From dc2d741791ac0f94d6eb2d322da1a9c7b87a1e95 Mon Sep 17 00:00:00 2001
From: Dongbo Wang <dongbow@microsoft.com>
Date: Wed, 27 Jun 2018 17:16:21 -0700
Subject: [PATCH] Add logging, formatting, and '$EnabledExperimentalFeatures'

---
 .../PowerShell.Core.Instrumentation.man       |  65 ++++++++
 .../PowerShellCore_format_ps1xml.cs           |  31 ++++
 .../ExperimentalFeature.cs                    | 140 +++++++++---------
 .../engine/Modules/ModuleCmdletBase.cs        |   2 +-
 .../engine/SessionState.cs                    |   9 +-
 .../engine/SpecialVariables.cs                |  16 +-
 .../engine/parser/TypeResolver.cs             |   4 +-
 .../engine/remoting/common/PSETWTracer.cs     |   5 +
 .../resources/Logging.resx                    |   9 ++
 .../resources/RunspaceInit.resx               |   3 +
 10 files changed, 197 insertions(+), 87 deletions(-)

diff --git a/src/PowerShell.Core.Instrumentation/PowerShell.Core.Instrumentation.man b/src/PowerShell.Core.Instrumentation/PowerShell.Core.Instrumentation.man
index 33c0a5f519..491e4a8746 100644
--- a/src/PowerShell.Core.Instrumentation/PowerShell.Core.Instrumentation.man
+++ b/src/PowerShell.Core.Instrumentation/PowerShell.Core.Instrumentation.man
@@ -98,6 +98,29 @@
               value="0xD003"
               version="1"
               />
+          <!--ExperimentalFeature event-->
+          <event
+              channel="C_OPERATIONAL"
+              level="win:Error"
+              message="$(string.PS_PROVIDER.event.E_O_ExperimentalFeatureInvalidName.message)"
+              opcode="Constructor"
+              symbol="ExperimentalFeatureInvalidName"
+              task="ExperimentalFeature"
+              template="T_ExperimentalFeatureInvalidName"
+              value="0x3001"
+              version="1"
+              />
+          <event
+              channel="C_OPERATIONAL"
+              level="win:Error"
+              message="$(string.PS_PROVIDER.event.E_O_ExperimentalFeatureReadConfigError.message)"
+              opcode="Constructor"
+              symbol="ExperimentalFeatureReadConfigError"
+              task="ExperimentalFeature"
+              template="T_ExperimentalFeatureReadConfigError"
+              value="0x3002"
+              version="1"
+              />
           <!--M3P events-->
           <event
               channel="C_ANALYTIC"
@@ -2368,6 +2391,12 @@
               symbol="T_EXECUTEPIEPLINE"
               value="106"
               />
+          <task
+              message="$(string.PS_PROVIDER.task.T_ExperimentalFeature.message)"
+              name="ExperimentalFeature"
+              symbol="T_EXPERIMENTALFEATURE"
+              value="107"
+              />
           <task
               message="$(string.PS_PROVIDER.task.T_ScheduledJob.message)"
               name="ScheduledJob"
@@ -3927,6 +3956,30 @@
                 name="InnerException"
                 />
           </template>
+          <template tid="T_ExperimentalFeatureInvalidName">
+            <data
+                inType="win:UnicodeString"
+                name="Name"
+                />
+            <data
+                inType="win:UnicodeString"
+                name="Message"
+                />
+          </template>
+          <template tid="T_ExperimentalFeatureReadConfigError">
+            <data
+                inType="win:UnicodeString"
+                name="Name"
+                />
+            <data
+                inType="win:UnicodeString"
+                name="Message"
+                />
+            <data
+                inType="win:UnicodeString"
+                name="StackTrace"
+                />
+          </template>
           <template tid="T_TrackingGuid">
             <data
                 inType="win:GUID"
@@ -5428,6 +5481,18 @@
             id="PS_PROVIDER.task.T_ScheduledJob.message"
             value="PowerShell Scheduled Jobs"
             />
+        <string
+            id="PS_PROVIDER.event.E_O_ExperimentalFeatureInvalidName.message"
+            value="Experimental Feature Initialization: Ignore the experimental feature %1 from the config file. %2"
+            />
+        <string
+            id="PS_PROVIDER.event.E_O_ExperimentalFeatureReadConfigError.message"
+            value="Experimental Feature Initialization: Failed to read the config file.%n Exception %1: %n Message: %2 %n StackTrace: %3 %n"
+            />
+        <string
+            id="PS_PROVIDER.task.T_ExperimentalFeature.message"
+            value="PowerShell Experimental Features"
+            />
         <string
             id="PS_PROVIDER.task.T_NamedPipe.message"
             value="PowerShell Named Pipe IPC"
diff --git a/src/System.Management.Automation/FormatAndOutput/DefaultFormatters/PowerShellCore_format_ps1xml.cs b/src/System.Management.Automation/FormatAndOutput/DefaultFormatters/PowerShellCore_format_ps1xml.cs
index 682acddb14..d33c54dd64 100644
--- a/src/System.Management.Automation/FormatAndOutput/DefaultFormatters/PowerShellCore_format_ps1xml.cs
+++ b/src/System.Management.Automation/FormatAndOutput/DefaultFormatters/PowerShellCore_format_ps1xml.cs
@@ -230,6 +230,10 @@ namespace System.Management.Automation.Runspaces
                 "System.Management.Automation.PSModuleInfo",
                 ViewsOf_System_Management_Automation_PSModuleInfo());
 
