Make Environment.GetCommandLineArgs() PNSE on Project N (#3881)

As opposed to NRE'ing due to using the result of a startup
helper that doesn't exist on the N toolchain...

5 files changed, 82 insertions, 62 deletions

diff --git a/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.CoreRT.cs b/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.CoreRT.cs
index 8174af9b5..c72b13b36 100644
--- a/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.CoreRT.cs
+++ b/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.CoreRT.cs
@@ -3,21 +3,15 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections;
 using System.Runtime;
-using System.Runtime.CompilerServices;
 
 namespace Internal.Runtime.Augments
 {
     /// <summary>For internal use only.  Exposes runtime functionality to the Environments implementation in corefx.</summary>
     public static partial class EnvironmentAugments
     {
-        public static int CurrentManagedThreadId => System.Threading.ManagedThreadId.Current;
-        public static void FailFast(string message, Exception error) => RuntimeExceptionHelpers.FailFast(message, error);
-
         public static void Exit(int exitCode)
         {
-#if CORERT
             s_latchedExitCode = exitCode;
 
             ShutdownCore();
@@ -25,28 +19,6 @@ namespace Internal.Runtime.Augments
             RuntimeImports.RhpShutdown();
 
             Interop.ExitProcess(s_latchedExitCode);
-#else
-            // This needs to be implemented for ProjectN.
-            throw new PlatformNotSupportedException();
-#endif
-        }
-
-        internal static void ShutdownCore()
-        {
-            // Here we'll handle AppDomain.ProcessExit, shut down threading etc.
-        }
-
-        private static int s_latchedExitCode;
-        public static int ExitCode
-        {
-            get
-            {
-                return s_latchedExitCode;
-            }
-            set
-            {
-                s_latchedExitCode = value;
-            }
         }
 
         private static string[] s_commandLineArgs;
@@ -58,38 +30,7 @@ namespace Internal.Runtime.Augments
 
