Add nullable annotations to System.DirectoryServices (#48454)

* Add nullable annotations to System.DirectoryServices

* apply PR feedback

* Fix nullability of classes deriving from CollectionBase

src/libraries/System.DirectoryServices/ref/System.DirectoryServices.csproj

@@ -2,6 +2,7 @@
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0</TargetFrameworks>
     <IncludeInternalObsoleteAttribute>true</IncludeInternalObsoleteAttribute>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="System.DirectoryServices.cs" />

src/libraries/System.DirectoryServices/src/Interop/AdsValueHelper2.cs

@@ -183,7 +183,7 @@ public object GetValue()
                 case AdsType.ADSTYPE_NUMERIC_STRING:
                 case AdsType.ADSTYPE_OBJECT_CLASS:
                     // The value is a String.
-                    return Marshal.PtrToStringUni(adsvalue.pointer.value);
+                    return Marshal.PtrToStringUni(adsvalue.pointer.value)!;
 
                 case AdsType.ADSTYPE_BOOLEAN:
                     // The value is a bool.
@@ -235,7 +235,7 @@ public object GetVlvValue()
             var vlv = new AdsVLV();
             Marshal.PtrToStructure(adsvalue.octetString.value, vlv);
 
-            byte[] bytes = null;
+            byte[]? bytes = null;
             if (vlv.contextID != (IntPtr)0 && vlv.contextIDlength != 0)
             {
                 bytes = new byte[vlv.contextIDlength];

src/libraries/System.DirectoryServices/src/Interop/SafeNativeMethods.cs

@@ -29,7 +29,7 @@ public const int
         public static extern unsafe int ADsGetLastError(out int error, char* errorBuffer, int errorBufferLength, char* nameBuffer, int nameBufferLength);
 
         [DllImport(ExternDll.Activeds, CharSet = CharSet.Unicode)]
-        public static extern int ADsSetLastError(int error, string errorString, string provider);
+        public static extern int ADsSetLastError(int error, string? errorString, string? provider);
 
         public class EnumVariant
         {
@@ -93,7 +93,7 @@ private void Advance()
                         if (numRead[0] > 0)
                         {
 #pragma warning disable 612, 618
-                            _currentValue = Marshal.GetObjectForNativeVariant(addr);
+                            _currentValue = Marshal.GetObjectForNativeVariant(addr)!;
 #pragma warning restore 612, 618
                         }
                     }

src/libraries/System.DirectoryServices/src/Interop/UnsafeNativeMethods.cs

@@ -29,9 +29,9 @@ internal struct Variant
     internal class UnsafeNativeMethods
     {
         [DllImport(ExternDll.Activeds, ExactSpelling = true, EntryPoint = "ADsOpenObject", CharSet = System.Runtime.InteropServices.CharSet.Unicode)]
-        private static extern int IntADsOpenObject(string path, string userName, string password, int flags, [In, Out] ref Guid iid, [Out, MarshalAs(UnmanagedType.Interface)] out object ppObject);
+        private static extern int IntADsOpenObject(string path, string? userName, string? password, int flags, [In, Out] ref Guid iid, [Out, MarshalAs(UnmanagedType.Interface)] out object ppObject);
 
-        public static int ADsOpenObject(string path, string userName, string password, int flags, [In, Out] ref Guid iid, [Out, MarshalAs(UnmanagedType.Interface)] out object ppObject)
+        public static int ADsOpenObject(string path, string? userName, string? password, int flags, [In, Out] ref Guid iid, [Out, MarshalAs(UnmanagedType.Interface)] out object ppObject)
         {
             try
             {
@@ -86,17 +86,17 @@ string Schema
 
             void SetInfo();
 
-            object Get([In, MarshalAs(UnmanagedType.BStr)] string bstrName);
+            object? Get([In, MarshalAs(UnmanagedType.BStr)] string bstrName);
 
-            void Put([In, MarshalAs(UnmanagedType.BStr)] string bstrName, [In] object vProp);
+            void Put([In, MarshalAs(UnmanagedType.BStr)] string bstrName, [In] object? vProp);
 
