1 // Copyright (c) 2019 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 #if defined(HAVE_CONFIG_H)
9 #include <config/bitcoin-config.h>
10 #endif
11
12 #include <tinyformat.h>
13
14 #include <stdexcept>
15
16 class NonFatalCheckError : public std::runtime_error
17 {
18 using std::runtime_error::runtime_error;
19 };
20
21 /**
22 * Throw a NonFatalCheckError when the condition evaluates to false
23 *
24 * This should only be used
25 * - where the condition is assumed to be true, not for error handling or validating user input
26 * - where a failure to fulfill the condition is recoverable and does not abort the program
27 *
28 * For example in RPC code, where it is undesirable to crash the whole program, this can be generally used to replace
29 * asserts or recoverable logic errors. A NonFatalCheckError in RPC code is caught and passed as a string to the RPC
30 * caller, which can then report the issue to the developers.
31 */
32 #define CHECK_NONFATAL(condition) \
33 do { \
34 if (!(condition)) { \
35 throw NonFatalCheckError( \
36 strprintf("%s:%d (%s)\n" \
37 "Internal bug detected: '%s'\n" \
38 "You may report this issue here: %s\n", \
39 __FILE__, __LINE__, __func__, \
40 (#condition), \
41 PACKAGE_BUGREPORT)); \
42 } \
43 } while (false)
44
45 #if defined(NDEBUG)
46 #error "Cannot compile without assertions!"
47 #endif
48
49 /** Helper for Assert(). TODO remove in C++14 and replace `decltype(get_pure_r_value(val))` with `T` (templated lambda) */
50 template <typename T>
get_pure_r_value(T && val)51 T get_pure_r_value(T&& val)
52 {
53 return std::forward<T>(val);
54 }
55
56 /** Identity function. Abort if the value compares equal to zero */
57 #define Assert(val) [&]() -> decltype(get_pure_r_value(val)) { auto&& check = (val); assert(#val && check); return std::forward<decltype(get_pure_r_value(val))>(check); }()
58
59 #endif // BITCOIN_UTIL_CHECK_H
60