check.h raw
1 // Copyright (c) 2019-present The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5 #ifndef BITCOIN_UTIL_CHECK_H
6 #define BITCOIN_UTIL_CHECK_H
7
8 #include <attributes.h>
9
10 #include <atomic>
11 // We use `util/check.h` to provide the `assert()` macro
12 // to ensure that `NDEBUG` is not defined.
13 #include <cassert> // IWYU pragma: export
14 #include <source_location>
15 #include <stdexcept>
16 #include <string>
17 #include <string_view>
18 #include <type_traits>
19 #include <utility>
20
21 constexpr bool G_FUZZING_BUILD{
22 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
23 true
24 #else
25 false
26 #endif
27 };
28 constexpr bool G_ABORT_ON_FAILED_ASSUME{G_FUZZING_BUILD ||
29 #ifdef ABORT_ON_FAILED_ASSUME
30 true
31 #else
32 false
33 #endif
34 };
35
36 extern std::atomic<bool> g_enable_dynamic_fuzz_determinism;
37
38 inline bool EnableFuzzDeterminism()
39 {
40 if constexpr (G_FUZZING_BUILD) {
41 return true;
42 } else if constexpr (!G_ABORT_ON_FAILED_ASSUME) {
43 // Running fuzz tests is always disabled if Assume() doesn't abort
44 // (ie, non-fuzz non-debug builds), as otherwise tests which
45 // should fail due to a failing Assume may still pass. As such,
46 // we also statically disable fuzz determinism in that case.
47 return false;
48 } else {
49 return g_enable_dynamic_fuzz_determinism;
50 }
51 }
52
53 extern bool g_detail_test_only_CheckFailuresAreExceptionsNotAborts;
54 struct test_only_CheckFailuresAreExceptionsNotAborts {
55 test_only_CheckFailuresAreExceptionsNotAborts() { g_detail_test_only_CheckFailuresAreExceptionsNotAborts = true; };
56 ~test_only_CheckFailuresAreExceptionsNotAborts() { g_detail_test_only_CheckFailuresAreExceptionsNotAborts = false; };
57 };
58
59 std::string StrFormatInternalBug(std::string_view msg, const std::source_location& loc);
60
61 class NonFatalCheckError : public std::runtime_error
62 {
63 public:
64 NonFatalCheckError(std::string_view msg, const std::source_location& loc);
65 };
66
67 /** Internal helper */
68 void assertion_fail(const std::source_location& loc, std::string_view assertion);
69
70 /** Helper for CHECK_NONFATAL() */
71 template <typename T>
72 T&& inline_check_non_fatal(LIFETIMEBOUND T&& val, const std::source_location& loc, std::string_view assertion)
73 {
74 if (!val) {
75 if constexpr (G_ABORT_ON_FAILED_ASSUME) {
76 assertion_fail(loc, assertion);
77 }
78 throw NonFatalCheckError{assertion, loc};
79 }
80 return std::forward<T>(val);
81 }
82
83 #if defined(NDEBUG)
84 #error "Cannot compile without assertions!"
85 #endif
86
87 /** Helper for Assert()/Assume() */
88 template <bool IS_ASSERT, typename T>
89 constexpr T&& inline_assertion_check(LIFETIMEBOUND T&& val, [[maybe_unused]] const std::source_location& loc, [[maybe_unused]] std::string_view assertion)
90 {
91 if (IS_ASSERT || std::is_constant_evaluated() || G_ABORT_ON_FAILED_ASSUME) {
92 if (!val) {
93 assertion_fail(loc, assertion);
94 }
95 }
96 return std::forward<T>(val);
97 }
98
99 #define STR_INTERNAL_BUG(msg) StrFormatInternalBug((msg), std::source_location::current())
100
101 /**
102 * Identity function. Throw a NonFatalCheckError when the condition evaluates to false
103 *
104 * This should only be used
105 * - where the condition is assumed to be true, not for error handling or validating user input
106 * - where a failure to fulfill the condition is recoverable and does not abort the program
107 *
108 * For example in RPC code, where it is undesirable to crash the whole program, this can be generally used to replace
109 * asserts or recoverable logic errors. A NonFatalCheckError in RPC code is caught and passed as a string to the RPC
110 * caller, which can then report the issue to the developers.
111 */
112 #define CHECK_NONFATAL(condition) \
113 inline_check_non_fatal(condition, std::source_location::current(), #condition)
114
115 /** Identity function. Abort if the value compares equal to zero */
116 #define Assert(val) inline_assertion_check<true>(val, std::source_location::current(), #val)
117
118 /**
119 * Assume is the identity function.
120 *
121 * - Should be used to run non-fatal checks. In debug builds it behaves like
122 * Assert()/assert() to notify developers and testers about non-fatal errors.
123 * In production it doesn't warn or log anything.
124 * - For fatal errors, use Assert().
125 * - For non-fatal errors in interactive sessions (e.g. RPC or command line
126 * interfaces), CHECK_NONFATAL() might be more appropriate.
127 */
128 #define Assume(val) inline_assertion_check<false>(val, std::source_location::current(), #val)
129
130 /**
131 * NONFATAL_UNREACHABLE() is a macro that is used to mark unreachable code. It throws a NonFatalCheckError.
132 */
133 #define NONFATAL_UNREACHABLE() \
134 throw NonFatalCheckError { "Unreachable code reached (non-fatal)", std::source_location::current() }
135
136 #if defined(__has_feature)
137 # if __has_feature(address_sanitizer)
138 # include <sanitizer/asan_interface.h>
139 # endif
140 #endif
141
142 #ifndef ASAN_POISON_MEMORY_REGION
143 # define ASAN_POISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
144 # define ASAN_UNPOISON_MEMORY_REGION(addr, size) ((void)(addr), (void)(size))
145 #endif
146
147 #endif // BITCOIN_UTIL_CHECK_H
148