lib/Fuzzer/FuzzerInterface.h

   1 //===- FuzzerInterface.h - Interface header for the Fuzzer ------*- C++ -* ===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 // Define the interface between libFuzzer and the library being tested.
  10 //===----------------------------------------------------------------------===//
  11
  12 // NOTE: the libFuzzer interface is thin and in the majority of cases
  13 // you should not include this file into your target. In 95% of cases
  14 // all you need is to define the following function in your file:
  15 // extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
  16
  17 // WARNING: keep the interface in C.
  18
  19 #ifndef LLVM_FUZZER_INTERFACE_H
  20 #define LLVM_FUZZER_INTERFACE_H
  21
  22 #include <stddef.h>
  23 #include <stdint.h>
  24
  25 #ifdef __cplusplus
  26 extern "C" {
  27 #endif  // __cplusplus
  28
  29 // Mandatory user-provided target function.
  30 // Executes the code under test with [Data, Data+Size) as the input.
  31 // libFuzzer will invoke this function *many* times with different inputs.
  32 // Must return 0.
  33 int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
  34
  35 // Optional user-provided initialization function.
  36 // If provided, this function will be called by libFuzzer once at startup.
  37 // It may read and modify argc/argv.
  38 // Must return 0.
  39 int LLVMFuzzerInitialize(int *argc, char ***argv);
  40
  41 // Optional user-provided custom mutator.
  42 // Mutates raw data in [Data, Data+Size) inplace.
  43 // Returns the new size, which is not greater than MaxSize.
  44 // Given the same Seed produces the same mutation.
  45 size_t LLVMFuzzerCustomMutator(uint8_t *Data, size_t Size, size_t MaxSize,
  46                                unsigned int Seed);
  47
  48 // Optional user-provided custom cross-over function.
  49 // Combines pieces of Data1 & Data2 together into Out.
  50 // Returns the new size, which is not greater than MaxOutSize.
  51 // Should produce the same mutation given the same Seed.
  52 size_t LLVMFuzzerCustomCrossOver(const uint8_t *Data1, size_t Size1,
  53                                  const uint8_t *Data2, size_t Size2,
  54                                  uint8_t *Out, size_t MaxOutSize,
  55                                  unsigned int Seed);
  56
  57 // Experimental, may go away in future.
  58 // libFuzzer-provided function to be used inside LLVMFuzzerCustomMutator.
  59 // Mutates raw data in [Data, Data+Size) inplace.
  60 // Returns the new size, which is not greater than MaxSize.
  61 size_t LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize);
  62
  63 #ifdef __cplusplus
  64 }  // extern "C"
  65 #endif  // __cplusplus
  66
  67 #endif  // LLVM_FUZZER_INTERFACE_H