[libFuzzer] warn if the corpus is empty
llvm-svn: 266670
diff --git a/llvm/lib/Fuzzer/FuzzerDriver.cpp b/llvm/lib/Fuzzer/FuzzerDriver.cpp
index e5cca6e..57532b4 100644
--- a/llvm/lib/Fuzzer/FuzzerDriver.cpp
+++ b/llvm/lib/Fuzzer/FuzzerDriver.cpp
@@ -376,8 +376,11 @@
F.SetMaxLen(
std::min(std::max(kMinDefaultLen, F.MaxUnitSizeInCorpus()), kMaxSaneLen));
- if (F.CorpusSize() == 0)
+ if (F.CorpusSize() == 0) {
F.AddToCorpus(Unit()); // Can't fuzz empty corpus, so add an empty input.
+ if (Options.Verbosity)
+ Printf("INFO: A corpus is not provided, starting from an empty corpus\n");
+ }
F.ShuffleAndMinimize();
if (Flags.drill)
F.Drill();
diff --git a/llvm/lib/Fuzzer/test/fuzzer.test b/llvm/lib/Fuzzer/test/fuzzer.test
index b42a49b..8794e88 100644
--- a/llvm/lib/Fuzzer/test/fuzzer.test
+++ b/llvm/lib/Fuzzer/test/fuzzer.test
@@ -118,3 +118,4 @@
RUN: LLVMFuzzer-SimpleTest -runs=10 --max_len=100 2>&1 | FileCheck %s --check-prefix=DASH_DASH
DASH_DASH: WARNING: did you mean '-max_len=100' (single dash)?
+DASH_DASH: INFO: A corpus is not provided, starting from an empty corpus