clearly establishes what macro bundles are

Previously it was enough to just extend scala.reflect.macros.Macro, which
created some loopholes, but now scalac enforces that bundles:
  1) Are static (not necessarily top-level, but just static)
  2) Are traits (objects shouldn't be bundles anyway, and classes bring
     complications with their ctors which require special treatment in
     generated classes, so why support them if they don't bring anything
     new to the table?)
  3) Are monomorphic (again, this brings unnecessary complications wrt
     auxiliary code generation, so I don't see merit in supporting
     polymorphic bundles, whatever that a polymorphic bundle could mean)
  4) Don't provide concrete implementation for Macro.c (if they do then
     what is the point?)

20 files changed, 169 insertions, 3 deletions

diff --git a/test/files/neg/macro-bundle-abstract.check b/test/files/neg/macro-bundle-abstract.check
new file mode 100644
index 0000000000..4b07adcc95
--- /dev/null
+++ b/test/files/neg/macro-bundle-abstract.check
@@ -0,0 +1,4 @@
+macro-bundle-abstract.scala:5: error: class Bundle$Bundle needs to be abstract, since method deferred in trait Bundle of type => Int is not defined
+trait Bundle extends Macro {
+      ^
+one error found
diff --git a/test/files/neg/macro-bundle-abstract.scala b/test/files/neg/macro-bundle-abstract.scala
new file mode 100644
index 0000000000..2b302045da
--- /dev/null
+++ b/test/files/neg/macro-bundle-abstract.scala
@@ -0,0 +1,12 @@
+import scala.language.experimental.macros
+import scala.reflect.macros.Macro
+import scala.reflect.macros.Context
+
+trait Bundle extends Macro {
+  def deferred: Int
+  def impl = ???
+}
+
+object Macros {
+  def foo = macro Bundle.impl
+}
\ No newline at end of file
diff --git a/test/files/neg/macro-bundle-class.check b/test/files/neg/macro-bundle-class.check
new file mode 100644
index 0000000000..92695390ab
--- /dev/null
+++ b/test/files/neg/macro-bundle-class.check
@@ -0,0 +1,4 @@
+macro-bundle-class.scala:10: error: macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member
+  def foo = macro Bundle.impl
+      ^
+one error found
diff --git a/test/files/neg/macro-bundle-class.scala b/test/files/neg/macro-bundle-class.scala
new file mode 100644
index 0000000000..4b92cdd40f
--- /dev/null
+++ b/test/files/neg/macro-bundle-class.scala
@@ -0,0 +1,11 @@
+import scala.language.experimental.macros
+import scala.reflect.macros.Macro
+import scala.reflect.macros.Context
+
+class Bundle(val c: Context) extends Macro {
+  def impl = ???
+}
+
+object Macros {
+  def foo = macro Bundle.impl
+}
\ No newline at end of file
diff --git a/test/files/neg/macro-bundle-nonmacro.check b/test/files/neg/macro-bundle-nonmacro.check
new file mode 100644
index 0000000000..5a265b5724
--- /dev/null
+++ b/test/files/neg/macro-bundle-nonmacro.check
@@ -0,0 +1,4 @@
+macro-bundle-nonmacro.scala:8: error: not found: value Bundle
+  def foo = Bundle.impl
+            ^
+one error found
diff --git a/test/files/neg/macro-bundle-nonmacro.scala b/test/files/neg/macro-bundle-nonmacro.scala
new file mode 100644
index 0000000000..c7d99f4582
--- /dev/null
+++ b/test/files/neg/macro-bundle-nonmacro.scala
@@ -0,0 +1,9 @@
+import scala.language.experimental.macros
+
+trait Bundle {
+  def impl = ???
