Move check to constructor

Author: liufengyun

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -41,8 +41,11 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def Super(qual: Tree, mixName: TypeName, inConstrCall: Boolean, mixinClass: Symbol = NoSymbol)(implicit ctx: Context): Super =
     Super(qual, if (mixName.isEmpty) untpd.EmptyTypeIdent else untpd.Ident(mixName), inConstrCall, mixinClass)
 
-  def Apply(fn: Tree, args: List[Tree])(implicit ctx: Context): Apply =
+  def Apply(fn: Tree, args: List[Tree])(implicit ctx: Context): Apply = {
+    assert(!fn.isInstanceOf[Block])
+    assert(!fn.isInstanceOf[If])
     ta.assignType(untpd.Apply(fn, args), fn, args)
+  }
 
   def TypeApply(fn: Tree, args: List[Tree])(implicit ctx: Context): TypeApply =
     ta.assignType(untpd.TypeApply(fn, args), fn, args)
@@ -182,8 +185,10 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def Alternative(trees: List[Tree])(implicit ctx: Context): Alternative =
     ta.assignType(untpd.Alternative(trees), trees)
 
-  def UnApply(fun: Tree, implicits: List[Tree], patterns: List[Tree], proto: Type)(implicit ctx: Context): UnApply =
+  def UnApply(fun: Tree, implicits: List[Tree], patterns: List[Tree], proto: Type)(implicit ctx: Context): UnApply = {
+    assert(!fun.isInstanceOf[Block])
     ta.assignType(untpd.UnApply(fun, implicits, patterns), proto)
+  }
 
   def ValDef(sym: TermSymbol, rhs: LazyTree = EmptyTree)(implicit ctx: Context): ValDef =
     ta.assignType(untpd.ValDef(sym.name, TypeTree(sym.info), rhs), sym)

compiler/src/dotty/tools/dotc/transform/TreeChecker.scala

@@ -279,7 +279,6 @@ class TreeChecker extends Phase with SymTransformer {
         case _ if tree.isType =>
           promote(tree)
         case _ =>
-          checkApplyNonBlock(tree)
           val tree1 = super.typedUnadapted(tree, pt, locked)
           def isSubType(tp1: Type, tp2: Type) =
             (tp1 eq tp2) || // accept NoType / NoType
@@ -301,12 +300,6 @@ class TreeChecker extends Phase with SymTransformer {
       res
     }
 
-    def checkApplyNonBlock(tree: untpd.Tree)(implicit ctx: Context) = tree match {
-      case tree: untpd.Apply => assert(!tree.fun.isInstanceOf[untpd.Block])
-      case tree: untpd.UnApply => assert(!tree.fun.isInstanceOf[untpd.Block])
-      case _ =>
-    }
-
     def checkNotRepeated(tree: Tree)(implicit ctx: Context): tree.type = {
       def allowedRepeated = tree.tpe.widen.isRepeatedParam