[PATCH] D43107: Support for the mno-stack-arg-probe flag

[Ruslan Nikolaev via Phabricator via llvm-commits]

nruslan added a comment.

@MatzeB : mstack-probe-size=0 is already used for a different purpose. It basically, if I remember correctly, always forces calls to chkstk regardless of the actual stack usage. Normally that would only happen after 4K. Regarding your second question -- do we really need to have these flags to be mutually-exclusive? They are related but serve a different purpose. stack-probe-size merely changes the default probe size from 4K to the specified value.  mstack-arg-probe/mno-stack-arg-probe enables/disables stack probes. If we disable stack probes, their size no longer matters,  but we do not necessarily have to prohibit stack-probe-size. So, in fact, I can imagine somebody may even define system-wide alias if they want to override 4K (for whatever reason). Then some Makefile (which is unaware of this alias) may, for example, disable stack probes completely (like in UEFI code case), and we do not necessarily want to prohibit this combination.


https://reviews.llvm.org/D43107