             [PreserveSig]
-            int GetEx([In, MarshalAs(UnmanagedType.BStr)] string bstrName, [Out] out object value);
+            int GetEx([In, MarshalAs(UnmanagedType.BStr)] string bstrName, [Out] out object? value);
 
             void PutEx(
                 [In, MarshalAs(UnmanagedType.U4)] int lnControlCode,
                 [In, MarshalAs(UnmanagedType.BStr)] string bstrName,
-                [In] object vProp);
+                [In] object? vProp);
 
             void GetInfoEx([In] object vProperties, [In, MarshalAs(UnmanagedType.U4)] int lnReserved);
         }
@@ -116,13 +116,13 @@ object _NewEnum
                 get;
             }
 
-            object Filter { get; set; }
+            object? Filter { get; set; }
 
             object Hints { get; set; }
 
             [return: MarshalAs(UnmanagedType.Interface)]
             object GetObject(
-                [In, MarshalAs(UnmanagedType.BStr)] string className,
+                [In, MarshalAs(UnmanagedType.BStr)] string? className,
                 [In, MarshalAs(UnmanagedType.BStr)] string relativeName);
 
             [return: MarshalAs(UnmanagedType.Interface)]
@@ -137,12 +137,12 @@ object _NewEnum
             [return: MarshalAs(UnmanagedType.Interface)]
             object CopyHere(
                 [In, MarshalAs(UnmanagedType.BStr)] string sourceName,
-                [In, MarshalAs(UnmanagedType.BStr)] string newName);
+                [In, MarshalAs(UnmanagedType.BStr)] string? newName);
 
             [return: MarshalAs(UnmanagedType.Interface)]
             object MoveHere(
                 [In, MarshalAs(UnmanagedType.BStr)] string sourceName,
-                [In, MarshalAs(UnmanagedType.BStr)] string newName);
+                [In, MarshalAs(UnmanagedType.BStr)] string? newName);
         }
 
         [ComImport, Guid("B2BD0902-8878-11D1-8C21-00C04FD8D503")]
@@ -320,8 +320,8 @@ public interface IDirectorySearch
             void SetSearchPreference([In] IntPtr /*ads_searchpref_info * */pSearchPrefs, int dwNumPrefs);
 
             void ExecuteSearch(
-                [In, MarshalAs(UnmanagedType.LPWStr)] string pszSearchFilter,
-                [In, MarshalAs(UnmanagedType.LPArray)] string[] pAttributeNames,
+                [In, MarshalAs(UnmanagedType.LPWStr)] string? pszSearchFilter,
+                [In, MarshalAs(UnmanagedType.LPArray)] string[]? pAttributeNames,
                 [In] int dwNumberAttributes,
                 [Out] out IntPtr hSearchResult);
 

src/libraries/System.DirectoryServices/src/System.DirectoryServices.csproj

@@ -4,6 +4,7 @@
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;netstandard2.0;netcoreapp2.0-windows</TargetFrameworks>
     <ExcludeCurrentNetCoreAppFromPackage>true</ExcludeCurrentNetCoreAppFromPackage>
     <IncludeInternalObsoleteAttribute>true</IncludeInternalObsoleteAttribute>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
   <PropertyGroup>

src/libraries/System.DirectoryServices/src/System/DirectoryServices/ActiveDirectory/ADAMInstance.cs

@@ -14,18 +14,18 @@ public class AdamInstance : DirectoryServer
         private bool _disposed;
 
         // for public properties
-        private string _cachedHostName;
+        private string? _cachedHostName;
         private int _cachedLdapPort = -1;
         private int _cachedSslPort = -1;
         private bool _defaultPartitionInitialized;
         private bool _defaultPartitionModified;
-        private ConfigurationSet _currentConfigSet;
-        private string _cachedDefaultPartition;
-        private AdamRoleCollection _cachedRoles;
+        private ConfigurationSet? _currentConfigSet;
+        private string? _cachedDefaultPartition;
+        private AdamRoleCollection? _cachedRoles;
 
         private IntPtr _ADAMHandle = (IntPtr)0;
         private IntPtr _authIdentity = IntPtr.Zero;
-        private SyncUpdateCallback _userDelegate;
+        private SyncUpdateCallback? _userDelegate;
         private readonly SyncReplicaFromAllServersCallback _syncAllFunctionPointer;
 
