[libFuzzer] allow users to supply their own implementation of rand

llvm-svn: 243078

1 files changed, 18 insertions, 2 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerInterface.cpp b/llvm/lib/Fuzzer/FuzzerInterface.cpp
index dcd4e746013..c7553f421fb 100644
--- a/llvm/lib/Fuzzer/FuzzerInterface.cpp
+++ b/llvm/lib/Fuzzer/FuzzerInterface.cpp
@@ -14,14 +14,30 @@
 #include "FuzzerInternal.h"
 
 namespace fuzzer {
+
+void FuzzerRandomLibc::ResetSeed(int seed) { srand(seed); }
+
+size_t FuzzerRandomLibc::Rand() { return rand(); }
+
+UserSuppliedFuzzer::UserSuppliedFuzzer()
+    : OwnRand(true), Rand(new FuzzerRandomLibc(0)) {}
+
+UserSuppliedFuzzer::UserSuppliedFuzzer(FuzzerRandomBase *Rand) : Rand(Rand) {}
+
+UserSuppliedFuzzer::~UserSuppliedFuzzer() {
+  if (OwnRand)
+    delete Rand;
+}
+
 size_t UserSuppliedFuzzer::BasicMutate(uint8_t *Data, size_t Size,
                                        size_t MaxSize) {
-  return ::fuzzer::Mutate(Data, Size, MaxSize);
+  return ::fuzzer::Mutate(Data, Size, MaxSize, *Rand);
 }
 size_t UserSuppliedFuzzer::BasicCrossOver(const uint8_t *Data1, size_t Size1,
                                           const uint8_t *Data2, size_t Size2,
                                           uint8_t *Out, size_t MaxOutSize) {
-  return ::fuzzer::CrossOver(Data1, Size1, Data2, Size2, Out, MaxOutSize);
+  return ::fuzzer::CrossOver(Data1, Size1, Data2, Size2, Out, MaxOutSize,
+                             *Rand);
 }
 
 }  // namespace fuzzer.