[clang] [CIR][Dialect] Add SourceLangAttr (PR #152511)

[Bruno Cardoso Lopes via cfe-commits]

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@@ -495,6 +498,27 @@ void CIRGenModule::setNonAliasAttributes(GlobalDecl gd, mlir::Operation *op) {
   assert(!cir::MissingFeatures::setTargetAttributes());
 }
 
+cir::SourceLanguage CIRGenModule::getCIRSourceLanguage() const {
+  using ClangStd = clang::LangStandard;
+  using CIRLang = cir::SourceLanguage;
+  auto opts = getLangOpts();
+
+  if (opts.OpenCL && !opts.OpenCLCPlusPlus)
+    llvm_unreachable("NYI");
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bcardosolopes wrote:

Use `cgm.errorNYI` here.

https://github.com/llvm/llvm-project/pull/152511