Re: [incremental] Patch: FYI: add missing bits to checksum

[Paolo Bonzini <bonzini at gnu dot org>]

> +    case CPP_KEYWORD:
> +      type = token->keyword;
> +      md5_process_bytes (&type, sizeof (type), current_hash);
> +      break;

Why not change this to sha1 since you're at it?  You cannot find a 
second pre-image for MD5, but you can find collisions pretty easily, so 
it could yield security problems (no I'm not exaggerating it *too 
much*---they would be wrong-code bugs, but if somebody plays with MD5 
collisions you can assume that they are doing something malicious).  You 
could have

  if ("A1" == "A2")
    foo ();
  else
    bar ();

compile to foo () if you had previously given

  if ("A2" == "A2")
    foo ();
  else
    bar ();

and (A1, A2) is a colliding pair.

Paolo