[libFuzzer] add a test for libFuzzer+ubsan, extend the docs on using libFuzzer+ubsan

llvm-svn: 268968

4 files changed, 56 insertions, 0 deletions

diff --git a/llvm/lib/Fuzzer/test/CMakeLists.txt b/llvm/lib/Fuzzer/test/CMakeLists.txt
index 81a996930f4..52ed2f5bbb3 100644
--- a/llvm/lib/Fuzzer/test/CMakeLists.txt
+++ b/llvm/lib/Fuzzer/test/CMakeLists.txt
@@ -57,6 +57,10 @@ set(TracePCTests
   FullCoverageSetTest
   )
 
+set(UbsanTests
+  SignedIntOverflowTest
+  )
+
 set(TestBinaries)
 
 foreach(Test ${Tests})
@@ -118,6 +122,12 @@ foreach(Test ${UninstrumentedTests})
   set(TestBinaries ${TestBinaries} LLVMFuzzer-${Test}-Uninstrumented)
 endforeach()
 
+add_subdirectory(ubsan)
+
+foreach(Test ${UbsanTests})
+  set(TestBinaries ${TestBinaries} LLVMFuzzer-${Test}-Ubsan)
+endforeach()
+
 add_subdirectory(trace-bb)
 
 foreach(Test ${TraceBBTests})
diff --git a/llvm/lib/Fuzzer/test/SignedIntOverflowTest.cpp b/llvm/lib/Fuzzer/test/SignedIntOverflowTest.cpp
new file mode 100644
index 00000000000..7df32ad5793
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/SignedIntOverflowTest.cpp
@@ -0,0 +1,28 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Test for signed-integer-overflow.
+#include <assert.h>
+#include <cstdint>
+#include <cstdlib>
+#include <cstddef>
+#include <iostream>
+#include <climits>
+
+static volatile int Sink;
+static int Large = INT_MAX;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  assert(Data);
+  if (Size > 0 && Data[0] == 'H') {
+    Sink = 1;
+    if (Size > 1 && Data[1] == 'i') {
+      Sink = 2;
+      if (Size > 2 && Data[2] == '!') {
+        Large++;  // int overflow.
+      }
+    }
+  }
+  return 0;
+}
+
diff --git a/llvm/lib/Fuzzer/test/fuzzer-ubsan.test b/llvm/lib/Fuzzer/test/fuzzer-ubsan.test
new file mode 100644
index 00000000000..0e8ad6c94a1
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/fuzzer-ubsan.test
@@ -0,0 +1,4 @@
+RUN: not LLVMFuzzer-SignedIntOverflowTest-Ubsan 2>&1 | FileCheck %s
+CHECK: runtime error: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
+CHECK: Test unit written to ./crash-
+
diff --git a/llvm/lib/Fuzzer/test/ubsan/CMakeLists.txt b/llvm/lib/Fuzzer/test/ubsan/CMakeLists.txt
new file mode 100644
index 00000000000..5547704525e
--- /dev/null
+++ b/llvm/lib/Fuzzer/test/ubsan/CMakeLists.txt
@@ -0,0 +1,14 @@
+# These tests are instrumented with ubsan in non-recovery mode.
+
+set(CMAKE_CXX_FLAGS_RELEASE
+  "${LIBFUZZER_FLAGS_BASE} -O0 -fsanitize=undefined -fno-sanitize-recover=all")
+
+foreach(Test ${UbsanTests})
+  add_executable(LLVMFuzzer-${Test}-Ubsan
+    ../${Test}.cpp
+    )
+  target_link_libraries(LLVMFuzzer-${Test}-Ubsan
+    LLVMFuzzer
+    )
+endforeach()
+