+}
+
+object Macros {
+  def foo = Bundle.impl
+}
\ No newline at end of file
diff --git a/test/files/neg/macro-bundle-object.check b/test/files/neg/macro-bundle-object.check
new file mode 100644
index 0000000000..e122001427
--- /dev/null
+++ b/test/files/neg/macro-bundle-object.check
@@ -0,0 +1,7 @@
+macro-bundle-object.scala:11: error: macro implementation has wrong shape:
+ required: (c: scala.reflect.macros.Context): c.Expr[Any]
+ found   : : Nothing
+number of parameter sections differ
+  def foo = macro Bundle.impl
+      ^
+one error found
diff --git a/test/files/neg/macro-bundle-object.scala b/test/files/neg/macro-bundle-object.scala
new file mode 100644
index 0000000000..98c4238a62
--- /dev/null
+++ b/test/files/neg/macro-bundle-object.scala
@@ -0,0 +1,12 @@
+import scala.language.experimental.macros
+import scala.reflect.macros.Macro
+import scala.reflect.macros.Context
+
+object Bundle extends Macro {
+  val c: Context = ???
+  def impl = ???
+}
+
+object Macros {
+  def foo = macro Bundle.impl
+}
\ No newline at end of file
diff --git a/test/files/neg/macro-bundle-polymorphic.check b/test/files/neg/macro-bundle-polymorphic.check
new file mode 100644
index 0000000000..204bd30bca
--- /dev/null
+++ b/test/files/neg/macro-bundle-polymorphic.check
@@ -0,0 +1,10 @@
+macro-bundle-polymorphic.scala:10: error: macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member
+  def foo = macro Bundle.impl
+      ^
+macro-bundle-polymorphic.scala:11: error: macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member
+  def foo = macro Bundle[Int].impl
+      ^
+macro-bundle-polymorphic.scala:12: error: macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member
+  def foo = macro Bundle[Int, Nothing].impl
+      ^
+three errors found
diff --git a/test/files/neg/macro-bundle-polymorphic.scala b/test/files/neg/macro-bundle-polymorphic.scala
new file mode 100644
index 0000000000..0468d841bd
--- /dev/null
+++ b/test/files/neg/macro-bundle-polymorphic.scala
@@ -0,0 +1,13 @@
+import scala.language.experimental.macros
+import scala.reflect.macros.Macro
+import scala.reflect.macros.Context
+
+trait Bundle[T] extends Macro {
+  def impl = ???
+}
+
+object Macros {
+  def foo = macro Bundle.impl
+  def foo = macro Bundle[Int].impl
+  def foo = macro Bundle[Int, Nothing].impl
+}
\ No newline at end of file
diff --git a/test/files/neg/macro-bundle-trait.check b/test/files/neg/macro-bundle-trait.check
new file mode 100644
index 0000000000..972788c577
--- /dev/null
+++ b/test/files/neg/macro-bundle-trait.check
@@ -0,0 +1,4 @@
+macro-bundle-trait.scala:11: error: macro bundles must be monomorphic traits extending scala.reflect.macros.Macro and not implementing its `val c: Context` member
+  def foo = macro Bundle.impl
+      ^
+one error found
diff --git a/test/files/neg/macro-bundle-trait.scala b/test/files/neg/macro-bundle-trait.scala
new file mode 100644
index 0000000000..ddc87f6db3
--- /dev/null
+++ b/test/files/neg/macro-bundle-trait.scala
@@ -0,0 +1,12 @@
+import scala.language.experimental.macros
+import scala.reflect.macros.Macro
+import scala.reflect.macros.Context
+
+trait Bundle extends Macro {
+  val c: Context = ???
+  def impl = ???
