Replace some read-only use of Span with ReadOnlySpan (#104864)

Author: stephentoub

src/coreclr/System.Private.CoreLib/src/System/Threading/WaitHandle.CoreCLR.cs

@@ -11,7 +11,7 @@ public abstract partial class WaitHandle
         [MethodImpl(MethodImplOptions.InternalCall)]
         private static extern int WaitOneCore(IntPtr waitHandle, int millisecondsTimeout, bool useTrivialWaits);
 
-        private static unsafe int WaitMultipleIgnoringSyncContextCore(Span<IntPtr> waitHandles, bool waitAll, int millisecondsTimeout)
+        private static unsafe int WaitMultipleIgnoringSyncContextCore(ReadOnlySpan<IntPtr> waitHandles, bool waitAll, int millisecondsTimeout)
         {
             fixed (IntPtr* pWaitHandles = &MemoryMarshal.GetReference(waitHandles))
             {

src/libraries/Common/src/Interop/BSD/System.Native/Interop.Sysctl.cs

@@ -22,7 +22,7 @@ internal static partial class Sys
         // This is 'raw' sysctl call, only wrapped to allocate memory if needed
         // caller always needs to free returned buffer using  Marshal.FreeHGlobal()
 
-        internal static unsafe void Sysctl(Span<int> name, ref byte* value, ref int len)
+        internal static unsafe void Sysctl(ReadOnlySpan<int> name, ref byte* value, ref int len)
         {
             fixed (int* ptr = &MemoryMarshal.GetReference(name))
             {

src/libraries/Common/src/Interop/FreeBSD/Interop.Process.GetProcInfo.cs

@@ -186,22 +186,9 @@ public unsafe struct @kinfo_proc
         /// <param name="count">The number of kinfo_proc entries returned.</param>
         public static unsafe kinfo_proc* GetProcInfo(int pid, bool threads, out int count)
         {
-            Span<int> sysctlName = stackalloc int[4];
-
-            if (pid == 0)
-            {
-                // get all processes
-                sysctlName[3] = 0;
-                sysctlName[2] = KERN_PROC_PROC;
-            }
-            else
-            {
-                // get specific process, possibly with threads
-                sysctlName[3] = pid;
-                sysctlName[2] = KERN_PROC_PID | (threads ? KERN_PROC_INC_THREAD : 0);
-            }
-            sysctlName[1] = KERN_PROC;
-            sysctlName[0] = CTL_KERN;
+            ReadOnlySpan<int> sysctlName = pid == 0 ?
+                [CTL_KERN, KERN_PROC, KERN_PROC_PROC, 0] : // get all processes
+                [CTL_KERN, KERN_PROC, KERN_PROC_PID | (threads ? KERN_PROC_INC_THREAD : 0), pid]; // get specific process, possibly with threads
 
             byte* pBuffer = null;
             int bytesLength = 0;

src/libraries/Common/src/Interop/FreeBSD/Interop.Process.cs

@@ -77,7 +77,7 @@ internal static unsafe int[] ListAllPids()
         /// <param name="pid">The PID of the process</param>
         public static unsafe string GetProcPath(int pid)
         {
-            Span<int> sysctlName = [CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, pid];
+            ReadOnlySpan<int> sysctlName = [CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, pid];
             byte* pBuffer = null;
             int bytesLength = 0;
 

src/libraries/Common/src/Interop/OSX/Interop.CoreFoundation.cs

@@ -154,7 +154,7 @@ internal static unsafe SafeCreateHandle CFArrayCreate(IntPtr[] values, UIntPtr n
         /// </summary>
         /// <param name="values">The values to put in the array</param>
         /// <returns>Returns a valid SafeCreateHandle to a CFArray on success; otherwise, returns an invalid SafeCreateHandle</returns>
-        internal static unsafe SafeCreateHandle CFArrayCreate(Span<IntPtr> values)
+        internal static unsafe SafeCreateHandle CFArrayCreate(ReadOnlySpan<IntPtr> values)
         {
             fixed (IntPtr* pValues = &MemoryMarshal.GetReference(values))
             {

src/libraries/Common/src/Interop/OSX/System.Security.Cryptography.Native.Apple/Interop.Ssl.cs

