MegaBites-AI/Windows-powershell

1// Copyright (c) Microsoft Corporation.2// Licensed under the MIT License.3 4using Dbg = System.Management.Automation;5 6#pragma warning disable 1634, 1691 // Stops compiler from warning about unknown warnings7#pragma warning disable 565008 9namespace System.Management.Automation10{11    /// <summary>12    /// Holds the state of a Monad Shell session.13    /// </summary>14    internal sealed partial class SessionStateInternal15    {16        /// <summary>17        /// The current scope. It is either the global scope or18        /// a nested scope within the global scope. The current19        /// scope is implied or can be accessed using $local in20        /// the shell.21        /// </summary>22        private SessionStateScope _currentScope;23 24        /// <summary>25        /// Cmdlet parameter name to return in the error message instead of "scopeID".26        /// </summary>27        internal const string ScopeParameterName = "Scope";28 29        /// <summary>30        /// Given a scope identifier, returns the proper session state scope.31        /// </summary>32        /// <param name="scopeID">33        /// A scope identifier that is either one of the "special" scopes like34        /// "global", "local", or "private, or a numeric ID of a relative scope35        /// to the current scope.36        /// </param>37        /// <returns>38        /// The scope identified by the scope ID or the current scope if the39        /// scope ID is not defined as a special or numeric scope identifier.40        /// </returns>41        /// <exception cref="ArgumentException">42        /// If <paramref name="scopeID"/> is less than zero, or not43        /// a number and not "script", "global", "local", or "private"44        /// </exception>45        /// <exception cref="ArgumentOutOfRangeException">46        /// If <paramref name="scopeID"/> is less than zero or greater than the number of currently47        /// active scopes.48        /// </exception>49        internal SessionStateScope GetScopeByID(string scopeID)50        {51            SessionStateScope result = _currentScope;52 53            if (!string.IsNullOrEmpty(scopeID))54            {55                if (string.Equals(56                        scopeID,57                        StringLiterals.Global,58                        StringComparison.OrdinalIgnoreCase))59                {60                    result = GlobalScope;61                }62                else if (string.Equals(63                            scopeID,64                            StringLiterals.Local,65                            StringComparison.OrdinalIgnoreCase))66                {67                    result = _currentScope;68                }69                else if (string.Equals(70                            scopeID,71                            StringLiterals.Private,72                            StringComparison.OrdinalIgnoreCase))73                {74                    result = _currentScope;75                }76                else if (string.Equals(77                            scopeID,78                            StringLiterals.Script,79                            StringComparison.OrdinalIgnoreCase))80                {81                    // Get the current script scope from the stack.82                    result = _currentScope.ScriptScope;83                }84                else85                {86                    // Since the scope is not any of the special scopes87                    // try parsing it as an ID88 89                    try90                    {91                        int scopeNumericID = Int32.Parse(scopeID, System.Globalization.CultureInfo.CurrentCulture);92 93                        if (scopeNumericID < 0)94                        {95                            throw PSTraceSource.NewArgumentOutOfRangeException(ScopeParameterName, scopeID);96                        }97 98                        result = GetScopeByID(scopeNumericID) ?? _currentScope;99                    }100                    catch (FormatException)101                    {102                        throw PSTraceSource.NewArgumentException(ScopeParameterName, AutomationExceptions.InvalidScopeIdArgument, ScopeParameterName);103                    }104                    catch (OverflowException)105                    {106                        throw PSTraceSource.NewArgumentOutOfRangeException(ScopeParameterName, scopeID);107                    }108                }109            }110 111            return result;112        }113 114        /// <summary>115        /// Given a scope ID, walks the scope list to the appropriate scope and returns it.116        /// </summary>117        /// <param name="scopeID">118        /// The numeric indexer to the scope relative to the current scope.119        /// </param>120        /// <returns>121        /// The scope at the index specified.  The index is relative to the current122        /// scope.123        /// </returns>124        /// <exception cref="ArgumentOutOfRangeException">125        /// If <paramref name="scopeID"/> is less than zero or greater than the number of currently126        /// active scopes.127        /// </exception>128        internal SessionStateScope GetScopeByID(int scopeID)129        {130            SessionStateScope processingScope = _currentScope;131            int originalID = scopeID;132 133            while (scopeID > 0 && processingScope != null)134            {135                processingScope = processingScope.Parent;136                scopeID--;137            }138 139            if (processingScope == null && scopeID >= 0)140            {141                ArgumentOutOfRangeException outOfRange =142                    PSTraceSource.NewArgumentOutOfRangeException(143                        ScopeParameterName,144                        originalID,145                        SessionStateStrings.ScopeIDExceedsAvailableScopes,146                        originalID);147                throw outOfRange;148            }149 150            return processingScope;151        }152 153        /// <summary>154        /// The global scope of session state.  