[libFuzzer] suggest a dictionary to the user of some of the trace-based dictionary entries were successful

llvm-svn: 257736

6 files changed, 30 insertions, 3 deletions

diff --git a/llvm/lib/Fuzzer/test/CMakeLists.txt b/llvm/lib/Fuzzer/test/CMakeLists.txt
index 2d526bdaa0b..91a61f43375 100644
--- a/llvm/lib/Fuzzer/test/CMakeLists.txt
+++ b/llvm/lib/Fuzzer/test/CMakeLists.txt
@@ -20,6 +20,7 @@ set(Tests
   FullCoverageSetTest
   MemcmpTest
   NullDerefTest
+  RepeatedMemcmp
   SimpleCmpTest
   SimpleDictionaryTest
   SimpleHashTest
diff --git a/llvm/lib/Fuzzer/test/FuzzerUnittest.cpp b/llvm/lib/Fuzzer/test/FuzzerUnittest.cpp
index b33e0c96145..b09f232bd0d 100644
--- a/llvm/lib/Fuzzer/test/FuzzerUnittest.cpp
+++ b/llvm/lib/Fuzzer/test/FuzzerUnittest.cpp
@@ -302,7 +302,7 @@ void TestAddWordFromDictionaryWithHint(Mutator M, int NumIter) {
 
 TEST(FuzzerMutate, AddWordFromDictionaryWithHint1) {
   TestAddWordFromDictionaryWithHint(
-      &MutationDispatcher::Mutate_AddWordFromAutoDictionary, 1 << 5);
+      &MutationDispatcher::Mutate_AddWordFromTemporaryAutoDictionary, 1 << 5);
 }
 
 TEST(FuzzerMutate, AddWordFromDictionaryWithHint2) {
diff --git a/llvm/lib/Fuzzer/test/MemcmpTest.cpp b/llvm/lib/Fuzzer/test/MemcmpTest.cpp
index c19c95717bb..c72f2c2cb51 100644
--- a/llvm/lib/Fuzzer/test/MemcmpTest.cpp
+++ b/llvm/lib/Fuzzer/test/MemcmpTest.cpp
@@ -9,7 +9,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
   if (Size >= 8 && memcmp(Data, "01234567", 8) == 0) {
     if (Size >= 12 && memcmp(Data + 8, "ABCD", 4) == 0) {
       if (Size >= 14 && memcmp(Data + 12, "XY", 2) == 0) {
-        if (Size >= 16 && memcmp(Data + 14, "KLM", 3) == 0) {
+        if (Size >= 17 && memcmp(Data + 14, "KLM", 3) == 0) {
           if (Size >= 27 && memcmp(Data + 17, "ABCDE-GHIJ", 10) == 0){
             fprintf(stderr, "BINGO %zd\n", Size);
             for (size_t i = 0; i < Size; i++) {
diff --git a/llvm/lib/Fuzzer/test/RepeatedMemcmp.cpp b/llvm/lib/Fuzzer/test/RepeatedMemcmp.cpp
new file mode 100644
index 00000000000..cb5e130003b
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/RepeatedMemcmp.cpp
@@ -0,0 +1,19 @@
+
+#include <cstring>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  int Matches = 0;
+  for (size_t i = 0; i + 2 < Size; i += 3) {
+    const char *Pat = i % 2 ? "foo" : "bar";
+    if (!memcmp(Data + i, Pat, 3))
+      Matches++;
+  }
+  if (Matches > 20) {
+    fprintf(stderr, "BINGO!\n");
+    exit(1);
+  }
+  return 0;
+}
diff --git a/llvm/lib/Fuzzer/test/fuzzer-dfsan.test b/llvm/lib/Fuzzer/test/fuzzer-dfsan.test
index 567086ed65a..b7c887b8b92 100644
--- a/llvm/lib/Fuzzer/test/fuzzer-dfsan.test
+++ b/llvm/lib/Fuzzer/test/fuzzer-dfsan.test
@@ -10,7 +10,7 @@ CHECK_DFSanMemcmpCallback: DFSanMemcmpCallback: Pos
 RUN: not LLVMFuzzer-SimpleCmpTest-DFSan -use_traces=1 -seed=1 -runs=1000000 -timeout=5 2>&1 | FileCheck %s --check-prefix=CHECK1
 RUN: LLVMFuzzer-SimpleCmpTest-DFSan -use_traces=1 -seed=1 -runs=100 -timeout=5 -verbosity=3 2>&1 | FileCheck %s  -check-prefix=CHECK_DFSanCmpCallback
 
-RUN: not LLVMFuzzer-MemcmpTest-DFSan -use_traces=1 -seed=1 -runs=10000 -timeout=5 2>&1 | FileCheck %s --check-prefix=CHECK2
+RUN: not LLVMFuzzer-MemcmpTest-DFSan -use_traces=1 -seed=1 -runs=100000 -timeout=5 2>&1 | FileCheck %s --check-prefix=CHECK2
 RUN: LLVMFuzzer-MemcmpTest-DFSan -use_traces=1 -seed=1 -runs=2 -timeout=5 -verbosity=3 2>&1 | FileCheck %s  -check-prefix=CHECK_DFSanMemcmpCallback
 
 RUN: not LLVMFuzzer-StrncmpTest-DFSan -use_traces=1 -seed=1 -runs=10000 -timeout=5 2>&1 | FileCheck %s --check-prefix=CHECK3
diff --git a/llvm/lib/Fuzzer/test/fuzzer-traces.test b/llvm/lib/Fuzzer/test/fuzzer-traces.test
index 3b8639b8e94..12d4e9b5e45 100644
--- a/llvm/lib/Fuzzer/test/fuzzer-traces.test
+++ b/llvm/lib/Fuzzer/test/fuzzer-traces.test
@@ -18,3 +18,10 @@ RUN:     LLVMFuzzer-SwitchTest               -seed=1 -runs=1000000  2>&1 | FileC
 
 RUN: not LLVMFuzzer-SimpleHashTest -use_traces=1 -seed=1 -runs=10000000  2>&1 | FileCheck %s
 RUN:     LLVMFuzzer-SimpleHashTest               -seed=1 -runs=10000000 2>&1 | FileCheck %s --check-prefix=Done10000000
+
+RUN: LLVMFuzzer-RepeatedMemcmp -use_traces=1 -seed=1 -runs=100000 2>&1 | FileCheck %s --check-prefix=RECOMMENDED_DICT
+RECOMMENDED_DICT:###### Recommended dictionary. ######
+RECOMMENDED_DICT-DAG: "foo"
+RECOMMENDED_DICT-DAG: "bar"
+RECOMMENDED_DICT:###### End of recommended dictionary. ######
+