| 
  
     ‘test’: events 1-3 
|     7 |     void *ptr = malloc(512); |  
 |                 ^~~~~~~~~~~ |  
 |                 | |  
 |                 (1) allocated here |  
|     8 |     free(ptr); |  
 |     ~~~~~~~~~     |  
 |     | |  
 |     (2) first ‘free’ here |  
|     9 |     free(ptr); /* { dg-warning "double-'free'" "" { xfail *-*-* } } */ |  
 |     ~~~~~~~~~     |  
 |     | |  
 |     (3) second ‘free’ here; first ‘free’ was at (2) |  
 
 |