Remove CodePage1252Encoding and try to use the built-in Encoding. If not...

Remove CodePage1252Encoding and try to use the built-in Encoding. If not available, then fallback to Latin1

src/Compilers/Core/Desktop/CodeAnalysis.Desktop.csproj

@@ -57,7 +57,6 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>CodeAnalysisDesktopResources.resx</DependentUpon>
     </Compile>
-    <Compile Include="CodePage1252Encoding.cs" />
     <Compile Include="CommandLine\CommandLineReference.cs" />
     <Compile Include="CommandLine\CommandLineSourceFile.cs" />
     <Compile Include="CommandLine\CommonCommandLineArguments.cs" />

src/Compilers/Core/Desktop/CodePage1252Encoding.cs

-using System;
-using System.Text;
-
-namespace Microsoft.CodeAnalysis.Text
-{
-    /// <summary>
-    /// CodePage 1252 decoder. This is a single byte character set encoding that is very close
-    /// to Latin1 except some of the code points in the control set 1 range (0x80 to 0x9F) are
-    /// replaced with typographic characters.
-    /// </summary>
-    internal sealed class CodePage1252Encoding : Encoding
-    {
-        public static readonly CodePage1252Encoding Instance = new CodePage1252Encoding();
-
-        public override int CodePage => 1252;
-
-        public override int GetByteCount(char[] chars, int index, int count)
-        {
-            // This is a decoder only
-            throw new NotSupportedException();
-        }
-
-        public override int GetBytes(char[] chars, int charIndex, int charCount, byte[] bytes, int byteIndex)
-        {
-            // This is a decoder only
-            throw new NotSupportedException();
-        }
-
-        // This is SBCS, so the number of characters is the same as the number of bytes.
-        public override int GetCharCount(byte[] bytes, int index, int count) => count;
-
-        // This is SBCS, so the number of characters is the same as the number of bytes.
-        public override unsafe int GetCharCount(byte* bytes, int count) => count;
-
-        public override int GetChars(byte[] bytes, int byteIndex, int byteCount, char[] chars, int charIndex)
-        {
-            int byteEndIndex = byteIndex + byteCount;
-            while (byteIndex < byteEndIndex)
-            {
-                chars[charIndex++] = Decode(bytes[byteIndex++]);
-            }
-
-            return byteCount;
-        }
-
-        public override unsafe int GetChars(byte* bytes, int byteCount, char* chars, int charCount)
-        {
-            if (charCount < byteCount)
-            {
-                throw new ArgumentException(nameof(charCount)); // The output char buffer is too small to contain the decoded characters
-            }
-
-            byte* end = bytes + byteCount;
-            while (bytes < end)
-            {
-                *chars++ = Decode(*bytes++);
-            }
-
-            return byteCount;
-        }
-
-        private static readonly char[] s_c1ControlChars =
-        {
-            /* x80 */ '\u20ac' /* Euro Sign */,
-            /* x81 */ '\u0081' /* <control> */,
-            /* x82 */ '\u201a' /* Colon Sign */,
-            /* x83 */ '\u0192' /* Latin Small Letter F With Hook */,
-            /* x84 */ '\u201e' /* Double Low-9 Quotation Mark */,
-            /* x85 */ '\u2026' /* Horizontal Ellipsis */,
-            /* x86 */ '\u2020' /* Dagger */,
-            /* x87 */ '\u2021' /* Double Dagger */,
-            /* x88 */ '\u02c6' /* Modifier Letter Cicumflex Accent */,
-            /* x89 */ '\u2030' /* Per Mille Sign */,
-            /* x8a */ '\u0160' /* Latin Capital Letter S With Caron */,
-            /* x8b */ '\u2039' /* Single Left-Pointing Angle Quotation Mark */,
-            /* x8c */ '\u0152' /* Latin Capital Ligature Oe */,
-            /* x8d */ '\u008d' /* Reverse Line Feed */,
-            /* x8e */ '\u017d' /* Latin Capital Letter Z With Caron */,
-            /* x8f */ '\u008f' /* Single Shift Three */,
-            /* x90 */ '\u0090' /* Device Control String */,
-            /* x91 */ '\u2018' /* Left Single Quotation Mark */,
-            /* x92 */ '\u2019' /* Right Single Quotation Mark */,
-            /* x93 */ '\u201c' /* Left Double Quotation Mark */,
-            /* x94 */ '\u201d' /* Right Double Quotation Mark */,
-            /* x95 */ '\u2022' /* Bullet */,
-            /* x96 */ '\u2013' /* En Dash */,
-            /* x97 */ '\u2014' /* Em Dash */,
-            /* x98 */ '\u02dc' /* Small Tilde */,
-            /* x99 */ '\u2122' /* Trade Mark Sign */,
-            /* x9a */ '\u0161' /* Latin Small Letter S With Caron */,
-            /* x9b */ '\u203a' /* Single Right-Pointing Angle Quotation Mark */,
-            /* x9c */ '\u0153' /* Latin Small Ligature Oe */,
-            /* x9d */ '\u009d' /* Operating System Command */,
-            /* x9e */ '\u017e' /* Latin Small Letter Z With Caron */,
-            /* x9f */ '\u0178' /* Latin Captial Letter Y With Diaeresis */,
-        };
-
-        private static char Decode(byte b)
-        {
-            // For characters in the C1 Control set (0x80 to 0x9F), use the table.
-            // Otherwise, the mapping is 1 to 1.
-            uint c1 = unchecked(b - 0x80u);
-            return c1 < 0x20u ? s_c1ControlChars[c1] : (char)b;
-        }
-
-        public override int GetMaxByteCount(int charCount)
-        {
-            // This is a decoder only
-            throw new NotSupportedException();
-        }
-
-        public override int GetMaxCharCount(int byteCount)
-        {
-            if (byteCount < 0)
-            {
-                throw new ArgumentOutOfRangeException(nameof(byteCount));
-            }
-
-            // This is SBCS, so everything is 1:1
-            return byteCount;
-        }
-    }
-}