         #region constructors
@@ -55,8 +55,8 @@ internal AdamInstance(DirectoryContext context, string adamHostName, DirectoryEn
 
             // the replica name should be in the form dnshostname:port
             this.replicaName = adamHostName;
-            string portNumber;
-            Utils.SplitServerNameAndPortNumber(context.Name, out portNumber);
+            string? portNumber;
+            Utils.SplitServerNameAndPortNumber(context.Name!, out portNumber);
             if (portNumber != null)
             {
                 this.replicaName = this.replicaName + ":" + portNumber;
@@ -109,8 +109,8 @@ protected override void Dispose(bool disposing)
 
         public static AdamInstance GetAdamInstance(DirectoryContext context)
         {
-            DirectoryEntryManager directoryEntryMgr = null;
-            string dnsHostName = null;
+            DirectoryEntryManager? directoryEntryMgr = null;
+            string? dnsHostName = null;
 
             // check that the context is not null
             if (context == null)
@@ -144,7 +144,7 @@ public static AdamInstance GetAdamInstance(DirectoryContext context)
                 {
                     throw new ActiveDirectoryObjectNotFoundException(SR.Format(SR.AINotFound, context.Name), typeof(AdamInstance), context.Name);
                 }
-                dnsHostName = (string)PropertyManager.GetPropertyValue(context, rootDSE, PropertyManager.DnsHostName);
+                dnsHostName = (string)PropertyManager.GetPropertyValue(context, rootDSE, PropertyManager.DnsHostName)!;
             }
             catch (COMException e)
             {
@@ -195,7 +195,7 @@ public static AdamInstance FindOne(DirectoryContext context, string partitionNam
 
         public static AdamInstanceCollection FindAll(DirectoryContext context, string partitionName)
         {
-            AdamInstanceCollection adamInstanceCollection = null;
+            AdamInstanceCollection? adamInstanceCollection = null;
 
             // validate parameters (partitionName validated by the call to ConfigSet)
             if (context == null)
@@ -264,7 +264,7 @@ public void SeizeRoleOwnership(AdamRole role)
         {
             // set the "fsmoRoleOwner" attribute on the appropriate role object
             // to the NTDSAObjectName of this ADAM Instance
-            string roleObjectDN = null;
+            string? roleObjectDN = null;
 
             CheckIfDisposed();
 
@@ -286,7 +286,7 @@ public void SeizeRoleOwnership(AdamRole role)
                     }
             }
 
-            DirectoryEntry roleObjectEntry = null;
+            DirectoryEntry? roleObjectEntry = null;
             try
             {
                 roleObjectEntry = DirectoryEntryManager.GetDirectoryEntry(context, roleObjectDN);
@@ -518,7 +518,7 @@ public string HostName
                 if (_cachedHostName == null)
                 {
                     DirectoryEntry serverEntry = directoryEntryMgr.GetCachedDirectoryEntry(ServerObjectName);
-                    _cachedHostName = (string)PropertyManager.GetPropertyValue(context, serverEntry, PropertyManager.DnsHostName);
+                    _cachedHostName = (string)PropertyManager.GetPropertyValue(context, serverEntry, PropertyManager.DnsHostName)!;
                 }
                 return _cachedHostName;
             }
@@ -532,7 +532,7 @@ public int LdapPort
                 if (_cachedLdapPort == -1)
                 {
                     DirectoryEntry ntdsaEntry = directoryEntryMgr.GetCachedDirectoryEntry(NtdsaObjectName);
-                    _cachedLdapPort = (int)PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.MsDSPortLDAP);
+                    _cachedLdapPort = (int)PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.MsDSPortLDAP)!;
                 }
                 return _cachedLdapPort;
             }
@@ -546,7 +546,7 @@ public int SslPort
                 if (_cachedSslPort == -1)
                 {
                     DirectoryEntry ntdsaEntry = directoryEntryMgr.GetCachedDirectoryEntry(NtdsaObjectName);
-                    _cachedSslPort = (int)PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.MsDSPortSSL);
+                    _cachedSslPort = (int)PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.MsDSPortSSL)!;
                 }
                 return _cachedSslPort;
             }
@@ -559,8 +559,8 @@ public AdamRoleCollection Roles
             get
             {
                 CheckIfDisposed();
-                DirectoryEntry schemaEntry = null;
-                DirectoryEntry partitionsEntry = null;
+                DirectoryEntry? schemaEntry = null;
+                DirectoryEntry? partitionsEntry = null;
 
