+1 Cheers, Keith
> On Apr 30, 2024, at 10:06 AM, Yusuke Suzuki via webkit-dev > <webkit-dev@lists.webkit.org> wrote: > > Hello WebKittens! > > Right now, MSVC support is putting significant burden on JavaScriptCore. It > lacks many features for JSC development, > as a result, we have so many workarounds for MSVC in JavaScriptCore (For > example, LLInt CLoop 16-bit opcode is disabled only for MSVC since MSVC > cannot compile it reasonably). > > I talked with JSC team and Don at Sony, and now I would like to propose > dropping MSVC support on Windows port and using clang-cl exclusively on > Windows. > > There are many motivating factors for this change. > > 1. Post-commit testing bots (WinCairo) are using clang-cl. So literally, > there is zero test coverage on MSVC build right now. > 2. On the other hand, EWS is using MSVC for build test. This discrepancy is > making maintenance of Windows ports harder and harder. > 3. MSVC has various compilation issues which makes JSC lesser quality. Lack > of `__builtin_frame_address` support makes JSC bloating JIT code much. > CheckedArith has bunch of special code due to lack of overflow-detecting > `__builtin_add_overflow` like operations, and so on. (but TBH, given there > is zero coverage, we even don't know whether it is working right now!) > 4. Major third-parties using Windows WebKit (e.g. Bun.js, praywright etc.) > are using clang-cl, not MSVC. > > Not only solving existing issues, using clang-cl opens significant code / > implementation quality improvements opportunities for Windows. > > 1. MSVC does not support various C++20 features, so it is putting our C++20 > adoption much behind (For example, we cannot use concept). By using > clang-cl, we can start much newer set of C++20 features, improving code > quality, static checks etc. > 2. This paves a way to make Windows JSC implementation super solid. clang-cl > offers sysv-abi feature for function attributes. This allows using Linux / > macOS amd64 ABI on certain annotated functions. This basically means that we > potentially unify our interpreter and JIT implementations completely in Linux > / macOS / Windows for x64, (which makes our LLInt / Wasm LLInt on Windows > super solid, plus, it paves a way to fully enable all JIT tiers on Windows > including FTL). > > We already discussed with Don and we agreed on this. > And now I would like to formally propose MSVC deprecation towards more > cleaner and solid Windows port. > > Best regards, > -Yusuke Suzuki > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org https://lists.webkit.org/mailman/listinfo/webkit-dev
