Merge pull request #3594 from densh/si/8331

SI-8331 make sure type select & applied type doesn't match terms

4 files changed, 67 insertions, 9 deletions

diff --git a/src/compiler/scala/tools/reflect/quasiquotes/Reifiers.scala b/src/compiler/scala/tools/reflect/quasiquotes/Reifiers.scala
index 5eae3b6e6f..c37d5a3273 100644
--- a/src/compiler/scala/tools/reflect/quasiquotes/Reifiers.scala
+++ b/src/compiler/scala/tools/reflect/quasiquotes/Reifiers.scala
@@ -185,6 +185,8 @@ trait Reifiers { self: Quasiquotes =>
         reifyBuildCall(nme.SyntacticApplied, fun, argss)
       case SyntacticTypeApplied(fun, targs) if targs.nonEmpty =>
         reifyBuildCall(nme.SyntacticTypeApplied, fun, targs)
+      case SyntacticAppliedType(tpt, targs) if targs.nonEmpty =>
+        reifyBuildCall(nme.SyntacticAppliedType, tpt, targs)
       case SyntacticFunction(args, body) =>
         reifyBuildCall(nme.SyntacticFunction, args, body)
       case SyntacticIdent(name, isBackquoted) =>
@@ -215,6 +217,9 @@ trait Reifiers { self: Quasiquotes =>
       // correctness of the trees produced by quasiquotes
       case Select(id @ Ident(nme.scala_), name) if id.symbol == ScalaPackage =>
         reifyBuildCall(nme.ScalaDot, name)
+      case Select(qual, name) =>
+        val ctor = if (name.isTypeName) nme.SyntacticSelectType else nme.SyntacticSelectTerm
+        reifyBuildCall(ctor, qual, name)
       case _ =>
         super.reifyTreeSyntactically(tree)
     }
diff --git a/src/reflect/scala/reflect/api/Internals.scala b/src/reflect/scala/reflect/api/Internals.scala
index 01f928ed61..d2e742726d 100644
--- a/src/reflect/scala/reflect/api/Internals.scala
+++ b/src/reflect/scala/reflect/api/Internals.scala
@@ -600,10 +600,11 @@ trait Internals { self: Universe =>
     }
 
     val SyntacticTypeApplied: SyntacticTypeAppliedExtractor
+    val SyntacticAppliedType: SyntacticTypeAppliedExtractor
 
     trait SyntacticTypeAppliedExtractor {
       def apply(tree: Tree, targs: List[Tree]): Tree
-      def unapply(tree: Tree): Some[(Tree, List[Tree])]
+      def unapply(tree: Tree): Option[(Tree, List[Tree])]
     }
 
     val SyntacticApplied: SyntacticAppliedExtractor
@@ -784,6 +785,18 @@ trait Internals { self: Universe =>
       def apply(expr: Tree, selectors: List[Tree]): Import
       def unapply(imp: Import): Some[(Tree, List[Tree])]
     }
+
+    val SyntacticSelectType: SyntacticSelectTypeExtractor
+    trait SyntacticSelectTypeExtractor {
+      def apply(qual: Tree, name: TypeName): Select
+      def unapply(tree: Tree): Option[(Tree, TypeName)]
+    }
+
+    val SyntacticSelectTerm: SyntacticSelectTermExtractor
+    trait SyntacticSelectTermExtractor {
+      def apply(qual: Tree, name: TermName): Select
+      def unapply(tree: Tree): Option[(Tree, TermName)]
+    }
   }
 
   @deprecated("Use `internal.reificationSupport` instead", "2.11.0")
diff --git a/src/reflect/scala/reflect/internal/ReificationSupport.scala b/src/reflect/scala/reflect/internal/ReificationSupport.scala
index 66ac4bc751..dfe1811ff0 100644
--- a/src/reflect/scala/reflect/internal/ReificationSupport.scala
+++ b/src/reflect/scala/reflect/internal/ReificationSupport.scala
@@ -101,7 +101,7 @@ trait ReificationSupport { self: SymbolTable =>
     }
 
     def mkAnnotation(tree: Tree): Tree = tree match {
-      case SyntacticNew(Nil, SyntacticApplied(SyntacticTypeApplied(_, _), _) :: Nil, noSelfType, Nil) =>
+      case SyntacticNew(Nil, SyntacticApplied(SyntacticAppliedType(_, _), _) :: Nil, noSelfType, Nil) =>
         tree
       case _ =>
         throw new IllegalArgumentException(s"Tree ${showRaw(tree)} isn't a correct representation of annotation." +
@@ -201,17 +201,35 @@ trait ReificationSupport { self: SymbolTable =>
       def unapply(flags: Long): Some[Long] = Some(flags)
     }
 
+    /** Construct/deconstruct type application term trees.
+     *  Treats other term trees as zero-argument type applications.
+     */
     object SyntacticTypeApplied extends SyntacticTypeAppliedExtractor {
       def apply(tree: Tree, targs: List[Tree]): Tree =
         if (targs.isEmpty) tree
         else if (tree.isTerm) TypeApply(tree, targs)
-        else if (tree.isType) AppliedTypeTree(tree, targs)
-        else throw new IllegalArgumentException(s"can't apply types to $tree")
+        else throw new IllegalArgumentException(s"can't apply type arguments to $tree")
 
