[PATCH] D69676: [WinCFG] Handle constant casts carefully in .gfids emission

[Reid Kleckner via Phabricator via llvm-commits]

rnk marked an inline comment as done.
rnk added a comment.

> I mentioned this on the bug, but do we care if a reference to a function is optimized away at the MIR level?

I don't think it's worth the work of tracking these things at the MIR level. The new implementation will come with its own set of bugs and quirks, some of which I mentioned on the bug: large code model, target specificity, separate codepath for emission as a global initializer.

We promise that adding -g doesn't change the code we generate, but we don't promise that adding -guard:cf,nochecks won't change the generated code.



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Comment at: llvm/lib/CodeGen/AsmPrinter/WinCFGuard.cpp:71
+        // constants, such as vtable initializers, to escape the function.
+        if (C->stripPointerCasts() == FnOrCast)
+          Users.push_back(FnUser);
----------------
efriedma wrote:
> Does stripPointerCasts do the right thing here?  It can look through multiple levels of casts.
Thanks, this should compare to Fn. I couldn't think of another simple way to identify pointer casts.


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