Merge pull request scala#2720 from adriaanm/ticket-7487

SI-7487 Revert "Removed -Ymacro-no-expand."

Author: adriaanm

src/compiler/scala/tools/nsc/settings/ScalaSettings.scala

@@ -166,6 +166,7 @@ trait ScalaSettings extends AbsScalaSettings
   val Yrangepos       = BooleanSetting    ("-Yrangepos", "Use range positions for syntax trees.")
   val Ymemberpos      = StringSetting     ("-Yshow-member-pos", "output style", "Show start and end positions of members", "") withPostSetHook (_ => Yrangepos.value = true)
   val Yreifycopypaste = BooleanSetting    ("-Yreify-copypaste", "Dump the reified trees in copypasteable representation.")
+  val Ymacronoexpand  = BooleanSetting    ("-Ymacro-no-expand", "Don't expand macros. Might be useful for scaladoc and presentation compiler, but will crash anything which uses macros and gets past typer.")
   val Yreplsync       = BooleanSetting    ("-Yrepl-sync", "Do not use asynchronous code for repl startup")
   val Yreploutdir     = StringSetting     ("-Yrepl-outdir", "path", "Write repl-generated classfiles to given output directory (use \"\" to generate a temporary dir)" , "")
   val YmethodInfer    = BooleanSetting    ("-Yinfer-argument-types", "Infer types for arguments of overriden methods.")

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

@@ -100,15 +100,17 @@ trait StdAttachments {
   /** Determines whether a tree should not be expanded, because someone has put SuppressMacroExpansionAttachment on it or one of its children.
    */
   def isMacroExpansionSuppressed(tree: Tree): Boolean =
-    if (tree.attachments.get[SuppressMacroExpansionAttachment.type].isDefined) true
-    else tree match {
-      // we have to account for the fact that during typechecking an expandee might become wrapped,
-      // i.e. surrounded by an inferred implicit argument application or by an inferred type argument application.
-      // in that case the expandee itself will no longer be suppressed and we need to look at the core
-      case Apply(fn, _) => isMacroExpansionSuppressed(fn)
-      case TypeApply(fn, _) => isMacroExpansionSuppressed(fn)
-      case _ => false
-    }
+    (  settings.Ymacronoexpand.value // SI-6812
+    || tree.attachments.get[SuppressMacroExpansionAttachment.type].isDefined
+    || (tree match {
+        // we have to account for the fact that during typechecking an expandee might become wrapped,
+        // i.e. surrounded by an inferred implicit argument application or by an inferred type argument application.
+        // in that case the expandee itself will no longer be suppressed and we need to look at the core
+        case Apply(fn, _)     => isMacroExpansionSuppressed(fn)
+        case TypeApply(fn, _) => isMacroExpansionSuppressed(fn)
+        case _                => false
+      })
+    )
 
   /** After being synthesized by the parser, primary constructors aren't fully baked yet.
    *  A call to super in such constructors is just a fill-me-in-later dummy resolved later
@@ -154,4 +156,4 @@ trait StdAttachments {
    *  because someone has put MacroImplRefAttachment on it.
    */
   def isMacroImplRef(tree: Tree): Boolean = tree.attachments.get[MacroImplRefAttachment.type].isDefined
-}
+}

test/scaladoc/run/SI-6812.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.Context
+    import language.experimental.macros
+
+    object Macros {
+      def impl(c: Context) = c.literalUnit
+      def foo = macro impl
+    }
+
+    class C {
+      def bar = Macros.foo
+    }
+  """
+
+  def scaladocSettings = ""
+  override def extraSettings = super.extraSettings + " -Ymacro-no-expand"
+  def testModel(root: Package) = ()
+}