Better windows only guard which can be removed by linker (#48594)

Also, remove superfluous test poking into an internal state to mimic non-Windows test environment
dotnet · Mar 17, 2021 · aeaa103 · aeaa103
1 parent e30397a
commit aeaa103
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Showing 2 changed files with 9 additions and 32 deletions.
diff --git a/...tem.Reflection.Metadata/src/System/Reflection/Internal/Utilities/FileStreamReadLightUp.cs b/...tem.Reflection.Metadata/src/System/Reflection/Internal/Utilities/FileStreamReadLightUp.cs
@@ -9,13 +9,16 @@ namespace System.Reflection.Internal
 {
     internal static class FileStreamReadLightUp
     {
-        // internal for testing
-        internal static bool readFileNotAvailable = Path.DirectorySeparatorChar != '\\'; // Available on Windows only
-        internal static bool safeFileHandleNotAvailable;
+        private static bool IsReadFileAvailable =>
+#if NETCOREAPP
+            OperatingSystem.IsWindows();
+#else
+            Path.DirectorySeparatorChar == '\\';
+#endif
 
         internal static bool IsFileStream(Stream stream) => stream is FileStream;
 
-        internal static SafeHandle? GetSafeFileHandle(Stream stream)
+        private static SafeHandle? GetSafeFileHandle(Stream stream)
         {
             SafeHandle handle;
             try
@@ -41,7 +44,7 @@ internal static class FileStreamReadLightUp
 
         internal static unsafe bool TryReadFile(Stream stream, byte* buffer, long start, int size)
         {
-            if (readFileNotAvailable)
+            if (!IsReadFileAvailable)
             {
                 return false;
             }
@@ -52,18 +55,7 @@ internal static unsafe bool TryReadFile(Stream stream, byte* buffer, long start,
                 return false;
             }
 
-            int result;
-            int bytesRead;
-
-            try
-            {
-                result = Interop.Kernel32.ReadFile(handle, buffer, size, out bytesRead, IntPtr.Zero);
-            }
-            catch
-            {
-                readFileNotAvailable = true;
-                return false;
-            }
+            int result = Interop.Kernel32.ReadFile(handle, buffer, size, out int bytesRead, IntPtr.Zero);
 
             if (result == 0 || bytesRead != size)
             {

diff --git a/src/libraries/System.Reflection.Metadata/tests/Utilities/AbstractMemoryBlockTests.cs b/src/libraries/System.Reflection.Metadata/tests/Utilities/AbstractMemoryBlockTests.cs
@@ -118,21 +118,6 @@ public void Stream()
             }
         }
 
-        [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsThreadingSupported))]
-        [ActiveIssue("https://github.com/dotnet/runtime/issues/34493", TestPlatforms.Windows, TargetFrameworkMonikers.Netcoreapp, TestRuntimes.Mono)]
-        public void FileStreamUnix()
-        {
-            try
-            {
-                FileStreamReadLightUp.readFileNotAvailable = true;
-                FileStream();
-            }
-            finally
-            {
-                FileStreamReadLightUp.readFileNotAvailable = false;
-            }
-        }
-
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsThreadingSupported))]
         [ActiveIssue("https://github.com/dotnet/runtime/issues/34493", TestPlatforms.Windows, TargetFrameworkMonikers.Netcoreapp, TestRuntimes.Mono)]
         public void FileStream()