Merge pull request #1885 from paulp/merge/pr-1844

Resolving new merge conflicts between #1844 and master.

44 files changed, 484 insertions, 165 deletions

diff --git a/src/compiler/scala/reflect/macros/runtime/Enclosures.scala b/src/compiler/scala/reflect/macros/runtime/Enclosures.scala
index e8b2961611..8fe0b09700 100644
--- a/src/compiler/scala/reflect/macros/runtime/Enclosures.scala
+++ b/src/compiler/scala/reflect/macros/runtime/Enclosures.scala
@@ -8,6 +8,10 @@ trait Enclosures {
 
   import universe._
 
+  type MacroRole = analyzer.MacroRole
+  def APPLY_ROLE = analyzer.APPLY_ROLE
+  def macroRole: MacroRole
+
   private lazy val site       = callsiteTyper.context
   private lazy val enclTrees  = site.enclosingContextChain map (_.tree)
   private lazy val enclPoses  = enclosingMacros map (_.macroApplication.pos) filterNot (_ eq NoPosition)
diff --git a/src/compiler/scala/reflect/reify/phases/Reshape.scala b/src/compiler/scala/reflect/reify/phases/Reshape.scala
index 75384ddce1..5dd5f08b45 100644
--- a/src/compiler/scala/reflect/reify/phases/Reshape.scala
+++ b/src/compiler/scala/reflect/reify/phases/Reshape.scala
@@ -89,8 +89,8 @@ trait Reshape {
     }
 
     private def undoMacroExpansion(tree: Tree): Tree =
-      tree.attachments.get[MacroExpansionAttachment] match {
-        case Some(MacroExpansionAttachment(original)) =>
+      tree.attachments.get[analyzer.MacroExpansionAttachment] match {
+        case Some(analyzer.MacroExpansionAttachment(original, _)) =>
           original match {
             // this hack is necessary until I fix implicit macros
             // so far tag materialization is implemented by sneaky macros hidden in scala-compiler.jar
diff --git a/src/compiler/scala/tools/nsc/ast/NodePrinters.scala b/src/compiler/scala/tools/nsc/ast/NodePrinters.scala
index deea4de707..602366a201 100644
--- a/src/compiler/scala/tools/nsc/ast/NodePrinters.scala
+++ b/src/compiler/scala/tools/nsc/ast/NodePrinters.scala
@@ -168,6 +168,13 @@ abstract class NodePrinters {
       }
     }
 
+    def typeApplyCommon(tree: Tree, fun: Tree, args: List[Tree]) {
+      printMultiline(tree) {
+        traverse(fun)
+        traverseList("[]", "type argument")(args)
+      }
+    }
+
     def treePrefix(tree: Tree) = showPosition(tree) + tree.productPrefix
     def printMultiline(tree: Tree)(body: => Unit) {
       printMultiline(treePrefix(tree), showAttributes(tree))(body)
@@ -203,9 +210,11 @@ abstract class NodePrinters {
       showPosition(tree)
 
       tree match {
-        case AppliedTypeTree(tpt, args) => applyCommon(tree, tpt, args)
-        case ApplyDynamic(fun, args)    => applyCommon(tree, fun, args)
-        case Apply(fun, args)           => applyCommon(tree, fun, args)
+        case ApplyDynamic(fun, args)      => applyCommon(tree, fun, args)
+        case Apply(fun, args)             => applyCommon(tree, fun, args)
+
+        case TypeApply(fun, args)         => typeApplyCommon(tree, fun, args)
+        case AppliedTypeTree(tpt, args)   => typeApplyCommon(tree, tpt, args)
 
         case Throw(Ident(name)) =>
           printSingle(tree, name)
@@ -312,11 +321,6 @@ abstract class NodePrinters {
           }
         case This(qual) =>
           printSingle(tree, qual)
-        case TypeApply(fun, args) =>
-          printMultiline(tree) {
-            traverse(fun)
-            traverseList("[]", "type argument")(args)
-          }
         case tt @ TypeTree() =>
           println(showTypeTree(tt))
 
diff --git a/src/compiler/scala/tools/nsc/interactive/Global.scala b/src/compiler/scala/tools/nsc/interactive/Global.scala
index 07ffe9e437..e3d59d83ea 100644
--- a/src/compiler/scala/tools/nsc/interactive/Global.scala
+++ b/src/compiler/scala/tools/nsc/interactive/Global.scala
@@ -1031,15 +1031,6 @@ class Global(settings: Settings, _reporter: Reporter, projectName: String = "")
 
   // ---------------- Helper classes ---------------------------
 
-  /** A transformer that replaces tree `from` with tree `to` in a given tree */
-  class TreeReplacer(from: Tree, to: Tree) extends Transformer {
-    override def transform(t: Tree): Tree = {
-      if (t == from) to
-      else if ((t.pos includes from.pos) || t.pos.isTransparent) super.transform(t)
-      else t
-    }
-  }
-
   /** The typer run */
   class TyperRun extends Run {
     // units is always empty
diff --git a/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala b/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala
index 5b0705a39e..84a47311e2 100644
--- a/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala
@@ -48,16 +48,19 @@ trait MemberHandlers {
     }
   }
 
+  private def isTermMacro(ddef: DefDef): Boolean = ddef.mods.isMacro
+
   def chooseHandler(member: Tree): MemberHandler = member match {
-    case member: DefDef        => new DefHandler(member)
-    case member: ValDef        => new ValHandler(member)
-    case member: ModuleDef     => new ModuleHandler(member)
-    case member: ClassDef      => new ClassHandler(member)
-    case member: TypeDef       => new TypeAliasHandler(member)
-    case member: Assign        => new AssignHandler(member)
-    case member: Import        => new ImportHandler(member)
-    case DocDef(_, documented) => chooseHandler(documented)
-    case member                => new GenericHandler(member)
+    case member: DefDef if isTermMacro(member) => new TermMacroHandler(member)
+    case member: DefDef                        => new DefHandler(member)
+    case member: ValDef                        => new ValHandler(member)
+    case member: ModuleDef                     => new ModuleHandler(member)
+    case member: ClassDef                      => new ClassHandler(member)
+    case member: TypeDef                       => new TypeAliasHandler(member)
+    case member: Assign                        => new AssignHandler(member)
+    case member: Import                        => new ImportHandler(member)
+    case DocDef(_, documented)                 => chooseHandler(documented)
+    case member                                => new GenericHandler(member)
   }
 
   sealed abstract class MemberDefHandler(override val member: MemberDef) extends MemberHandler(member) {
@@ -122,14 +125,23 @@ trait MemberHandlers {
   }
 
   class DefHandler(member: DefDef) extends MemberDefHandler(member) {
-    private def vparamss = member.vparamss
-    private def isMacro = member.symbol hasFlag MACRO
-    // true if not a macro and 0-arity
-    override def definesValue = !isMacro && flattensToEmpty(vparamss)
+    override def definesValue = flattensToEmpty(member.vparamss) // true if 0-arity
     override def resultExtractionCode(req: Request) =
       if (mods.isPublic) codegenln(name, ": ", req.typeOf(name)) else ""
   }
 
