[Bug middle-end/33631] [4.1/4.2/4.3 Regression] auto structure not initialized correctly

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2008-02-04 17:04 -------
The warning persists for me on the trunk, and the initialization is not done:

main (c, v)
{
  int D.2713;
  int D.2714;
  int j[3];
  typedef struct
  {
    int c;
    int * j;
    union pthread_mutex_t m;
  } struct struct 
  { 
    int c;
    int * j;
    union pthread_mutex_t m;
  };
  struct
  {
    int c;
    int * j;
    union pthread_mutex_t m;
  } r;

  r.j = &j;
  r.m.__data.__lock = 0;
  r.m.__data.__count = 0;
  r.m.__data.__owner = 0;
  r.m.__data.__nusers = 0;
  r.m.__data.__kind = 0;
  r.m.__data.__spins = 0;
  r.m.__data.__list.__prev = 0B;
  r.m.__data.__list.__next = 0B;
  D.2713 = r.c;
  printf (&"current should be zero but is %d\n"[0], D.2713);
  D.2714 = 0;
  return D.2714;
}

This worked in 4.0.3 and 4.1.1 which generated

  r = {};
  r.j = &j;
  D.1158 = r.c;

So, this is likely a middle-end/gimplification issue (again).


"Reduced" testcase:

typedef struct __pthread_internal_list
{
  void *__prev;
  void *__next;
} __pthread_list_t;
typedef union
{
  struct __pthread_mutex_s
  {
    int __lock;
    unsigned int __count;
    int __owner;
    unsigned int __nusers;
    int __kind;
    int __spins;
    __pthread_list_t __list;
  } __data;
  char __size[40];
  long int __align;
} pthread_mutex_t;

extern int printf (__const char *__restrict __format, ...);

int main(int c, char **v)
{
    int j[3];
    struct { int c, *j; pthread_mutex_t m; } r = {
       .j = j, .m = { { 0, 0, 0, 0, 0, 0, { 0, 0 } } },
    };
    printf("current should be zero but is %d\n", r.c);
    return 0;
}


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|c                           |middle-end
     Ever Confirmed|0                           |1
      Known to fail|                            |4.0.4 4.1.2 4.2.0 4.2.3
                   |                            |4.3.0
      Known to work|                            |4.0.3 4.1.1
   Last reconfirmed|0000-00-00 00:00:00         |2008-02-04 17:04:08
               date|                            |
            Summary|auto structure not          |[4.1/4.2/4.3 Regression]
                   |initialized correctly       |auto structure not
                   |                            |initialized correctly
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33631