cmd/compile: remove ir.TypeAssertExpr.Ntype

As with ir.CompLitExpr.Ntype, there's no need for
ir.TypeAssertExpr.Ntype in a pure-types2 world.

Change-Id: Iff48c98330f072fd6b26099e13a19c56adecdc42
Reviewed-on: https://go-review.googlesource.com/c/go/+/403842
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

src/cmd/compile/internal/ir/expr.go

@@ -648,18 +648,20 @@ func (n *StarExpr) SetOTYPE(t *types.Type) {
 // Before type-checking, the type is Ntype.
 type TypeAssertExpr struct {
 	miniExpr
-	X     Node
-	Ntype Ntype
+	X Node
 
 	// Runtime type information provided by walkDotType for
 	// assertions from non-empty interface to concrete type.
 	Itab *AddrExpr `mknode:"-"` // *runtime.itab for Type implementing X's type
 }
 
-func NewTypeAssertExpr(pos src.XPos, x Node, typ Ntype) *TypeAssertExpr {
-	n := &TypeAssertExpr{X: x, Ntype: typ}
+func NewTypeAssertExpr(pos src.XPos, x Node, typ *types.Type) *TypeAssertExpr {
+	n := &TypeAssertExpr{X: x}
 	n.pos = pos
 	n.op = ODOTTYPE
+	if typ != nil {
+		n.SetType(typ)
+	}
 	return n
 }
 

src/cmd/compile/internal/ir/fmt.go

@@ -717,10 +717,6 @@ func exprFmt(n Node, s fmt.State, prec int) {
 	case ODOTTYPE, ODOTTYPE2:
 		n := n.(*TypeAssertExpr)
 		exprFmt(n.X, s, nprec)
-		if n.Ntype != nil {
-			fmt.Fprintf(s, ".(%v)", n.Ntype)
-			return
-		}
 		fmt.Fprintf(s, ".(%v)", n.Type())
 
 	case OINDEX, OINDEXMAP:

src/cmd/compile/internal/ir/node_gen.go

@@ -1249,9 +1249,6 @@ func (n *TypeAssertExpr) doChildren(do func(Node) bool) bool {
 	if n.X != nil && do(n.X) {
 		return true
 	}
-	if n.Ntype != nil && do(n.Ntype) {
-		return true
-	}
 	return false
 }
 func (n *TypeAssertExpr) editChildren(edit func(Node) Node) {
@@ -1259,9 +1256,6 @@ func (n *TypeAssertExpr) editChildren(edit func(Node) Node) {
 	if n.X != nil {
 		n.X = edit(n.X).(Node)
 	}
-	if n.Ntype != nil {
-		n.Ntype = edit(n.Ntype).(Ntype)
-	}
 }
 
 func (n *TypeSwitchGuard) Format(s fmt.State, verb rune) { fmtNode(n, s, verb) }

src/cmd/compile/internal/noder/reader.go

@@ -1638,7 +1638,7 @@ func (r *reader) expr() (res ir.Node) {
 		if typ, ok := typ.(*ir.DynamicType); ok && typ.Op() == ir.ODYNAMICTYPE {
 			return typed(typ.Type(), ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, x, typ.X))
 		}
-		return typecheck.Expr(ir.NewTypeAssertExpr(pos, x, typ.(ir.Ntype)))
+		return typecheck.Expr(ir.NewTypeAssertExpr(pos, x, typ.Type()))
 
 	case exprUnaryOp:
 		op := r.op()

src/cmd/compile/internal/noder/stencil.go

@@ -2266,15 +2266,12 @@ func closureSym(outer *ir.Func, prefix string, n int) *types.Sym {
 // assertToBound returns a new node that converts a node rcvr with interface type to
 // the 'dst' interface type.
 func assertToBound(info *instInfo, dictVar *ir.Name, pos src.XPos, rcvr ir.Node, dst *types.Type) ir.Node {
-	if dst.HasShape() {
-		ix := findDictType(info, dst)
-		assert(ix >= 0)
-		rt := getDictionaryType(info, dictVar, pos, ix)
-		rcvr = ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, rcvr, rt)
-		typed(dst, rcvr)
-	} else {
-		rcvr = ir.NewTypeAssertExpr(pos, rcvr, nil)
-		typed(dst, rcvr)
+	if !dst.HasShape() {
+		return typed(dst, ir.NewTypeAssertExpr(pos, rcvr, nil))
 	}
-	return rcvr
+
+	ix := findDictType(info, dst)
+	assert(ix >= 0)
+	rt := getDictionaryType(info, dictVar, pos, ix)
+	return typed(dst, ir.NewDynamicTypeAssertExpr(pos, ir.ODYNAMICDOTTYPE, rcvr, rt))
 }

src/cmd/compile/internal/typecheck/expr.go

@@ -532,14 +532,7 @@ func tcDotType(n *ir.TypeAssertExpr) ir.Node {
 		return n
 	}
 
-	if n.Ntype != nil {
-		n.Ntype = typecheckNtype(n.Ntype)
-		n.SetType(n.Ntype.Type())
-		n.Ntype = nil
-		if n.Type() == nil {
-			return n
-		}
-	}
+	base.AssertfAt(n.Type() != nil, n.Pos(), "missing type: %v", n)
 
 	if n.Type() != nil && !n.Type().IsInterface() {
 		var missing, have *types.Field

src/cmd/compile/internal/typecheck/iimport.go

@@ -1480,8 +1480,7 @@ func (r *importReader) node() ir.Node {
 		return n
 
 	case ir.ODOTTYPE, ir.ODOTTYPE2:
-		n := ir.NewTypeAssertExpr(r.pos(), r.expr(), nil)
-		n.SetType(r.typ())
+		n := ir.NewTypeAssertExpr(r.pos(), r.expr(), r.typ())
 		n.SetOp(op)
 		return n
 

src/cmd/compile/internal/typecheck/typecheck.go

@@ -234,10 +234,6 @@ func Func(fn *ir.Func) {
 	}
 }
 
-func typecheckNtype(n ir.Ntype) ir.Ntype {
-	return typecheck(n, ctxType).(ir.Ntype)
-}
-
 // typecheck type checks node n.
 // The result of typecheck MUST be assigned back to n, e.g.
 //

src/cmd/compile/internal/walk/switch.go

@@ -567,8 +567,7 @@ func (s *typeSwitch) Add(pos src.XPos, n1 ir.Node, caseVar *ir.Name, jmp ir.Node
 	switch n1.Op() {
 	case ir.OTYPE:
 		// Static type assertion (non-generic)
-		dot := ir.NewTypeAssertExpr(pos, s.facename, nil)
-		dot.SetType(typ) // iface.(type)
+		dot := ir.NewTypeAssertExpr(pos, s.facename, typ) // iface.(type)
 		as.Rhs = []ir.Node{dot}
 	case ir.ODYNAMICTYPE:
 		// Dynamic type assertion (generic)