Re: [Valgrind-developers] valgrind: r6640 - trunk/memcheck

[Julian S. <js...@ac...>]

> Patch is below.

Nice!  Did it allow you to track down the original problem with
env vars (now lost in the mists of time) ?

My only concerns are (mostly the 2nd point):

- could you change 'int result' to 'Word result' (64-bit paranoia
  w.r.t the horrible CALL_FN_W.. macros)

- how do we stop some future gcc-5.7.2 from noticing that
  "if (p) while (*p++) ;" does not compute anything useful and
  and therefore optimising it away?

  Only solution I can think of (is horrible) is:

  if (p) {
     while (*p++)
        ;
     __asm__ __volatile__( "" : /*out*/ : /*in*/ "r"(p) );
  }

  Since gcc has no way to know what is going in inside the asm, it
  has to believe our claim that it reads p.

  Nicer suggestions welcomed.

J