+  abstract class MacroHandler(member: DefDef) extends MemberDefHandler(member) {
+    override def definesValue = false
+    override def definesTerm: Option[TermName] = Some(name.toTermName)
+    override def definesType: Option[TypeName] = None
+    override def resultExtractionCode(req: Request) = if (mods.isPublic) codegenln(notification(req)) else ""
+    def notification(req: Request): String
+  }
+
+  class TermMacroHandler(member: DefDef) extends MacroHandler(member) {
+    def notification(req: Request) = s"defined term macro $name: ${req.typeOf(name)}"
+  }
+
   class AssignHandler(member: Assign) extends MemberHandler(member) {
     val Assign(lhs, rhs) = member
     override lazy val name = newTermName(freshInternalVarName())
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala b/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
index efe7519d5e..c8b7fcee8f 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
@@ -77,11 +77,7 @@ abstract class Pickler extends SubComponent {
         }
 
         if (!t.isDef && t.hasSymbolField && t.symbol.isTermMacro) {
-          unit.error(t.pos, t.symbol.typeParams.length match {
-            case 0 => "macro has not been expanded"
-            case 1 => "this type parameter must be specified"
-            case _ => "these type parameters must be specified"
-          })
+          unit.error(t.pos, "macro has not been expanded")
           return
         }
       }
diff --git a/src/compiler/scala/tools/nsc/transform/Mixin.scala b/src/compiler/scala/tools/nsc/transform/Mixin.scala
index 0769b67282..6a253a98b1 100644
--- a/src/compiler/scala/tools/nsc/transform/Mixin.scala
+++ b/src/compiler/scala/tools/nsc/transform/Mixin.scala
@@ -1089,7 +1089,7 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL {
             // add forwarders
             assert(sym.alias != NoSymbol, sym)
             // debuglog("New forwarder: " + sym.defString + " => " + sym.alias.defString)
-            if (!sym.isTermMacro) addDefDef(sym, Apply(staticRef(sym.alias), gen.mkAttributedThis(clazz) :: sym.paramss.head.map(Ident)))
+            if (!sym.isMacro) addDefDef(sym, Apply(staticRef(sym.alias), gen.mkAttributedThis(clazz) :: sym.paramss.head.map(Ident)))
           }
         }
       }
diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
index ea03aca8c4..2d4054e93b 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
@@ -562,11 +562,13 @@ trait ContextErrors {
 
       //adapt
       def MissingArgsForMethodTpeError(tree: Tree, meth: Symbol) = {
-        issueNormalTypeError(tree,
-          "missing arguments for " + meth.fullLocationString + (
+        val message =
+          if (meth.isMacro) MacroPartialApplicationErrorMessage
+          else "missing arguments for " + meth.fullLocationString + (
             if (meth.isConstructor) ""
             else ";\nfollow this method with `_' if you want to treat it as a partially applied function"
-          ))
+          )
+        issueNormalTypeError(tree, message)
         setError(tree)
       }
 
@@ -670,6 +672,14 @@ trait ContextErrors {
         setError(tree)
       }
 
+      def MacroTooManyArgumentListsError(expandee: Tree, fun: Symbol) = {
+        NormalTypeError(expandee, "too many argument lists for " + fun)
+      }
+
+      def MacroInvalidExpansionError(expandee: Tree, role: String, allowedExpansions: String) = {
+        issueNormalTypeError(expandee, s"macro in $role role can only expand into $allowedExpansions")
+      }
+
       // same reason as for MacroBodyTypecheckException
       case object MacroExpansionException extends Exception with scala.util.control.ControlThrowable
 
@@ -681,10 +691,11 @@ trait ContextErrors {
         throw MacroExpansionException
       }
 
+      def MacroPartialApplicationErrorMessage = "macros cannot be partially applied"
       def MacroPartialApplicationError(expandee: Tree) = {
         // macroExpansionError won't work => swallows positions, hence needed to do issueTypeError
         // kinda contradictory to the comment in `macroExpansionError`, but this is how it works
-        issueNormalTypeError(expandee, "macros cannot be partially applied")
+        issueNormalTypeError(expandee, MacroPartialApplicationErrorMessage)
         setError(expandee)
         throw MacroExpansionException
       }
@@ -750,13 +761,16 @@ trait ContextErrors {
         macroExpansionError(expandee, template(sym.name.nameKind).format(sym.name + " " + sym.origin, forgotten))
       }
 
-      def MacroExpansionIsNotExprError(expandee: Tree, expanded: Any) =
+      def MacroExpansionHasInvalidTypeError(expandee: Tree, expanded: Any) = {
+        val expected = "expr"
+        val isPathMismatch = expanded != null && expanded.isInstanceOf[scala.reflect.api.Exprs#Expr[_]]
         macroExpansionError(expandee,
-          "macro must return a compiler-specific expr; returned value is " + (
+          s"macro must return a compiler-specific $expected; returned value is " + (
             if (expanded == null) "null"
-            else if (expanded.isInstanceOf[Expr[_]]) " Expr, but it doesn't belong to this compiler's universe"
+            else if (isPathMismatch) s" $expected, but it doesn't belong to this compiler"
             else " of " + expanded.getClass
         ))
+      }
 
       def MacroImplementationNotFoundError(expandee: Tree) =
         macroExpansionError(expandee,
diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
index 64d76d6a83..5b27fd9352 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
@@ -5,6 +5,7 @@ import symtab.Flags._
 import scala.tools.nsc.util._
 import scala.reflect.runtime.ReflectionUtils
 import scala.collection.mutable.ListBuffer
+import scala.reflect.ClassTag
 import scala.reflect.internal.util.Statistics
 import scala.reflect.macros.util._
 import scala.util.control.ControlThrowable
@@ -357,7 +358,7 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
     // Phase I: sanity checks
     val macroDef = macroDdef.symbol
     macroLogVerbose("typechecking macro def %s at %s".format(macroDef, macroDdef.pos))
-    assert(macroDef.isTermMacro, macroDdef)
+    assert(macroDef.isMacro, macroDdef)
     if (fastTrack contains macroDef) MacroDefIsFastTrack()
     if (!typer.checkFeature(macroDdef.pos, MacrosFeature, immediate = true)) MacroFeatureNotEnabled()
 
@@ -372,7 +373,7 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
         // doesn't manifest itself as an error in the resulting tree
         val prevNumErrors = reporter.ERROR.count
         var rhs1 = typer.typed1(rhs, EXPRmode, WildcardType)
-        def rhsNeedsMacroExpansion = rhs1.symbol != null && rhs1.symbol.isTermMacro && !rhs1.symbol.isErroneous
+        def rhsNeedsMacroExpansion = rhs1.symbol != null && rhs1.symbol.isMacro && !rhs1.symbol.isErroneous
         while (rhsNeedsMacroExpansion) {
           rhs1 = macroExpand1(typer, rhs1) match {
             case Success(expanded) =>
@@ -385,8 +386,12 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
               }
             case Fallback(fallback) =>
               typer.typed1(fallback, EXPRmode, WildcardType)
-            case Other(result) =>
-              result
+            case Delayed(delayed) =>
+              delayed
+            case Skipped(skipped) =>
+              skipped
+            case Failure(failure) =>
+              failure
           }
         }
         val typecheckedWithErrors = (rhs1 exists (_.isErroneous)) || reporter.ERROR.count != prevNumErrors
@@ -533,15 +538,17 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
     }
   }
 
-  private def macroContext(typer: Typer, prefixTree: Tree, expandeeTree: Tree): MacroContext =
+  private def macroContext(typer: Typer, prefixTree: Tree, expandeeTree: Tree): MacroContext = {
     new {
       val universe: self.global.type = self.global
       val callsiteTyper: universe.analyzer.Typer = typer.asInstanceOf[global.analyzer.Typer]
-      val expandee = expandeeTree
+      val expandee = universe.analyzer.macroExpanderAttachment(expandeeTree).original orElse expandeeTree
+      val macroRole = universe.analyzer.macroExpanderAttachment(expandeeTree).role
     } with UnaffiliatedMacroContext {
       val prefix = Expr[Nothing](prefixTree)(TypeTag.Nothing)
       override def toString = "MacroContext(%s@%s +%d)".format(expandee.symbol.name, expandee.pos, enclosingMacros.length - 1 /* exclude myself */)
     }
+  }
 
   /** Calculate the arguments to pass to a macro implementation when expanding the provided tree.
    */
@@ -645,21 +652,37 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
   private def popMacroContext() = _openMacros = _openMacros.tail
   def enclosingMacroPosition = openMacros map (_.macroApplication.pos) find (_ ne NoPosition) getOrElse NoPosition
 
-  private sealed abstract class MacroExpansionResult
-  private case class Success(expanded: Tree) extends MacroExpansionResult
-  private case class Fallback(fallback: Tree) extends MacroExpansionResult { currentRun.seenMacroExpansionsFallingBack = true }
-  private case class Other(result: Tree) extends MacroExpansionResult
-  private def Delay(expanded: Tree) = Other(expanded)
-  private def Skip(expanded: Tree) = Other(expanded)
-  private def Cancel(expandee: Tree) = Other(expandee)
-  private def Failure(expandee: Tree) = Other(expandee)
+  /** Describes the role that the macro expandee is performing.
+   */
+  type MacroRole = String
+  final def APPLY_ROLE: MacroRole = "APPLY_ROLE"
+  private val roleNames = Map(APPLY_ROLE -> "apply")
 
