1/*
2 * Copyright 2016-present Facebook, Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16#include <folly/ExceptionWrapper.h>
17
18#include <iostream>
19
20#include <folly/GLog.h>
21
22namespace folly {
23
24exception_wrapper::VTable const exception_wrapper::uninit_{
25 &noop_<void, exception_wrapper const*, exception_wrapper*>,
26 &noop_<void, exception_wrapper*, exception_wrapper*>,
27 &noop_<void, exception_wrapper*>,
28 &noop_<void, exception_wrapper const*>,
29 &uninit_type_,
30 &noop_<std::exception const*, exception_wrapper const*>,
31 &noop_<exception_wrapper, exception_wrapper const*>};
32
33exception_wrapper::VTable const exception_wrapper::ExceptionPtr::ops_{
34 copy_,
35 move_,
36 delete_,
37 throw_,
38 type_,
39 get_exception_,
40 get_exception_ptr_};
41
42exception_wrapper::VTable const exception_wrapper::SharedPtr::ops_{
43 copy_,
44 move_,
45 delete_,
46 throw_,
47 type_,
48 get_exception_,
49 get_exception_ptr_};
50
51namespace {
52std::exception const* get_std_exception_(std::exception_ptr eptr) noexcept {
53 try {
54 std::rethrow_exception(eptr);
55 } catch (const std::exception& ex) {
56 return &ex;
57 } catch (...) {
58 return nullptr;
59 }
60}
61} // namespace
62
63exception_wrapper exception_wrapper::from_exception_ptr(
64 std::exception_ptr const& ptr) noexcept {
65 if (!ptr) {
66 return exception_wrapper();
67 }
68 try {
69 std::rethrow_exception(ptr);
70 } catch (std::exception& e) {
71 return exception_wrapper(std::current_exception(), e);
72 } catch (...) {
73 return exception_wrapper(std::current_exception());
74 }
75}
76
77exception_wrapper::exception_wrapper(std::exception_ptr ptr) noexcept
78 : exception_wrapper{} {
79 if (ptr) {
80 if (auto e = get_std_exception_(ptr)) {
81 LOG(DFATAL)
82 << "Performance error: Please construct exception_wrapper with a "
83 "reference to the std::exception along with the "
84 "std::exception_ptr.";
85 *this = exception_wrapper{std::move(ptr), *e};
86 } else {
87 Unknown uk;
88 *this = exception_wrapper{ptr, uk};
89 }
90 }
91}
92
93[[noreturn]] void exception_wrapper::onNoExceptionError(
94 char const* const name) {
95 std::ios_base::Init ioinit_; // ensure std::cerr is alive
96 std::cerr << "Cannot use `" << name
97 << "` with an empty folly::exception_wrapper" << std::endl;
98 std::terminate();
99}
100
101fbstring exceptionStr(exception_wrapper const& ew) {
102 return ew.what();
103}
104
105} // namespace folly
106