1  // Copyright (c) 2020-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  #include <test/fuzz/FuzzedDataProvider.h>
 6  #include <test/fuzz/fuzz.h>
 7  #include <test/fuzz/util.h>
 8  #include <util/overflow.h>
 9  
10  #include <cstdint>
11  #include <string>
12  #include <vector>
13  
14  namespace {
15  template <typename T>
16  void TestAdditionOverflow(FuzzedDataProvider& fuzzed_data_provider)
17  {
18      const T i = fuzzed_data_provider.ConsumeIntegral<T>();
19      const T j = fuzzed_data_provider.ConsumeIntegral<T>();
20      const bool is_addition_overflow_custom = AdditionOverflow(i, j);
21      const auto maybe_add{CheckedAdd(i, j)};
22      const auto sat_add{SaturatingAdd(i, j)};
23      assert(is_addition_overflow_custom == !maybe_add.has_value());
24      assert(is_addition_overflow_custom == AdditionOverflow(j, i));
25      assert(maybe_add == CheckedAdd(j, i));
26      assert(sat_add == SaturatingAdd(j, i));
27  #ifndef _MSC_VER
28      T result_builtin;
29      const bool is_addition_overflow_builtin = __builtin_add_overflow(i, j, &result_builtin);
30      assert(is_addition_overflow_custom == is_addition_overflow_builtin);
31      if (!is_addition_overflow_custom) {
32          assert(i + j == result_builtin);
33      }
34  #endif
35      if (is_addition_overflow_custom) {
36          assert(sat_add == std::numeric_limits<T>::min() || sat_add == std::numeric_limits<T>::max());
37      } else {
38          const auto add{i + j};
39          assert(add == maybe_add.value());
40          assert(add == sat_add);
41      }
42  }
43  } // namespace
44  
45  FUZZ_TARGET(addition_overflow)
46  {
47      FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
48      TestAdditionOverflow<int64_t>(fuzzed_data_provider);
49      TestAdditionOverflow<uint64_t>(fuzzed_data_provider);
50      TestAdditionOverflow<int32_t>(fuzzed_data_provider);
51      TestAdditionOverflow<uint32_t>(fuzzed_data_provider);
52      TestAdditionOverflow<int16_t>(fuzzed_data_provider);
53      TestAdditionOverflow<uint16_t>(fuzzed_data_provider);
54      TestAdditionOverflow<char>(fuzzed_data_provider);
55      TestAdditionOverflow<unsigned char>(fuzzed_data_provider);
56      TestAdditionOverflow<signed char>(fuzzed_data_provider);
57  }