   /** Performs macro expansion:
-   *    1) Checks whether the expansion needs to be delayed (see `mustDelayMacroExpansion`)
-   *    2) Loads macro implementation using `macroMirror`
-   *    3) Synthesizes invocation arguments for the macro implementation
-   *    4) Checks that the result is a tree bound to this universe
-   *    5) Typechecks the result against the return type of the macro definition
+   *
+   *  ========= Expandable trees =========
+   *
+   *  A term of one of the following shapes:
+   *
+   *    Ident(<term macro>)
+   *    Select(<any qualifier>, <term macro>)
+   *    TypeApply(<any of the above>, <targs>)
+   *    Apply(...Apply(<any of the above>, <args1>)...<argsN>)
+   *
+   *  ========= Macro expansion =========
+   *
+   *  First of all `macroExpandXXX`:
+   *    1) If necessary desugars the `expandee` to fit into `macroExpand1`
+   *
+   *  Then `macroExpand1`:
+   *    2) Checks whether the expansion needs to be delayed (see `mustDelayMacroExpansion`)
+   *    3) Loads macro implementation using `macroMirror`
+   *    4) Synthesizes invocation arguments for the macro implementation
+   *    5) Checks that the result is a tree or an expr bound to this universe
+   *
+   *  Finally `macroExpandXXX`:
+   *    6) Validates the expansion against the white list of supported tree shapes
+   *    7) Typechecks the result as required by the circumstances of the macro application
    *
    *  If -Ymacro-debug-lite is enabled, you will get basic notifications about macro expansion
    *  along with macro expansions logged in the form that can be copy/pasted verbatim into REPL.
@@ -670,52 +693,118 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
    *
    *  @return
    *    the expansion result                    if the expansion has been successful,
-   *    the fallback method invocation          if the expansion has been unsuccessful, but there is a fallback,
+   *    the fallback tree                       if the expansion has been unsuccessful, but there is a fallback,
    *    the expandee unchanged                  if the expansion has been delayed,
    *    the expandee fully expanded             if the expansion has been delayed before and has been expanded now,
    *    the expandee with an error marker set   if the expansion has been cancelled due malformed arguments or implementation
    *    the expandee with an error marker set   if there has been an error
    */
-  def macroExpand(typer: Typer, expandee: Tree, mode: Mode = EXPRmode, pt: Type = WildcardType): Tree = {
-    val start = if (Statistics.canEnable) Statistics.startTimer(macroExpandNanos) else null
-    if (Statistics.canEnable) Statistics.incCounter(macroExpandCount)
-    try {
-      macroExpand1(typer, expandee) match {
-        case Success(expanded) =>
-          try {
-            def typecheck(phase: String, tree: Tree, pt: Type): Tree = {
-              if (tree.isErroneous) return tree
-              macroLogVerbose(s"typechecking against $phase $pt: $expanded")
-              val numErrors    = reporter.ERROR.count
-              def hasNewErrors = reporter.ERROR.count > numErrors
-              val result = typer.context.withImplicitsEnabled(typer.typed(tree, EXPRmode, pt))
-              macroTraceVerbose(s"""${if (hasNewErrors) "failed to typecheck" else "successfully typechecked"} against $phase $pt:\n$result\n""")(result)
+  private abstract class MacroExpander[Result: ClassTag](val role: MacroRole, val typer: Typer, val expandee: Tree) {
+    def allowExpandee(expandee: Tree): Boolean = true
+    def allowExpanded(expanded: Tree): Boolean = true
+    def allowedExpansions: String = "anything"
+    def allowResult(result: Result): Boolean = true
+
+    def onSuccess(expanded: Tree): Result
+    def onFallback(expanded: Tree): Result
+    def onSuppressed(expandee: Tree): Result = expandee match { case expandee: Result => expandee }
+    def onDelayed(expanded: Tree): Result = expanded match { case expanded: Result => expanded }
+    def onSkipped(expanded: Tree): Result = expanded match { case expanded: Result => expanded }
+    def onFailure(expanded: Tree): Result = { typer.infer.setError(expandee); expandee match { case expandee: Result => expandee } }
+
+    def apply(desugared: Tree): Result = {
+      if (isMacroExpansionSuppressed(desugared)) onSuppressed(expandee)
+      else expand(desugared)
+    }
+
+    protected def expand(desugared: Tree): Result = {
+      def showDetailed(tree: Tree) = showRaw(tree, printIds = true, printTypes = true)
+      def summary() = s"expander = $this, expandee = ${showDetailed(expandee)}, desugared = ${if (expandee == desugared) () else showDetailed(desugared)}"
+      if (macroDebugVerbose) println(s"macroExpand: ${summary()}")
+      assert(allowExpandee(expandee), summary())
+
+      val start = if (Statistics.canEnable) Statistics.startTimer(macroExpandNanos) else null
+      if (Statistics.canEnable) Statistics.incCounter(macroExpandCount)
+      try {
+        linkExpandeeAndDesugared(expandee, desugared, role)
+        macroExpand1(typer, desugared) match {
+          case Success(expanded) =>
+            if (allowExpanded(expanded)) {
+              // also see http://groups.google.com/group/scala-internals/browse_thread/thread/492560d941b315cc
+              val expanded1 = try onSuccess(duplicateAndKeepPositions(expanded)) finally popMacroContext()
+              if (!hasMacroExpansionAttachment(expanded1)) linkExpandeeAndExpanded(expandee, expanded1)
+              if (allowResult(expanded1)) expanded1 else onFailure(expanded)
+            } else {
+              typer.TyperErrorGen.MacroInvalidExpansionError(expandee, roleNames(role), allowedExpansions)
+              onFailure(expanded)
             }
+          case Fallback(fallback) => onFallback(fallback)
+          case Delayed(delayed) => onDelayed(delayed)
+          case Skipped(skipped) => onSkipped(skipped)
+          case Failure(failure) => onFailure(failure)
+        }
+      } finally {
+        if (Statistics.canEnable) Statistics.stopTimer(macroExpandNanos, start)
+      }
+    }
+  }
 
-            var expectedTpe = expandee.tpe
-            if (isNullaryInvocation(expandee)) expectedTpe = expectedTpe.finalResultType
-            // also see http://groups.google.com/group/scala-internals/browse_thread/thread/492560d941b315cc
-            val expanded0 = duplicateAndKeepPositions(expanded)
-            val expanded1 = typecheck("macro def return type", expanded0, expectedTpe)
-            val expanded2 = typecheck("expected type", expanded1, pt)
-            expanded2
-          } finally {
-            popMacroContext()
-          }
-        case Fallback(fallback) =>
-          typer.context.withImplicitsEnabled(typer.typed(fallback, EXPRmode, pt))
-        case Other(result) =>
-          result
+  /** Expands a tree that carries a term, which happens to be a term macro.
+   *  @see MacroExpander
+   */
+   private abstract class TermMacroExpander(role: MacroRole, typer: Typer, expandee: Tree, mode: Mode, pt: Type)
+                  extends MacroExpander[Tree](role, typer, expandee) {
+      override def allowedExpansions: String = "term trees"
+      override def allowExpandee(expandee: Tree) = expandee.isTerm
+      override def onSuccess(expanded: Tree) = typer.typed(expanded, mode, pt)
+      override def onFallback(fallback: Tree) = typer.typed(fallback, mode, pt)
+   }
+
+  /** Expands a term macro used in apply role as `M(2)(3)` in `val x = M(2)(3)`.
+   *  @see MacroExpander
+   */
+  def macroExpandApply(typer: Typer, expandee: Tree, mode: Mode, pt: Type) = {
+    object expander extends TermMacroExpander(APPLY_ROLE, typer, expandee, mode, pt) {
+      override def onSuccess(expanded: Tree) = {
+        // prematurely annotate the tree with a macro expansion attachment
+        // so that adapt called indirectly by typer.typed knows that it needs to apply the existential fixup
+        linkExpandeeAndExpanded(expandee, expanded)
+        var expectedTpe = expandee.tpe
+        if (isNullaryInvocation(expandee)) expectedTpe = expectedTpe.finalResultType
+        // `macroExpandApply` is called from `adapt`, where implicit conversions are disabled
+        // therefore we need to re-enable the conversions back temporarily
+        if (macroDebugVerbose) println(s"typecheck #1 (against expectedTpe = $expectedTpe): $expanded")
+        val expanded1 = typer.context.withImplicitsEnabled(typer.typed(expanded, mode, expectedTpe))
+        if (expanded1.isErrorTyped) {
+          if (macroDebugVerbose) println(s"typecheck #1 has failed: ${typer.context.errBuffer}")
+          expanded1
+        } else {
+          if (macroDebugVerbose) println(s"typecheck #2 (against pt = $pt): $expanded1")
+          val expanded2 = typer.context.withImplicitsEnabled(super.onSuccess(expanded1))
+          if (macroDebugVerbose && expanded2.isErrorTyped) println(s"typecheck #2 has failed: ${typer.context.errBuffer}")
+          expanded2
+        }
       }
-    } finally {
-      if (Statistics.canEnable) Statistics.stopTimer(macroExpandNanos, start)
     }
+    expander(expandee)
   }
 