src/Compilers/Core/Desktop/EncodedStringText.cs

@@ -18,12 +18,29 @@ internal static class EncodedStringText
         /// </summary>
         private static readonly Encoding s_fallbackEncoding = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false, throwOnInvalidBytes: true);
 
+        /// <summary>
+        /// Encoding to use when UTF-8 fails. If available, we use CodePage 1252. If not, we use Latin1.
+        /// </summary>
+        private static readonly Encoding s_defaultEncoding = GetDefaultEncoding();
+
+        private static Encoding GetDefaultEncoding()
+        {
+            try
+            {
+                return Encoding.GetEncoding(codepage: 1252);
+            }
+            catch (NotSupportedException)
+            {
+                return Encoding.GetEncoding(name: "Latin1");
+            }
+        }
+
         /// <summary>
         /// Initializes an instance of <see cref="SourceText"/> from the provided stream. This version differs
         /// from <see cref="SourceText.From(Stream, Encoding, SourceHashAlgorithm, bool)"/> in two ways:
         /// 1. It attempts to minimize allocations by trying to read the stream into a byte array.
         /// 2. If <paramref name="defaultEncoding"/> is null, it will first try UTF8 and, if that fails, it will
-        ///    try CodePage 1252.
+        ///    try CodePage 1252. If CodePage 1252 is not available on the system, then it will try Latin1.
         /// </summary>
         /// <param name="stream">The stream containing encoded text.</param>
         /// <param name="defaultEncoding">
@@ -57,7 +74,7 @@ internal static SourceText Create(Stream stream, Encoding defaultEncoding = null
 
             try
             {
-                return Decode(stream, defaultEncoding ?? CodePage1252Encoding.Instance, checksumAlgorithm, throwIfBinaryDetected: detectEncoding);
+                return Decode(stream, defaultEncoding ?? s_defaultEncoding, checksumAlgorithm, throwIfBinaryDetected: detectEncoding);
             }
             catch (DecoderFallbackException e)
             {

src/Workspaces/Core/Desktop/Workspaces.Desktop.csproj

@@ -62,9 +62,6 @@
     <Compile Include="..\..\..\Compilers\Core\Desktop\AssemblyReferenceResolver.cs">
       <Link>InternalUtilities\AssemblyReferenceResolver.cs</Link>
     </Compile>
-    <Compile Include="..\..\..\Compilers\Core\Desktop\CodePage1252Encoding.cs">
-      <Link>InternalUtilities\CodePage1252Encoding.cs</Link>
-    </Compile>
     <Compile Include="..\..\..\Compilers\Core\Desktop\MetadataFileReferenceResolver.cs">
       <Link>InternalUtilities\MetadataFileReferenceResolver.cs</Link>
     </Compile>