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-rw-r--r--src/test/fuzz/FuzzedDataProvider.h84
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);
}