{"ExprStmt", `append@(s, 1, 2, 3)`},

	{"SendStmt", `ch @<- x`},

	{"DeclStmt", `@const x = 0`},
	{"DeclStmt", `@const (x = 0)`},
	{"DeclStmt", `@type T int`},
	{"DeclStmt", `@type T = int`},
	{"DeclStmt", `@type (T1 = int; T2 = float32)`},
	{"DeclStmt", `@var x = 0`},
	{"DeclStmt", `@var x, y, z int`},
	{"DeclStmt", `@var (a, b = 1, 2)`},

	{"AssignStmt", `x @= y`},
	{"AssignStmt", `a, b, x @= 1, 2, 3`},

// If s is labeled, label is the label name; otherwise s
// is "".
func (check *Checker) isTerminating(s syntax.Stmt, label string) bool {
	switch s := s.(type) {
	default:
		panic("unreachable")

	case *syntax.DeclStmt, *syntax.EmptyStmt, *syntax.SendStmt,
		*syntax.AssignStmt, *syntax.CallStmt:
		// no chance

	case *syntax.LabeledStmt:
		return check.isTerminating(s.Stmt, s.Label.Value)

	case *syntax.ExprStmt:

// If s is labeled, label is the label name; otherwise s
// is "".
func (check *Checker) isTerminating(s ast.Stmt, label string) bool {
	switch s := s.(type) {
	default:
		panic("unreachable")

	case *ast.BadStmt, *ast.DeclStmt, *ast.EmptyStmt, *ast.SendStmt,
		*ast.IncDecStmt, *ast.AssignStmt, *ast.GoStmt, *ast.DeferStmt,
		*ast.RangeStmt:
		// no chance

	case *ast.LabeledStmt:
		return check.isTerminating(s.Stmt, s.Label.Name)

}

// declVar declares a variable with a given name type and initializer value.
func (r *rewriter) declVar(name string, typ types2.Type, init syntax.Expr) *types2.Var {
	if r.declStmt == nil {
		r.declStmt = &syntax.DeclStmt{}
	}
	stmt := r.declStmt
	obj, n := r.makeVarName(stmt.Pos(), name, typ)
	stmt.DeclList = append(stmt.DeclList, &syntax.VarDecl{
		NameList: []*syntax.Name{n},
		// Note: Type is ignored

		// case *MapType:
		// case *ChanType:

		// statements
		// case *EmptyStmt:
		// case *LabeledStmt:
		// case *BlockStmt:
		// case *ExprStmt:
		case *SendStmt:
			m = n.Chan
		// case *DeclStmt:
		case *AssignStmt:
			m = n.Lhs
		// case *BranchStmt:
		// case *CallStmt:
		// case *ReturnStmt:
		// case *IfStmt:
		// case *ForStmt:
		// case *SwitchStmt:
		// case *SelectStmt:

	switch x := stmt.(type) {
	default:
		log.Fatalf("%s: internal error in findLabels: unexpected statement %T", d.pass.Fset.Position(x.Pos()), x)

	case *ast.AssignStmt,
		*ast.BadStmt,
		*ast.DeclStmt,
		*ast.DeferStmt,
		*ast.EmptyStmt,
		*ast.ExprStmt,
		*ast.GoStmt,
		*ast.IncDecStmt,
		*ast.ReturnStmt,
		*ast.SendStmt:
		// no statements inside

	case *ast.BlockStmt:

		return 1 << nCommClause
	case *ast.Comment:
		return 1 << nComment
	case *ast.CommentGroup:
		return 1 << nCommentGroup
	case *ast.CompositeLit:
		return 1 << nCompositeLit
	case *ast.DeclStmt:
		return 1 << nDeclStmt
	case *ast.DeferStmt:
		return 1 << nDeferStmt
	case *ast.Ellipsis:
		return 1 << nEllipsis
	case *ast.EmptyStmt:
		return 1 << nEmptyStmt
	case *ast.ExprStmt:
		return 1 << nExprStmt

	// syntax errors for which no correct statement nodes can be
	// created.
	//
	BadStmt struct {
		From, To token.Pos // position range of bad statement
	}

	// A DeclStmt node represents a declaration in a statement list.
	DeclStmt struct {
		Decl Decl // *GenDecl with CONST, TYPE, or VAR token
	}

	// An EmptyStmt node represents an empty statement.
	// The "position" of the empty statement is the position

		fwdJumps = append(fwdJumps, check.blockBranches(all, b, lstmt, list)...)
	}

	var stmtBranches func(ast.Stmt)
	stmtBranches = func(s ast.Stmt) {
		switch s := s.(type) {
		case *ast.DeclStmt:
			if d, _ := s.Decl.(*ast.GenDecl); d != nil && d.Tok == token.VAR {
				recordVarDecl(d.Pos())
			}

		case *ast.LabeledStmt:
			// declare non-blank label
			if name := s.Label.Name; name != "_" {

		Walk(v, n.Methods)

	case *MapType:
		Walk(v, n.Key)
		Walk(v, n.Value)

	case *ChanType:
		Walk(v, n.Value)

	// Statements
	case *BadStmt:
		// nothing to do

	case *DeclStmt:
		Walk(v, n.Decl)

	case *EmptyStmt:
		// nothing to do

	case *LabeledStmt:
		Walk(v, n.Label)
		Walk(v, n.Stmt)

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

	case *SendStmt: