Replace more Unsafe.As usage with pointers

src/coreclr/vm/corelib.h

@@ -693,7 +693,6 @@ DEFINE_METHOD(UNSAFE,               AS_POINTER,             AsPointer, NoSig)
 DEFINE_METHOD(UNSAFE,               BYREF_IS_NULL,          IsNullRef, NoSig)
 DEFINE_METHOD(UNSAFE,               BYREF_NULLREF,          NullRef, NoSig)
 DEFINE_METHOD(UNSAFE,               AS_REF_IN,              AsRef, GM_RefT_RetRefT)
-DEFINE_METHOD(UNSAFE,               AS_REF_POINTER,         AsRef, GM_VoidPtr_RetRefT)
 DEFINE_METHOD(UNSAFE,               BYREF_AS,               As, GM_RefTFrom_RetRefTTo)
 DEFINE_METHOD(UNSAFE,               OBJECT_AS,              As, GM_Obj_RetT)
 DEFINE_METHOD(UNSAFE,               BYREF_ADD,              Add, GM_RefT_Int_RetRefT)

src/coreclr/vm/jitinterface.cpp

@@ -6791,7 +6791,6 @@ bool getILIntrinsicImplementationForUnsafe(MethodDesc * ftn,
     }
     else if (tk == CoreLibBinder::GetMethod(METHOD__UNSAFE__BYREF_AS)->GetMemberDef() ||
              tk == CoreLibBinder::GetMethod(METHOD__UNSAFE__OBJECT_AS)->GetMemberDef() ||
-             tk == CoreLibBinder::GetMethod(METHOD__UNSAFE__AS_REF_POINTER)->GetMemberDef() ||
              tk == CoreLibBinder::GetMethod(METHOD__UNSAFE__AS_REF_IN)->GetMemberDef())
     {
         // Return the argument that was passed in.

src/libraries/Common/src/Interop/Unix/System.Native/Interop.MountPoints.cs

@@ -7,6 +7,8 @@
 using System.Runtime.ExceptionServices;
 using System.Runtime.InteropServices;
 
+#pragma warning disable 8500 // takes address of managed type
+
 internal static partial class Interop
 {
     internal static partial class Sys
@@ -23,15 +25,14 @@ private struct AllMountPointsContext
         [UnmanagedCallersOnly]
         private static unsafe void AddMountPoint(void* context, byte* name)
         {
-            ref AllMountPointsContext callbackContext = ref Unsafe.As<byte, AllMountPointsContext>(ref *(byte*)context);
-
+            AllMountPointsContext* callbackContext = (AllMountPointsContext*)context;
             try
             {
-                callbackContext._results.Add(Marshal.PtrToStringUTF8((IntPtr)name)!);
+                callbackContext->_results.Add(Marshal.PtrToStringUTF8((IntPtr)name)!);
             }
             catch (Exception e)
             {
-                callbackContext._exception = ExceptionDispatchInfo.Capture(e);
+                callbackContext->_exception = ExceptionDispatchInfo.Capture(e);
             }
         }
 
@@ -42,7 +43,7 @@ internal static string[] GetAllMountPoints()
 
             unsafe
             {
-                GetAllMountPoints(&AddMountPoint, Unsafe.AsPointer(ref context));
+                GetAllMountPoints(&AddMountPoint, &context);
             }
 
             context._exception?.Throw();

src/libraries/System.Net.NetworkInformation/src/System/Net/NetworkInformation/BsdIPv4GlobalStatistics.cs

@@ -6,6 +6,8 @@
 using System.Runtime.InteropServices;
 using System.Runtime.Versioning;
 
+#pragma warning disable 8500 // taking address of managed types
+
 namespace System.Net.NetworkInformation
 {
     internal sealed class BsdIPv4GlobalStatistics : IPGlobalStatistics
@@ -37,10 +39,10 @@ private struct Context
         [UnmanagedCallersOnly]
         private static unsafe void ProcessIpv4Address(void* pContext, byte* ifaceName, Interop.Sys.IpAddressInfo* ipAddr)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
 
-            context._interfaceSet.Add(new string((sbyte*)ifaceName));
-            context._numIPAddresses++;
+            context->_interfaceSet.Add(new string((sbyte*)ifaceName));
+            context->_numIPAddresses++;
         }
 
         public unsafe BsdIPv4GlobalStatistics()
@@ -71,7 +73,7 @@ public unsafe BsdIPv4GlobalStatistics()
             context._interfaceSet = new HashSet<string>();
 
             Interop.Sys.EnumerateInterfaceAddresses(
-                Unsafe.AsPointer(ref context),
+                &context,
                 &ProcessIpv4Address,
                 null,
                 null);

src/libraries/System.Net.NetworkInformation/src/System/Net/NetworkInformation/BsdIpInterfaceProperties.cs

