fuzz: Assume presence of __builtin_*_overflow, without checks

Author: MarcoFalke

src/test/fuzz/addition_overflow.cpp

@@ -11,14 +11,6 @@
 #include <string>
 #include <vector>
 
-#if defined(__has_builtin)
-#if __has_builtin(__builtin_add_overflow)
-#define HAVE_BUILTIN_ADD_OVERFLOW
-#endif
-#elif defined(__GNUC__)
-#define HAVE_BUILTIN_ADD_OVERFLOW
-#endif
-
 namespace {
 template <typename T>
 void TestAdditionOverflow(FuzzedDataProvider& fuzzed_data_provider)
@@ -32,14 +24,12 @@ void TestAdditionOverflow(FuzzedDataProvider& fuzzed_data_provider)
     assert(is_addition_overflow_custom == AdditionOverflow(j, i));
     assert(maybe_add == CheckedAdd(j, i));
     assert(sat_add == SaturatingAdd(j, i));
-#if defined(HAVE_BUILTIN_ADD_OVERFLOW)
     T result_builtin;
     const bool is_addition_overflow_builtin = __builtin_add_overflow(i, j, &result_builtin);
     assert(is_addition_overflow_custom == is_addition_overflow_builtin);
     if (!is_addition_overflow_custom) {
         assert(i + j == result_builtin);
     }
-#endif
     if (is_addition_overflow_custom) {
         assert(sat_add == std::numeric_limits<T>::min() || sat_add == std::numeric_limits<T>::max());
     } else {

src/test/fuzz/multiplication_overflow.cpp

@@ -10,33 +10,19 @@
 #include <string>
 #include <vector>
 
-#if defined(__has_builtin)
-#if __has_builtin(__builtin_mul_overflow)
-#define HAVE_BUILTIN_MUL_OVERFLOW
-#endif
-#elif defined(__GNUC__)
-#define HAVE_BUILTIN_MUL_OVERFLOW
-#endif
-
 namespace {
 template <typename T>
 void TestMultiplicationOverflow(FuzzedDataProvider& fuzzed_data_provider)
 {
     const T i = fuzzed_data_provider.ConsumeIntegral<T>();
     const T j = fuzzed_data_provider.ConsumeIntegral<T>();
     const bool is_multiplication_overflow_custom = MultiplicationOverflow(i, j);
-#if defined(HAVE_BUILTIN_MUL_OVERFLOW)
     T result_builtin;
     const bool is_multiplication_overflow_builtin = __builtin_mul_overflow(i, j, &result_builtin);
     assert(is_multiplication_overflow_custom == is_multiplication_overflow_builtin);
     if (!is_multiplication_overflow_custom) {
         assert(i * j == result_builtin);
     }
-#else
-    if (!is_multiplication_overflow_custom) {
-        (void)(i * j);
-    }
-#endif
 }
 } // namespace