+#if HAVE_SANITIZE_ADDRESS_FIBER_SUPPORT
+#include <sanitizer/asan_interface.h>
+#define ASAN_EVAL(expr) (expr)
+#define ASAN_START_SWITCH(fake_stack_save, bottom, size) __sanitizer_start_switch_fiber(fake_stack_save, bottom, size)
+#define ASAN_FINISH_SWITCH(fake_stack_save, bottom_old, size_old) \
+ __sanitizer_finish_switch_fiber(fake_stack_save, bottom_old, size_old)
+#else
+#define ASAN_EVAL(expr) (void)0
+#define ASAN_START_SWITCH(fake_stack_save, bottom, size) (void)0
+#define ASAN_FINISH_SWITCH(fake_stack_save, bottom_old, size_old) (void)(fake_stack_save)
+#endif
+