Use macro expandee, rather than expansion, in pres. compiler

The presentation compiler is primarily interested in trees that
represent the code that one sees in the IDE, not the expansion of
macros.

This commit continues to expand macros, but adds a hook in which
the presentation compiler discards the expansion, retaining instead
the expandee. The expandee is attributed with the type of the
expansion, which allows white box macros to work. In addition,
any domain specific errors and warnings issued by the macro will
still be reported, as a side-effect of the expansion.

The failing test from the last commit now correctly resolves
hyperlinks in macro arguments.

Related IDE ticket:

  https://www.assembla.com/spaces/scala-ide/tickets/1001449#

This facility is configured as follows:

    // expand macros as per normal
    -Ymacro-expand:normal

    // don't expand the macro, takes the place of -Ymacro-no-expand
    -Ymacro-expand:none

    // expand macros to compute type and emit warnings,
    // but retain expandee. Set automatically be the presentation
    // compiler
    -Ymacro-expand:discard

This leaves to door ajar for a new option:

    // Don't expand blackbox macros; expand whitebox
    // but retain expandee
    -Ymacro-expand:discard-whitebox-only

The existing test for SI-6812 has been duplicated. One copy exercises
the now-deprecated -Ymacro-no-expand, and the other uses the new
option.

4 files changed, 27 insertions, 1 deletions

diff --git a/test/scaladoc/run/SI-6812.check b/test/scaladoc/run/SI-6812.check
index 619c56180b..3be8a300e7 100644
--- a/test/scaladoc/run/SI-6812.check
+++ b/test/scaladoc/run/SI-6812.check
@@ -1 +1,2 @@
+warning: -Ymacro-no-expand is deprecated: Use -Ymacro-expand:none
 Done.
diff --git a/test/scaladoc/run/SI-6812.scala b/test/scaladoc/run/SI-6812.scala
index 059c327e7e..6893e816d0 100644
--- a/test/scaladoc/run/SI-6812.scala
+++ b/test/scaladoc/run/SI-6812.scala
@@ -19,6 +19,6 @@ object Test extends ScaladocModelTest {
   """
 
   def scaladocSettings = ""
-  override def extraSettings = super.extraSettings + " -Ymacro-no-expand"
+  override def extraSettings = super.extraSettings + " -Ymacro-no-expand -deprecation"
   def testModel(root: Package) = ()
 }
diff --git a/test/scaladoc/run/SI-6812b.check b/test/scaladoc/run/SI-6812b.check
new file mode 100644
index 0000000000..619c56180b
--- /dev/null
+++ b/test/scaladoc/run/SI-6812b.check
@@ -0,0 +1 @@
+Done.
diff --git a/test/scaladoc/run/SI-6812b.scala b/test/scaladoc/run/SI-6812b.scala
new file mode 100644
index 0000000000..b8a8140357
--- /dev/null
+++ b/test/scaladoc/run/SI-6812b.scala
@@ -0,0 +1,24 @@
+import scala.tools.nsc.doc.model._
+import scala.tools.partest.ScaladocModelTest
+import language._
+
+object Test extends ScaladocModelTest {
+
+  override def code = """
+    import scala.reflect.macros.BlackboxContext
+    import language.experimental.macros
+
+    object Macros {
+      def impl(c: BlackboxContext) = c.literalUnit
+      def foo: Unit = macro impl
+    }
+
+    class C {
+      def bar = Macros.foo
+    }
+  """
+
+  def scaladocSettings = ""
+  override def extraSettings = super.extraSettings + " -Ymacro-expand:none"
+  def testModel(root: Package) = ()
+}