+            yield return new ExtendedTypeDefinition(
+                "System.Management.Automation.ExperimentalFeature",
+                ViewsOf_System_Management_Automation_ExperimentalFeature());
+
             var td46 = new ExtendedTypeDefinition(
                 "Microsoft.PowerShell.Commands.BasicHtmlWebResponseObject",
                 ViewsOf_Microsoft_PowerShell_Commands_BasicHtmlWebResponseObject());
@@ -1240,6 +1244,33 @@ namespace System.Management.Automation.Runspaces
                 .EndList());
         }
 
+        private static IEnumerable<FormatViewDefinition> ViewsOf_System_Management_Automation_ExperimentalFeature()
+        {
+            yield return new FormatViewDefinition("ExperimentalFeature",
+                TableControl.Create()
+                    .AddHeader(Alignment.Left, width: 35)
+                    .AddHeader(Alignment.Right, width: 10)
+                    .AddHeader(Alignment.Left, width: 35)
+                    .AddHeader(Alignment.Left)
+                    .StartRowDefinition()
+                        .AddPropertyColumn("Name")
+                        .AddPropertyColumn("Enabled")
+                        .AddPropertyColumn("Source")
+                        .AddPropertyColumn("Description")
+                    .EndRowDefinition()
+                .EndTable());
+
+            yield return new FormatViewDefinition("ExperimentalFeature",
+                ListControl.Create()
+                    .StartEntry()
+                        .AddItemProperty("Name")
+                        .AddItemProperty("Enabled")
+                        .AddItemProperty("Source")
+                        .AddItemProperty("Description")
+                    .EndEntry()
+                .EndList());
+        }
+
         private static IEnumerable<FormatViewDefinition> ViewsOf_Microsoft_PowerShell_Commands_BasicHtmlWebResponseObject()
         {
             yield return new FormatViewDefinition("Microsoft.PowerShell.Commands.BasicHtmlWebResponseObject",
diff --git a/src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs b/src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs
index 7a76b0075b..cabccc1ce2 100644
--- a/src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs
+++ b/src/System.Management.Automation/engine/ExperimentalFeature/ExperimentalFeature.cs
@@ -7,6 +7,7 @@ using System.Collections.Immutable;
 using System.Linq;
 using System.Management.Automation.Configuration;
 using System.Management.Automation.Internal;
+using System.Management.Automation.Tracing;
 using System.Runtime.CompilerServices;
 
 namespace System.Management.Automation
@@ -42,7 +43,7 @@ namespace System.Management.Automation
         /// <summary>
         /// Indicate whether the feature is enabled.
         /// </summary>
-        public bool IsEnabled { get; private set; }
+        public bool Enabled { get; private set; }
 