@@ -6,6 +6,8 @@
 using System.Runtime.InteropServices;
 using System.Runtime.Versioning;
 
+#pragma warning disable 8500 // taking address of managed types
+
 namespace System.Net.NetworkInformation
 {
     internal sealed class BsdIpInterfaceProperties : UnixIPInterfaceProperties
@@ -74,7 +76,7 @@ private static unsafe GatewayIPAddressInformationCollection GetGatewayAddresses(
             Context context;
             context._interfaceIndex = interfaceIndex;
             context._addressSet = new HashSet<IPAddress>();
-            if (Interop.Sys.EnumerateGatewayAddressesForInterface(Unsafe.AsPointer(ref context), (uint)interfaceIndex, &OnGatewayFound) == -1)
+            if (Interop.Sys.EnumerateGatewayAddressesForInterface(&context, (uint)interfaceIndex, &OnGatewayFound) == -1)
             {
                 throw new NetworkInformationException(SR.net_PInvokeError);
             }
@@ -91,15 +93,15 @@ private static unsafe GatewayIPAddressInformationCollection GetGatewayAddresses(
         [UnmanagedCallersOnly]
         private static unsafe void OnGatewayFound(void* pContext, Interop.Sys.IpAddressInfo* gatewayAddressInfo)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
 
             IPAddress ipAddress = new IPAddress(new ReadOnlySpan<byte>(gatewayAddressInfo->AddressBytes, gatewayAddressInfo->NumAddressBytes));
             if (ipAddress.IsIPv6LinkLocal)
             {
                 // For Link-Local addresses add ScopeId as that is not part of the route entry.
-                ipAddress.ScopeId = context._interfaceIndex;
+                ipAddress.ScopeId = context->_interfaceIndex;
             }
-            context._addressSet.Add(ipAddress);
+            context->_addressSet.Add(ipAddress);
         }
     }
 }

src/libraries/System.Net.NetworkInformation/src/System/Net/NetworkInformation/BsdNetworkInterface.cs

@@ -5,6 +5,8 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
+#pragma warning disable 8500 // taking address of managed types
+
 namespace System.Net.NetworkInformation
 {
     internal sealed class BsdNetworkInterface : UnixNetworkInterface
@@ -72,42 +74,42 @@ internal void AddException(Exception e)
         [UnmanagedCallersOnly]
         private static unsafe void ProcessIpv4Address(void* pContext, byte* ifaceName, Interop.Sys.IpAddressInfo* ipAddr)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
             try
             {
-                context.GetOrCreate(ifaceName, ipAddr->InterfaceIndex).ProcessIpv4Address(ipAddr);
+                context->GetOrCreate(ifaceName, ipAddr->InterfaceIndex).ProcessIpv4Address(ipAddr);
             }
             catch (Exception e)
             {
-                context.AddException(e);
+                context->AddException(e);
             }
         }
 
         [UnmanagedCallersOnly]
         private static unsafe void ProcessIpv6Address(void* pContext, byte* ifaceName, Interop.Sys.IpAddressInfo* ipAddr, uint* scopeId)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
             try
             {
-                context.GetOrCreate(ifaceName, ipAddr->InterfaceIndex).ProcessIpv6Address(ipAddr, *scopeId);
+                context->GetOrCreate(ifaceName, ipAddr->InterfaceIndex).ProcessIpv6Address(ipAddr, *scopeId);
             }
             catch (Exception e)
             {
-                context.AddException(e);
+                context->AddException(e);
             }
         }
 
         [UnmanagedCallersOnly]
         private static unsafe void ProcessLinkLayerAddress(void* pContext, byte* ifaceName, Interop.Sys.LinkLayerAddressInfo* llAddr)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
             try
             {
-                context.GetOrCreate(ifaceName, llAddr->InterfaceIndex).ProcessLinkLayerAddress(llAddr);
+                context->GetOrCreate(ifaceName, llAddr->InterfaceIndex).ProcessLinkLayerAddress(llAddr);
             }
             catch (Exception e)
             {
-                context.AddException(e);
+                context->AddException(e);
             }
         }
 
@@ -123,7 +125,7 @@ public static unsafe NetworkInterface[] GetBsdNetworkInterfaces()
                 // Because these callbacks are executed in a reverse-PInvoke, we do not want any exceptions
                 // to propagate out, because they will not be catchable. Instead, we track all the exceptions
                 // that are thrown in these callbacks, and aggregate them at the end.
-                int result = Interop.Sys.EnumerateInterfaceAddresses(Unsafe.AsPointer(ref context), &ProcessIpv4Address, &ProcessIpv6Address, &ProcessLinkLayerAddress);
+                int result = Interop.Sys.EnumerateInterfaceAddresses(&context, &ProcessIpv4Address, &ProcessIpv6Address, &ProcessLinkLayerAddress);
                 if (context._exceptions != null)
                 {
                     throw new NetworkInformationException(SR.net_PInvokeError, new AggregateException(context._exceptions));

src/libraries/System.Net.NetworkInformation/src/System/Net/NetworkInformation/UnixIPGlobalProperties.cs

