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// Copyright (c) 2019, Paul Dreik
// License: see LICENSE.rst in the fmt root directory
#include <fmt/chrono.h>
#include <fmt/core.h>
#include <cstdint>
#include <stdexcept>
#include <type_traits>
#include <vector>
#include "fuzzer_common.h"
template <typename Item1>
void invoke_fmt(const uint8_t* Data, size_t Size, unsigned int argsize) {
constexpr auto N1 = sizeof(Item1);
static_assert(N1 <= fmt_fuzzer::Nfixed, "Nfixed too small");
if (Size <= fmt_fuzzer::Nfixed) {
return;
}
const Item1 item1 = fmt_fuzzer::assignFromBuf<Item1>(Data);
Data += fmt_fuzzer::Nfixed;
Size -= fmt_fuzzer::Nfixed;
// how many chars should be used for the argument name?
if (argsize <= 0 || argsize >= Size) {
return;
}
// allocating buffers separately is slower, but increases chances
// of detecting memory errors
#if FMT_FUZZ_SEPARATE_ALLOCATION
std::vector<char> argnamebuffer(argsize + 1);
std::memcpy(argnamebuffer.data(), Data, argsize);
auto argname = argnamebuffer.data();
#else
auto argname = fmt_fuzzer::as_chars(Data);
#endif
Data += argsize;
Size -= argsize;
#if FMT_FUZZ_SEPARATE_ALLOCATION
// allocates as tight as possible, making it easier to catch buffer overruns.
std::vector<char> fmtstringbuffer(Size);
std::memcpy(fmtstringbuffer.data(), Data, Size);
auto fmtstring = fmt::string_view(fmtstringbuffer.data(), Size);
#else
auto fmtstring = fmt::string_view(fmt_fuzzer::as_chars(Data), Size);
#endif
#if FMT_FUZZ_FORMAT_TO_STRING
std::string message = fmt::format(fmtstring, fmt::arg(argname, item1));
#else
fmt::memory_buffer outbuf;
fmt::format_to(outbuf, fmtstring, fmt::arg(argname, item1));
#endif
}
// for dynamic dispatching to an explicit instantiation
template <typename Callback> void invoke(int index, Callback callback) {
switch (index) {
case 0:
callback(bool{});
break;
case 1:
callback(char{});
break;
case 2:
using sc = signed char;
callback(sc{});
break;
case 3:
using uc = unsigned char;
callback(uc{});
break;
case 4:
callback(short{});
break;
case 5:
using us = unsigned short;
callback(us{});
break;
case 6:
callback(int{});
break;
case 7:
callback(unsigned{});
break;
case 8:
callback(long{});
break;
case 9:
using ul = unsigned long;
callback(ul{});
break;
case 10:
callback(float{});
break;
case 11:
callback(double{});
break;
case 12:
using LD = long double;
callback(LD{});
break;
}
}
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, size_t Size) {
if (Size <= 3) {
return 0;
}
// switch types depending on the first byte of the input
const auto first = Data[0] & 0x0F;
const unsigned int second = (Data[0] & 0xF0) >> 4;
Data++;
Size--;
auto outerfcn = [=](auto param1) {
invoke_fmt<decltype(param1)>(Data, Size, second);
};
try {
invoke(first, outerfcn);
} catch (std::exception& /*e*/) {
}
return 0;
}
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