// C-style interface around internal sanitizer libc functions.
extern "C" {
-// Libc++ calls these hooks from __cxa_guard_acquire. Normally, they should go
-// into google3 fiber scheduler code. But in the canned symbolizer they are
-// both unnecessary and lead to deadlocks as symbolizer calls arbitrary google3
-// code during race reporting.
-void __google_potentially_blocking_region_begin() {}
-void __google_potentially_blocking_region_end() {}
-
#define RETURN_OR_SET_ERRNO(T, res) \
int rverrno; \
if (__sanitizer::internal_iserror(res, &rverrno)) { \