1 | //===- llvm/ADT/ScopeExit.h - Execute code at scope exit --------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | // |
9 | // This file defines the make_scope_exit function, which executes user-defined |
10 | // cleanup logic at scope exit. |
11 | // |
12 | //===----------------------------------------------------------------------===// |
13 | |
14 | #ifndef LLVM_ADT_SCOPEEXIT_H |
15 | #define LLVM_ADT_SCOPEEXIT_H |
16 | |
17 | #include "llvm/Support/Compiler.h" |
18 | |
19 | #include <type_traits> |
20 | #include <utility> |
21 | |
22 | namespace llvm { |
23 | namespace detail { |
24 | |
25 | template <typename Callable> class scope_exit { |
26 | Callable ExitFunction; |
27 | bool Engaged = true; // False once moved-from or release()d. |
28 | |
29 | public: |
30 | template <typename Fp> |
31 | explicit scope_exit(Fp &&F) : ExitFunction(std::forward<Fp>(F)) {} |
32 | |
33 | scope_exit(scope_exit &&Rhs) |
34 | : ExitFunction(std::move(Rhs.ExitFunction)), Engaged(Rhs.Engaged) { |
35 | Rhs.release(); |
36 | } |
37 | scope_exit(const scope_exit &) = delete; |
38 | scope_exit &operator=(scope_exit &&) = delete; |
39 | scope_exit &operator=(const scope_exit &) = delete; |
40 | |
41 | void release() { Engaged = false; } |
42 | |
43 | ~scope_exit() { |
44 | if (Engaged) |
45 | ExitFunction(); |
46 | } |
47 | }; |
48 | |
49 | } // end namespace detail |
50 | |
51 | // Keeps the callable object that is passed in, and execute it at the |
52 | // destruction of the returned object (usually at the scope exit where the |
53 | // returned object is kept). |
54 | // |
55 | // Interface is specified by p0052r2. |
56 | template <typename Callable> |
57 | LLVM_NODISCARD detail::scope_exit<typename std::decay<Callable>::type> |
58 | make_scope_exit(Callable &&F) { |
59 | return detail::scope_exit<typename std::decay<Callable>::type>( |
60 | std::forward<Callable>(F)); |
61 | } |
62 | |
63 | } // end namespace llvm |
64 | |
65 | #endif |
66 | |