+  /** Captures statuses of macro expansions performed by `macroExpand1'.
+   */
+  private sealed abstract class MacroStatus(val result: Tree)
+  private case class Success(expanded: Tree) extends MacroStatus(expanded)
+  private case class Fallback(fallback: Tree) extends MacroStatus(fallback) { currentRun.seenMacroExpansionsFallingBack = true }
+  private case class Delayed(delayed: Tree) extends MacroStatus(delayed)
+  private case class Skipped(skipped: Tree) extends MacroStatus(skipped)
+  private case class Failure(failure: Tree) extends MacroStatus(failure)
+  private def Delay(expanded: Tree) = Delayed(expanded)
+  private def Skip(expanded: Tree) = Skipped(expanded)
+  private def Cancel(expandee: Tree) = Failure(expandee)
+
   /** Does the same as `macroExpand`, but without typechecking the expansion
    *  Meant for internal use within the macro infrastructure, don't use it elsewhere.
    */
-  private def macroExpand1(typer: Typer, expandee: Tree): MacroExpansionResult = {
+  private def macroExpand1(typer: Typer, expandee: Tree): MacroStatus = {
     // verbose printing might cause recursive macro expansions, so I'm shutting it down here
     withInfoLevel(nodePrinters.InfoLevel.Quiet) {
       if (expandee.symbol.isErroneous || (expandee exists (_.isErroneous))) {
@@ -736,14 +825,18 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
   /** Expands a macro when a runtime (i.e. the macro implementation) can be successfully loaded
    *  Meant for internal use within the macro infrastructure, don't use it elsewhere.
    */
-  private def macroExpandWithRuntime(typer: Typer, expandee: Tree, runtime: MacroRuntime): MacroExpansionResult = {
+  private def macroExpandWithRuntime(typer: Typer, expandee: Tree, runtime: MacroRuntime): MacroStatus = {
     val wasDelayed  = isDelayed(expandee)
     val undetparams = calculateUndetparams(expandee)
     val nowDelayed  = !typer.context.macrosEnabled || undetparams.nonEmpty
 
     (wasDelayed, nowDelayed) match {
-      case (true, true) => Delay(expandee)
-      case (true, false) => Skip(macroExpandAll(typer, expandee))
+      case (true, true) =>
+        Delay(expandee)
+      case (true, false) =>
+        val expanded = macroExpandAll(typer, expandee)
+        if (expanded exists (_.isErroneous)) Failure(expandee)
+        else Skip(expanded)
       case (false, true) =>
         macroLogLite("macro expansion is delayed: %s".format(expandee))
         delayed += expandee -> undetparams
@@ -758,15 +851,16 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
           def hasNewErrors = reporter.ERROR.count > numErrors
           val expanded = { pushMacroContext(args.c); runtime(args) }
           if (hasNewErrors) MacroGeneratedTypeError(expandee)
+          def validateResultingTree(expanded: Tree) = {
+            macroLogVerbose("original:")
+            macroLogLite("" + expanded + "\n" + showRaw(expanded))
+            val freeSyms = expanded.freeTerms ++ expanded.freeTypes
+            freeSyms foreach (sym => MacroFreeSymbolError(expandee, sym))
+            Success(atPos(enclosingMacroPosition.focus)(expanded))
+          }
           expanded match {
-            case expanded: Expr[_] =>
-              macroLogVerbose("original:")
-              macroLogLite("" + expanded.tree + "\n" + showRaw(expanded.tree))
-              val freeSyms = expanded.tree.freeTerms ++ expanded.tree.freeTypes
-              freeSyms foreach (sym => MacroFreeSymbolError(expandee, sym))
-              Success(atPos(enclosingMacroPosition.focus)(expanded.tree updateAttachment MacroExpansionAttachment(expandee)))
-            case _ =>
-              MacroExpansionIsNotExprError(expandee, expanded)
+            case expanded: Expr[_] if expandee.symbol.isTermMacro => validateResultingTree(expanded.tree)
+            case _ => MacroExpansionHasInvalidTypeError(expandee, expanded)
           }
         } catch {
           case ex: Throwable =>
@@ -787,7 +881,7 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
   /** Expands a macro when a runtime (i.e. the macro implementation) cannot be loaded
    *  Meant for internal use within the macro infrastructure, don't use it elsewhere.
    */
-  private def macroExpandWithoutRuntime(typer: Typer, expandee: Tree): MacroExpansionResult = {
+  private def macroExpandWithoutRuntime(typer: Typer, expandee: Tree): MacroStatus = {
     import typer.TyperErrorGen._
     val fallbackSym = expandee.symbol.nextOverriddenSymbol orElse MacroImplementationNotFoundError(expandee)
     macroTraceLite("falling back to: ")(fallbackSym)
@@ -857,13 +951,13 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
     new Transformer {
       override def transform(tree: Tree) = super.transform(tree match {
         // todo. expansion should work from the inside out
-        case tree if (delayed contains tree) && calculateUndetparams(tree).isEmpty =>
+        case tree if (delayed contains tree) && calculateUndetparams(tree).isEmpty && !tree.isErroneous =>
           val context = tree.attachments.get[MacroRuntimeAttachment].get.typerContext
           delayed -= tree
           context.implicitsEnabled = typer.context.implicitsEnabled
           context.enrichmentEnabled = typer.context.enrichmentEnabled
           context.macrosEnabled = typer.context.macrosEnabled
-          macroExpand(newTyper(context), tree, EXPRmode, WildcardType)
+          macroExpandApply(newTyper(context), tree, EXPRmode, WildcardType)
         case _ =>
           tree
       })
diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index b5160c0519..352090892e 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -878,7 +878,7 @@ trait Namers extends MethodSynthesis {
         else tpt.tpe
       }
 
-      val parents = typer.parentTypes(templ) map checkParent
+      val parents = typer.typedParentTypes(templ) map checkParent
 
       enterSelf(templ.self)
 
@@ -1054,7 +1054,7 @@ trait Namers extends MethodSynthesis {
       // because @macroImpl annotation only gets assigned during typechecking
       // otherwise macro defs wouldn't be able to robustly coexist with their clients
       // because a client could be typechecked before a macro def that it uses
-      if (ddef.symbol.isTermMacro) {
+      if (ddef.symbol.isMacro) {
         val pt = resultPt.substSym(tparamSyms, tparams map (_.symbol))
         typer.computeMacroDefType(ddef, pt)
       }
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 8a34d58e6e..e88447c46d 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -424,9 +424,9 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
                      member.isValue && !member.isLazy) {
             overrideError("must be declared lazy to override a concrete lazy value")
           } else if (other.isDeferred && member.isTermMacro) { // (1.9)
-            overrideError("cannot override an abstract method")
+            overrideError("cannot be used here - term macros cannot override abstract methods")
           } else if (other.isTermMacro && !member.isTermMacro) { // (1.10)
-            overrideError("cannot override a macro")
+            overrideError("cannot be used here - only term macros can override term macros")
           } else {
             checkOverrideTypes()
             checkOverrideDeprecated()
diff --git a/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala b/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala
index 20db479463..64fcda3b80 100644
--- a/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala
@@ -14,6 +14,102 @@ trait StdAttachments {
   type MacroContext = UnaffiliatedMacroContext { val universe: self.global.type }
   case class MacroRuntimeAttachment(delayed: Boolean, typerContext: Context, macroContext: Option[MacroContext])
 
