Merge commit '625397b02e'; commit 'refs/pull/396/head' into develop

2 files changed, 14 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index b4e0ad6edf..4fb9362ccc 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -166,7 +166,7 @@ trait Implicits {
     }
 
     def isCyclicOrErroneous =
-      try containsError(tpe)
+      try sym.hasFlag(LOCKED) || containsError(tpe)
       catch { case _: CyclicReference => true }
 
     var useCountArg: Int = 0
diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
index 988b821d1a..b7e0eaef2b 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
@@ -184,8 +184,21 @@ trait Macros { self: Analyzer =>
   def typedMacroBody(typer: Typer, ddef: DefDef): Tree = {
     import typer.context
     if (macroDebug) println("typechecking macro def %s at %s".format(ddef.symbol, ddef.pos))
+
     typer.checkFeature(ddef.pos, MacrosFeature)
 
+    // [Eugene to Martin] todo. copy/pasted this from checkFeature, because don't know a better way
+    // this is necessary to prevent macros from typechecking/expanding when they are not enabled
+    // `checkFeature` call alone is not enough, because it merely posts validation callback to unit.toCheck
+    def hasImport = inferImplicit(EmptyTree: Tree, MacrosFeature.tpe, true, false, typer.context) != SearchFailure
+    val nestedOwners = MacrosFeature.owner.ownerChain.takeWhile(_ != languageFeatureModule.moduleClass).reverse
+    val featureName = (nestedOwners map (_.name + ".")).mkString + MacrosFeature.name
+    def hasOption = settings.language.value contains featureName
+    if (!hasImport && !hasOption) {
+      ddef.symbol setFlag IS_ERROR
+      return EmptyTree
+    }
+
     implicit class AugmentedString(s: String) {
       def abbreviateCoreAliases: String = { // hack!
         var result = s