I also tested MSVC vs ClangCL recently, because someone requested MSVC support, and I have no Windows machine. mingw cross worked fine for several years. on app

I also tested MSVC vs ClangCL recently, because someone requested MSVC support, and I have no Windows machine. mingw cross worked fine for several years. on apple and linux. So I installed clangcl and cross-compiled the project on linux to windows via clangcl, fixed all missing compat pieces (not much, because MS got much better recently, mostly adding some _ prefixes to std functions), and then tried a native MSVC CI (Github Actions and appveyor). clangcl indeed caught a lot of problems, but not all. msvc still deviated more than with chrome. The clangcl/msvc wrong size reports were very good! Here are the additional MSVC fixes I had to add, over clangcl: VS2019 specific fixes, __VA_ARGS__, __attribute__, suppress warnings * __VA_ARGS__ macro support (illegal ...) * __attribute__ only with __GCC__ * suppress C4101 uninitialized recount warnings, and strcpy insecure warnings. * no proper const var support (with the even weirder error: cannot allocate an array of constant size) * much stricter typecasts (silly cl compiler) * strict dllexport/dllimport decls: fix various omissions clangcl is not error compatible to msvc, msvc errors much more. While I was there: tcc was fine, for chibicc I had to file some PR's with large files, and pcc is currently broken, some tricky cpp regressions, which I couldn't fix.