                 try
                 {
@@ -570,14 +570,14 @@ public AdamRoleCollection Roles
                         ArrayList roleList = new ArrayList();
                         schemaEntry = DirectoryEntryManager.GetDirectoryEntry(context, directoryEntryMgr.ExpandWellKnownDN(WellKnownDN.SchemaNamingContext));
 
-                        if (NtdsaObjectName.Equals((string)PropertyManager.GetPropertyValue(context, schemaEntry, PropertyManager.FsmoRoleOwner)))
+                        if (NtdsaObjectName.Equals((string)PropertyManager.GetPropertyValue(context, schemaEntry, PropertyManager.FsmoRoleOwner)!))
                         {
                             roleList.Add(AdamRole.SchemaRole);
                         }
 
                         partitionsEntry = DirectoryEntryManager.GetDirectoryEntry(context, directoryEntryMgr.ExpandWellKnownDN(WellKnownDN.PartitionsContainer));
 
-                        if (NtdsaObjectName.Equals((string)PropertyManager.GetPropertyValue(context, partitionsEntry, PropertyManager.FsmoRoleOwner)))
+                        if (NtdsaObjectName.Equals((string)PropertyManager.GetPropertyValue(context, partitionsEntry, PropertyManager.FsmoRoleOwner)!))
                         {
                             roleList.Add(AdamRole.NamingRole);
                         }
@@ -604,7 +604,7 @@ public AdamRoleCollection Roles
             }
         }
 
-        public string DefaultPartition
+        public string? DefaultPartition
         {
             get
             {
@@ -622,7 +622,7 @@ public string DefaultPartition
                         }
                         else
                         {
-                            _cachedDefaultPartition = (string)PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.MsDSDefaultNamingContext);
+                            _cachedDefaultPartition = (string)PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.MsDSDefaultNamingContext)!;
                         }
                     }
                     catch (COMException e)
@@ -667,7 +667,7 @@ public string DefaultPartition
             }
         }
 
-        public override string IPAddress
+        public override string? IPAddress
         {
             get
             {
@@ -695,7 +695,7 @@ public override string SiteName
                     DirectoryEntry siteEntry = DirectoryEntryManager.GetDirectoryEntry(context, SiteObjectName);
                     try
                     {
-                        cachedSiteName = (string)PropertyManager.GetPropertyValue(context, siteEntry, PropertyManager.Cn);
+                        cachedSiteName = (string)PropertyManager.GetPropertyValue(context, siteEntry, PropertyManager.Cn)!;
                     }
                     finally
                     {
@@ -742,7 +742,7 @@ internal string ServerObjectName
                     DirectoryEntry rootDSE = DirectoryEntryManager.GetDirectoryEntry(context, WellKnownDN.RootDSE);
                     try
                     {
-                        cachedServerObjectName = (string)PropertyManager.GetPropertyValue(context, rootDSE, PropertyManager.ServerName);
+                        cachedServerObjectName = (string)PropertyManager.GetPropertyValue(context, rootDSE, PropertyManager.ServerName)!;
                     }
                     catch (COMException e)
                     {
@@ -767,7 +767,7 @@ internal string NtdsaObjectName
                     DirectoryEntry rootDSE = DirectoryEntryManager.GetDirectoryEntry(context, WellKnownDN.RootDSE);
                     try
                     {
-                        cachedNtdsaObjectName = (string)PropertyManager.GetPropertyValue(context, rootDSE, PropertyManager.DsServiceName);
+                        cachedNtdsaObjectName = (string)PropertyManager.GetPropertyValue(context, rootDSE, PropertyManager.DsServiceName)!;
                     }
                     catch (COMException e)
                     {
@@ -790,14 +790,14 @@ internal Guid NtdsaObjectGuid
                 if (cachedNtdsaObjectGuid == Guid.Empty)
                 {
                     DirectoryEntry ntdsaEntry = directoryEntryMgr.GetCachedDirectoryEntry(NtdsaObjectName);
-                    byte[] guidByteArray = (byte[])PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.ObjectGuid);
+                    byte[] guidByteArray = (byte[])PropertyManager.GetPropertyValue(context, ntdsaEntry, PropertyManager.ObjectGuid)!;
                     cachedNtdsaObjectGuid = new Guid(guidByteArray);
                 }
                 return cachedNtdsaObjectGuid;
             }
         }
 
