FuzzTest support

Overview

Functions
fuzzer::Domain< Request >	pw::allocator::test::ArbitraryRequest (size_t max_size)
template<size_t kMaxRequests, size_t kMaxSize>
auto	pw::allocator::test::ArbitraryRequests ()
template<size_t kIndex, typename... Args>
Request	pw::allocator::test::MakeRequest (Args... args)
auto	pw::allocator::test::DefaultArbitraryRequests ()

Variables
constexpr size_t	pw::allocator::test::kMaxRequests = 256
constexpr size_t	pw::allocator::test::kMaxSize = 2048

Function Documentation

ArbitraryRequest()

fuzzer::Domain< Request > pw::allocator::test::ArbitraryRequest

(

size_t

max_size

)

Returns a FuzzTest domain for producing arbitrary allocator requests.

This method integrates with FuzzTest to use code coverage to produce guided mutations.

See https://github.com/google/fuzztest/blob/main/doc/domains-reference.md

Parameters

max_size

Size of the largest allocation that can be requested.

ArbitraryRequests()

template<size_t kMaxRequests, size_t kMaxSize>

auto pw::allocator::test::ArbitraryRequests

(

)

Returns a FuzzTest domain for producing sequences of arbitrary allocator requests.

This method can be used to drive an AllocatorTestHarness as part of a fuzz test.

See https://github.com/google/fuzztest/blob/main/doc/domains-reference.md

Parameters

max_size

Size of the largest allocation that can be requested.

MakeRequest()

template<size_t kIndex, typename... Args>

Request pw::allocator::test::MakeRequest

(

Args...

args

)

Builds an Request from an index and values.

Unfortunately, the reproducer emitted by FuzzTest for vectors of Requests cannot simply be copied and pasted. To create a reproducer, create a pw::Vector of the appropriate size, and populate it using this method with the correct index.

For example, consider the following sample output:

The test fails with input:
argument 0: {(index=0, value={0, 1}), (index=0, value={1209, 8}),
(index=2, value={9223372036854775807, 2048})}
 
=================================================================
=== Reproducer test
 
TEST(MyAllocatorFuzzTest, NeverCrashesU16Regression) {
  NeverCrashes(
    {{0, 1}, {1209, 8}, {9223372036854775807, 2048},
  );
}

A valid reproducer might be:

    TEST(MyAllocatorFuzzTest, NeverCrashesU16Regression) {
      Vector<test::Request, 3> input({
        test::MakeRequest<0>(0u, 1u),
        test::MakeRequest<0>(1209u, 8u),
        test::MakeRequest<2>(9223372036854775807u, 2048u),
      });
      NeverCrashes(input);
// }