From 0a03aa9b81eeac93a6c6fa238d4123a60009d0f6 Mon Sep 17 00:00:00 2001
From: Marek Safar <marek.safar@gmail.com>
Date: Tue, 1 Jan 2019 21:13:31 +0100
Subject: [PATCH] Moves AppContext to shared location (#21734)

---
 .../System.Private.CoreLib.csproj                  |  2 +-
 .../shared/System.Private.CoreLib.Shared.projitems |  1 +
 .../{src => shared}/System/AppContext.cs           | 29 +++++-----------------
 .../src/System/AppContext.CoreCLR.cs               | 29 ++++++++++++++++++++++
 4 files changed, 37 insertions(+), 24 deletions(-)
 rename src/System.Private.CoreLib/{src => shared}/System/AppContext.cs (82%)
 create mode 100644 src/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs

diff --git a/src/System.Private.CoreLib/System.Private.CoreLib.csproj b/src/System.Private.CoreLib/System.Private.CoreLib.csproj
index be9dabd..0541c4b 100644
--- a/src/System.Private.CoreLib/System.Private.CoreLib.csproj
+++ b/src/System.Private.CoreLib/System.Private.CoreLib.csproj
@@ -125,7 +125,7 @@
     <Compile Include="$(BclSourcesRoot)\Microsoft\Win32\Win32Native.cs" />
     <Compile Include="$(BclSourcesRoot)\System\__Canon.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Activator.cs" />
-    <Compile Include="$(BclSourcesRoot)\System\AppContext.cs" />
+    <Compile Include="$(BclSourcesRoot)\System\AppContext.CoreCLR.cs" />
     <Compile Include="$(BclSourcesRoot)\System\ArgIterator.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Array.cs" />
     <Compile Include="$(BclSourcesRoot)\System\Attribute.cs" />
diff --git a/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems b/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems
index 7364bb2..6a93908 100644
--- a/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems
+++ b/src/System.Private.CoreLib/shared/System.Private.CoreLib.Shared.projitems
@@ -29,6 +29,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Microsoft\Win32\SafeHandles\SafeWaitHandle.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\Action.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\AccessViolationException.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)System\AppContext.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\ApplicationException.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\AggregateException.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)System\ArgumentException.cs" />
diff --git a/src/System.Private.CoreLib/src/System/AppContext.cs b/src/System.Private.CoreLib/shared/System/AppContext.cs
similarity index 82%
rename from src/System.Private.CoreLib/src/System/AppContext.cs
rename to src/System.Private.CoreLib/shared/System/AppContext.cs
index d559e88..11760ad 100644
--- a/src/System.Private.CoreLib/src/System/AppContext.cs
+++ b/src/System.Private.CoreLib/shared/System/AppContext.cs
@@ -2,9 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-
 using System.Collections.Generic;
-using System.IO;
 using System.Reflection;
 using System.Runtime.ExceptionServices;
 using System.Runtime.Loader;
@@ -13,18 +11,11 @@ using System.Threading;
 
 namespace System
 {
-    public static class AppContext
+    public static partial class AppContext
     {
         private static readonly Dictionary<string, object> s_dataStore = new Dictionary<string, object>();
         private static Dictionary<string, bool> s_switches;
-
-        internal static unsafe void Setup(char** pNames, char** pValues, int count)
-        {
-            for (int i = 0; i < count; i++)
-            {
-                s_dataStore.Add(new string(pNames[i]), new string(pValues[i]));
-            }
-        }
+        private static string s_defaultBaseDirectory;
 
         public static string BaseDirectory
         {
@@ -32,15 +23,8 @@ namespace System
             {
                 // The value of APP_CONTEXT_BASE_DIRECTORY key has to be a string and it is not allowed to be any other type. 
                 // Otherwise the caller will get invalid cast exception
-                string baseDirectory = (string)GetData("APP_CONTEXT_BASE_DIRECTORY");
-                if (baseDirectory != null)
-                    return baseDirectory;
-
-                // Fallback path for hosts that do not set APP_CONTEXT_BASE_DIRECTORY explicitly
-                string directory = Path.GetDirectoryName(Assembly.GetEntryAssembly()?.Location);
-                if (directory != null && !PathInternal.EndsInDirectorySeparator(directory))
-                    directory += Path.DirectorySeparatorChar;
-                return directory;
+                return (string)GetData("APP_CONTEXT_BASE_DIRECTORY") ??
+                    (s_defaultBaseDirectory ?? (s_defaultBaseDirectory = GetBaseDirectoryCore()));
             }
         }
 
@@ -116,10 +100,9 @@ namespace System
             }
 
             string value = GetData(switchName) as string;
-            if (value != null)
+            if (value != null && bool.TryParse(value, out isEnabled))
             {
-                if (bool.TryParse(value, out isEnabled))
-                    return true;
+               return true;
             }
 
             isEnabled = false;
diff --git a/src/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs b/src/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs
new file mode 100644
index 0000000..4d11c16
--- /dev/null
+++ b/src/System.Private.CoreLib/src/System/AppContext.CoreCLR.cs
@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.IO;
+using System.Reflection;
+
+namespace System
+{
+    public static partial class AppContext
+    {
+        internal static unsafe void Setup(char** pNames, char** pValues, int count)
+        {
+            for (int i = 0; i < count; i++)
+            {
+                s_dataStore.Add(new string(pNames[i]), new string(pValues[i]));
+            }
+        }
+
+        private static string GetBaseDirectoryCore()
+        {
+            // Fallback path for hosts that do not set APP_CONTEXT_BASE_DIRECTORY explicitly
+            string directory = Path.GetDirectoryName(Assembly.GetEntryAssembly()?.Location);
+            if (directory != null && !PathInternal.EndsInDirectorySeparator(directory))
+                directory += Path.DirectorySeparatorChar;
+            return directory;
+        }
+    }
+}
-- 
2.7.4