1 // RUN: %clangxx_tsan -c -O1 -fno-sanitize=thread %s -o %t.o
2 // RUN: %clangxx_tsan -O1 %s %t.o -o %t && %run %t 2>&1 | FileCheck %s
3 
4 #include <stdio.h>
5 #include <stdlib.h>
6 
7 #if !__has_feature(thread_sanitizer)
8 
9 // Defined by tsan.
10 extern "C" void *__interceptor_malloc(unsigned long size);
11 extern "C" void __interceptor_free(void *p);
12 extern "C" void *malloc(unsigned long size) {
13   static int first = 0;
14   if (__sync_lock_test_and_set(&first, 1) == 0)
15     fprintf(stderr, "user malloc\n");
16   return __interceptor_malloc(size);
17 }
18 
19 extern "C" void free(void *p) {
20   __interceptor_free(p);
21 }
22 
23 #else
24 
25 int main() {
26   volatile char *p = (char*)malloc(10);
27   p[0] = 0;
28   free((void*)p);
29 }
30 
31 #endif
32 
33 // CHECK: user malloc
34 // CHECK-NOT: ThreadSanitizer
35 
36