[clang] [CIR] Implement 'typeid' operator lowering (PR #184449)

[Erich Keane via cfe-commits]

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@@ -1550,6 +1558,49 @@ mlir::Attribute CIRGenItaniumRTTIBuilder::buildTypeInfo(
   return builder.getGlobalViewAttr(builder.getUInt8PtrTy(), gv);
 }
 
+bool CIRGenItaniumCXXABI::shouldTypeidBeNullChecked(QualType srcTy) {
+  return true;
+}
+
+void CIRGenItaniumCXXABI::emitBadTypeidCall(CIRGenFunction &cgf,
+                                            mlir::Location loc) {
+  // void __cxa_bad_typeid();
+  cir::FuncType fnTy =
+      cgf.getBuilder().getFuncType({}, cgf.getBuilder().getVoidTy());
+  mlir::NamedAttrList attrs;
+  attrs.set(cir::CIRDialect::getNoReturnAttrName(),
+            mlir::UnitAttr::get(&cgf.cgm.getMLIRContext()));
+
+  cgf.emitRuntimeCall(
+      loc, cgf.cgm.createRuntimeFunction(fnTy, "__cxa_bad_typeid", attrs), {},
+      attrs);
+  cir::UnreachableOp::create(cgf.getBuilder(), loc);
+  cgf.getBuilder().clearInsertionPoint();
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erichkeane wrote:

That... is an excellent question.  I don't see why I did that at all.

https://github.com/llvm/llvm-project/pull/184449