| //===-- printf_fixed_conv_fuzz.cpp ----------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /// |
| /// Fuzzing test for llvm-libc printf %f/e/g/a implementations. |
| /// |
| //===----------------------------------------------------------------------===// |
| #include "src/stdio/snprintf.h" |
| |
| #include "include/llvm-libc-macros/stdfix-macros.h" |
| #include "src/__support/fixed_point/fx_bits.h" |
| #include "src/__support/fixed_point/fx_rep.h" |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "utils/MPFRWrapper/mpfr_inc.h" |
| |
| constexpr int MAX_SIZE = 10000; |
| |
| inline bool simple_streq(char *first, char *second, int length) { |
| for (int i = 0; i < length; ++i) |
| if (first[i] != second[i]) |
| return false; |
| |
| return true; |
| } |
| |
| inline int clamp(int num, int max) { |
| if (num > max) |
| return max; |
| if (num < -max) |
| return -max; |
| return num; |
| } |
| |
| enum class TestResult { |
| Success, |
| BufferSizeFailed, |
| LengthsDiffer, |
| StringsNotEqual, |
| }; |
| |
| template <typename F> |
| inline TestResult test_vals(const char *fmt, uint64_t num, int prec, |
| int width) { |
| typename LIBC_NAMESPACE::fixed_point::FXRep<F>::StorageType raw_num = num; |
| |
| auto raw_num_bits = LIBC_NAMESPACE::fixed_point::FXBits<F>(raw_num); |
| |
| // This needs to be a float with enough bits of precision to hold the fixed |
| // point number. |
| static_assert(sizeof(long double) > sizeof(long accum)); |
| |
| // build a long double that is equivalent to the fixed point number. |
| long double ld_num = |
| static_cast<long double>(raw_num_bits.get_integral()) + |
| (static_cast<long double>(raw_num_bits.get_fraction()) / |
| static_cast<long double>(1ll << raw_num_bits.get_exponent())); |
| |
| if (raw_num_bits.get_sign()) |
| ld_num = -ld_num; |
| |
| // Call snprintf on a nullptr to get the buffer size. |
| int buffer_size = LIBC_NAMESPACE::snprintf(nullptr, 0, fmt, width, prec, num); |
| |
| if (buffer_size < 0) |
| return TestResult::BufferSizeFailed; |
| |
| char *test_buff = new char[buffer_size + 1]; |
| char *reference_buff = new char[buffer_size + 1]; |
| |
| int test_result = 0; |
| int reference_result = 0; |
| |
| test_result = LIBC_NAMESPACE::snprintf(test_buff, buffer_size + 1, fmt, width, |
| prec, num); |
| |
| // The fixed point format is defined to be %f equivalent. |
| reference_result = mpfr_snprintf(reference_buff, buffer_size + 1, "%*.*Lf", |
| width, prec, ld_num); |
| |
| // All of these calls should return that they wrote the same amount. |
| if (test_result != reference_result || test_result != buffer_size) |
| return TestResult::LengthsDiffer; |
| |
| if (!simple_streq(test_buff, reference_buff, buffer_size)) |
| return TestResult::StringsNotEqual; |
| |
| delete[] test_buff; |
| delete[] reference_buff; |
| return TestResult::Success; |
| } |
| |
| extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { |
| // const uint8_t raw_data[] = {0x8d,0x43,0x40,0x0,0x0,0x0,}; |
| // data = raw_data; |
| // size = sizeof(raw_data); |
| int prec = 0; |
| int width = 0; |
| |
| LIBC_NAMESPACE::fixed_point::FXRep<long accum>::StorageType raw_num = 0; |
| |
| // Copy as many bytes of data as will fit into num, prec, and with. Any extras |
| // are ignored. |
| for (size_t cur = 0; cur < size; ++cur) { |
| if (cur < sizeof(raw_num)) { |
| raw_num = (raw_num << 8) + data[cur]; |
| } else if (cur < sizeof(raw_num) + sizeof(prec)) { |
| prec = (prec << 8) + data[cur]; |
| } else if (cur < sizeof(raw_num) + sizeof(prec) + sizeof(width)) { |
| width = (width << 8) + data[cur]; |
| } |
| } |
| |
| width = clamp(width, MAX_SIZE); |
| prec = clamp(prec, MAX_SIZE); |
| |
| TestResult result; |
| result = test_vals<long accum>("%*.*lk", raw_num, prec, width); |
| if (result != TestResult::Success) |
| __builtin_trap(); |
| |
| result = test_vals<unsigned long accum>("%*.*lK", raw_num, prec, width); |
| if (result != TestResult::Success) |
| __builtin_trap(); |
| |
| return 0; |
| } |