         /// <summary>
         /// Constructor for ExperimentalFeature.
@@ -52,7 +53,7 @@ namespace System.Management.Automation
             Name = name;
             Description = description;
             Source = source;
-            IsEnabled = isEnabled;
+            Enabled = isEnabled;
         }
 
         #endregion
@@ -85,7 +86,7 @@ namespace System.Management.Automation
                 new ExperimentalFeature(name: "PSFileSystemProviderV2",
                                         description: "Replace the old FileSystemProvider with cleaner design and faster code",
                                         source: EngineSource,
-                                        isEnabled: false))
+                                        isEnabled: false)),
                 */
             };
             EngineExperimentalFeatures = new ReadOnlyCollection<ExperimentalFeature>(engineFeatures);
@@ -102,39 +103,64 @@ namespace System.Management.Automation
             //      instead, it will be done when the type is used for the first time, which is always earlier than
             //      any experimental features take effect.
             string[] enabledFeatures = Utils.EmptyArray<string>();
-            try { enabledFeatures = PowerShellConfig.Instance.GetExperimentalFeatures(); }
-            catch (Exception ex) when (LogException(ex, "Placeholder")) { }
+            try { enabledFeatures = PowerShellConfig.Instance.GetExperimentalFeatures(); } catch (Exception e) when (LogException(e)) { }
 
             EnabledExperimentalFeatureNames = ProcessEnabledFeatures(enabledFeatures);
         }
 
         /// <summary>
-        /// Check if the specified experimental feature has been enabled.
+        /// Process the array of enabled feature names retrieved from configuration.
+        /// Ignore invalid feature names and unavailable engine feature names, and
+        /// return an ImmutableHashSet of the valid enabled feature names.
         /// </summary>
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public static bool HasEnabled(string featureName)
+        private static ImmutableHashSet<string> ProcessEnabledFeatures(string[] enabledFeatures)
         {
-            return EnabledExperimentalFeatureNames.Contains(featureName);
+            if (enabledFeatures.Length == 0) { return ImmutableHashSet.Create<string>(); }
+
+            var list = new List<string>(enabledFeatures.Length);
+            foreach (string name in enabledFeatures)
+            {
+                if (IsModuleFeatureName(name))
+                {
+                    list.Add(name);
+                }
+                else if (IsEngineFeatureName(name))
+                {
+                    if (EngineExperimentalFeatureMap.TryGetValue(name, out ExperimentalFeature feature))
+                    {
+                        feature.Enabled = true;
+                        list.Add(name);
+                    }
+                    else
+                    {
+                        string message = StringUtil.Format(Logging.EngineExperimentalFeatureNotFound, name);
+                        LogError(PSEventId.ExperimentalFeature_InvalidName, name, message);
+                    }
+                }
+                else
+                {
+                    string message = StringUtil.Format(Logging.InvalidExperimentalFeatureName, name);
+                    LogError(PSEventId.ExperimentalFeature_InvalidName, name, message);
+                }
+            }
+            return ImmutableHashSet.CreateRange(StringComparer.OrdinalIgnoreCase, list);
         }
 