@@ -174,7 +174,7 @@ private static partial int AppleCryptoNative_SslIsHostnameMatch(
         [LibraryImport(Interop.Libraries.AppleCryptoNative, EntryPoint = "AppleCryptoNative_SslSetCertificateAuthorities")]
         internal static partial int SslSetCertificateAuthorities(SafeSslHandle sslHandle, SafeCreateHandle certificateOrArray, int replaceExisting);
 
-        internal static unsafe void SslSetCertificateAuthorities(SafeSslHandle sslHandle, Span<IntPtr> certificates, bool replaceExisting)
+        internal static unsafe void SslSetCertificateAuthorities(SafeSslHandle sslHandle, ReadOnlySpan<IntPtr> certificates, bool replaceExisting)
         {
             using (SafeCreateHandle cfCertRefs = CoreFoundation.CFArrayCreate(certificates))
             {

src/libraries/Common/src/Interop/Windows/BCrypt/Interop.BCryptEncryptDecrypt.RSA.cs

@@ -52,7 +52,7 @@ private static unsafe int BCryptEncryptRsa(
             BCryptEncryptFlags dwFlags)
         {
             // BCryptEncrypt does not accept null/0, only non-null/0.
-            Span<byte> notNull = stackalloc byte[1];
+            ReadOnlySpan<byte> notNull = stackalloc byte[1];
             scoped ReadOnlySpan<byte> effectiveSource;
 
             if (source.IsEmpty)

src/libraries/Common/src/Interop/Windows/IpHlpApi/Interop.NetworkInformation.cs

@@ -503,7 +503,7 @@ internal static unsafe partial uint GetAdaptersAddresses(
             uint* outBufLen);
 
         [LibraryImport(Interop.Libraries.IpHlpApi)]
-        internal static unsafe partial uint GetBestInterfaceEx(Span<byte> ipAddress, int* index);
+        internal static unsafe partial uint GetBestInterfaceEx(ReadOnlySpan<byte> ipAddress, int* index);
 
         [LibraryImport(Interop.Libraries.IpHlpApi)]
         internal static partial uint GetIfEntry2(ref MibIfRow2 pIfRow);

src/libraries/Common/src/Interop/Windows/Kernel32/Interop.FormatMessage.cs

@@ -61,7 +61,7 @@ internal static unsafe string GetMessage(int errorCode, IntPtr moduleHandle)
                     int length = FormatMessage(flags | FORMAT_MESSAGE_ALLOCATE_BUFFER, moduleHandle, unchecked((uint)errorCode), 0, &nativeMsgPtr, 0, IntPtr.Zero);
                     if (length > 0)
                     {
-                        return GetAndTrimString(new Span<char>((char*)nativeMsgPtr, length));
+                        return GetAndTrimString(new ReadOnlySpan<char>((char*)nativeMsgPtr, length));
                     }
                 }
                 finally
@@ -74,7 +74,7 @@ internal static unsafe string GetMessage(int errorCode, IntPtr moduleHandle)
             return $"Unknown error (0x{errorCode:x})";
         }
 
-        private static string GetAndTrimString(Span<char> buffer)
+        private static string GetAndTrimString(ReadOnlySpan<char> buffer)
         {
             int length = buffer.Length;
             while (length > 0 && buffer[length - 1] <= 32)

src/libraries/Common/src/Interop/Windows/NCrypt/Interop.NCryptDeriveKeyMaterial.cs

@@ -218,26 +218,22 @@ internal static unsafe byte[] DeriveKeyMaterialTls(
             byte[] seed,
             SecretAgreementFlags flags)
         {
-            Span<NCryptBuffer> buffers = stackalloc NCryptBuffer[2];
-
             fixed (byte* pLabel = label, pSeed = seed)
             {
                 NCryptBuffer labelBuffer = default;
                 labelBuffer.cbBuffer = label.Length;
                 labelBuffer.BufferType = BufferType.KdfTlsLabel;
                 labelBuffer.pvBuffer = new IntPtr(pLabel);
-                buffers[0] = labelBuffer;
 
                 NCryptBuffer seedBuffer = default;
                 seedBuffer.cbBuffer = seed.Length;
                 seedBuffer.BufferType = BufferType.KdfTlsSeed;
                 seedBuffer.pvBuffer = new IntPtr(pSeed);
-                buffers[1] = seedBuffer;
 
                 return DeriveKeyMaterial(
                     secretAgreement,
                     BCryptNative.KeyDerivationFunction.Tls,
-                    buffers,
+                    [labelBuffer, seedBuffer],
                     flags);
             }
         }