+}
+
+object Macros {
+  def foo = macro Bundle.impl
+}
\ No newline at end of file
diff --git a/test/files/run/macro-bundle-static.check b/test/files/run/macro-bundle-static.check
new file mode 100644
index 0000000000..37c8eaf27a
--- /dev/null
+++ b/test/files/run/macro-bundle-static.check
@@ -0,0 +1,6 @@
+()
+Int
+()
+true
+IntInt
+true
diff --git a/test/files/run/macro-bundle-static/Impls_Macros_1.scala b/test/files/run/macro-bundle-static/Impls_Macros_1.scala
new file mode 100644
index 0000000000..831dac6df5
--- /dev/null
+++ b/test/files/run/macro-bundle-static/Impls_Macros_1.scala
@@ -0,0 +1,31 @@
+import scala.reflect.macros.Context
+import scala.reflect.macros.Macro
+import scala.language.experimental.macros
+
+object Enclosing {
+  trait Impl extends Macro {
+    def mono = c.literalUnit
+    def poly[T: c.WeakTypeTag] = c.literal(c.weakTypeOf[T].toString)
+    def weird = macro mono
+  }
+}
+
+object Macros {
+  def mono = macro Enclosing.Impl.mono
+  def poly[T] = macro Enclosing.Impl.poly[T]
+}
+
+package pkg {
+  object Enclosing {
+    trait Impl extends Macro {
+      def mono = c.literalTrue
+      def poly[T: c.WeakTypeTag] = c.literal(c.weakTypeOf[T].toString + c.weakTypeOf[T].toString)
+      def weird = macro mono
+    }
+  }
+
+  object Macros {
+    def mono = macro Enclosing.Impl.mono
+    def poly[T] = macro Enclosing.Impl.poly[T]
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/macro-bundle-static/Test_2.scala b/test/files/run/macro-bundle-static/Test_2.scala
new file mode 100644
index 0000000000..72160f6ec2
--- /dev/null
+++ b/test/files/run/macro-bundle-static/Test_2.scala
@@ -0,0 +1,8 @@
+object Test extends App {
+  println(Macros.mono)
+  println(Macros.poly[Int])
+  println(new Enclosing.Impl{val c = ???}.weird)
+  println(pkg.Macros.mono)
+  println(pkg.Macros.poly[Int])
+  println(new pkg.Enclosing.Impl{val c = ???}.weird)
+}
\ No newline at end of file
diff --git a/test/files/run/macro-bundle-toplevel.check b/test/files/run/macro-bundle-toplevel.check
new file mode 100644
index 0000000000..37c8eaf27a
--- /dev/null
+++ b/test/files/run/macro-bundle-toplevel.check
@@ -0,0 +1,6 @@
+()
+Int
+()
+true
+IntInt
+true
diff --git a/test/files/run/macro-bundle.flags b/test/files/run/macro-bundle-toplevel.flags
index cd66464f2f..cd66464f2f 100644
--- a/test/files/run/macro-bundle.flags
+++ b/test/files/run/macro-bundle-toplevel.flags
diff --git a/test/files/run/macro-bundle/Impls_Macros_1.scala b/test/files/run/macro-bundle-toplevel/Impls_Macros_1.scala
index 3f651c9a43..676935682e 100644
--- a/test/files/run/macro-bundle/Impls_Macros_1.scala
+++ b/test/files/run/macro-bundle-toplevel/Impls_Macros_1.scala
@@ -10,4 +10,17 @@ trait Impl extends Macro {
 object Macros {
   def mono = macro Impl.mono
   def poly[T] = macro Impl.poly[T]
+}
+
+package pkg {
+  trait Impl extends Macro {
+    def mono = c.literalTrue
+    def poly[T: c.WeakTypeTag] = c.literal(c.weakTypeOf[T].toString + c.weakTypeOf[T].toString)
+    def weird = macro mono
+  }
+
+  object Macros {
+    def mono = macro Impl.mono
+    def poly[T] = macro Impl.poly[T]
+  }
 }
\ No newline at end of file
diff --git a/test/files/run/macro-bundle/Test_2.scala b/test/files/run/macro-bundle-toplevel/Test_2.scala
index 428f809f9d..139cc5bef2 100644
--- a/test/files/run/macro-bundle/Test_2.scala
+++ b/test/files/run/macro-bundle-toplevel/Test_2.scala
@@ -2,4 +2,7 @@ object Test extends App {
   println(Macros.mono)
   println(Macros.poly[Int])
   println(new Impl{val c = ???}.weird)
+  println(pkg.Macros.mono)
+  println(pkg.Macros.poly[Int])
+  println(new pkg.Impl{val c = ???}.weird)
 }
\ No newline at end of file
diff --git a/test/files/run/macro-bundle.check b/test/files/run/macro-bundle.check
deleted file mode 100644
index 2107454960..0000000000
--- a/test/files/run/macro-bundle.check
+++ /dev/null
@@ -1,3 +0,0 @@
-()
-Int
-()