@@ -8,6 +8,8 @@
 using System.Threading;
 using System.Threading.Tasks;
 
+#pragma warning disable 8500 // taking address of managed types
+
 namespace System.Net.NetworkInformation
 {
     internal abstract class UnixIPGlobalProperties : IPGlobalProperties
@@ -70,36 +72,36 @@ internal void AddException(Exception e)
         [UnmanagedCallersOnly]
         private static unsafe void ProcessIpv4Address(void* pContext, byte* ifaceName, Interop.Sys.IpAddressInfo* ipAddr)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
             try
             {
                 IPAddress ipAddress = IPAddressUtil.GetIPAddressFromNativeInfo(ipAddr);
                 if (!IPAddressUtil.IsMulticast(ipAddress))
                 {
-                    context._collection.InternalAdd(new UnixUnicastIPAddressInformation(ipAddress, ipAddr->PrefixLength));
+                    context->_collection.InternalAdd(new UnixUnicastIPAddressInformation(ipAddress, ipAddr->PrefixLength));
                 }
             }
             catch (Exception e)
             {
-                context.AddException(e);
+                context->AddException(e);
             }
         }
 
         [UnmanagedCallersOnly]
         private static unsafe void ProcessIpv6Address(void* pContext, byte* ifaceName, Interop.Sys.IpAddressInfo* ipAddr, uint* scopeId)
         {
-            ref Context context = ref Unsafe.As<byte, Context>(ref *(byte*)pContext);
+            Context* context = (Context*)pContext;
             try
             {
                 IPAddress ipAddress = IPAddressUtil.GetIPAddressFromNativeInfo(ipAddr);
                 if (!IPAddressUtil.IsMulticast(ipAddress))
                 {
-                    context._collection.InternalAdd(new UnixUnicastIPAddressInformation(ipAddress, ipAddr->PrefixLength));
+                    context->_collection.InternalAdd(new UnixUnicastIPAddressInformation(ipAddress, ipAddr->PrefixLength));
                 }
             }
             catch (Exception e)
             {
-                context.AddException(e);
+                context->AddException(e);
             }
         }
 
@@ -110,7 +112,7 @@ public override unsafe UnicastIPAddressInformationCollection GetUnicastAddresses
             context._exceptions = null;
 
             // Ignore link-layer addresses that are discovered; don't create a callback.
-            Interop.Sys.EnumerateInterfaceAddresses(Unsafe.AsPointer(ref context), &ProcessIpv4Address, &ProcessIpv6Address, null);
+            Interop.Sys.EnumerateInterfaceAddresses(&context, &ProcessIpv4Address, &ProcessIpv6Address, null);
 
             if (context._exceptions != null)
                 throw new NetworkInformationException(SR.net_PInvokeError, new AggregateException(context._exceptions));

src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketAsyncEventArgs.Windows.cs

@@ -237,7 +237,7 @@ private unsafe SocketError ProcessIOCPResult(bool success, int bytesTransferred,
                 socketError = (SocketError)(packedResult & 0xFFFFFFFF);
                 if (socketError != SocketError.Success)
                 {
-                    GetOverlappedResultOnError(ref socketError, ref Unsafe.As<int, uint>(ref bytesTransferred), ref socketFlags, overlapped);
+                    GetOverlappedResultOnError(ref socketError, ref *(uint*)&bytesTransferred, ref socketFlags, overlapped);
                 }
                 FreeNativeOverlapped(ref overlapped);
             }

src/libraries/System.Private.CoreLib/src/System/Globalization/CalendarData.Icu.cs

@@ -427,11 +427,13 @@ private static unsafe void EnumCalendarInfoCallback(char* calendarStringPtr, Int
             try
             {
                 ReadOnlySpan<char> calendarStringSpan = MemoryMarshal.CreateReadOnlySpanFromNullTerminated(calendarStringPtr);
-                ref IcuEnumCalendarsData callbackContext = ref Unsafe.As<byte, IcuEnumCalendarsData>(ref *(byte*)context);
+#pragma warning disable 8500
+                IcuEnumCalendarsData* callbackContext = (IcuEnumCalendarsData*)context;
+#pragma warning restore 8500
 
