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			78 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
// Copyright (c) 2019, Paul Dreik
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// For the license information refer to format.h.
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#ifndef FUZZER_COMMON_H
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#define FUZZER_COMMON_H
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#include <fmt/core.h>
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#include <cstdint>  // std::uint8_t
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#include <cstring>  // memcpy
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#include <vector>
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// One can format to either a string, or a buffer. The latter is faster, but
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// one may be interested in formatting to a string instead to verify it works
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// as intended. To avoid a combinatoric explosion, select this at compile time
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// instead of dynamically from the fuzz data.
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#define FMT_FUZZ_FORMAT_TO_STRING 0
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// If {fmt} is given a buffer that is separately allocated, chances that address
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// sanitizer detects out of bound reads is much higher. However, it slows down
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// the fuzzing.
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#define FMT_FUZZ_SEPARATE_ALLOCATION 1
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// The size of the largest possible type in use.
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// To let the the fuzzer mutation be efficient at cross pollinating between
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// different types, use a fixed size format. The same bit pattern, interpreted
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// as another type, is likely interesting.
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constexpr auto fixed_size = 16;
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// Casts data to a char pointer.
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template <typename T> inline const char* as_chars(const T* data) {
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  return reinterpret_cast<const char*>(data);
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}
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// Casts data to a byte pointer.
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template <typename T> inline const std::uint8_t* as_bytes(const T* data) {
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  return reinterpret_cast<const std::uint8_t*>(data);
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}
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// Blits bytes from data to form an (assumed trivially constructible) object
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// of type Item.
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template <class Item> inline Item assign_from_buf(const std::uint8_t* data) {
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  auto item = Item();
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  std::memcpy(&item, data, sizeof(Item));
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  return item;
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}
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// Reads a boolean value by looking at the first byte from data.
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template <> inline bool assign_from_buf<bool>(const std::uint8_t* data) {
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  return *data != 0;
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}
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struct data_to_string {
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#if FMT_FUZZ_SEPARATE_ALLOCATION
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  std::vector<char> buffer;
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  data_to_string(const uint8_t* data, size_t size, bool add_terminator = false)
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      : buffer(size + (add_terminator ? 1 : 0)) {
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    if (size) {
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      std::memcpy(buffer.data(), data, size);
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    }
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  }
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  fmt::string_view get() const { return {buffer.data(), buffer.size()}; }
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#else
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  fmt::string_view sv;
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  data_to_string(const uint8_t* data, size_t size, bool = false)
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      : str(as_chars(data), size) {}
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  fmt::string_view get() const { return sv; }
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#endif
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  const char* data() const { return get().data(); }
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};
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#endif  // FUZZER_COMMON_H
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