[clang] [CodeGen] Implement Objective-C WebAssembly exception handling support (PR #215562)

[David Chisnall via cfe-commits]

Hendrik =?utf-8?q?Hübner?= <hhuebner at hhuebnerMacBookPro.local>,
Hendrik =?utf-8?q?Hübner?= <hhuebner at hhuebnerMacBookPro.local>,
Hendrik =?utf-8?q?Hübner?= <hhuebner at MacBookPro.lan>,
Hendrik =?utf-8?q?Hübner?= <hhuebner at MacBookPro.lan>
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In-Reply-To: <llvm.org/llvm/llvm-project/pull/215562 at github.com>


davidchisnall wrote:

> I would like to note that since then, #209282 has been merged, providing the ability to have custom EH personalities on Wasm.
> 
> @hmelder was the one who originally proposed such, specifically for for Obj-C. Don't know if it'd still help, or using the C++ personality is beneficial in other ways.

We have code in the runtime that wraps Objective-C exceptions to look like C++ ones and use the C++ personality for MinGW because MinGW’s weird atom smashing of SEH and Itanium ABIs ends up hiding some of the symbols that are essential for interoperability. Reusing the same code paths for WAsm is probably the right approach, since it reduces the amount of bespoke code necessary.

https://github.com/llvm/llvm-project/pull/215562