r278882 - If possible, set the stack rlimit to at least 8MiB on cc1 startup, and work

[Joerg Sonnenberger via cfe-commits]

On Fri, Aug 19, 2016 at 03:30:42PM -0700, Richard Smith wrote:
> It typically does; the default stack ulimit is likely tuned for "normal"
> applications that are not expected (by an ISO standard) to cope with
> recursing a thousand levels deep. If the system administrator really wants
> to control the stack space for some stupid reason, they can set a hard
> ulimit. If people actually do that, and then file bugs on clang crashing
> (which they do today), we may want to resort to spawning a separate thread
> with a higher ulimit if we detect the problem.

Thread stacks by default are even smaller and for good reason.
Especially on 32bit platforms, it would be unusable otherwise. To put
this into perspective: if you need to support a recursion level of 1000
and can't do that with a 4MB stack, it means you are using more than 4KB
per recursion level. That's a very high stack use and certainly
something that qualifies as the kind of abusive behavior the process
limit is designed for in first place.

> It *is* unreasonable to expect them to fiddle with stack ulimits to get the
> compiler to accept programs that, say, use certain components of boost (and
> fit within the standard's recommended limits).

I fundamentally disagree with this statement. Effectively, this seems to
me to be papering over excessive stack use and nothing else.

Joerg