual, bundleName.toTypeName), methName, targs)
       case Applied(Ident(methName), targs, Nil) =>
         (Ident(context.owner.enclClass), methName, targs)
@@ -41,30 +41,36 @@ trait Resolvers {
         (EmptyTree, TermName(""), Nil)
     }
 
-    val untypedImplRef = typer.silent(_.typedType(maybeBundleRef)) match {
-      case SilentResultValue(result) if isMacroBundleType(result.tpe) =>
-        val bundleClass = result.tpe.typeSymbol
-        if (!bundleClass.owner.isPackageClass) abort(macroDef.pos, "macro bundles can only be defined as top-level classes or traits")
+    val untypedImplRef = typer.silent(_.typedTypeConstructor(maybeBundleRef)) match {
+      case SilentResultValue(result) if result.tpe.baseClasses.contains(MacroClass) =>
+        val bundleProto = result.tpe.typeSymbol
+        val bundlePkg = bundleProto.enclosingPackageClass
+        if (!isMacroBundleProtoType(bundleProto.tpe)) MacroBundleWrongShapeError()
+        if (!bundleProto.owner.isStaticOwner) MacroBundleNonStaticError()
 
-        // synthesize the invoker, i.e. given a top-level `trait Foo extends Macro { def expand = ... } `
-        // create a top-level definition `class FooInvoker(val c: Context) extends Foo` in MACRO_INVOKER_PACKAGE
-        val invokerPid = gen.mkUnattributedRef(nme.MACRO_INVOKER_PACKAGE)
-        val invokerName = TypeName(bundleClass.fullName.split('.').map(_.capitalize).mkString("") + nme.MACRO_INVOKER_SUFFIX)
-        val invokerFullName = TypeName(s"$invokerPid.$invokerName")
-        val existingInvoker = rootMirror.getClassIfDefined(invokerFullName)
-        if (!currentRun.compiles(existingInvoker)) {
+        // synthesize the bundle, i.e. given a static `trait Foo extends Macro { def expand = ... } `
+        // create a top-level definition `class Foo$Bundle(val c: Context) extends Foo` in a package next to `Foo`
+        val bundlePid = gen.mkUnattributedRef(bundlePkg)
+        val bundlePrefix =
+          if (bundlePkg == EmptyPackageClass) bundleProto.fullName('$')
+          else bundleProto.fullName('$').substring(bundlePkg.fullName('$').length + 1)
+        val bundleName = TypeName(bundlePrefix + tpnme.MACRO_BUNDLE_SUFFIX)
+        val existingBundle = bundleProto.enclosingPackageClass.info.decl(bundleName)
+        if (!currentRun.compiles(existingBundle)) {
           def mkContextValDef(flags: Long) = ValDef(Modifiers(flags), nme.c, TypeTree(ctxTpe), EmptyTree)
           val contextField = mkContextValDef(PARAMACCESSOR)
           val contextParam = mkContextValDef(PARAM | PARAMACCESSOR)
-          val invokerCtor = DefDef(Modifiers(), nme.CONSTRUCTOR, Nil, List(List(contextParam)), TypeTree(), Block(List(pendingSuperCall), Literal(Constant(()))))
-          val invoker = atPos(bundleClass.pos)(ClassDef(NoMods, invokerName, Nil, Template(List(Ident(bundleClass)), noSelfType, List(contextField, invokerCtor))))
-          currentRun.compileLate(PackageDef(invokerPid, List(invoker)))
+          val bundleCtor = DefDef(Modifiers(), nme.CONSTRUCTOR, Nil, List(List(contextParam)), TypeTree(), Block(List(pendingSuperCall), Literal(Constant(()))))
+          val bundleParent = gen.mkAppliedTypeTree(Ident(bundleProto), bundleProto.typeParams.map(sym => Ident(sym.name)))
+          val bundleTemplate = Template(List(bundleParent), noSelfType, List(contextField, bundleCtor))
+          val bundle = atPos(bundleProto.pos)(ClassDef(NoMods, bundleName, bundleProto.typeParams.map(TypeDef(_)), bundleTemplate))
+          currentRun.compileLate(bundleName + ".scala", PackageDef(bundlePid, List(bundle)))
         }
 
         // synthesize the macro impl reference, which is going to look like:
-        // `new Foo$invoker(???).expand` plus the optional type arguments
-        val instanceOfInvoker = New(Select(invokerPid, invokerName), List(List(Select(scalaDot(nme.Predef), nme.???))))
-        gen.mkTypeApply(Select(instanceOfInvoker, methName), targs)
+        // `new FooBundle(???).macroName` plus the optional type arguments
+        val bundleInstance = New(Select(bundlePid, bundleName), List(List(Ident(Predef_???))))
+        atPos(macroDdef.rhs.pos)(gen.mkTypeApply(Select(bundleInstance, methName), targs))
       case _ =>
         macroDdef.rhs
     }
diff --git a/src/compiler/scala/tools/nsc/Global.scala b/src/compiler/scala/tools/nsc/Global.scala
index ef9d8a310e..92bfe6e0fe 100644
--- a/src/compiler/scala/tools/nsc/Global.scala
+++ b/src/compiler/scala/tools/nsc/Global.scala
@@ -1692,19 +1692,19 @@ class Global(var currentSettings: Settings, var reporter: Reporter)
       }
     }
 
-    // TODO: provide a way to specify a pretty name for debugging purposes
-    private def randomFileName() = (
-      "compileLateSynthetic-" + randomUUID().toString.replace("-", "") + ".scala"
-    )
-
-    def compileLate(code: PackageDef) {
+    /** Create and compile a synthetic compilation unit from the provided tree.
+     *
+     *  This needs to create a virtual file underlying the compilation unit in order to appease SBT.
+     *  However this file cannot have a randomly generated name, because then SBT 0.13 goes into a vicious loop
+     *  as described on the mailing list: https://groups.google.com/forum/#!msg/scala-user/r1SgSoVfs0U/Wv4av0LOKukJ
+     *  Therefore I have introduced an additional parameter that makes everyone specify meaningful file names.
+     */
+    def compileLate(virtualFileName: String, code: PackageDef) {
       // 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 syntheticFileName = randomFileName()
-      val fakeJfile = new java.io.File(syntheticFileName)
-      val virtualFile = new VirtualFile(syntheticFileName) { override def file = fakeJfile }
+      val fakeJfile = new java.io.File(virtualFileName)
+      val virtualFile = new VirtualFile(virtualFileName) { override def file = fakeJfile }
       val sourceFile = new BatchSourceFile(virtualFile, code.toString)
       val unit = new CompilationUnit(sourceFile)
       unit.body = code