==7809== Memcheck, a memory error detector
==7809== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==7809== Using Valgrind-3.12.0.SVN and LibVEX; rerun with -h for copyright info
==7809== Command: ./src/grep -E (?|)(\\1\\1|t1|\\?7)+
==7809== 
==7809== Stack overflow in thread #1: can't grow stack to 0xffe801000
grep: stack overflow
==7809== 
==7809== HEAP SUMMARY:
==7809==     in use at exit: 20,970 bytes in 157 blocks
==7809==   total heap usage: 363 allocs, 206 frees, 45,866 bytes allocated
==7809== 
==7809== LEAK SUMMARY:
==7809==    definitely lost: 0 bytes in 0 blocks
==7809==    indirectly lost: 0 bytes in 0 blocks
==7809==      possibly lost: 128 bytes in 1 blocks
==7809==    still reachable: 20,842 bytes in 156 blocks
==7809==         suppressed: 0 bytes in 0 blocks
==7809== Rerun with --leak-check=full to see details of leaked memory
==7809== 
==7809== For counts of detected and suppressed errors, rerun with: -v
==7809== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)