diff options
| -rw-r--r-- | src/test/fuzz/FuzzedDataProvider.h | 84 |
1 files changed, 72 insertions, 12 deletions
diff --git a/src/test/fuzz/FuzzedDataProvider.h b/src/test/fuzz/FuzzedDataProvider.h index 1b5b4bb012..3e069eba69 100644 --- a/src/test/fuzz/FuzzedDataProvider.h +++ b/src/test/fuzz/FuzzedDataProvider.h @@ -13,11 +13,10 @@ #ifndef LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_ #define LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_ -#include <limits.h> -#include <stddef.h> -#include <stdint.h> - #include <algorithm> +#include <climits> +#include <cstddef> +#include <cstdint> #include <cstring> #include <initializer_list> #include <string> @@ -25,8 +24,10 @@ #include <utility> #include <vector> +// In addition to the comments below, the API is also briefly documented at +// https://github.com/google/fuzzing/blob/master/docs/split-inputs.md#fuzzed-data-provider class FuzzedDataProvider { -public: + public: // |data| is an array of length |size| that the FuzzedDataProvider wraps to // provide more granular access. |data| must outlive the FuzzedDataProvider. FuzzedDataProvider(const uint8_t *data, size_t size) @@ -143,9 +144,9 @@ public: return ConsumeBytes<T>(remaining_bytes_); } + // Returns a std::string containing all remaining bytes of the input data. // Prefer using |ConsumeRemainingBytes| unless you actually need a std::string // object. - // Returns a std::vector containing all remaining bytes of the input data. std::string ConsumeRemainingBytesAsString() { return ConsumeBytesAsString(remaining_bytes_); } @@ -161,7 +162,7 @@ public: // Reads one byte and returns a bool, or false when no data remains. bool ConsumeBool() { return 1 & ConsumeIntegral<uint8_t>(); } - // Returns a copy of a value selected from a fixed-size |array|. + // Returns a copy of the value selected from the given fixed-size |array|. template <typename T, size_t size> T PickValueInArray(const T (&array)[size]) { static_assert(size > 0, "The array must be non empty."); @@ -170,11 +171,14 @@ public: template <typename T> T PickValueInArray(std::initializer_list<const T> list) { - // static_assert(list.size() > 0, "The array must be non empty."); + // TODO(Dor1s): switch to static_assert once C++14 is allowed. + if (!list.size()) + abort(); + return *(list.begin() + ConsumeIntegralInRange<size_t>(0, list.size() - 1)); } - // Return an enum value. The enum must start at 0 and be contiguous. It must + // Returns an enum value. The enum must start at 0 and be contiguous. It must // also contain |kMaxValue| aliased to its largest (inclusive) value. Such as: // enum class Foo { SomeValue, OtherValue, kMaxValue = OtherValue }; template <typename T> T ConsumeEnum() { @@ -183,10 +187,60 @@ public: 0, static_cast<uint32_t>(T::kMaxValue))); } + // Returns a floating point number in the range [0.0, 1.0]. If there's no + // input data left, always returns 0. + template <typename T> T ConsumeProbability() { + static_assert(std::is_floating_point<T>::value, + "A floating point type is required."); + + // Use different integral types for different floating point types in order + // to provide better density of the resulting values. + using IntegralType = + typename std::conditional<(sizeof(T) <= sizeof(uint32_t)), uint32_t, + uint64_t>::type; + + T result = static_cast<T>(ConsumeIntegral<IntegralType>()); + result /= static_cast<T>(std::numeric_limits<IntegralType>::max()); + return result; + } + + // Returns a floating point value in the range [Type's lowest, Type's max] by + // consuming bytes from the input data. If there's no input data left, always + // returns approximately 0. + template <typename T> T ConsumeFloatingPoint() { + return ConsumeFloatingPointInRange<T>(std::numeric_limits<T>::lowest(), + std::numeric_limits<T>::max()); + } + + // Returns a floating point value in the given range by consuming bytes from + // the input data. If there's no input data left, returns |min|. Note that + // |min| must be less than or equal to |max|. + template <typename T> T ConsumeFloatingPointInRange(T min, T max) { + if (min > max) + abort(); + + T range = .0; + T result = min; + constexpr T zero(.0); + if (max > zero && min < zero && max > min + std::numeric_limits<T>::max()) { + // The diff |max - min| would overflow the given floating point type. Use + // the half of the diff as the range and consume a bool to decide whether + // the result is in the first of the second part of the diff. + range = (max / 2.0) - (min / 2.0); + if (ConsumeBool()) { + result += range; + } + } else { + range = max - min; + } + + return result + range * ConsumeProbability<T>(); + } + // Reports the remaining bytes available for fuzzed input. size_t remaining_bytes() { return remaining_bytes_; } -private: + private: FuzzedDataProvider(const FuzzedDataProvider &) = delete; FuzzedDataProvider &operator=(const FuzzedDataProvider &) = delete; @@ -209,6 +263,12 @@ private: // which seems to be a natural choice for other implementations as well. // To increase the odds even more, we also call |shrink_to_fit| below. std::vector<T> result(size); + if (size == 0) { + if (num_bytes_to_consume != 0) + abort(); + return result; + } + std::memcpy(result.data(), data_ptr_, num_bytes_to_consume); Advance(num_bytes_to_consume); @@ -230,9 +290,9 @@ private: // Avoid using implementation-defined unsigned to signer conversions. // To learn more, see https://stackoverflow.com/questions/13150449. - if (value <= std::numeric_limits<TS>::max()) + if (value <= std::numeric_limits<TS>::max()) { return static_cast<TS>(value); - else { + } else { constexpr auto TS_min = std::numeric_limits<TS>::min(); return TS_min + static_cast<char>(value - TS_min); } |