case *ast.Ident, *ast.BasicLit, *ast.SelectorExpr:
		// An identifier denoting a constant, a constant literal,
		// or a qualified identifier (imported untyped constant).
		// No operands to take care of.

	case *ast.ParenExpr:
		check.updateExprType0(x, x.X, typ, final)

	case *ast.UnaryExpr:
		// If x is a constant, the operands were constants.
		// The operands don't need to be updated since they

		return baseTypeName(t.X)
	case *ast.SelectorExpr:
		if _, ok := t.X.(*ast.Ident); ok {
			// only possible for qualified type names;
			// assume type is imported
			return t.Sel.Name, true
		}
	case *ast.ParenExpr:
		return baseTypeName(t.X)
	case *ast.StarExpr:
		return baseTypeName(t.X)
	}
	return "", false
}

// An embeddedSet describes a set of embedded types.
type embeddedSet map[*namedType]bool

	// work for other invalid receivers, but we don't care. The
	// validity of receiver expressions is checked elsewhere.
	for {
		switch t := rtyp.(type) {
		case *syntax.ParenExpr:
			rtyp = t.X
		// case *ast.StarExpr:
		//      ptr = true
		// 	rtyp = t.X
		case *syntax.Operation:
			if t.Op != syntax.Mul || t.Y != nil {
				break
			}
			ptr = true
			rtyp = t.X

	// work for other invalid receivers, but we don't care. The
	// validity of receiver expressions is checked elsewhere.
	for {
		switch t := rtyp.(type) {
		case *ast.ParenExpr:
			rtyp = t.X
		case *ast.StarExpr:
			ptr = true
			rtyp = t.X
		default:
			break L
		}
	}

	// unpack type parameters, if any
	switch rtyp.(type) {

		// An identifier denoting a constant, a constant literal,
		// or a qualified identifier (imported untyped constant).
		// No operands to take care of.

	case *syntax.ParenExpr:
		check.updateExprType0(x, x.X, typ, final)

	// case *syntax.UnaryExpr:
	// 	// If x is a constant, the operands were constants.
	// 	// The operands don't need to be updated since they

	}
	return n
}

// typecheck1 should ONLY be called from typecheck.
func typecheck1(n ir.Node, top int) ir.Node {
	// Skip over parens.
	for n.Op() == ir.OPAREN {
		n = n.(*ir.ParenExpr).X
	}

	switch n.Op() {
	default:
		ir.Dump("typecheck", n)
		base.Fatalf("typecheck %v", n.Op())
		panic("unreachable")

	case ir.ONAME:
		n := n.(*ir.Name)
		if n.BuiltinOp != 0 {

	case *ast.SelectorExpr:
		u.node(node.X)
	case *ast.UnaryExpr:
		u.node(node.X)
	case *ast.BinaryExpr:
		u.node(node.X)
		u.node(node.Y)
	case *ast.StarExpr:
		u.node(node.X)
	case *ast.ParenExpr:
		u.node(node.X)
	case *ast.IndexExpr:
		u.node(node.X)
		u.node(node.Index)
	case *ast.TypeAssertExpr:
		u.node(node.X)
		u.node(node.Type)
	case *ast.Ident:

		{"Package.Imports", Field, 0},
		{"Package.Name", Field, 0},
		{"Package.Scope", Field, 0},
		{"PackageExports", Func, 0},
		{"ParenExpr", Type, 0},
		{"ParenExpr.Lparen", Field, 0},
		{"ParenExpr.Rparen", Field, 0},
		{"ParenExpr.X", Field, 0},
		{"Pkg", Const, 0},
		{"Print", Func, 0},
		{"RECV", Const, 0},
		{"RangeStmt", Type, 0},
		{"RangeStmt.Body", Field, 0},

			"rune", "string",
			"uint", "uint8", "uint16", "uint32", "uint64", "uintptr":

			return true
		}
		if strings.HasPrefix(t.Name, "_Ctype_") {
			return true
		}
	case *ast.ParenExpr:
		return p.isType(t.X)
	case *ast.StarExpr:
		return p.isType(t.X)
	case *ast.ArrayType, *ast.StructType, *ast.FuncType, *ast.InterfaceType,
		*ast.MapType, *ast.ChanType:

		return true
	}