[PATCH] D17094: [safestack] Add -safe-stack-subr-acc-as-unsafe option

[Michael LeMay via llvm-commits]

mlemay-intel added a comment.

In http://reviews.llvm.org/D17094#375794, @pcc wrote:

>


I apologize for not responding to this until now.  Email notifications of new activity on my patches are apparently not making it to my inbox for some reason.

> Regarding the first motivation, the code is already being conservative. As far as I know, the nocapture readnone attributes are stronger than what safestack requires of a pointer. For example, they forbid loading from a pointer at a constant offset (which safestack could conceivably allow). Rather than adding this flag, we should in the long term be adding an attribute that specifically means what safestack requires.


Thank you for pointing out my misinterpretation of the FIXME.  I will update the commit message accordingly.

> Regarding the second motivation, if we do intend to start using segment selectors on x86 in some cases, we should probably make this behavior gated on the target (e.g. the `separate-stack-seg` feature you appear to be adding) rather than on a flag.


This would result in simpler command line option sequences.  I'll try to revise this patch to do what you suggested.


http://reviews.llvm.org/D17094