From 499c5e722843e7941e891ed8092483e3a169bc29 Mon Sep 17 00:00:00 2001
From: Martin Duhem <martin.duhem@gmail.com>
Date: Fri, 6 Nov 2015 11:27:40 +0100
Subject: [PATCH] Correct fix against SO and macros problem

---
 .../src/main/scala/xsbt/Compat.scala          | 26 +++++++++++++++++++
 .../src/main/scala/xsbt/ExtractAPI.scala      | 13 +++++-----
 2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/compile/interface/src/main/scala/xsbt/Compat.scala b/compile/interface/src/main/scala/xsbt/Compat.scala
index 3b007d252..472858380 100644
--- a/compile/interface/src/main/scala/xsbt/Compat.scala
+++ b/compile/interface/src/main/scala/xsbt/Compat.scala
@@ -87,6 +87,8 @@ abstract class Compat {
     def enclosingTopLevelClass: Symbol = sym.toplevelClass
     def toplevelClass: Symbol = sourceCompatibilityOnly
     def isMacro: Boolean = false
+    def orElse(alt: => Symbol) = alt
+    def asType: TypeSymbol = sym.asInstanceOf[TypeSymbol]
   }
 
   val DummyValue = 0
@@ -101,6 +103,30 @@ abstract class Compat {
 
   private[this] final implicit def miscCompat(n: AnyRef): MiscCompat = new MiscCompat
 
+  object DetectMacroImpls {
+
+    private implicit def withRootMirror(x: Any): WithRootMirror = new WithRootMirror(x)
+    private class DummyMirror {
+      def getClassIfDefined(x: String): Symbol = NoSymbol
+    }
+    private class WithRootMirror(x: Any) {
+      def rootMirror = new DummyMirror
+    }
+    private class WithIsScala211(x: Any) {
+      def isScala211 = false
+    }
+    private[this] implicit def withIsScala211(x: Any): WithIsScala211 = new WithIsScala211(x)
+
+    // Copied from scala/scala since these methods do not exists in Scala < 2.11.x
+    private def Context_210 = if (settings.isScala211) NoSymbol else global.rootMirror.getClassIfDefined("scala.reflect.macros.Context")
+    lazy val BlackboxContextClass = global.rootMirror.getClassIfDefined("scala.reflect.macros.blackbox.Context").orElse(Context_210)
+    lazy val WhiteboxContextClass = global.rootMirror.getClassIfDefined("scala.reflect.macros.whitebox.Context").orElse(Context_210)
+    def isContextCompatible(sym: Symbol) = {
+      sym.isNonBottomSubClass(BlackboxContextClass) || sym.isNonBottomSubClass(WhiteboxContextClass)
+    }
+
+  }
+
   object MacroExpansionOf {
     def unapply(tree: Tree): Option[Tree] = {
 
diff --git a/compile/interface/src/main/scala/xsbt/ExtractAPI.scala b/compile/interface/src/main/scala/xsbt/ExtractAPI.scala
index efea1af20..ea198111c 100644
--- a/compile/interface/src/main/scala/xsbt/ExtractAPI.scala
+++ b/compile/interface/src/main/scala/xsbt/ExtractAPI.scala
@@ -178,15 +178,14 @@ class ExtractAPI[GlobalType <: CallbackGlobal](val global: GlobalType,
 
   private def viewer(s: Symbol) = (if (s.isModule) s.moduleClass else s).thisType
   private def printMember(label: String, in: Symbol, t: Type) = println(label + " in " + in + " : " + t + " (debug: " + debugString(t) + " )")
+
   private def defDef(in: Symbol, s: Symbol): List[xsbti.api.Def] =
     {
-      def collectAll(acc: Set[Symbol], s: Symbol): Set[Symbol] =
-        if (acc contains s) acc
-        else
-          ((s.info.members.sorted ++ s.children) foldLeft (acc + s)) {
-            case (acc, sym) => collectAll(acc, sym)
-          }
-      val inspectPostErasure = !collectAll(Set.empty, in.enclosingTopLevelClass).exists(_.isMacro)
+      import DetectMacroImpls._
+      def hasContextAsParameter(meth: MethodSymbol): Boolean =
+        meth.paramss.flatten exists (p => isContextCompatible(p.info.typeSymbol))
+
+      val inspectPostErasure = !hasContextAsParameter(s.asMethod)
       def build(t: Type, typeParams: Array[xsbti.api.TypeParameter], valueParameters: List[xsbti.api.ParameterList]): List[xsbti.api.Def] =
         {
           def parameterList(syms: List[Symbol]): xsbti.api.ParameterList =