+  /** Scratchpad for the macro expander, which is used to store all intermediate data except the details about the runtime.
+   */
+  case class MacroExpanderAttachment(original: Tree, desugared: Tree, role: MacroRole)
+
+  /** Loads underlying MacroExpanderAttachment from a macro expandee or returns a default value for that attachment.
+   */
+ def macroExpanderAttachment(tree: Tree): MacroExpanderAttachment =
+    tree.attachments.get[MacroExpanderAttachment] getOrElse {
+      tree match {
+        case Apply(fn, _) if tree.isInstanceOf[ApplyToImplicitArgs] => macroExpanderAttachment(fn)
+        case _ => MacroExpanderAttachment(tree, EmptyTree, APPLY_ROLE)
+      }
+    }
+
+  /** After macro expansion is completed, links the expandee and the expansion result
+   *  by annotating them both with a `MacroExpansionAttachment`.
+   */
+  def linkExpandeeAndDesugared(expandee: Tree, desugared: Tree, role: MacroRole): Unit = {
+    val metadata = MacroExpanderAttachment(expandee, desugared, role)
+    expandee updateAttachment metadata
+    desugared updateAttachment metadata
+  }
+
+  /** Is added by the macro engine to originals and results of macro expansions.
+   *  Stores the original expandee as it entered the `macroExpand` function.
+   */
+  case class MacroExpansionAttachment(expandee: Tree, expanded: Any)
+
+  /** Determines whether the target is either an original or a result of a macro expansion.
+   *  The parameter is of type `Any`, because macros can expand both into trees and into annotations.
+   */
+  def hasMacroExpansionAttachment(any: Any): Boolean = any match {
+    case tree: Tree => tree.attachments.get[MacroExpansionAttachment].isDefined
+    case _ => false
+  }
+
+  /** After macro expansion is completed, links the expandee and the expansion result by annotating them both with a `MacroExpansionAttachment`.
+   *  The `expanded` parameter is of type `Any`, because macros can expand both into trees and into annotations.
+   */
+  def linkExpandeeAndExpanded(expandee: Tree, expanded: Any): Unit = {
+    val metadata = MacroExpansionAttachment(expandee, expanded)
+    expandee updateAttachment metadata
+    expanded match {
+      case expanded: Tree => expanded updateAttachment metadata
+      case _ => // do nothing
+    }
+  }
+
+  /** Checks whether there is any tree resulting from a macro expansion and associated with the current tree.
+   */
+  object ExpandedIntoTree {
+    def unapply(tree: Tree): Option[Tree] = tree.attachments.get[MacroExpansionAttachment] match {
+      case Some(MacroExpansionAttachment(_, tree: Tree)) => Some(tree)
+      case _ => None
+    }
+  }
+
+  /** When present, suppresses macro expansion for the host.
+   *  This is occasionally necessary, e.g. to prohibit eta-expansion of macros.
+   *
+   *  Does not affect expandability of child nodes, there's context.withMacrosDisabled for that
+   *  (but think thrice before using that API - see the discussion at https://github.com/scala/scala/pull/1639).
+   */
+  case object SuppressMacroExpansionAttachment
+
+  /** Suppresses macro expansion of the tree by putting SuppressMacroExpansionAttachment on it.
+   */
+  def suppressMacroExpansion(tree: Tree) = tree.updateAttachment(SuppressMacroExpansionAttachment)
+
+  /** Unsuppresses macro expansion of the tree by removing SuppressMacroExpansionAttachment from it and its children.
+   */
+  def unsuppressMacroExpansion(tree: Tree): Tree = {
+    tree.removeAttachment[SuppressMacroExpansionAttachment.type]
+    tree match {
+      // see the comment to `isMacroExpansionSuppressed` to learn why we need
+      // a special traversal strategy here
+      case Apply(fn, _) => unsuppressMacroExpansion(fn)
+      case TypeApply(fn, _) => unsuppressMacroExpansion(fn)
+      case _ => // do nothing
+    }
+    tree
+  }
+
+  /** 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
+    }
+
   /** 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
    *  by `parentTypes`. This attachment coordinates `parentTypes` and `typedTemplate` and
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index ff6752703f..96a93e2a20 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -830,7 +830,7 @@ trait Typers extends Adaptations with Tags {
           case Block(_, tree1) => tree1.symbol
           case _               => tree.symbol
         }
-        if (!meth.isConstructor && !meth.isTermMacro && isFunctionType(pt)) { // (4.2)
+        if (!meth.isConstructor && isFunctionType(pt)) { // (4.2)
           debuglog("eta-expanding " + tree + ":" + tree.tpe + " to " + pt)
           checkParamsConvertible(tree, tree.tpe)
           val tree0 = etaExpand(context.unit, tree, this)
@@ -1059,10 +1059,11 @@ trait Typers extends Adaptations with Tags {
           adaptToImplicitMethod(mt)
 
         case mt: MethodType if (((mode & (EXPRmode | FUNmode | LHSmode)) == EXPRmode) &&
-          (context.undetparams.isEmpty || mode.inPolyMode)) && !(tree.symbol != null && tree.symbol.isTermMacro) =>
+          (context.undetparams.isEmpty || mode.inPolyMode)) && !treeInfo.isMacroApplicationOrBlock(tree) =>
           instantiateToMethodType(mt)
 
         case _ =>
+        def vanillaAdapt(tree: Tree) = {
           def shouldInsertApply(tree: Tree) = mode.inAll(EXPRmode | FUNmode) && (tree.tpe match {
             case _: MethodType | _: OverloadedType | _: PolyType => false
             case _                                               => applyPossible
@@ -1078,11 +1079,6 @@ trait Typers extends Adaptations with Tags {
           }
           if (tree.isType)
             adaptType()
-          else if (
-              mode.inExprModeButNot(FUNmode) && !tree.isDef &&   // typechecking application
-              tree.symbol != null && tree.symbol.isTermMacro &&   // of a macro
-              !tree.attachments.get[SuppressMacroExpansionAttachment.type].isDefined)
-            macroExpand(this, tree, mode, pt)
           else if (mode.inAll(PATTERNmode | FUNmode))
             adaptConstrPattern()
           else if (shouldInsertApply(tree))
@@ -1211,6 +1207,9 @@ trait Typers extends Adaptations with Tags {
             }
             fallBack
           }
+        }
+        val tree1 = if (mode.inExprModeButNot(FUNmode) && treeInfo.isMacroApplication(tree)) macroExpandApply(this, tree, mode, pt) else tree
+        if (tree == tree1) vanillaAdapt(tree1) else tree1
       }
     }
 
@@ -1589,7 +1588,11 @@ trait Typers extends Adaptations with Tags {
           else
             map2(preSuperStats, preSuperVals)((ldef, gdef) => gdef.tpt setType ldef.symbol.tpe)
 
-          if (superCall1 == cunit) EmptyTree else cbody2
+          if (superCall1 == cunit) EmptyTree
+          else cbody2 match {
+            case Block(_, expr) => expr
+            case tree => tree
+          }
         case _ =>
           EmptyTree
       }
@@ -1632,7 +1635,7 @@ trait Typers extends Adaptations with Tags {
         )
     }
 
