[libfuzzer] adding std:string to allowed adaptable argument.

llvm-svn: 262757

llvm/lib/Fuzzer/FuzzerFnAdapter.h

@@ -92,6 +92,17 @@ size_t UnpackSingle<std::vector<uint8_t>>(const uint8_t *Data, size_t Size,
   return Size - Len - 1;
 }
 
+template <>
+size_t UnpackSingle<std::string>(const uint8_t *Data, size_t Size,
+    std::string *Value) {
+  if (Size < 1)
+    return Size;
+  size_t Len = std::min(static_cast<size_t>(*Data), Size - 1);
+  std::string S(Data + 1, Data + 1 + Len);
+  Value->swap(S);
+  return Size - Len - 1;
+}
+
 // Unpacking into arbitrary tuple.
 
 // Recursion guard.

llvm/lib/Fuzzer/test/FuzzerFnAdapterUnittest.cpp

@@ -70,6 +70,15 @@ TEST(Unpack, Vector) {
   EXPECT_EQ(8, V[1]);
 }
 
+TEST(Unpack, String) {
+  std::tuple<std::string> T;
+  const auto &S = std::get<0>(T);
+
+  EXPECT_TRUE(Unpack(&T, {2, 3}));
+  EXPECT_EQ(1ul, S.size());
+  EXPECT_EQ(3, S[0]);
+}
+
 template <typename Fn>
 bool UnpackAndApply(Fn F, std::initializer_list<uint8_t> Data) {
   std::vector<uint8_t> V(Data);