[Bug tree-optimization/61410] [4.7 Regression] strcat overwrites destination string when compiling with optimizations

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61410

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
      Known to work|                            |4.6.4, 4.8.1
           Keywords|                            |wrong-code
   Last reconfirmed|                            |2014-06-04
     Ever confirmed|0                           |1
            Summary|strcat overwrites           |[4.7 Regression] strcat
                   |destination string when     |overwrites destination
                   |compiling with              |string when compiling with
                   |optimizations               |optimizations
   Target Milestone|---                         |4.7.4
      Known to fail|                            |4.7.0, 4.7.3, 4.8.0

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed anyway, this was fixed between 4.8.0 and 4.8.1.  Bug in strlen pass:

Optimizing: D.2544_1 = __builtin_strlen (&str);
into: D.2544_1 = 0;
main ()
{
  char str[250];
  char * D.2545;
  long unsigned int D.2544;

<bb 2>:
  __builtin_memcpy (&str, " ", 2);
  str[0] = 95;
  D.2544_1 = 0;
  D.2545_2 = &str + D.2544_1;
  __builtin_memcpy (D.2545_2, ",", 2);
  puts (&str);

looks like PR57230 missed a 4.7 backport.