-    def parentTypes(templ: Template): List[Tree] = templ.parents match {
+    def typedParentTypes(templ: Template): List[Tree] = templ.parents match {
       case Nil => List(atPos(templ.pos)(TypeTree(AnyRefClass.tpe)))
       case first :: rest =>
         try {
@@ -1654,7 +1657,7 @@ trait Typers extends Adaptations with Tags {
           case ex: TypeError =>
             // fallback in case of cyclic errors
             // @H none of the tests enter here but I couldn't rule it out
-            // upd. @E when a definitions inherits itself, we end up here
+            // upd. @E when a definition inherits itself, we end up here
             // because `typedParentType` triggers `initialize` for parent types symbols
             log("Type error calculating parents in template " + templ)
             log("Error: " + ex)
@@ -1765,7 +1768,7 @@ trait Typers extends Adaptations with Tags {
       reenterTypeParams(cdef.tparams)
       val tparams1 = cdef.tparams mapConserve (typedTypeDef)
       val impl1 = typerReportAnyContextErrors(context.make(cdef.impl, clazz, newScope)) {
-        _.typedTemplate(cdef.impl, parentTypes(cdef.impl))
+        _.typedTemplate(cdef.impl, typedParentTypes(cdef.impl))
       }
       val impl2 = finishMethodSynthesis(impl1, clazz, context)
       if (clazz.isTrait && clazz.info.parents.nonEmpty && clazz.info.firstParent.typeSymbol == AnyClass)
@@ -1805,7 +1808,7 @@ trait Typers extends Adaptations with Tags {
       )
       val impl1 = typerReportAnyContextErrors(context.make(mdef.impl, clazz, newScope)) {
         _.typedTemplate(mdef.impl, {
-          parentTypes(mdef.impl) ++ (
+          typedParentTypes(mdef.impl) ++ (
             if (noSerializable) Nil
             else {
               clazz.makeSerializable()
@@ -2205,7 +2208,7 @@ trait Typers extends Adaptations with Tags {
                meth.owner.isAnonOrRefinementClass))
             InvalidConstructorDefError(ddef)
           typed(ddef.rhs)
-        } else if (meth.isTermMacro) {
+        } else if (meth.isMacro) {
           // typechecking macro bodies is sort of unconventional
           // that's why we employ our custom typing scheme orchestrated outside of the typer
           transformedOr(ddef.rhs, typedMacroBody(this, ddef))
@@ -2912,7 +2915,6 @@ trait Typers extends Adaptations with Tags {
             else BYVALmode
           )
           var tree = typedArg(args.head, mode, typedMode, adapted.head)
-          if (hasPendingMacroExpansions) tree = macroExpandAll(this, tree)
           // formals may be empty, so don't call tail
           tree :: loop(args.tail, formals drop 1, adapted.tail)
         }
@@ -3078,7 +3080,7 @@ trait Typers extends Adaptations with Tags {
             val lencmp = compareLengths(args, formals)
 
             def checkNotMacro() = {
-              if (fun.symbol != null && fun.symbol.filter(sym => sym != null && sym.isTermMacro && !sym.isErroneous) != NoSymbol)
+              if (treeInfo.isMacroApplication(fun))
                 tryTupleApply getOrElse duplErrorTree(NamedAndDefaultArgumentsNotSupportedForMacros(tree, fun))
             }
 
@@ -3249,7 +3251,8 @@ trait Typers extends Adaptations with Tags {
           doTypedUnapply(tree, fun0, fun, args, mode, pt)
 
         case _ =>
-          duplErrorTree(ApplyWithoutArgsError(tree, fun))
+          if (treeInfo.isMacroApplication(tree)) duplErrorTree(MacroTooManyArgumentListsError(tree, fun.symbol))
+          else duplErrorTree(ApplyWithoutArgsError(tree, fun))
       }
     }
 
@@ -4972,9 +4975,9 @@ trait Typers extends Adaptations with Tags {
             // that typecheck must not trigger macro expansions, so we explicitly prohibit them
             // however we cannot do `context.withMacrosDisabled`
             // because `expr` might contain nested macro calls (see SI-6673)
-            val exprTyped = typed1(expr updateAttachment SuppressMacroExpansionAttachment, mode, pt)
+            val exprTyped = typed1(suppressMacroExpansion(expr), mode, pt)
             exprTyped match {
-              case macroDef if macroDef.symbol != null && macroDef.symbol.isTermMacro && !macroDef.symbol.isErroneous =>
+              case macroDef if treeInfo.isMacroApplication(macroDef) =>
                 MacroEtaError(exprTyped)
               case _ =>
                 typedEta(checkDead(exprTyped))
@@ -5227,7 +5230,12 @@ trait Typers extends Adaptations with Tags {
         }
 
         tree1 modifyType (addAnnotations(tree1, _))
-        val result = if (tree1.isEmpty) tree1 else adapt(tree1, mode, pt, tree)
+        val result =
+          if (tree1.isEmpty) tree1
+          else {
+            val result = adapt(tree1, mode, pt, tree)
+            if (hasPendingMacroExpansions) macroExpandAll(this, result) else result
+          }
 
         if (!alreadyTyped) {
           printTyping("adapted %s: %s to %s, %s".format(
@@ -5360,7 +5368,7 @@ trait Typers extends Adaptations with Tags {
 
     def computeType(tree: Tree, pt: Type): Type = {
       // macros employ different logic of `computeType`
-      assert(!context.owner.isTermMacro, context.owner)
+      assert(!context.owner.isMacro, context.owner)
       val tree1 = typed(tree, pt)
       transformed(tree) = tree1
       val tpe = packedType(tree1, context.owner)
@@ -5369,8 +5377,8 @@ trait Typers extends Adaptations with Tags {
     }
 
     def computeMacroDefType(tree: Tree, pt: Type): Type = {
-      assert(context.owner.isTermMacro, context.owner)
-      assert(tree.symbol.isTermMacro, tree.symbol)
+      assert(context.owner.isMacro, context.owner)
+      assert(tree.symbol.isMacro, tree.symbol)
       assert(tree.isInstanceOf[DefDef], tree.getClass)
       val ddef = tree.asInstanceOf[DefDef]
 
diff --git a/src/reflect/scala/reflect/internal/StdAttachments.scala b/src/reflect/scala/reflect/internal/StdAttachments.scala
index b782353ed3..6c5bbc9774 100644
--- a/src/reflect/scala/reflect/internal/StdAttachments.scala
+++ b/src/reflect/scala/reflect/internal/StdAttachments.scala
@@ -29,17 +29,4 @@ trait StdAttachments {
    *  Therefore we need this hack (see `Reshape.toPreTyperTypeTree` for a detailed explanation).
    */
   case class CompoundTypeTreeOriginalAttachment(parents: List[Tree], stats: List[Tree])
-
-  /** Is added by the macro engine to the results of macro expansions.
-   *  Stores the original expandee as it entered the `macroExpand` function.
-   */
-  case class MacroExpansionAttachment(original: Tree)
-
-  /** When present, suppresses macro expansion for the host.
-   *  This is occasionally necessary, e.g. to prohibit eta-expansion of macros.
-   *
-   *  Does not affect expandability of child nodes, there's context.withMacrosDisabled for that
-   *  (but think thrice before using that API - see the discussion at https://github.com/scala/scala/pull/1639).
-   */
-  case object SuppressMacroExpansionAttachment
 }
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index 0127bd988b..2d42d2df58 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -654,7 +654,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
       info.firstParent.typeSymbol == AnyValClass && !isPrimitiveValueClass
 
     final def isMethodWithExtension =
-      isMethod && owner.isDerivedValueClass && !isParamAccessor && !isConstructor && !hasFlag(SUPERACCESSOR) && !isTermMacro
+      isMethod && owner.isDerivedValueClass && !isParamAccessor && !isConstructor && !hasFlag(SUPERACCESSOR) && !isMacro
 
     final def isAnonymousFunction = isSynthetic && (name containsName tpnme.ANON_FUN_NAME)
     final def isDefinedInPackage  = effectiveOwner.isPackageClass
@@ -2241,7 +2241,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
     private case class SymbolKind(accurate: String, sanitized: String, abbreviation: String)
     private def symbolKind: SymbolKind = {
       var kind =
-        if (isTermMacro) ("macro method", "macro method", "MAC")
+        if (isTermMacro) ("term macro", "macro method", "MACM")
         else if (isInstanceOf[FreeTermSymbol]) ("free term", "free term", "FTE")
         else if (isInstanceOf[FreeTypeSymbol]) ("free type", "free type", "FTY")
         else if (isPackage) ("package", "package", "PK")
diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala
index 9614513458..032a4aebef 100644
--- a/src/reflect/scala/reflect/internal/TreeInfo.scala
+++ b/src/reflect/scala/reflect/internal/TreeInfo.scala
@@ -735,4 +735,15 @@ abstract class TreeInfo {
       case tree: RefTree => true
       case _ => false
     })
+
+  def isMacroApplication(tree: Tree): Boolean =
+    !tree.isDef && tree.symbol != null && tree.symbol.isMacro && !tree.symbol.isErroneous
+
+  def isMacroApplicationOrBlock(tree: Tree): Boolean = tree match {
+    case Block(_, expr) => isMacroApplicationOrBlock(expr)
+    case tree => isMacroApplication(tree)
+  }
+
+  def isNonTrivialMacroApplication(tree: Tree): Boolean =
+    isMacroApplication(tree) && dissectApplied(tree).core != tree
 }
diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala
index 308ab93c07..3c2249bfb5 100644
--- a/src/reflect/scala/reflect/internal/Trees.scala
+++ b/src/reflect/scala/reflect/internal/Trees.scala
@@ -164,6 +164,9 @@ trait Trees extends api.Trees { self: SymbolTable =>
     override def substituteThis(clazz: Symbol, to: Tree): Tree =
       new ThisSubstituter(clazz, to) transform this
 
