LLVM  16.0.0git
ScopeExit.h
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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 /// \file
10 /// This file defines the make_scope_exit function, which executes user-defined
11 /// cleanup logic at scope exit.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_ADT_SCOPEEXIT_H
16 #define LLVM_ADT_SCOPEEXIT_H
17 
18 #include "llvm/Support/Compiler.h"
19 
20 #include <type_traits>
21 #include <utility>
22 
23 namespace llvm {
24 namespace detail {
25 
26 template <typename Callable> class scope_exit {
27  Callable ExitFunction;
28  bool Engaged = true; // False once moved-from or release()d.
29 
30 public:
31  template <typename Fp>
32  explicit scope_exit(Fp &&F) : ExitFunction(std::forward<Fp>(F)) {}
33 
35  : ExitFunction(std::move(Rhs.ExitFunction)), Engaged(Rhs.Engaged) {
36  Rhs.release();
37  }
38  scope_exit(const scope_exit &) = delete;
39  scope_exit &operator=(scope_exit &&) = delete;
40  scope_exit &operator=(const scope_exit &) = delete;
41 
42  void release() { Engaged = false; }
43 
45  if (Engaged)
46  ExitFunction();
47  }
48 };
49 
50 } // end namespace detail
51 
52 // Keeps the callable object that is passed in, and execute it at the
53 // destruction of the returned object (usually at the scope exit where the
54 // returned object is kept).
55 //
56 // Interface is specified by p0052r2.
57 template <typename Callable>
58 [[nodiscard]] detail::scope_exit<std::decay_t<Callable>>
59 make_scope_exit(Callable &&F) {
60  return detail::scope_exit<std::decay_t<Callable>>(std::forward<Callable>(F));
61 }
62 
63 } // end namespace llvm
64 
65 #endif
llvm::detail::scope_exit::release
void release()
Definition: ScopeExit.h:42
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::detail::scope_exit::scope_exit
scope_exit(Fp &&F)
Definition: ScopeExit.h:32
F
#define F(x, y, z)
Definition: MD5.cpp:55
llvm::detail::scope_exit::~scope_exit
~scope_exit()
Definition: ScopeExit.h:44
llvm::detail::scope_exit
Definition: ScopeExit.h:26
llvm::detail::scope_exit::scope_exit
scope_exit(scope_exit &&Rhs)
Definition: ScopeExit.h:34
llvm::move
OutputIt move(R &&Range, OutputIt Out)
Provide wrappers to std::move which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1861
Compiler.h
llvm::make_scope_exit
detail::scope_exit< std::decay_t< Callable > > make_scope_exit(Callable &&F)
Definition: ScopeExit.h:59
std
Definition: BitVector.h:851
llvm::detail::scope_exit::operator=
scope_exit & operator=(scope_exit &&)=delete