Merge pull request #23911 from aschwaighofer/retainAutoreleasedReturnValueMarker_module_flag

Emit the clang.arc.retainAutoreleasedReturnValueMarker as a module flag.

Author: aschwaighofer

lib/IRGen/GenObjC.cpp

@@ -126,13 +126,10 @@ llvm::InlineAsm *IRGenModule::getObjCRetainAutoreleasedReturnValueMarker() {
   // and let the late ARC pass insert it, but don't generate any calls
   // right now.
   if (IRGen.Opts.shouldOptimize()) {
-    llvm::NamedMDNode *metadata =
-      Module.getOrInsertNamedMetadata(
-                            "clang.arc.retainAutoreleasedReturnValueMarker");
-    assert(metadata->getNumOperands() <= 1);
-    if (metadata->getNumOperands() == 0) {
-      auto *string = llvm::MDString::get(LLVMContext, asmString);
-      metadata->addOperand(llvm::MDNode::get(LLVMContext, string));
+    const char *markerKey = "clang.arc.retainAutoreleasedReturnValueMarker";
+    if (!Module.getModuleFlag(markerKey)) {
+      auto *str = llvm::MDString::get(LLVMContext, asmString);
+      Module.addModuleFlag(llvm::Module::Error, markerKey, str);
     }
 
     cache = nullptr;