         /// <summary>
-        /// Determine the action to take for the specified experiment name and action.
+        /// Log the exception without rewinding the stack.
         /// </summary>
-        internal static ExperimentAction GetActionToTake(string experimentName, ExperimentAction experimentAction)
+        private static bool LogException(Exception e)
         {
-            if (experimentName == null || experimentAction == ExperimentAction.None)
-            {
-                // If either the experiment name or action is not defined, then return 'Show' by default.
-                // This could happen to 'ParameterAttribute' when no experimental related field is declared.
-                return ExperimentAction.Show;
-            }
+            LogError(PSEventId.ExperimentalFeature_ReadConfig_Error, e.GetType().FullName, e.Message, e.StackTrace);
+            return false;
+        }
 
-            ExperimentAction action = experimentAction;
-            if (!HasEnabled(experimentName))
-            {
-                action = (action == ExperimentAction.Hide) ? ExperimentAction.Show : ExperimentAction.Hide;
-            }
-            return action;
+        /// <summary>
+        /// Log an error message.
+        /// </summary>
+        private static void LogError(PSEventId eventId, params object[] args)
+        {
+            PSEtwLog.LogOperationalError(eventId, PSOpcode.Constructor, PSTask.ExperimentalFeature, PSKeyword.UseAlwaysOperational, args);
         }
 
         /// <summary>
@@ -167,56 +193,32 @@ namespace System.Management.Automation
         }
 
         /// <summary>
-        /// Log the exception without rewinding the stack.
+        /// Determine the action to take for the specified experiment name and action.
         /// </summary>
-        private static bool LogException(Exception ex, string errorTemplate)
+        internal static ExperimentAction GetActionToTake(string experimentName, ExperimentAction experimentAction)
         {
-            // TODO: Logging
-            return false;
-        }
-
-        /// <summary>
-        /// Log an error message.
-        /// </summary>
-        private static void LogError(string message)
-        {
-            // TODO: Logging
-        }
-
-        /// <summary>
-        /// Process the array of enabled feature names retrieved from configuration.
-        /// Ignore invalid feature names and unavailable engine feature names, and
-        /// return an ImmutableHashSet of the valid enabled feature names.
-        /// </summary>
-        private static ImmutableHashSet<string> ProcessEnabledFeatures(string[] enabledFeatures)
-        {
-            if (enabledFeatures.Length == 0) { return ImmutableHashSet.Create<string>(); }
-
-            var list = new List<string>(enabledFeatures.Length);
-            foreach (string name in enabledFeatures)
+            if (experimentName == null || experimentAction == ExperimentAction.None)
             {
-                if (IsModuleFeatureName(name))
-                {
-                    list.Add(name);
-                }
-                else if (IsEngineFeatureName(name))
-                {
-                    if (EngineExperimentalFeatureMap.TryGetValue(name, out ExperimentalFeature feature))
-                    {
-                        feature.IsEnabled = true;
-                        list.Add(name);
-                    }
-                    else
-                    {
-                        LogError("No such engine feature registered. Ignore it.");
-                    }
-                }
-                else
-                {
-                    LogError("Invalid experimental feature name. Ignore it");
-                }
+                // If either the experiment name or action is not defined, then return 'Show' by default.
+                // This could happen to 'ParameterAttribute' when no experimental related field is declared.
+                return ExperimentAction.Show;
             }
-            return ImmutableHashSet.CreateRange(StringComparer.OrdinalIgnoreCase, list);
+
+            ExperimentAction action = experimentAction;
+            if (!HasEnabled(experimentName))
+            {
+                action = (action == ExperimentAction.Hide) ? ExperimentAction.Show : ExperimentAction.Hide;
+            }
+            return action;
+        }
+
+        /// <summary>
+        /// Check if the specified experimental feature has been enabled.
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool HasEnabled(string featureName)
+        {
+            return EnabledExperimentalFeatureNames.Contains(featureName);
         }
 
