On Mon, Oct 1, 2018 at 10:53 AM, Nathan Sidwell <nat...@acm.org> wrote: > Ian, > this patch implements the pipe error channel you suggested a while back. > Before the (v)fork we create a pipe and set it up for CLOEXEC. If exec > failure happens in the child, we write errno & the fnname to the pipe. In > the parent we attempt to read the pipe. We'll get EOF if the child was > successful. Otherwise we get the error and fn, which we pass back to our > caller. As both child and parent are in the same address space, it's > perfectly fine to pass string literal addresses down the pipe. > > An example of the difference is the behaviour of: > ./xg++ -Bbogus ... > > before the patch we get: > xg++: error trying to exec 'cc1plus': execvp: No such file or directory > > with the patch we get: > xg++: fatal error: cannot execute ‘cc1plus’: execvp: No such file or > directory > compilation terminated. > > Martin has been kind enough to test this patch in his profiled-bootstrap > build, and I've tested on AIX (where vfork is fork) as well asx86_64-linux.
Thanks for doing this. This is OK. Ian
