Merge pull request #21862 from compnerd/decldats

IRGen: ensure that declarations are not COMDATed

Author: compnerd

lib/IRGen/GenDecl.cpp

@@ -1903,6 +1903,8 @@ Address IRGenModule::getAddrOfSILGlobalVariable(SILGlobalVariable *var,
     /// Add a zero initializer.
     if (forDefinition)
       gvar->setInitializer(llvm::Constant::getNullValue(storageTypeWithContainer));
+    else
+      gvar->setComdat(nullptr);
   }
   llvm::Constant *addr = gvar;
   if (var->isInitializedObject()) {
@@ -2184,8 +2186,11 @@ llvm::Function *IRGenModule::getAddrOfSILFunction(
   // associated with it.  The combination of the two allows us to identify the
   // @_silgen_name functions.  These are locally defined function thunks used in
   // the standard library.  Do not give them DLLImport DLL Storage.
-  if (useDllStorage() && f->hasCReferences() && !forDefinition)
-    fn->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
+  if (!forDefinition) {
+    fn->setComdat(nullptr);
+    if (f->hasCReferences())
+      fn->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
+  }
 
   // If we have an order number for this function, set it up as appropriate.
   if (hasOrderNumber) {