+    def replace(from: Tree, to: Tree): Tree =
+      new TreeReplacer(from, to, positionAware = false) transform this
+
     def hasSymbolWhich(f: Symbol => Boolean) =
       (symbol ne null) && (symbol ne NoSymbol) && f(symbol)
 
@@ -1381,6 +1384,16 @@ trait Trees extends api.Trees { self: SymbolTable =>
       if (tree eq orig) super.transform(tree)
       else tree
   }
+
+  /** A transformer that replaces tree `from` with tree `to` in a given tree */
+  class TreeReplacer(from: Tree, to: Tree, positionAware: Boolean) extends Transformer {
+    override def transform(t: Tree): Tree = {
+      if (t == from) to
+      else if (!positionAware || (t.pos includes from.pos) || t.pos.isTransparent) super.transform(t)
+      else t
+    }
+  }
+
   // Create a readable string describing a substitution.
   private def substituterString(fromStr: String, toStr: String, from: List[Any], to: List[Any]): String = {
     "subst[%s, %s](%s)".format(fromStr, toStr, (from, to).zipped map (_ + " -> " + _) mkString ", ")
diff --git a/src/reflect/scala/reflect/macros/Enclosures.scala b/src/reflect/scala/reflect/macros/Enclosures.scala
index 1e366ccbc3..723b94016d 100644
--- a/src/reflect/scala/reflect/macros/Enclosures.scala
+++ b/src/reflect/scala/reflect/macros/Enclosures.scala
@@ -17,6 +17,19 @@ trait Enclosures {
    */
   def macroApplication: Tree
 
+  /** The semantic role that `macroApplication` plays in the code.
+   */
+  type MacroRole
+
+  /** The role that represents an application of a term macro,
+   *  e.g. `M(2)(3)` in `val x = M(2)(3)` or `M(a, b)` in `x match { case x @ M(a, b) => }`.
+   */
+  def APPLY_ROLE: MacroRole
+
+  /** The semantic role that `macroApplication` plays in the code.
+   */
+  def macroRole: MacroRole
+
   /** Contexts that represent macros in-flight, including the current one. Very much like a stack trace, but for macros only.
    *  Can be useful for interoperating with other macros and for imposing compiler-friendly limits on macro expansion.
    *
diff --git a/src/reflect/scala/reflect/runtime/JavaMirrors.scala b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
index 67b24cbdea..cdb9e7159c 100644
--- a/src/reflect/scala/reflect/runtime/JavaMirrors.scala
+++ b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
@@ -319,7 +319,7 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
     lazy val bytecodefulObjectMethods = Set[Symbol](Object_clone, Object_equals, Object_finalize, Object_hashCode, Object_toString,
                                         Object_notify, Object_notifyAll) ++ ObjectClass.info.member(nme.wait_).asTerm.alternatives.map(_.asMethod)
     private def isBytecodelessMethod(meth: MethodSymbol): Boolean = {
-      if (isGetClass(meth) || isStringConcat(meth) || meth.owner.isPrimitiveValueClass || meth == Predef_classOf || meth.isTermMacro) return true
+      if (isGetClass(meth) || isStringConcat(meth) || meth.owner.isPrimitiveValueClass || meth == Predef_classOf || meth.isMacro) return true
       bytecodelessMethodOwners(meth.owner) && !bytecodefulObjectMethods(meth)
     }
 