-        public override SyncUpdateCallback SyncFromAllServersCallback
+        public override SyncUpdateCallback? SyncFromAllServersCallback
         {
             get
             {

src/libraries/System.DirectoryServices/src/System/DirectoryServices/ActiveDirectory/ADAMInstanceCollection.cs

@@ -17,7 +17,7 @@ internal AdamInstanceCollection(ArrayList values)
             }
         }
 
-        public AdamInstance this[int index] => (AdamInstance)InnerList[index];
+        public AdamInstance this[int index] => (AdamInstance)InnerList[index]!;
 
         public bool Contains(AdamInstance adamInstance)
         {
@@ -28,7 +28,7 @@ public bool Contains(AdamInstance adamInstance)
 
             for (int i = 0; i < InnerList.Count; i++)
             {
-                AdamInstance tmp = (AdamInstance)InnerList[i];
+                AdamInstance tmp = (AdamInstance)InnerList[i]!;
                 if (Utils.Compare(tmp.Name, adamInstance.Name) == 0)
                 {
                     return true;
@@ -46,7 +46,7 @@ public int IndexOf(AdamInstance adamInstance)
 
             for (int i = 0; i < InnerList.Count; i++)
             {
-                AdamInstance tmp = (AdamInstance)InnerList[i];
+                AdamInstance tmp = (AdamInstance)InnerList[i]!;
                 if (Utils.Compare(tmp.Name, adamInstance.Name) == 0)
                 {
                     return i;

src/libraries/System.DirectoryServices/src/System/DirectoryServices/ActiveDirectory/ADSearcher.cs

@@ -26,7 +26,7 @@ public ADSearcher(DirectoryEntry searchRoot, string filter, string[] propertiesT
             _searcher.PageSize = 512;
         }
 
-        public ADSearcher(DirectoryEntry searchRoot, string filter, string[] propertiesToLoad, SearchScope scope, bool pagedSearch, bool cacheResults)
+        public ADSearcher(DirectoryEntry searchRoot, string? filter, string[] propertiesToLoad, SearchScope scope, bool pagedSearch, bool cacheResults)
         {
             _searcher = new DirectorySearcher(searchRoot, filter, propertiesToLoad, scope);
             // set proper time out
@@ -40,13 +40,13 @@ public ADSearcher(DirectoryEntry searchRoot, string filter, string[] propertiesT
             _searcher.CacheResults = cacheResults;
         }
 
-        public SearchResult FindOne() => _searcher.FindOne();
+        public SearchResult? FindOne() => _searcher.FindOne();
 
         public SearchResultCollection FindAll() => _searcher.FindAll();
 
         public StringCollection PropertiesToLoad => _searcher.PropertiesToLoad;
 
-        public string Filter
+        public string? Filter
         {
             get => _searcher.Filter;
             set => _searcher.Filter = value;