         #endregion
diff --git a/src/System.Management.Automation/engine/Modules/ModuleCmdletBase.cs b/src/System.Management.Automation/engine/Modules/ModuleCmdletBase.cs
index 79ec351b28..412b3446db 100644
--- a/src/System.Management.Automation/engine/Modules/ModuleCmdletBase.cs
+++ b/src/System.Management.Automation/engine/Modules/ModuleCmdletBase.cs
@@ -418,7 +418,7 @@ namespace Microsoft.PowerShell.Commands
         /// <summary>
         /// Extra variables that are allowed to be referenced in module manifest file
         /// </summary>
-        private static readonly string[] s_extraAllowedVariables = new string[] { "PSScriptRoot", "PSEdition" };
+        private static readonly string[] s_extraAllowedVariables = new string[] { SpecialVariables.PSScriptRoot, SpecialVariables.PSEdition, SpecialVariables.EnabledExperimentalFeatures };
 
         /// <summary>
         /// Load and execute the manifest psd1 file or a localized manifest psd1 file.
diff --git a/src/System.Management.Automation/engine/SessionState.cs b/src/System.Management.Automation/engine/SessionState.cs
index 4f66c42110..311b904ccb 100644
--- a/src/System.Management.Automation/engine/SessionState.cs
+++ b/src/System.Management.Automation/engine/SessionState.cs
@@ -363,13 +363,18 @@ namespace System.Management.Automation
             this.GlobalScope.SetVariable(v.Name, v, false, true, this, CommandOrigin.Internal, fastPath: true);
 
             // $PSHOME
-            // This depends on the shellId. If we cannot read the application base
-            // registry key, set the variable to empty string
             string applicationBase = Utils.DefaultPowerShellAppBase;
             v = new PSVariable(SpecialVariables.PSHome, applicationBase,
                     ScopedItemOptions.Constant | ScopedItemOptions.AllScope,
                     RunspaceInit.PSHOMEDescription);
             this.GlobalScope.SetVariable(v.Name, v, false, true, this, CommandOrigin.Internal, fastPath: true);
+
+            // $EnabledExperimentalFeatures
+            v = new PSVariable(SpecialVariables.EnabledExperimentalFeatures,
+                               ExperimentalFeature.EnabledExperimentalFeatureNames,
+                               ScopedItemOptions.Constant | ScopedItemOptions.AllScope,
+                               RunspaceInit.EnabledExperimentalFeatures);
+            this.GlobalScope.SetVariable(v.Name, v, false, true, this, CommandOrigin.Internal, fastPath: true);
         }
 
         /// <summary>
diff --git a/src/System.Management.Automation/engine/SpecialVariables.cs b/src/System.Management.Automation/engine/SpecialVariables.cs
index f1a2c32315..c95689e5ba 100644
--- a/src/System.Management.Automation/engine/SpecialVariables.cs
+++ b/src/System.Management.Automation/engine/SpecialVariables.cs
@@ -225,20 +225,7 @@ namespace System.Management.Automation
         internal const string PSVersionTable = "PSVersionTable";
         internal const string PSEdition = "PSEdition";
         internal const string ShellId = "ShellId";
-
-        internal static List<string> AllScopeSessionVariables = new List<string>
-        {
-            ExecutionContext,
-            Home,
-            Host,
-            PID,
-            PSCulture,
-            PSHome,
-            PSUICulture,
-            PSVersionTable,
-            PSEdition,
-            ShellId
-        };
+        internal const string EnabledExperimentalFeatures = "EnabledExperimentalFeatures";
 
         #endregion AllScope variables created in every session
 
@@ -304,6 +291,7 @@ namespace System.Management.Automation
                                                                   SpecialVariables.PSEdition,
                                                                   SpecialVariables.ShellId,
                                                                   SpecialVariables.True,
+                                                                  SpecialVariables.EnabledExperimentalFeatures,
                                                               };
 
