[clang] [WebAssembly] Refactor Wasm EH/SjLj error checking (PR #122466)

[Heejin Ahn via cfe-commits]

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@@ -413,53 +422,11 @@ void WebAssembly::addClangTargetOptions(const ArgList &DriverArgs,
       }
     }
 
-    if (Opt.starts_with("-wasm-enable-sjlj")) {
-      // '-mllvm -wasm-enable-sjlj' is not compatible with
-      // '-mno-exception-handling'
-      if (DriverArgs.hasFlag(options::OPT_mno_exception_handing,
-                             options::OPT_mexception_handing, false))
-        getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-            << "-mllvm -wasm-enable-sjlj"
-            << "-mno-exception-handling";
-      // '-mllvm -wasm-enable-sjlj' is not compatible with
-      // '-mllvm -enable-emscripten-cxx-exceptions'
-      // because we don't allow Emscripten EH + Wasm SjLj
-      for (const Arg *A : DriverArgs.filtered(options::OPT_mllvm)) {
-        if (StringRef(A->getValue(0)) == "-enable-emscripten-cxx-exceptions")
-          getDriver().Diag(diag::err_drv_argument_not_allowed_with)
-              << "-mllvm -wasm-enable-sjlj"
-              << "-mllvm -enable-emscripten-cxx-exceptions";
+    for (const auto *Option : {"-wasm-enable-eh", "-wasm-enable-sjlj"}) {
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aheejin wrote:

We were not checking `-wasm-enable-eh` before because emscripten does not set it directly; it sets `-fwasm-exceptions`, which sets `-wasm-enable-eh`:
https://github.com/llvm/llvm-project/blob/9c85cdec4ad29389c27cc2372d45f73d1ca8053a/clang/lib/Driver/ToolChains/WebAssembly.cpp#L365-L367

But this adds checks for it too for symmetry because it's not hard and users can in theory give that to clang too.

https://github.com/llvm/llvm-project/pull/122466