-      def unapply(tree: Tree): Some[(Tree, List[Tree])] = tree match {
+      def unapply(tree: Tree): Option[(Tree, List[Tree])] = tree match {
         case TypeApply(fun, targs) => Some((fun, targs))
+        case _ if tree.isTerm      => Some((tree, Nil))
+        case _                     => None
+      }
+    }
+
+    /** Construct/deconstruct applied type trees.
+     *  Treats other types as zero-arity applied types.
+     */
+    object SyntacticAppliedType extends SyntacticTypeAppliedExtractor {
+      def apply(tree: Tree, targs: List[Tree]): Tree =
+        if (targs.isEmpty) tree
+        else if (tree.isType) AppliedTypeTree(tree, targs)
+        else throw new IllegalArgumentException(s"can't create applied type from non-type $tree")
+
+      def unapply(tree: Tree): Option[(Tree, List[Tree])] = tree match {
         case AppliedTypeTree(tpe, targs) => Some((tpe, targs))
-        case _ => Some((tree, Nil))
+        case _ if tree.isType            => Some((tree, Nil))
+        case _                           => None
       }
     }
 
@@ -223,7 +241,10 @@ trait ReificationSupport { self: SymbolTable =>
         case UnApply(treeInfo.Unapplied(Select(fun, nme.unapply)), pats) =>
           Some((fun, pats :: Nil))
         case treeInfo.Applied(fun, targs, argss) =>
-          Some((SyntacticTypeApplied(fun, targs), argss))
+          val callee =
+            if (fun.isTerm) SyntacticTypeApplied(fun, targs)
+            else SyntacticAppliedType(fun, targs)
+          Some((callee, argss))
       }
     }
 
@@ -489,8 +510,8 @@ trait ReificationSupport { self: SymbolTable =>
         gen.mkNew(parents, mkSelfType(selfType), earlyDefs ::: body, NoPosition, NoPosition)
 
       def unapply(tree: Tree): Option[(List[Tree], List[Tree], ValDef, List[Tree])] = tree match {
-        case SyntacticApplied(Select(New(SyntacticTypeApplied(ident, targs)), nme.CONSTRUCTOR), argss) =>
-          Some((Nil, SyntacticApplied(SyntacticTypeApplied(ident, targs), argss) :: Nil, noSelfType, Nil))
+        case SyntacticApplied(Select(New(SyntacticAppliedType(ident, targs)), nme.CONSTRUCTOR), argss) =>
+          Some((Nil, SyntacticApplied(SyntacticAppliedType(ident, targs), argss) :: Nil, noSelfType, Nil))
         case SyntacticBlock(SyntacticClassDef(_, tpnme.ANON_CLASS_NAME, Nil, _, ListOfNil, earlyDefs, parents, selfType, body) ::
                             Apply(Select(New(Ident(tpnme.ANON_CLASS_NAME)), nme.CONSTRUCTOR), Nil) :: Nil) =>
           Some((earlyDefs, parents, selfType, body))
@@ -987,6 +1008,22 @@ trait ReificationSupport { self: SymbolTable =>
         Some((imp.expr, selectors))
       }
     }
+
+    object SyntacticSelectType extends SyntacticSelectTypeExtractor {
+      def apply(qual: Tree, name: TypeName): Select = Select(qual, name)
+      def unapply(tree: Tree): Option[(Tree, TypeName)] = tree match {
+        case Select(qual, name: TypeName) => Some((qual, name))
+        case _                            => None
+      }
+    }
+
+    object SyntacticSelectTerm extends SyntacticSelectTermExtractor {
+      def apply(qual: Tree, name: TermName): Select = Select(qual, name)
+      def unapply(tree: Tree): Option[(Tree, TermName)] = tree match {
+        case Select(qual, name: TermName) => Some((qual, name))
+        case _                            => None
+      }
+    }
   }
 
   val build = new ReificationSupportImpl
diff --git a/src/reflect/scala/reflect/internal/StdNames.scala b/src/reflect/scala/reflect/internal/StdNames.scala
index 339923a061..640e0606c7 100644
--- a/src/reflect/scala/reflect/internal/StdNames.scala
+++ b/src/reflect/scala/reflect/internal/StdNames.scala
@@ -613,6 +613,7 @@ trait StdNames {
     val SingleType: NameType           = "SingleType"
     val SuperType: NameType            = "SuperType"
     val SyntacticApplied: NameType     = "SyntacticApplied"
+    val SyntacticAppliedType: NameType = "SyntacticAppliedType"
     val SyntacticAssign: NameType      = "SyntacticAssign"
     val SyntacticBlock: NameType       = "SyntacticBlock"
     val SyntacticClassDef: NameType    = "SyntacticClassDef"
@@ -630,6 +631,8 @@ trait StdNames {
     val SyntacticObjectDef: NameType   = "SyntacticObjectDef"
     val SyntacticPackageObjectDef: NameType = "SyntacticPackageObjectDef"
     val SyntacticPatDef: NameType      = "SyntacticPatDef"
+    val SyntacticSelectType: NameType  = "SyntacticSelectType"
+    val SyntacticSelectTerm: NameType  = "SyntacticSelectTerm"
     val SyntacticTraitDef: NameType    = "SyntacticTraitDef"
     val SyntacticTry: NameType         = "SyntacticTry"
     val SyntacticTuple: NameType       = "SyntacticTuple"