[libFuzzer] better document the -merge=1 flag, part 2

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268958 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/LibFuzzer.rst b/docs/LibFuzzer.rst
index d7947eba6adfbf547ec65c1b6a9866c1307de8cc..e2f6d943b0dae18661718d01078d5a9d7a51dad7 100644 (file)
--- a/docs/LibFuzzer.rst
+++ b/docs/LibFuzzer.rst
@@ -81,6 +81,13 @@ is to use the `-merge=1` flag:
   mkdir NEW_CORPUS_DIR  # Store minimized corpus here.
   ./my-fuzzer -merge=1 NEW_CORPUS_DIR FULL_CORPUS_DIR
 
+You may use the same flag to add more interesting items to an existing corpus.
+Only the inputs that trigger new coverage will be added to the first corpus.
+
+.. code-block:: console
+
+  ./my-fuzzer -merge=1 CURRNT_CORPUS_DIR NEW_POTENTIALLY_INTERESTING_INPUTS_DIR
+
 Getting Started
 ===============