Cleanup | Centralise AppContext switches (#3492)

* Move globalization invariant mode detection to LocalAppContextSwitches

* Move TruncateScaledDecimal switch to LocalAppContextSwitches

* Move UseManagedSNI to LocalAppContextSwitches

* Add ILLink.Substitutions.xml resources to trim unused SNI

* Remove now-unused constants

* Respond to code review on SqlClient

Move string constants and variables together; add a comment to UseManagedNetworking explaining that it can be turned into a constant by ILLink.

* Sync LocalAppContextSwitchesHelper

* Updated TestScaledDecimalParameter tests

These tests no longer directly set the AppContext switches to round or truncate decimals, since these switches are cached when first queried.

* Remove hardcoded reference to TruncateScaledDecimal switch

Author: edwardneal

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -960,6 +960,11 @@
 
     <Compile Include="Microsoft\Data\SqlClient\TdsParser.Windows.cs" />
     <Compile Include="Microsoft\Data\SqlClient\TdsParserStateObjectNative.cs" />
+
+    <EmbeddedResource Include="$(CommonSourceRoot)Resources\ILLink.Substitutions.Windows.xml">
+      <LogicalName>ILLink.Substitutions.xml</LogicalName>
+      <Link>Resources\ILLink.Substitutions.Windows.xml</Link>
+    </EmbeddedResource>
   </ItemGroup>
 
   <!-- Unix only -->
@@ -1002,6 +1007,11 @@
     </Compile>
 
     <Compile Include="Microsoft\Data\SqlClient\TdsParser.Unix.cs" />
+
+    <EmbeddedResource Include="$(CommonSourceRoot)Resources\ILLink.Substitutions.Unix.xml">
+      <LogicalName>ILLink.Substitutions.xml</LogicalName>
+      <Link>Resources\ILLink.Substitutions.Unix.xml</Link>
+    </EmbeddedResource>
   </ItemGroup>
 
   <!-- Resources -->

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnection.cs

@@ -31,13 +31,6 @@ namespace Microsoft.Data.SqlClient
     [DesignerCategory("")]
     public sealed partial class SqlConnection : DbConnection, ICloneable
     {
-        private enum CultureCheckState : uint
-        {
-            Unknown = 0,
-            Standard = 1,
-            Invariant = 2
-        }
-
         private bool _AsyncCommandInProgress;
 
         // SQLStatistics support
@@ -75,9 +68,6 @@ private enum CultureCheckState : uint
         // using SqlConnection.Open() method.
         internal bool _applyTransientFaultHandling = false;
 
-        // status of invariant culture environment check
-        private static CultureCheckState _cultureCheckState;
-
         // System column encryption key store providers are added by default
         private static readonly Dictionary<string, SqlColumnEncryptionKeyStoreProvider> s_systemColumnEncryptionKeyStoreProviders
             = new(capacity: 3, comparer: StringComparer.OrdinalIgnoreCase)
@@ -1956,48 +1946,9 @@ private bool TryOpen(TaskCompletionSource<DbConnectionInternal> retry, SqlConnec
         {
             SqlConnectionString connectionOptions = (SqlConnectionString)ConnectionOptions;
 
