// *T is valid, but **T is not
			if op, _ := base.(*syntax.Operation); op == nil || ptrBase(op) == nil {
				return embeddedFieldIdent(e.X)
			}
		}
	case *syntax.SelectorExpr:
		return e.Sel
	case *syntax.IndexExpr:
		return embeddedFieldIdent(e.X)
	}
	return nil // invalid embedded field
}

func (check *Checker) declareInSet(oset *objset, pos syntax.Pos, obj Object) bool {
	if alt := oset.insert(obj); alt != nil {

	return v
}

// checkAddr checks to make sure n is a properly aligned address for a 64-bit atomic operation.
func (v *Visitor) checkAddr(n ast.Node) {
	switch n := n.(type) {
	case *ast.IndexExpr:
		// Alignment of an array element is the same as the whole array.
		v.checkAddr(n.X)
		return
	case *ast.Ident:
		key := "var " + v.print(n)
		if !v.checked[key] {

		return e
	case *ast.StarExpr:
		// *T is valid, but **T is not
		if _, ok := e.X.(*ast.StarExpr); !ok {
			return embeddedFieldIdent(e.X)
		}
	case *ast.SelectorExpr:
		return e.Sel
	case *ast.IndexExpr:
		return embeddedFieldIdent(e.X)
	case *ast.IndexListExpr:
		return embeddedFieldIdent(e.X)
	}
	return nil // invalid embedded field
}

	case *CompositeLit:
		if n.Type != nil {
			Walk(v, n.Type)
		}
		walkList(v, n.Elts)

	case *ParenExpr:
		Walk(v, n.X)

	case *SelectorExpr:
		Walk(v, n.X)
		Walk(v, n.Sel)

	case *IndexExpr:
		Walk(v, n.X)
		Walk(v, n.Index)

	case *IndexListExpr:
		Walk(v, n.X)
		walkList(v, n.Indices)

	case *SliceExpr:
		Walk(v, n.X)
		if n.Low != nil {
			Walk(v, n.Low)
		}

		w.node(n.Value)

	case *FuncLit:
		w.node(n.Type)
		w.node(n.Body)

	case *ParenExpr:
		w.node(n.X)

	case *SelectorExpr:
		w.node(n.X)
		w.node(n.Sel)

	case *IndexExpr:
		w.node(n.X)
		w.node(n.Index)

	case *SliceExpr:
		w.node(n.X)
		for _, x := range n.Index {
			if x != nil {
				w.node(x)
			}
		}

	case *AssertExpr:
		w.node(n.X)

}

// IndexMapRType asserts that n is a map index operation, and returns
// an expression that yields the *runtime._type value representing the
// map type.
func IndexMapRType(pos src.XPos, n *ir.IndexExpr) ir.Node {
	assertOp(n, ir.OINDEXMAP)
	if hasRType(n, n.RType, "RType") {
		return n.RType
	}
	return mapRType(pos, n.X.Type())
}

// MakeChanRType asserts that n is a "make" operation for a channel

	{"CompositeLit", `struct{x, y int}@{}`},

	{"KeyValueExpr", `"foo"@: true`},
	{"KeyValueExpr", `"a"@: b`},

	{"FuncLit", `@func (){}`},
	{"ParenExpr", `@(x)`},
	{"SelectorExpr", `a@.b`},
	{"IndexExpr", `a@[i]`},

	{"SliceExpr", `a@[:]`},
	{"SliceExpr", `a@[i:]`},
	{"SliceExpr", `a@[:j]`},
	{"SliceExpr", `a@[i:j]`},
	{"SliceExpr", `a@[i:j:k]`},

	{"AssertExpr", `x@.(T)`},

	{"Operation", `@*b`},