-                if (callbackContext.DisallowDuplicates)
+                if (callbackContext->DisallowDuplicates)
                 {
-                    foreach (string existingResult in callbackContext.Results)
+                    foreach (string existingResult in callbackContext->Results)
                     {
                         if (string.CompareOrdinal(calendarStringSpan, existingResult) == 0)
                         {
@@ -441,7 +443,7 @@ private static unsafe void EnumCalendarInfoCallback(char* calendarStringPtr, Int
                     }
                 }
 
-                callbackContext.Results.Add(calendarStringSpan.ToString());
+                callbackContext->Results.Add(calendarStringSpan.ToString());
             }
             catch (Exception e)
             {

src/libraries/System.Private.CoreLib/src/System/Globalization/CalendarData.Nls.cs

@@ -6,6 +6,8 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
+#pragma warning disable 8500 // taking address of managed type
+
 namespace System.Globalization
 {
     internal sealed partial class CalendarData
@@ -61,16 +63,16 @@ private struct EnumData
         [UnmanagedCallersOnly]
         private static unsafe Interop.BOOL EnumCalendarInfoCallback(char* lpCalendarInfoString, uint calendar, IntPtr pReserved, void* lParam)
         {
-            ref EnumData context = ref Unsafe.As<byte, EnumData>(ref *(byte*)lParam);
+            EnumData* context = (EnumData*)lParam;
             try
             {
                 string calendarInfo = new string(lpCalendarInfoString);
 
                 // If we had a user override, check to make sure this differs
-                if (context.userOverride != calendarInfo)
+                if (context->userOverride != calendarInfo)
                 {
-                    Debug.Assert(context.strings != null);
-                    context.strings.Add(calendarInfo);
+                    Debug.Assert(context->strings != null);
+                    context->strings!.Add(calendarInfo); // TODO https://github.com/dotnet/roslyn/issues/65634: Remove ! when no longer needed
                 }
 
                 return Interop.BOOL.TRUE;
@@ -93,12 +95,12 @@ public struct NlsEnumCalendarsData
         [UnmanagedCallersOnly]
         private static unsafe Interop.BOOL EnumCalendarsCallback(char* lpCalendarInfoString, uint calendar, IntPtr reserved, void* lParam)
         {
-            ref NlsEnumCalendarsData context = ref Unsafe.As<byte, NlsEnumCalendarsData>(ref *(byte*)lParam);
+            NlsEnumCalendarsData* context = (NlsEnumCalendarsData*)lParam;
             try
             {
                 // If we had a user override, check to make sure this differs
-                if (context.userOverride != calendar)
-                    context.calendars.Add((int)calendar);
+                if (context->userOverride != calendar)
+                    context->calendars.Add((int)calendar);
 
                 return Interop.BOOL.TRUE;
             }

src/libraries/System.Private.CoreLib/src/System/Globalization/CalendarData.Windows.cs

@@ -5,6 +5,8 @@
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
+#pragma warning disable 8500 // taking address of managed type
+
 namespace System.Globalization
 {
     internal sealed partial class CalendarData
@@ -265,7 +267,7 @@ private static unsafe bool CallEnumCalendarInfo(string localeName, CalendarId ca
             }
 
             // Now call the enumeration API. Work is done by our callback function
-            Interop.Kernel32.EnumCalendarInfoExEx(&EnumCalendarInfoCallback, localeName, (uint)calendar, null, calType, Unsafe.AsPointer(ref context));
+            Interop.Kernel32.EnumCalendarInfoExEx(&EnumCalendarInfoCallback, localeName, (uint)calendar, null, calType, &context);
 
             // Now we have a list of data, fail if we didn't find anything.
             Debug.Assert(context.strings != null);
@@ -417,7 +419,7 @@ private static int NlsGetCalendars(string localeName, bool useUserOverride, Cale
 
             unsafe
             {
-                Interop.Kernel32.EnumCalendarInfoExEx(&EnumCalendarsCallback, localeName, ENUM_ALL_CALENDARS, null, CAL_ICALINTVALUE, Unsafe.AsPointer(ref data));
+                Interop.Kernel32.EnumCalendarInfoExEx(&EnumCalendarsCallback, localeName, ENUM_ALL_CALENDARS, null, CAL_ICALINTVALUE, &data);
             }
 
             // Copy to the output array

src/libraries/System.Private.CoreLib/src/System/Globalization/CharUnicodeInfo.cs

@@ -245,7 +245,7 @@ private static double GetNumericValueNoBoundsCheck(uint codePoint)
             {
                 ulong temp = Unsafe.ReadUnaligned<ulong>(ref refToValue);
                 temp = BinaryPrimitives.ReverseEndianness(temp);
-                return Unsafe.As<ulong, double>(ref temp);
+                return BitConverter.UInt64BitsToDouble(temp);
             }
         }