[asan] flatten the asan-rt build slightly
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@145631 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/asan_internal.h b/lib/asan/asan_internal.h
index 2c64303..16d8e42 100644
--- a/lib/asan/asan_internal.h
+++ b/lib/asan/asan_internal.h
@@ -14,6 +14,10 @@
#ifndef ASAN_INTERNAL_H
#define ASAN_INTERNAL_H
+#if !defined(__linux__) && !defined(__APPLE__)
+# error "This operating system is not supported by AddressSanitizer"
+#endif
+
#include <stdint.h> // for __WORDSIZE
#include <stdlib.h> // for size_t
#include <unistd.h> // for _exit