[libFuzzer] add an experimental flag -experimental_len_control=1 that sets max_len to 1M and tries to increases the actual max sizes of mutations very gradually. Also remove a bit of dead code

llvm-svn: 289998

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Fuzzer/FuzzerDriver.cpp b/llvm/lib/Fuzzer/FuzzerDriver.cpp
index 8a8c12fd6cb..30cdb8063bb 100644
--- a/llvm/lib/Fuzzer/FuzzerDriver.cpp
+++ b/llvm/lib/Fuzzer/FuzzerDriver.cpp
@@ -390,6 +390,9 @@ int FuzzerDriver(int *argc, char ***argv, UserCallback Callback) {
   FuzzingOptions Options;
   Options.Verbosity = Flags.verbosity;
   Options.MaxLen = Flags.max_len;
+  Options.ExperimentalLenControl = Flags.experimental_len_control;
+  if (Flags.experimental_len_control && Flags.max_len == 64)
+    Options.MaxLen = 1 << 20;
   Options.UnitTimeoutSec = Flags.timeout;
   Options.ErrorExitCode = Flags.error_exitcode;
   Options.TimeoutExitCode = Flags.timeout_exitcode;