Avoid using abort_message from test

Author: ldionne

libcxxabi/src/abort_message.h

@@ -14,12 +14,15 @@
 extern "C" _LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN void
 abort_message(const char *format, ...) __attribute__((format(printf, 1, 2)));
 
-#define _LIBCXXABI_ASSERT(expr, msg)                                                                                   \
-  do {                                                                                                                 \
-    if (!(expr)) {                                                                                                     \
-      char const* __msg = (msg);                                                                                       \
-      ::abort_message("%s:%d: %s", __FILE__, __LINE__, __msg);                                                         \
-    }                                                                                                                  \
-  } while (false)
+#ifndef _LIBCXXABI_ASSERT
+#  define _LIBCXXABI_ASSERT(expr, msg)                                                                                 \
+    do {                                                                                                               \
+      if (!(expr)) {                                                                                                   \
+        char const* __msg = (msg);                                                                                     \
+        ::abort_message("%s:%d: %s", __FILE__, __LINE__, __msg);                                                       \
+      }                                                                                                                \
+    } while (false)
 
 #endif
+
+#endif // __ABORT_MESSAGE_H_

libcxxabi/test/test_fallback_malloc.pass.cpp

@@ -27,6 +27,8 @@ typedef std::deque<void *> container;
 
 TEST_DIAGNOSTIC_PUSH
 TEST_CLANG_DIAGNOSTIC_IGNORED("-Wprivate-header")
+#define _LIBCXXABI_ASSERT(expr, msg) assert((expr) && (msg))
+
 // #define  DEBUG_FALLBACK_MALLOC
 #define INSTRUMENT_FALLBACK_MALLOC
 #include "../src/fallback_malloc.cpp"