[libFuzzer] Make -fsanitize=memory,fuzzer work.

This patch allows libFuzzer to fuzz applications instrumented with MSan
without recompiling libFuzzer with MSan instrumentation.

Fixes https://github.com/google/sanitizers/issues/958.

Differential Revision: https://reviews.llvm.org/D48891

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@336619 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 27 insertions, 0 deletions

diff --git a/test/fuzzer/UseAfterDtor.cpp b/test/fuzzer/UseAfterDtor.cpp
new file mode 100644
index 000000000..dcefca5cc
--- /dev/null
+++ b/test/fuzzer/UseAfterDtor.cpp
@@ -0,0 +1,27 @@
+#include <cstdint>
+#include <cstdio>
+
+struct Simple {
+  int x_;
+  Simple() {
+    x_ = 5;
+  }
+  ~Simple() {
+    x_ += 1;
+  }
+};
+
+Simple *volatile SimpleSink;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  if (Size < 4) return 0;
+  if (Data[0] == 'F' && Data[1] == 'U' && Data[2] == 'Z' && Data[3] == 'Z') {
+    {
+      Simple S;
+      SimpleSink = &S;
+    }
+    if (SimpleSink->x_) fprintf(stderr, "Failed to catch use-after-dtor\n");
+  }
+  return 0;
+}
+