[Bug tree-optimization/102238] alias_offset in gimple-ssa-sprintf.c is broken

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102238

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |---

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Martin Sebor from comment #2)
> The source and the destination arrays in the test case do not overlap so
> there is no warning.  The preprocessed output makes it easier to see than
> the original (the destination of the call is the a member of the object
> pointed to by the function argument s3 and the %s argument the local array
> 'a'):

Silly mistake on my part, it is still buggy:

/* 
   { dg-do compile }
   { dg-options "-O2 -Wno-format-overflow -Wrestrict -ftrack-macro-expansion=0"
}
*/
void sink (int);
#define S10 "0123456789"
extern char a2[2][22];
#define T(d, ...) do {                                  \
    char a[tttttttt22] = S10;                           \
    sink (__builtin_sprintf ((d), __VA_ARGS__));        \
  } while (0)
struct S {
  char a[4];
  char b[4];
};
struct S2 {
  struct S s_1;
  struct S s_2;
  struct S sa3[3];
};
struct S3 {
  struct S2 s2_1;
  struct S2 s2_2;

  struct {
    struct {
      struct {
        struct S sa_3[3];
      } a_1[3];
    } a_2[3][3];
  } a_3[3][3][3];

  char fa[];
};
void test_struct_member_array (struct S3 *s3, int i)
{
  char *a1 = (char*)s3;
  char *d;
  const char *s;
  d = s3->s2_2.s_1.a;
  s = s3->s2_2.s_1.a;
  T (d, "%s", a1 + 40);   /* { dg-warning "overlaps" } */
  T (d, "%s", a1 + 41);   /* { dg-warning "may overlap" } */
  T (d, "%s", a1 + 42);   /* { dg-warning "may overlap" } */
}