         public static string[] GetCommandLineArgs()
         {
-            return (string[])s_commandLineArgs?.Clone();
+            return (string[])s_commandLineArgs.Clone();
         }
-
-        public static bool HasShutdownStarted => false; // .NET Core does not have shutdown finalization
-
-        public static string StackTrace
-        {
-            // Disable inlining to have predictable stack frame to skip
-            [MethodImpl(MethodImplOptions.NoInlining)]
-            get
-            {
-                // RhGetCurrentThreadStackTrace returns the number of frames(cFrames) added to input buffer.
-                // It returns a negative value, -cFrames which is the required array size, if the buffer is too small.
-                // Initial array length is deliberately chosen to be 0 so that we reallocate to exactly the right size
-                // for StackFrameHelper.FormatStackTrace call. If we want to do this optimistically with one call change
-                // FormatStackTrace to accept an explicit length.
-                IntPtr[] frameIPs = Array.Empty<IntPtr>();
-                int cFrames = RuntimeImports.RhGetCurrentThreadStackTrace(frameIPs);
-                if (cFrames < 0)
-                {
-                    frameIPs = new IntPtr[-cFrames];
-                    cFrames = RuntimeImports.RhGetCurrentThreadStackTrace(frameIPs);
-                    if (cFrames < 0)
-                    {
-                        return "";
-                    }
-                }
-
-                return Internal.Diagnostics.StackTraceHelper.FormatStackTrace(frameIPs, 1, true);
-            }
-        }
-
-        public static int TickCount => Environment.TickCount;
     }
 }
diff --git a/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.ProjectN.cs b/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.ProjectN.cs
new file mode 100644
index 000000000..f0fbc7b20
--- /dev/null
+++ b/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.ProjectN.cs
@@ -0,0 +1,23 @@
+// 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;
+
+namespace Internal.Runtime.Augments
+{
+    /// <summary>For internal use only.  Exposes runtime functionality to the Environments implementation in corefx.</summary>
+    public static partial class EnvironmentAugments
+    {
+        public static void Exit(int exitCode)
+        {
+            // This needs to be implemented for ProjectN.
+            throw new PlatformNotSupportedException();
+        }
+
+        public static string[] GetCommandLineArgs()
+        {
+            throw new PlatformNotSupportedException(SR.PlatformNotSupported_GetCommandLineArgs);
+        }
+    }
+}
diff --git a/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.cs b/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.cs
index 0780db2ea..1ad18b8d6 100644
--- a/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.cs
+++ b/src/System.Private.CoreLib/src/Internal/Runtime/Augments/EnvironmentAugments.cs
@@ -109,5 +109,57 @@ namespace Internal.Runtime.Augments
             else
                 throw new ArgumentOutOfRangeException(nameof(target), target, SR.Format(SR.Arg_EnumIllegalVal, target));
         }
+
+        public static int CurrentManagedThreadId => System.Threading.ManagedThreadId.Current;
+        public static void FailFast(string message, Exception error) => RuntimeExceptionHelpers.FailFast(message, error);
+
+        internal static void ShutdownCore()
+        {
+            // Here we'll handle AppDomain.ProcessExit, shut down threading etc.
+        }
+
+        private static int s_latchedExitCode;
+        public static int ExitCode
+        {
+            get
+            {
+                return s_latchedExitCode;
+            }
+            set
+            {
+                s_latchedExitCode = value;
+            }
+        }
+
+        public static bool HasShutdownStarted => false; // .NET Core does not have shutdown finalization
+
+        public static string StackTrace
+        {
+            // Disable inlining to have predictable stack frame to skip
+            [MethodImpl(MethodImplOptions.NoInlining)]
+            get
+            {
+                // RhGetCurrentThreadStackTrace returns the number of frames(cFrames) added to input buffer.
+                // It returns a negative value, -cFrames which is the required array size, if the buffer is too small.
+                // Initial array length is deliberately chosen to be 0 so that we reallocate to exactly the right size
+                // for StackFrameHelper.FormatStackTrace call. If we want to do this optimistically with one call change
+                // FormatStackTrace to accept an explicit length.
+                IntPtr[] frameIPs = Array.Empty<IntPtr>();
+                int cFrames = RuntimeImports.RhGetCurrentThreadStackTrace(frameIPs);
+                if (cFrames < 0)
+                {
+                    frameIPs = new IntPtr[-cFrames];
+                    cFrames = RuntimeImports.RhGetCurrentThreadStackTrace(frameIPs);
+                    if (cFrames < 0)
+                    {
+                        return "";
+                    }
+                }
+
+                return Internal.Diagnostics.StackTraceHelper.FormatStackTrace(frameIPs, 1, true);
+            }
+        }
+
+        public static int TickCount => Environment.TickCount;
     }
 }
diff --git a/src/System.Private.CoreLib/src/Resources/Strings.resx b/src/System.Private.CoreLib/src/Resources/Strings.resx
index 53a8ed147..9e8c957ee 100644
--- a/src/System.Private.CoreLib/src/Resources/Strings.resx
+++ b/src/System.Private.CoreLib/src/Resources/Strings.resx
@@ -2449,4 +2449,7 @@
   <data name="Arg_OpenType" xml:space="preserve">
     <value>Cannot create an instance of {0} as it is an open type.</value>
   </data>
+  <data name="PlatformNotSupported_GetCommandLineArgs" xml:space="preserve">
+    <value>Environment.GetCommandLineArgs() is not supported on this platform.</value>
+  </data>
 </root>
diff --git a/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj b/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj
index 7bb5fecda..330c5adb9 100644
--- a/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj
+++ b/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj
@@ -116,7 +116,8 @@
     <Compile Include="Internal\Runtime\Augments\DynamicDelegateAugments.cs" />
     <Compile Include="Internal\Runtime\Augments\EnumInfo.cs" />
     <Compile Include="Internal\Runtime\Augments\EnvironmentAugments.cs" />
-    <Compile Include="Internal\Runtime\Augments\EnvironmentAugments.CoreRT.cs" />
+    <Compile Condition="'$(IsProjectNLibrary)' != 'true'" Include="Internal\Runtime\Augments\EnvironmentAugments.CoreRT.cs" />
+    <Compile Condition="'$(IsProjectNLibrary)' == 'true'" Include="Internal\Runtime\Augments\EnvironmentAugments.ProjectN.cs" />
     <Compile Condition="'$(TargetsWindows)'=='true'" Include="Internal\Runtime\Augments\EnvironmentAugments.Windows.cs" />
     <Compile Condition="'$(TargetsUnix)'=='true'" Include="Internal\Runtime\Augments\EnvironmentAugments.Unix.cs" />
     <Compile Include="Internal\Runtime\Augments\RuntimeThread.cs" />
@@ -852,4 +853,4 @@
   </ItemGroup>
   <Import Project="..\shared\System.Private.CoreLib.Shared.projitems" Label="Shared" />
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
-</Project>
\ No newline at end of file
+</Project>