[cfe-dev] Disallow rtti

[John McCall via cfe-dev]

> On Oct 24, 2017, at 9:28 AM, Andreas Bergmeier via cfe-dev <cfe-dev at lists.llvm.org> wrote:
> 
> I am currently starting implementing a new toolchain and want to disable rtti there.
> Now saw CalculateRTTIMode in lib/Driver/ToolChain.cpp. Now I would like to warn the user that rtti is actually no supported on that platform (for -frtti). Currently it seems like all rtti handling in Toolchain is hard coded.
> What is the best way to indicate missing rtti on a platform?

How is it "missing"?  You just want to have a policy that those language features don't work on your target?  We don't have any existing targets that do that, so it's not surprising that you might need to provide some customization hook for it.

John.