text: // RUN: %clang_tsan -O1 %s -o %t
  // RUN: not %t 2>&1 | FileCheck %s --check-prefix=CHECK-NOZUPP
  // RUN: TSAN_OPTIONS="suppressions=%s.supp print_suppressions=1" %t 2>&1 | FileCheck %s --check-prefix=CHECK-SUPP
  
  #include <pthread.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <stddef.h>
  #include <unistd.h>
  
  int *mem;
  pthread_mutex_t mtx;
  
  void *Thread1(void *x) {
    pthread_mutex_lock(&mtx);
    free(mem);
    pthread_mutex_unlock(&mtx);
    return NULL;
  }
  
  void *Thread2(void *x) {
    sleep(1);
    pthread_mutex_lock(&mtx);
    mem[0] = 42;
    pthread_mutex_unlock(&mtx);
    return NULL;
  }
  
  int main() {
    mem = (int*)malloc(100);
    pthread_mutex_init(&mtx, 0);
    pthread_t t;
    pthread_create(&t, NULL, Thread1, NULL);
    Thread2(0);
    pthread_join(t, NULL);
    pthread_mutex_destroy(&mtx);
    return 0;
  }
  
  // CHECK-NOZUPP: WARNING: ThreadSanitizer: heap-use-after-free
  // CHECK-NOZUPP:   Write of size 4 at {{.*}} by main thread{{.*}}:
  // CHECK-NOZUPP:     #0 Thread2
  // CHECK-NOZUPP:     #1 main
  // CHECK-NOZUPP:   Previous write of size 8 at {{.*}} by thread T1{{.*}}:
  // CHECK-NOZUPP:     #0 free
  // CHECK-NOZUPP:     #{{(1|2)}} Thread1
  // CHECK-NOZUPP: SUMMARY: ThreadSanitizer: heap-use-after-free{{.*}}Thread2
  // CHECK-SUPP:   ThreadSanitizer: Matched 1 suppressions
  // CHECK-SUPP:    1 race:^Thread2$
  