Can be accessed155        /// using $global in the shell.156        /// </summary>157        internal SessionStateScope GlobalScope { get; }158 159        /// <summary>160        /// The module scope of a session state. This is only used internally161        /// by the engine. There is no module scope qualifier.162        /// </summary>163        internal SessionStateScope ModuleScope { get; }164 165        /// <summary>166        /// Gets the session state current scope.167        /// </summary>168        internal SessionStateScope CurrentScope169        {170            get171            {172                return _currentScope;173            }174 175            set176            {177                Diagnostics.Assert(178                    value != null,179                    "A null scope should never be set");180#if DEBUG181                // This code is ifdef'd for DEBUG because it may pose a significant182                // performance hit and is only really required to validate our internal183                // code. There is no way anyone outside the Monad codebase can cause184                // these error conditions to be hit.185 186                // Need to make sure the new scope is in the global scope lineage187 188                SessionStateScope scope = value;189                bool inGlobalScopeLineage = false;190 191                while (scope != null)192                {193                    if (scope == GlobalScope)194                    {195                        inGlobalScopeLineage = true;196                        break;197                    }198 199                    scope = scope.Parent;200                }201 202                Diagnostics.Assert(203                    inGlobalScopeLineage,204                    "The scope specified to be set in CurrentScope is not in the global scope lineage. All scopes must originate from the global scope.");205#endif206 207                _currentScope = value;208            }209        }210 211        /// <summary>212        /// Gets the session state current script scope.213        /// </summary>214        internal SessionStateScope ScriptScope { get { return _currentScope.ScriptScope; } }215 216        /// <summary>217        /// Creates a new scope in the scope tree and assigns the parent218        /// and child scopes appropriately.219        /// </summary>220        /// <param name="isScriptScope">221        /// If true, the new scope is pushed on to the script scope stack and222        /// can be referenced using $script:223        /// </param>224        /// <returns>225        /// A new SessionStateScope which is a child of the current scope.226        /// </returns>227        internal SessionStateScope NewScope(bool isScriptScope)228        {229            Diagnostics.Assert(230                _currentScope != null,231                "The currentScope should always be set.");232 233            // Create the new child scope.234 235            SessionStateScope newScope = new SessionStateScope(_currentScope);236 237            if (isScriptScope)238            {239                newScope.ScriptScope = newScope;240            }241 242            return newScope;243        }244 245        /// <summary>246        /// Removes the current scope from the scope tree and247        /// changes the current scope to the parent scope.248        /// </summary>249        /// <param name="scope">250        /// The scope to cleanup and remove.251        /// </param>252        /// <exception cref="SessionStateUnauthorizedAccessException">253        /// The global scope cannot be removed.254        /// </exception>255        internal void RemoveScope(SessionStateScope scope)256        {257            Diagnostics.Assert(258                _currentScope != null,259                "The currentScope should always be set.");260 261            if (scope == GlobalScope)262            {263                SessionStateUnauthorizedAccessException e =264                    new SessionStateUnauthorizedAccessException(265                            StringLiterals.Global,266                            SessionStateCategory.Scope,267                            "GlobalScopeCannotRemove",268                            SessionStateStrings.GlobalScopeCannotRemove);269 270                throw e;271            }272 273            // Give the provider a chance to cleanup the drive data associated274            // with drives in this scope275 276            foreach (PSDriveInfo drive in scope.Drives)277            {278                if (drive == null)279                {280                    continue;281                }282 283                CmdletProviderContext context = new CmdletProviderContext(this.ExecutionContext);284 285                // Call CanRemoveDrive to give the provider a chance to cleanup286                // but ignore the return value and exceptions287 288                try289                {290                    CanRemoveDrive(drive, context);291                }292                catch (LoopFlowException)293                {294                    throw;295                }296                catch (PipelineStoppedException)297                {298                    throw;299                }300                catch (ActionPreferenceStopException)301                {302                    throw;303                }304                catch (Exception) // Catch-all OK, 3rd party callout.305                {306                    // Ignore all exceptions from the provider as we are307                    // going to force the removal anyway308                }309            }310 311            scope.RemoveAllDrives();312 313            // If the scope being removed is the current scope,314            // then it must be removed from the tree.315 316            if (scope == _currentScope && _currentScope.Parent != null)317            {318                _currentScope = _currentScope.Parent;319            }320 321            scope.Parent = null;322        }323    }324}325 326#pragma warning restore 56500327