Index: lib/asan/asan_flags.inc
===================================================================
--- lib/asan/asan_flags.inc
+++ lib/asan/asan_flags.inc
@@ -78,7 +78,7 @@
 ASAN_FLAG(bool, unmap_shadow_on_exit, false,
           "If set, explicitly unmaps the (huge) shadow at exit.")
 ASAN_FLAG(
-    bool, abort_on_error, false,
+    bool, abort_on_error, (SANITIZER_MAC == 1),
     "If set, the tool calls abort() instead of _exit() after printing the "
     "error report.")
 ASAN_FLAG(bool, print_stats, false,
Index: lib/asan/tests/asan_test_main.cc
===================================================================
--- lib/asan/tests/asan_test_main.cc
+++ lib/asan/tests/asan_test_main.cc
@@ -15,7 +15,7 @@
 // Default ASAN_OPTIONS for the unit tests. Let's turn symbolication off to
 // speed up testing (unit tests don't use it anyway).
 extern "C" const char* __asan_default_options() {
-  return "symbolize=false";
+  return "symbolize=false:abort_on_error=0";
 }
 
 int main(int argc, char **argv) {
Index: test/asan/TestCases/Darwin/abort_on_error-darwin.cc
===================================================================
--- test/asan/TestCases/Darwin/abort_on_error-darwin.cc
+++ test/asan/TestCases/Darwin/abort_on_error-darwin.cc
@@ -0,0 +1,16 @@
+// Check that with empty ASAN_OPTIONS, ASan reports on OS X actually crash
+// the process (abort_on_error=1). See also Linux/abort_on_error-linux.cc.
+
+// RUN: %clangxx_asan %s -o %t
+
+// Intentionally don't inherit the default ASAN_OPTIONS.
+// RUN: ASAN_OPTIONS="" not --crash %run %t 2>&1 | FileCheck %s
+
+#include <stdlib.h>
+int main() {
+  char *x = (char*)malloc(10 * sizeof(char));
+  free(x);
+  return x[5];
+  // CHECK: {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+  // CHECK:   {{0x.* at pc 0x.* bp 0x.* sp 0x.*}}
+}
Index: test/asan/TestCases/Linux/abort_on_error-linux.cc
===================================================================
--- test/asan/TestCases/Linux/abort_on_error-linux.cc
+++ test/asan/TestCases/Linux/abort_on_error-linux.cc
@@ -0,0 +1,16 @@
+// Check that with empty ASAN_OPTIONS, ASan reports on Linux don't crash
+// the process (abort_on_error=0). See also Darwin/abort_on_error-darwin.cc.
+
+// RUN: %clangxx_asan %s -o %t
+
+// Intentionally don't inherit the default ASAN_OPTIONS.
+// RUN: ASAN_OPTIONS="" not run %t 2>&1 | FileCheck %s
+
+#include <stdlib.h>
+int main() {
+  char *x = (char*)malloc(10 * sizeof(char));
+  free(x);
+  return x[5];
+  // CHECK: {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+  // CHECK:   {{0x.* at pc 0x.* bp 0x.* sp 0x.*}}
+}
Index: test/asan/lit.cfg
===================================================================
--- test/asan/lit.cfg
+++ test/asan/lit.cfg
@@ -30,7 +30,7 @@
 config.name = 'AddressSanitizer' + config.name_suffix
 
 # Setup default ASAN_OPTIONS
-config.environment['ASAN_OPTIONS'] = 'symbolize_vs_style=false'
+config.environment['ASAN_OPTIONS'] = 'symbolize_vs_style=false:abort_on_error=0'
 
 # testFormat: The test format to use to interpret tests.
 external_bash = (not sys.platform in ['win32'])