tsan: enable clone interceptor only on Linux

[dvyukov]

Summary

Clone does not exist on Mac.
There are chances it will break on other OSes.
Enable it incrementally starting with Linux only,
other OSes can enable it later as needed.

[dvyukov]

fix include path in the test

[thakis]

lg

compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

TSAN_INTERCEPTOR(int, vfork, int fake) {
   // We could disable interceptors in the child process. But it's not possible
   // to simply intercept and wrap vfork, because vfork child is not allowed
   // to return from the function that calls vfork, and that's exactly what
   // we would do. So this would require some assembly trickery as well.
   // Instead we simply turn vfork into fork.
   return WRAP(fork)(fake);
 }
 
+#if SANITIZER_LINUX
 TSAN_INTERCEPTOR(int, clone, int (*fn)(void *), void *stack, int flags,
                  void *arg, int *parent_tid, void *tls, pid_t *child_tid) {
   SCOPED_INTERCEPTOR_RAW(clone, fn, stack, flags, arg, parent_tid, tls,
                          child_tid);
   struct Arg {
     int (*fn)(void *);
     void *arg;
   };
   auto wrapper = +[](void *p) -> int {
     auto *thr = cur_thread();
     uptr pc = GET_CURRENT_PC();
     ForkChildAfter(thr, pc);
     FdOnFork(thr, pc);
     auto *arg = static_cast<Arg *>(p);
     return arg->fn(arg->arg);
   };
   ForkBefore(thr, pc);
   Arg arg_wrapper = {fn, arg};
   int pid = REAL(clone)(wrapper, stack, flags, &arg_wrapper, parent_tid, tls,
                         child_tid);
   ForkParentAfter(thr, pc);
   return pid;
 }
+#endif
 
 #if !SANITIZER_MAC && !SANITIZER_ANDROID
 typedef int (*dl_iterate_phdr_cb_t)(__sanitizer_dl_phdr_info *info, SIZE_T size,
                                     void *data);
 struct dl_iterate_phdr_data {
   ThreadState *thr;
   uptr pc;
   dl_iterate_phdr_cb_t cb;
#endif
   TSAN_INTERCEPT(usleep);
   TSAN_INTERCEPT(nanosleep);
   TSAN_INTERCEPT(pause);
   TSAN_INTERCEPT(gettimeofday);
   TSAN_INTERCEPT(getaddrinfo);
 
   TSAN_INTERCEPT(fork);
   TSAN_INTERCEPT(vfork);
+#if SANITIZER_LINUX
   TSAN_INTERCEPT(clone);
+#endif
 #if !SANITIZER_ANDROID
   TSAN_INTERCEPT(dl_iterate_phdr);
 #endif
   TSAN_MAYBE_INTERCEPT_ON_EXIT;
   TSAN_INTERCEPT(__cxa_atexit);
   TSAN_INTERCEPT(_exit);
 
 #ifdef NEED_TLS_GET_ADDR

compiler-rt/test/tsan/Linux/clone_deadlock.cpp

 // RUN: %clangxx_tsan -O1 %s -o %t && %env_tsan_opts=atexit_sleep_ms=0 %run %t 2>&1 | FileCheck %s
-#include "test.h"
+#include "../test.h"
 #include <errno.h>
 #include <sched.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
 long counter;
 
 static void *incrementer(void *arg) {