@@ -457,7 +457,7 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
           case sym if isStringConcat(sym)             => receiver.toString + objArg0
           case sym if sym.owner.isPrimitiveValueClass => invokePrimitiveMethod
           case sym if sym == Predef_classOf           => fail("Predef.classOf is a compile-time function")
-          case sym if sym.isTermMacro                 => fail(s"${symbol.fullName} is a macro, i.e. a compile-time function")
+          case sym if sym.isMacro                     => fail(s"${symbol.fullName} is a macro, i.e. a compile-time function")
           case _                                      => abort(s"unsupported symbol $symbol when invoking $this")
         }
       }
diff --git a/test/files/neg/macro-override-macro-overrides-abstract-method-a.check b/test/files/neg/macro-override-macro-overrides-abstract-method-a.check
index 895e0dca50..8c8f039225 100644
--- a/test/files/neg/macro-override-macro-overrides-abstract-method-a.check
+++ b/test/files/neg/macro-override-macro-overrides-abstract-method-a.check
@@ -1,5 +1,5 @@
 Impls_Macros_1.scala:12: error: overriding method foo in trait Foo of type (x: Int)Int;
- macro method foo cannot override an abstract method
+ macro method foo cannot be used here - term macros cannot override abstract methods
   def foo(x: Int) = macro Impls.impl
       ^
 one error found
diff --git a/test/files/neg/macro-override-macro-overrides-abstract-method-b.check b/test/files/neg/macro-override-macro-overrides-abstract-method-b.check
index 895e0dca50..8c8f039225 100644
--- a/test/files/neg/macro-override-macro-overrides-abstract-method-b.check
+++ b/test/files/neg/macro-override-macro-overrides-abstract-method-b.check
@@ -1,5 +1,5 @@
 Impls_Macros_1.scala:12: error: overriding method foo in trait Foo of type (x: Int)Int;
- macro method foo cannot override an abstract method
+ macro method foo cannot be used here - term macros cannot override abstract methods
   def foo(x: Int) = macro Impls.impl
       ^
 one error found
diff --git a/test/files/neg/macro-override-method-overrides-macro.check b/test/files/neg/macro-override-method-overrides-macro.check
index 66dc11be96..e8cba5d029 100644
--- a/test/files/neg/macro-override-method-overrides-macro.check
+++ b/test/files/neg/macro-override-method-overrides-macro.check
@@ -1,5 +1,5 @@
 Macros_Test_2.scala:8: error: overriding macro method foo in class B of type (x: String)Unit;
- method foo cannot override a macro
+ method foo cannot be used here - only term macros can override term macros
   override def foo(x: String) = println("fooDString")
                ^
 one error found
diff --git a/test/files/neg/t5353.check b/test/files/neg/t5353.check
deleted file mode 100644
index 75e2435600..0000000000
--- a/test/files/neg/t5353.check
+++ /dev/null
@@ -1,4 +0,0 @@
-t5353.scala:2: error: this type parameter must be specified
-  def f(x: Boolean) = if (x) Array("abc") else Array()
-                                                    ^
-one error found
diff --git a/test/files/neg/t5353.scala b/test/files/neg/t5353.scala
deleted file mode 100644
index 1ee869aac1..0000000000
--- a/test/files/neg/t5353.scala
+++ /dev/null
@@ -1,3 +0,0 @@
-class A {
-  def f(x: Boolean) = if (x) Array("abc") else Array()
-}
diff --git a/test/files/neg/t5692a.check b/test/files/pos/t5692a.check
index 7fbfb5dba7..7fbfb5dba7 100644
--- a/test/files/neg/t5692a.check
+++ b/test/files/pos/t5692a.check
diff --git a/test/files/neg/t5692a.flags b/test/files/pos/t5692a.flags
index cd66464f2f..cd66464f2f 100644
--- a/test/files/neg/t5692a.flags
+++ b/test/files/pos/t5692a.flags
diff --git a/test/files/neg/t5692a/Macros_1.scala b/test/files/pos/t5692a/Macros_1.scala
index 06b5a3de36..06b5a3de36 100644
--- a/test/files/neg/t5692a/Macros_1.scala
+++ b/test/files/pos/t5692a/Macros_1.scala
diff --git a/test/files/neg/t5692a/Test_2.scala b/test/files/pos/t5692a/Test_2.scala
index 08d510cc6f..08d510cc6f 100644
--- a/test/files/neg/t5692a/Test_2.scala
+++ b/test/files/pos/t5692a/Test_2.scala
diff --git a/test/files/neg/t5692b.check b/test/files/pos/t5692b.check
index 16796826b4..16796826b4 100644
--- a/test/files/neg/t5692b.check
+++ b/test/files/pos/t5692b.check
diff --git a/test/files/neg/t5692b.flags b/test/files/pos/t5692b.flags
index cd66464f2f..cd66464f2f 100644
--- a/test/files/neg/t5692b.flags
+++ b/test/files/pos/t5692b.flags
diff --git a/test/files/neg/t5692b/Macros_1.scala b/test/files/pos/t5692b/Macros_1.scala
index b28d19f903..b28d19f903 100644
--- a/test/files/neg/t5692b/Macros_1.scala
+++ b/test/files/pos/t5692b/Macros_1.scala
diff --git a/test/files/neg/t5692b/Test_2.scala b/test/files/pos/t5692b/Test_2.scala
index 08d510cc6f..08d510cc6f 100644
--- a/test/files/neg/t5692b/Test_2.scala
+++ b/test/files/pos/t5692b/Test_2.scala
diff --git a/test/files/run/macro-expand-unapply-a.check b/test/files/run/macro-expand-unapply-a.check
new file mode 100644
index 0000000000..7c2976e51e
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-a.check
@@ -0,0 +1,2 @@
+(1,2)
+(1,2,3)
diff --git a/test/files/run/macro-expand-unapply-a.flags b/test/files/run/macro-expand-unapply-a.flags
new file mode 100644
index 0000000000..cd66464f2f
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-a.flags
@@ -0,0 +1 @@
+-language:experimental.macros
\ No newline at end of file
diff --git a/test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala b/test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala
new file mode 100644
index 0000000000..61d6345f16
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-a/Impls_Macros_1.scala
@@ -0,0 +1,15 @@
+import scala.reflect.macros.Context
+
+object Helper {
+  def unapplySeq[T](x: List[T]): Option[Seq[T]] = List.unapplySeq[T](x)
+}
+
+object Macros {
+  def impl[T: c.WeakTypeTag](c: Context)(x: c.Expr[List[T]]) = {
+    c.universe.reify(Helper.unapplySeq(x.splice))
+  }
+
+  object UnapplyMacro {
+    def unapplySeq[T](x: List[T]): Option[Seq[T]] = macro impl[T]
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/macro-expand-unapply-a/Test_2.scala b/test/files/run/macro-expand-unapply-a/Test_2.scala
new file mode 100644
index 0000000000..6169d86b19
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-a/Test_2.scala
@@ -0,0 +1,6 @@
+import Macros._
+
+object Test extends App {
+  List(1, 2) match { case UnapplyMacro(x, y) => println((x, y)) }
+  List(1, 2, 3) match { case UnapplyMacro(x, y, z) => println((x, y, z)) }
+}
\ No newline at end of file
diff --git a/test/files/run/macro-expand-unapply-b.check b/test/files/run/macro-expand-unapply-b.check
new file mode 100644
index 0000000000..5272f0d00a
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-b.check
@@ -0,0 +1,2 @@
+(1,List(2))
+List(1)
diff --git a/test/files/run/macro-expand-unapply-b.flags b/test/files/run/macro-expand-unapply-b.flags
new file mode 100644
index 0000000000..cd66464f2f
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-b.flags
@@ -0,0 +1 @@
+-language:experimental.macros
\ No newline at end of file
diff --git a/test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala b/test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala
new file mode 100644
index 0000000000..d0300bdf7e
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-b/Impls_Macros_1.scala
@@ -0,0 +1,37 @@
+import language.experimental.macros
+import scala.reflect.macros.Context
+
+object Macros {
+  implicit class ContextExtensions(c: StringContext) {
+    object q {
+      def unapply(x: Any): Option[Any] = macro impl
+    }
+  }
+
+  def impl(c: Context)(x: c.Expr[Any]): c.Expr[Option[Any]] = {
+    import c.universe._
+    import Flag._
+
+    // parts here will be string literals - static parts of the string interpolation
+    // e.g. for q"$x, $y" parts will be Literal(Constant("")), Literal(Constant(", ")) and Literal(Constant(""))
+    val Apply(Select(Select(Apply(_, List(Apply(_, parts))), _), _), _) = c.macroApplication
+    val nresults = parts.length - 1
+
+    def results() =
+      ((1 to (nresults - 1)).toList map (i => Literal(Constant(i)))) :+  // (n - 1) results of type Int
+      Apply(Ident(TermName("List")), List(Literal(Constant(nresults))))  // and also one result of a different type
+    def extractorBody() =
+      if (nresults == 0) Literal(Constant(true))
+      else if (nresults == 1) Apply(Ident(TermName("Some")), results())
+      else Apply(Ident(TermName("Some")), List(Apply(Ident(TermName("Tuple" + nresults)), results())))
+
+    val name = TermName(java.util.UUID.randomUUID().toString.replace("-", ""))
+    val mdef = ModuleDef(NoMods, name, Template(List(Select(Ident(TermName("scala")), TypeName("AnyRef"))), emptyValDef, List(
+      DefDef(Modifiers(), nme.CONSTRUCTOR, List(), List(List()), TypeTree(),
+        Block(List(pendingSuperCall), Literal(Constant(())))),
+      DefDef(Modifiers(), TermName("unapply"), List(), List(List(ValDef(Modifiers(PARAM), TermName("x"), Ident(TypeName("Any")), EmptyTree))), TypeTree(),
+        extractorBody()))))
+    c.introduceTopLevel(nme.EMPTY_PACKAGE_NAME.toString, mdef)
+    c.Expr[Option[Any]](Apply(Select(Ident(name), TermName("unapply")), List(x.tree)))
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/macro-expand-unapply-b/Test_2.scala b/test/files/run/macro-expand-unapply-b/Test_2.scala
new file mode 100644
index 0000000000..5352160dfe
--- /dev/null
+++ b/test/files/run/macro-expand-unapply-b/Test_2.scala
@@ -0,0 +1,8 @@
+object Test extends App {
+  import Macros._
+  def whatever() = null
+  val q"$x1, $y1" = whatever()
+  println(x1, y1)
+  val q"$x2" = whatever()
+  println(x2)
+}
diff --git a/test/files/run/macro-repl-dontexpand.check b/test/files/run/macro-repl-dontexpand.check
index 628a9146c4..99b70ea3dc 100644
--- a/test/files/run/macro-repl-dontexpand.check
+++ b/test/files/run/macro-repl-dontexpand.check
@@ -7,6 +7,6 @@ scala> def bar(c: scala.reflect.macros.Context) = ???
 bar: (c: scala.reflect.macros.Context)Nothing
 
 scala> def foo = macro bar
-foo: Any
+defined term macro foo: Any
 
 scala> 
diff --git a/test/files/run/t5353.check b/test/files/run/t5353.check
new file mode 100644
index 0000000000..a2906793ed
--- /dev/null
+++ b/test/files/run/t5353.check
@@ -0,0 +1,2 @@
+1
+[Ljava.lang.Object; cannot be cast to [Ljava.lang.String;
diff --git a/test/files/run/t5353.scala b/test/files/run/t5353.scala
new file mode 100644
index 0000000000..5208fe527f
--- /dev/null
+++ b/test/files/run/t5353.scala
@@ -0,0 +1,9 @@
+object Test extends App {
+  def f(x: Boolean) = if (x) Array("abc") else Array()
+  try {
+    println(f(true).length)
+    println(f(false).length)
+  } catch {
+    case ex: Throwable => println(ex.getMessage)
+  }
+}
diff --git a/test/files/run/t6381.check b/test/files/run/t6381.check
index b51cfd0398..5070b67e46 100644
--- a/test/files/run/t6381.check
+++ b/test/files/run/t6381.check
@@ -9,7 +9,7 @@ scala> def pos_impl(c: reflect.macros.Context): c.Expr[String] =
 pos_impl: (c: scala.reflect.macros.Context)c.Expr[String]
 
 scala> def pos = macro pos_impl
-pos: String
+defined term macro pos: String
 
 scala> pos
 res0: String = class scala.reflect.internal.util.RangePosition