Move libFuzzer to compiler_rt.

Resulting library binaries will be named libclang_rt.fuzzer*, and will
be placed in Clang toolchain, allowing redistribution.

Differential Revision: https://reviews.llvm.org/D36908

llvm-svn: 311407
diff --git a/compiler-rt/test/fuzzer/FlagsTest.cpp b/compiler-rt/test/fuzzer/FlagsTest.cpp
new file mode 100644
index 0000000..ac64b9d
--- /dev/null
+++ b/compiler-rt/test/fuzzer/FlagsTest.cpp
@@ -0,0 +1,32 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Parse some flags
+#include <string>
+#include <vector>
+
+static std::vector<std::string> Flags;
+
+extern "C" int LLVMFuzzerInitialize(int *Argc, char ***Argv) {
+  // Parse --flags and anything after -ignore_remaining_args=1 is passed.
+  int I = 1;
+  while (I < *Argc) {
+    std::string S((*Argv)[I++]);
+    if (S == "-ignore_remaining_args=1")
+      break;
+    if (S.substr(0, 2) == "--")
+      Flags.push_back(S);
+  }
+  while (I < *Argc)
+    Flags.push_back(std::string((*Argv)[I++]));
+
+  return 0;
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  fprintf(stderr, "BINGO ");
+  for (auto Flag : Flags)
+    fprintf(stderr, "%s ", Flag.c_str());
+  fprintf(stderr, "\n");
+  exit(0);
+}