[libFuzzer] use raw C IO to reduce the risk of a deadlock in a signal handler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244707 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Fuzzer/FuzzerIO.cpp b/lib/Fuzzer/FuzzerIO.cpp
index 1d25389770fa27f38735fad7894d2189e494fa72..f0295e9a730875aa545c50fb361bf6879631d554 100644 (file)
--- a/lib/Fuzzer/FuzzerIO.cpp
+++ b/lib/Fuzzer/FuzzerIO.cpp
@@ -66,8 +66,11 @@ void CopyFileToErr(const std::string &Path) {
 }
 
 void WriteToFile(const Unit &U, const std::string &Path) {
-  std::ofstream OF(Path);
-  OF.write((const char*)U.data(), U.size());
+  // Use raw C interface because this function may be called from a sig handler.
+  FILE *Out = fopen(Path.c_str(), "w");
+  if (!Out) return;
+  fwrite(U.data(), sizeof(U[0]), U.size(), Out);
+  fclose(Out);
 }
 
 void ReadDirToVectorOfUnits(const char *Path, std::vector<Unit> *V,