-            if (_cultureCheckState != CultureCheckState.Standard)
+            if (LocalAppContextSwitches.GlobalizationInvariantMode)
             {
-                // .NET Core 2.0 and up supports a Globalization Invariant Mode to reduce the size of
-                // required libraries for applications which don't need globalization support. SqlClient
-                // requires those libraries for core functionality and will throw exceptions later if they
-                // are not present. Throwing on open with a meaningful message helps identify the issue.
-                if (_cultureCheckState == CultureCheckState.Unknown)
-                {
-                    // check if invariant state has been set by appcontext switch directly 
-                    if (AppContext.TryGetSwitch("System.Globalization.Invariant", out bool isEnabled) && isEnabled)
-                    {
-                        _cultureCheckState = CultureCheckState.Invariant;
-                    }
-                    else
-                    {
-                        // check if invariant state has been set through environment variables
-                        string envValue = Environment.GetEnvironmentVariable("DOTNET_SYSTEM_GLOBALIZATION_INVARIANT");
-                        if (string.Equals(envValue, bool.TrueString, StringComparison.OrdinalIgnoreCase) || string.Equals(envValue, "1", StringComparison.OrdinalIgnoreCase))
-                        {
-                            _cultureCheckState = CultureCheckState.Invariant;
-                        }
-                        else
-                        {
-                            // if it hasn't been manually set it could still apply if the os doesn't have
-                            //  icu libs installed or is a native binary with icu support trimmed away
-                            // netcore 3.1 to net5 do not throw in attempting to create en-us in inariant mode
-                            // net6 and greater will throw so catch and infer invariant mode from the exception
-                            try
-                            {
-                                _cultureCheckState = CultureInfo.GetCultureInfo("en-US").EnglishName.Contains("Invariant") ? CultureCheckState.Invariant : CultureCheckState.Standard;
-                            }
-                            catch (CultureNotFoundException)
-                            {
-                                _cultureCheckState = CultureCheckState.Invariant;
-                            }
-                        }
-                    }
-                }
-                if (_cultureCheckState == CultureCheckState.Invariant)
-                {
-                    throw SQL.GlobalizationInvariantModeNotSupported();
-                }
+                throw SQL.GlobalizationInvariantModeNotSupported();
             }
 
             _applyTransientFaultHandling = (!overrides.HasFlag(SqlConnectionOverrides.OpenWithoutRetry) && connectionOptions != null && connectionOptions.ConnectRetryCount > 0);

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.Windows.cs

@@ -11,7 +11,7 @@ internal sealed partial class TdsParser
     {
         internal void PostReadAsyncForMars()
         {
-            if (TdsParserStateObjectFactory.UseManagedSNI)
+            if (LocalAppContextSwitches.UseManagedNetworking)
                 return;
 
             // HACK HACK HACK - for Async only

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -69,7 +69,6 @@ internal sealed partial class TdsParser
         // Constants
         private const int constBinBufferSize = 4096; // Size of the buffer used to read input parameter of type Stream
         private const int constTextBufferSize = 4096; // Size of the buffer (in chars) user to read input parameter of type TextReader
-        private const string enableTruncateSwitch = "Switch.Microsoft.Data.SqlClient.TruncateScaledDecimal"; // for applications that need to maintain backwards compatibility with the previous behavior
 
         // State variables
         internal TdsParserState _state = TdsParserState.Closed; // status flag for connection
@@ -204,16 +203,6 @@ internal SqlInternalConnectionTds Connection
             }
         }
 
-        private static bool EnableTruncateSwitch
-        {
-            get
-            {
-                bool value;
-                value = AppContext.TryGetSwitch(enableTruncateSwitch, out value) ? value : false;
-                return value;
-            }
-        }
-
         internal SqlInternalTransaction CurrentTransaction
         {
             get
@@ -631,7 +620,7 @@ internal void EnableMars()
                 // Cache physical stateObj and connection.
                 _pMarsPhysicalConObj = _physicalStateObj;
 
-                if (TdsParserStateObjectFactory.UseManagedSNI)
+                if (LocalAppContextSwitches.UseManagedNetworking)
                     _pMarsPhysicalConObj.IncrementPendingCallbacks();
 
                 uint info = 0;
@@ -1489,7 +1478,7 @@ internal SqlError ProcessSNIError(TdsParserStateObject stateObj)
                  * !=null       | == 0     | replace text left of errorMessage
                  */
 
-                if (TdsParserStateObjectFactory.UseManagedSNI)
+                if (LocalAppContextSwitches.UseManagedNetworking)
                 {
                     Debug.Assert(!string.IsNullOrEmpty(details.ErrorMessage) || details.SniErrorNumber != 0, "Empty error message received from SNI");
                     SqlClientEventSource.Log.TryAdvancedTraceEvent("<sc.TdsParser.ProcessSNIError |ERR|ADV > Empty error message received from SNI. Error Message = {0}, SNI Error Number ={1}", details.ErrorMessage, details.SniErrorNumber);
@@ -1538,7 +1527,7 @@ internal SqlError ProcessSNIError(TdsParserStateObject stateObj)
                 }
                 else
                 {
-                    if (TdsParserStateObjectFactory.UseManagedSNI)
+                    if (LocalAppContextSwitches.UseManagedNetworking)
                     {
                         // SNI error. Append additional error message info if available and hasn't been included.
                         string sniLookupMessage = SQL.GetSNIErrorMessage(details.SniErrorNumber);
@@ -7653,7 +7642,7 @@ internal static SqlDecimal AdjustSqlDecimalScale(SqlDecimal d, int newScale)
         {
             if (d.Scale != newScale)
             {
-                bool round = !EnableTruncateSwitch;
+                bool round = !LocalAppContextSwitches.TruncateScaledDecimal;
                 return SqlDecimal.AdjustScale(d, newScale - d.Scale, round);
             }
 
