}
	return nil
}

// targets describes the target statements within which break
// or continue statements are valid.
type targets struct {
	breaks    Stmt     // *ForStmt, *SwitchStmt, *SelectStmt, or nil
	continues *ForStmt // or nil
	caseIndex int      // case index of immediately enclosing switch statement, or < 0
}

// blockBranches processes a block's body starting at start and returns the

	case *ast.SwitchStmt:
		b.switchStmt(s, label)

	case *ast.TypeSwitchStmt:
		b.typeSwitchStmt(s, label)

	case *ast.SelectStmt:
		b.selectStmt(s, label)

	case *ast.ForStmt:
		b.forStmt(s, label)

	case *ast.RangeStmt:
		b.rangeStmt(s, label)

	default:
		panic(fmt.Sprintf("unexpected statement kind: %T", s))
	}
}

func (b *builder) stmtList(list []ast.Stmt) {

}

func run(pass *analysis.Pass) (interface{}, error) {
	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)

	nodeFilter := []ast.Node{
		(*ast.File)(nil),
		(*ast.RangeStmt)(nil),
		(*ast.ForStmt)(nil),
	}
	inspect.Nodes(nodeFilter, func(n ast.Node, push bool) bool {
		if !push {
			// inspect.Nodes is slightly suboptimal as we only use push=true.
			return true
		}

	}
	return r.useObj(r.nextVar)
}

// forRangeFunc checks whether n is a range-over-func.
// If so, it returns n.(*syntax.ForStmt), true.
// Otherwise it returns nil, false.
func forRangeFunc(n syntax.Node) (*syntax.ForStmt, bool) {
	nfor, ok := n.(*syntax.ForStmt)
	if !ok {
		return nil, false
	}
	nrange, ok := nfor.Init.(*syntax.RangeClause)
	if !ok {
		return nil, false
	}

	}

	// A SelectStmt node represents a select statement.
	SelectStmt struct {
		Select token.Pos  // position of "select" keyword
		Body   *BlockStmt // CommClauses only
	}

	// A ForStmt represents a for statement.
	ForStmt struct {
		For  token.Pos // position of "for" keyword
		Init Stmt      // initialization statement; or nil
		Cond Expr      // condition; or nil
		Post Stmt      // post iteration statement; or nil

			tok(n.Opening, len("(")), // or len("[")
			tok(n.Closing, len(")"))) // or len("]")

	case *ast.File:
		// TODO test: Doc
		children = append(children,
			tok(n.Package, len("package")))

	case *ast.ForStmt:
		children = append(children,
			tok(n.For, len("for")))

	case *ast.FuncDecl:
		// TODO(adonovan): FuncDecl.Comment?

		// Uniquely, FuncDecl breaks the invariant that

	{name: "for1", format: "package main; func main() { «for x { «» }» }", scope: true, scopeMultiplier: 2},                          // Scopes: ForStmt, BlockStmt
	{name: "for3", format: "package main; func main() { «for f(); g(); h() { «» }» }", scope: true, scopeMultiplier: 2},              // Scopes: ForStmt, BlockStmt

	case *ast.IfStmt:
		found, pos := hasFuncLiteral(s.Init)
		if found {
			return pos
		}
		found, pos = hasFuncLiteral(s.Cond)
		if found {
			return pos
		}
		return s.Body.Lbrace
	case *ast.ForStmt:
		found, pos := hasFuncLiteral(s.Init)
		if found {
			return pos
		}
		found, pos = hasFuncLiteral(s.Cond)
		if found {
			return pos
		}
		found, pos = hasFuncLiteral(s.Post)
		if found {

	// Check if the enclosing statement is inside another node.
	switch expr := path[enclosingIndex+1].(type) {
	case *ast.IfStmt:
		// Get the base if statement.
		return baseIfStmt(path, enclosingIndex+1)
	case *ast.ForStmt:
		if expr.Init == enclosingStmt || expr.Post == enclosingStmt {
			return expr
		}
	}
	return enclosingStmt.(ast.Stmt)
}

// baseIfStmt walks up the if/else-if chain until we get to

		f.walk(n.Body, ctxTypeSwitch, visit)
	case *ast.CommClause:
		f.walk(n.Comm, ctxStmt, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.SelectStmt:
		f.walk(n.Body, ctxStmt, visit)
	case *ast.ForStmt:
		f.walk(n.Init, ctxStmt, visit)
		f.walk(&n.Cond, ctxExpr, visit)
		f.walk(n.Post, ctxStmt, visit)
		f.walk(n.Body, ctxStmt, visit)
	case *ast.RangeStmt:
		f.walk(&n.Key, ctxExpr, visit)