[libFuzzer] add one more OOM test, which we currently don't handle very well

llvm-svn: 272240

lib/Fuzzer/test/CMakeLists.txt

@@ -78,6 +78,7 @@ set(Tests
   NullDerefTest
   NullDerefOnEmptyTest
   NthRunCrashTest
+  OneHugeAllocTest
   OutOfMemoryTest
   RepeatedMemcmp
   SimpleCmpTest

lib/Fuzzer/test/OneHugeAllocTest.cpp

@@ -0,0 +1,29 @@
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+
+// Tests OOM handling when there is a single large allocation.
+#include <assert.h>
+#include <cstdint>
+#include <cstdlib>
+#include <cstddef>
+#include <cstring>
+#include <iostream>
+#include <unistd.h>
+
+static volatile char *SinkPtr;
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
+  if (Size > 0 && Data[0] == 'H') {
+    if (Size > 1 && Data[1] == 'i') {
+      if (Size > 2 && Data[2] == '!') {
+        size_t kSize = (size_t)1 << 31;
+        char *p = new char[kSize];
+        memset(p, 0, kSize);
+        SinkPtr = p;
+        delete [] p;
+      }
+    }
+  }
+  return 0;
+}
+