@@ -7666,7 +7655,7 @@ internal static decimal AdjustDecimalScale(decimal value, int newScale)
 
             if (newScale != oldScale)
             {
-                bool round = !EnableTruncateSwitch;
+                bool round = !LocalAppContextSwitches.TruncateScaledDecimal;
                 SqlDecimal num = new SqlDecimal(value);
                 num = SqlDecimal.AdjustScale(num, newScale - oldScale, round);
                 return num.Value;

src/Microsoft.Data.SqlClient/netfx/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -69,7 +69,6 @@ internal sealed partial class TdsParser
         // Constants
         private const int constBinBufferSize = 4096; // Size of the buffer used to read input parameter of type Stream
         private const int constTextBufferSize = 4096; // Size of the buffer (in chars) user to read input parameter of type TextReader
-        private const string enableTruncateSwitch = "Switch.Microsoft.Data.SqlClient.TruncateScaledDecimal"; // for applications that need to maintain backwards compatibility with the previous behavior
 
         // State variables
         internal TdsParserState _state = TdsParserState.Closed; // status flag for connection
@@ -205,16 +204,6 @@ internal SqlInternalConnectionTds Connection
             }
         }
 
-        private static bool EnableTruncateSwitch
-        {
-            get
-            {
-                bool value;
-                value = AppContext.TryGetSwitch(enableTruncateSwitch, out value) ? value : false;
-                return value;
-            }
-        }
-
         internal SqlInternalTransaction CurrentTransaction
         {
             get
@@ -7849,7 +7838,7 @@ internal static SqlDecimal AdjustSqlDecimalScale(SqlDecimal d, int newScale)
         {
             if (d.Scale != newScale)
             {
-                bool round = !EnableTruncateSwitch;
+                bool round = !LocalAppContextSwitches.TruncateScaledDecimal;
                 return SqlDecimal.AdjustScale(d, newScale - d.Scale, round);
             }
 
@@ -7862,7 +7851,7 @@ internal static decimal AdjustDecimalScale(decimal value, int newScale)
 
             if (newScale != oldScale)
             {
-                bool round = !EnableTruncateSwitch;
+                bool round = !LocalAppContextSwitches.TruncateScaledDecimal;
                 SqlDecimal num = new SqlDecimal(value);
                 num = SqlDecimal.AdjustScale(num, newScale - oldScale, round);
                 return num.Value;

src/Microsoft.Data.SqlClient/src/Microsoft/Data/Sql/SqlDataSourceEnumerator.Windows.cs

@@ -15,7 +15,7 @@ private partial DataTable GetDataSourcesInternal()
 #if NETFRAMEWORK
             return SqlDataSourceEnumeratorNativeHelper.GetDataSources();
 #else
-            return SqlClient.TdsParserStateObjectFactory.UseManagedSNI ? SqlDataSourceEnumeratorManagedHelper.GetDataSources() : SqlDataSourceEnumeratorNativeHelper.GetDataSources();
+            return SqlClient.LocalAppContextSwitches.UseManagedNetworking ? SqlDataSourceEnumeratorManagedHelper.GetDataSources() : SqlDataSourceEnumeratorNativeHelper.GetDataSources();
 #endif
         }
     }

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/ConnectionPool/DbConnectionPoolIdentity.Windows.cs

@@ -28,7 +28,7 @@ internal static WindowsIdentity GetCurrentWindowsIdentity()
 #else
         internal static DbConnectionPoolIdentity GetCurrent()
         {
-            return TdsParserStateObjectFactory.UseManagedSNI ? GetCurrentManaged() : GetCurrentNative();
+            return LocalAppContextSwitches.UseManagedNetworking ? GetCurrentManaged() : GetCurrentNative();
         }
 #endif