         private static readonly HashSet<string> s_classMethodsAccessibleVariables = new HashSet<string>
diff --git a/src/System.Management.Automation/engine/parser/TypeResolver.cs b/src/System.Management.Automation/engine/parser/TypeResolver.cs
index d347457358..2be4113385 100644
--- a/src/System.Management.Automation/engine/parser/TypeResolver.cs
+++ b/src/System.Management.Automation/engine/parser/TypeResolver.cs
@@ -731,8 +731,10 @@ namespace System.Management.Automation
                     { typeof(DateTime),                                    new[] { "datetime" } },
                     { typeof(decimal),                                     new[] { "decimal" } },
                     { typeof(double),                                      new[] { "double" } },
-                    { typeof(DscResourceAttribute),                        new[] { "DscResource"} },
+                    { typeof(DscResourceAttribute),                        new[] { "DscResource" } },
+                    { typeof(ExperimentAction),                            new[] { "ExperimentAction" } },
                     { typeof(ExperimentalAttribute),                       new[] { "Experimental" } },
+                    { typeof(ExperimentalFeature),                         new[] { "ExperimentalFeature" } },
                     { typeof(float),                                       new[] { "float", "single" } },
                     { typeof(Guid),                                        new[] { "guid" } },
                     { typeof(Hashtable),                                   new[] { "hashtable" } },
diff --git a/src/System.Management.Automation/engine/remoting/common/PSETWTracer.cs b/src/System.Management.Automation/engine/remoting/common/PSETWTracer.cs
index 05164306f5..b898725769 100644
--- a/src/System.Management.Automation/engine/remoting/common/PSETWTracer.cs
+++ b/src/System.Management.Automation/engine/remoting/common/PSETWTracer.cs
@@ -159,6 +159,10 @@ namespace System.Management.Automation.Internal
         Settings = 0x1F04,
         Engine_Trace = 0x1F06,
 
+        // Experimental Features
+        ExperimentalFeature_InvalidName = 0x3001,
+        ExperimentalFeature_ReadConfig_Error = 0x3002,
+
         // Scheduled Jobs
         ScheduledJob_Start = 0xD001,
         ScheduledJob_Complete = 0xD002,
@@ -232,6 +236,7 @@ namespace System.Management.Automation.Internal
         ProviderStart = 0x68,
         ProviderStop = 0x69,
         ExecutePipeline = 0x6A,
+        ExperimentalFeature = 0x6B,
         ScheduledJob = 0x6E,
         NamedPipe = 0x6F,
         ISEOperation = 0x78
diff --git a/src/System.Management.Automation/resources/Logging.resx b/src/System.Management.Automation/resources/Logging.resx
index 7a4d98e500..b8cb1b2947 100644
--- a/src/System.Management.Automation/resources/Logging.resx
+++ b/src/System.Management.Automation/resources/Logging.resx
@@ -288,4 +288,13 @@ AdditionalInfo:
   <data name="UnknownUserName" xml:space="preserve">
     <value>UNKNOWN</value>
   </data>
+  <data name="EngineExperimentalFeatureNotFound" xml:space="preserve">
+    <value>The engine experimental feature '{0}' declared in the config file is not registered in the current PowerShell.</value>
+  </data>
+  <data name="InvalidExperimentalFeatureName" xml:space="preserve">
+    <value>The experimental feature '{0}' declared in the config file is invalid.
+The name of an experimental feature should follow the convention below: 
+    Engine Feature Name: 'PS[FeatureName]'
+    Module Feature Name: '[ModuleName].[FeatureName]'</value>
+  </data>
 </root>
diff --git a/src/System.Management.Automation/resources/RunspaceInit.resx b/src/System.Management.Automation/resources/RunspaceInit.resx
index b8aee86a25..c4a485121c 100644
--- a/src/System.Management.Automation/resources/RunspaceInit.resx
+++ b/src/System.Management.Automation/resources/RunspaceInit.resx
@@ -117,6 +117,9 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
+  <data name="EnabledExperimentalFeatures" xml:space="preserve">
+    <value>Variable to hold the enabled experimental feature names</value>
+  </data>
   <data name="PSHOMEDescription" xml:space="preserve">
     <value>Parent folder of the host application of the current runspace</value>
   </data>