1 files changed, 11 insertions, 36 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerInternal.h b/llvm/lib/Fuzzer/FuzzerInternal.h
index f57e24f739f..c966b267786 100644
--- a/llvm/lib/Fuzzer/FuzzerInternal.h
+++ b/llvm/lib/Fuzzer/FuzzerInternal.h
@@ -98,41 +98,16 @@ bool IsASCII(const Unit &U);
 int NumberOfCpuCores();
 int GetPid();
 
-class FuzzerRandomBase {
+class Random {
  public:
-  FuzzerRandomBase(){}
-  virtual ~FuzzerRandomBase(){};
-  virtual void ResetSeed(unsigned int seed) = 0;
-  // Return a random number.
-  virtual size_t Rand() = 0;
-  // Return a random number in range [0,n).
+  Random(unsigned int seed) : R(seed) {}
+  size_t Rand() { return R(); }
+  size_t RandBool() { return Rand() % 2; }
   size_t operator()(size_t n) { return n ? Rand() % n : 0; }
-  bool RandBool() { return Rand() % 2; }
-};
-
-// Using libc's stand/rand.
-class FuzzerRandomLibc : public FuzzerRandomBase {
- public:
-  FuzzerRandomLibc(unsigned int seed) { ResetSeed(seed); }
-  void ResetSeed(unsigned int seed) override;
-  ~FuzzerRandomLibc() override {};
-  size_t Rand() override;
-};
-
-// Using std::mt19937
-class FuzzerRandom_mt19937 : public FuzzerRandomBase {
- public:
-  FuzzerRandom_mt19937(unsigned int seed) { ResetSeed(seed); }
-  void ResetSeed(unsigned int seed) override;
-  ~FuzzerRandom_mt19937() override;
-  size_t Rand() override;
  private:
-  struct Impl;
-  Impl *R = nullptr;
+  std::mt19937 R;
 };
 
-
-
 // Dictionary.
 
 // Parses one dictionary entry.
@@ -145,7 +120,7 @@ bool ParseDictionaryFile(const std::string &Text, std::vector<Unit> *Units);
 
 class MutationDispatcher {
 public:
-  MutationDispatcher(FuzzerRandomBase &Rand);
+  MutationDispatcher(Random &Rand);
   ~MutationDispatcher();
   /// Indicate that we are about to start a new sequence of mutations.
   void StartMutationSequence();
@@ -199,14 +174,14 @@ public:
   void SetCorpus(const std::vector<Unit> *Corpus);
 
 private:
-  FuzzerRandomBase &Rand;
+  Random &Rand;
   struct Impl;
   Impl *MDImpl;
 };
 
 class UserSuppliedFuzzer {
  public:
-  UserSuppliedFuzzer(FuzzerRandomBase *Rand);
+  UserSuppliedFuzzer(Random *Rand);
   /// Executes the target function on 'Size' bytes of 'Data'.
   virtual int TargetFunction(const uint8_t *Data, size_t Size) = 0;
   /// Mutates 'Size' bytes of data in 'Data' inplace into up to 'MaxSize' bytes,
@@ -219,13 +194,13 @@ class UserSuppliedFuzzer {
                            uint8_t *Out, size_t MaxOutSize);
   virtual ~UserSuppliedFuzzer();
 
-  FuzzerRandomBase &GetRand() { return *Rand; }
+  Random &GetRand() { return *Rand; }
 
   MutationDispatcher &GetMD() { return *MD; }
 
  private:
   bool OwnRand = false;
-  FuzzerRandomBase *Rand;
+  Random *Rand;
   MutationDispatcher *MD;
 };
 
@@ -370,7 +345,7 @@ private:
 
 class SimpleUserSuppliedFuzzer : public UserSuppliedFuzzer {
 public:
-  SimpleUserSuppliedFuzzer(FuzzerRandomBase *Rand, UserCallback Callback)
+  SimpleUserSuppliedFuzzer(Random *Rand, UserCallback Callback)
       : UserSuppliedFuzzer(Rand), Callback(Callback) {}
 
   virtual int TargetFunction(const uint8_t *Data, size_t Size) override {