ext-fmt/test/fuzzing/float.cc
2021-12-05 07:26:58 -08:00

40 lines
1.2 KiB
C++

// A fuzzer for floating-point formatter.
// For the license information refer to format.h.
#include <fmt/format.h>
#include <cstdint>
#include <cstdlib>
#include <limits>
#include <stdexcept>
#include "fuzzer-common.h"
void check_round_trip(fmt::string_view format_str, double value) {
auto buffer = fmt::memory_buffer();
fmt::format_to(std::back_inserter(buffer), format_str, value);
if (std::isnan(value)) {
auto nan = std::signbit(value) ? "-nan" : "nan";
if (fmt::string_view(buffer.data(), buffer.size()) != nan)
throw std::runtime_error("round trip failure");
return;
}
buffer.push_back('\0');
char* ptr = nullptr;
if (std::strtod(buffer.data(), &ptr) != value)
throw std::runtime_error("round trip failure");
if (ptr + 1 != buffer.end()) throw std::runtime_error("unparsed output");
}
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
if (size <= sizeof(double) || !std::numeric_limits<double>::is_iec559)
return 0;
check_round_trip("{}", assign_from_buf<double>(data));
// A larger than necessary precision is used to trigger the fallback
// formatter.
check_round_trip("{:.50g}", assign_from_buf<double>(data));
return 0;
}