BuildManager.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ FXUpdate3074 / FXUpdate3074 / 1.1 / DEVDIV / depot / DevDiv / releases / whidbey / QFE / ndp / fx / src / xsp / System / Web / Compilation / BuildManager.cs / 12 / BuildManager.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/************************************************************************************************************/ 
 

 
namespace System.Web.Compilation {

using System;
using System.IO; 
using System.Collections;
using System.Collections.Generic; 
using System.Collections.Specialized; 
using System.Reflection;
using System.Runtime.Remoting.Messaging; 
using System.Text;
using System.Xml;
using System.Globalization;
using System.Resources; 
using System.CodeDom;
using System.CodeDom.Compiler; 
using System.Configuration; 
using System.Web.Configuration;
using System.Web.Util; 
using System.Web.Caching;
using System.Web.UI;
#if ORCAS
using System.Web.UI.Imaging; 
#endif
using System.Web.Hosting; 
using System.Web.Profile; 
using System.Web.Security;
using System.Threading; 
using System.Security.Permissions;
using System.Web.Management;

 
/// 
///     
///       IProvider compilation related services 
///    
///  
[AspNetHostingPermission(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Medium)]
public sealed class BuildManager {

    /// Contants relating to generated assembly names 

    // All generated assemblies start with this prefix 
    internal const string AssemblyNamePrefix = "App_"; 

    // Web assemblies are the assemblies generated from web files (aspx, ascx, ...) 
    internal const string WebAssemblyNamePrefix = AssemblyNamePrefix + "Web_";

    internal const string AppThemeAssemblyNamePrefix = AssemblyNamePrefix + "Theme_";
    internal const string GlobalThemeAssemblyNamePrefix = AssemblyNamePrefix + "GlobalTheme_"; 
    internal const string AppBrowserCapAssemblyNamePrefix = AssemblyNamePrefix + "Browsers";
 
    private const string CodeDirectoryAssemblyName = AssemblyNamePrefix + "Code"; 
    internal const string SubCodeDirectoryAssemblyNamePrefix = AssemblyNamePrefix + "SubCode_";
    private const string ResourcesDirectoryAssemblyName = AssemblyNamePrefix + "GlobalResources"; 
    private const string LocalResourcesDirectoryAssemblyName = AssemblyNamePrefix + "LocalResources";
    private const string WebRefDirectoryAssemblyName = AssemblyNamePrefix + "WebReferences";
    internal const string GlobalAsaxAssemblyName = AssemblyNamePrefix + HttpApplicationFactory.applicationFileName;
 
    private const string LicensesAssemblyName = AssemblyNamePrefix + "Licenses";
 
    internal const string UpdatableInheritReplacementToken = "__ASPNET_INHERITS"; 

    private static System.Security.Cryptography.RNGCryptoServiceProvider _rng = new System.Security.Cryptography.RNGCryptoServiceProvider(); 
    private static bool _theBuildManagerInitialized;
    private static Exception _initializeException;
    private static BuildManager _theBuildManager = new BuildManager();  // single instance of the class
    private static long s_topLevelHash; 
    internal static BuildManager TheBuildManager { get { return _theBuildManager; } }
 
    // Precompilation related fields 
    private const string precompMarkerFileName = "PrecompiledApp.config";
    private string _precompTargetPhysicalDir; 
    private PrecompilationFlags _precompilationFlags;
    private bool _isPrecompiledApp;
    private bool _isPrecompiledAppComputed;
    private bool _isUpdatablePrecompiledApp; 
    private bool _precompilingApp;  // we're in the process of precompiling an app
 
    private string _strongNameKeyFile; 
    private string _strongNameKeyContainer;
 
    // filepath to the generated web.hash file, This file should only be re-created when
    // the appdomain is restarted and the top-level generated assemblies need to be recompiled.
    private string _webHashFilePath;
    internal static String WebHashFilePath { 
        get { return _theBuildManager._webHashFilePath; }
    } 
 
    private BuildResultCache[] _caches;
    private MemoryBuildResultCache _memoryCache; 

    private bool _topLevelFilesCompiledStarted;
    private bool _topLevelFilesCompiledCompleted;
    private Exception _topLevelFileCompilationException; 

    private BuildResultCompiledGlobalAsaxType _globalAsaxBuildResult; 
    private Type _profileType; 

    // Special top level directories that are treated differently from regular web directories 
    // during precompilation (e.g. App_Code)
    private StringSet _excludedTopLevelDirectories;

    // Directories that are not requestable 
    private StringSet _forbiddenTopLevelDirectories;
 
    private StringSet _excludedCodeSubdirectories; 

    private CompilationStage _compilationStage = CompilationStage.PreTopLevelFiles; 
    internal static CompilationStage CompilationStage { get { return _theBuildManager._compilationStage; } }

    private VirtualPath _scriptVirtualDir;
    private VirtualPath _globalAsaxVirtualPath; 
    internal static VirtualPath ScriptVirtualDir { get { return _theBuildManager._scriptVirtualDir; } }
    internal static VirtualPath GlobalAsaxVirtualPath { get { return _theBuildManager._globalAsaxVirtualPath; } } 
 
    private BuildManager() { }
 
    internal static bool InitializeBuildManager() {

        // If we already tried and got an exception, just rethrow it
        if (_initializeException != null) { 
            // We need to wrap it in a new exception, otherwise we lose the original stack.
            throw new HttpException(_initializeException.Message, _initializeException); 
        } 

        if (!_theBuildManagerInitialized) { 

            // If Fusion was not yet initialized, skip the init.
            // This can happen when there is a very early failure (e.g. see
            Debug.Trace("BuildManager", "InitializeBuildManager " + HttpRuntime.FusionInited); 
            if (!HttpRuntime.FusionInited)
                return false; 
 
            // Likewise, if the trust level has not yet been determined, skip the init (
            if (HttpRuntime.TrustLevel == null) 
                return false;

            _theBuildManagerInitialized = true;
            try { 
                _theBuildManager.Initialize();
            } 
            catch (Exception e) { 
                _theBuildManagerInitialized = false;
                _initializeException = e; 
                throw;
            }
        }
 
        return true;
    } 
 
    private ClientBuildManagerCallback _cbmCallback;
    internal static ClientBuildManagerCallback CBMCallback { get { return _theBuildManager._cbmCallback; } } 

    private static bool _parseErrorReported;
    internal static void ReportParseError(ParserError parseError) {
        // If there is a CBM callback, inform it of the error 
        if (BuildManager.CBMCallback != null) {
            _parseErrorReported = true; 
            BuildManager.CBMCallback.ReportParseError(parseError); 
        }
    } 

    private void ReportTopLevelCompilationException() {
        Debug.Assert(_topLevelFileCompilationException != null);
 
        // Try to report the cached error to the CBM callback
        ReportErrorsFromException(_topLevelFileCompilationException); 
 
        // We need to wrap it in a new exception, otherwise we lose the original stack.
        throw new HttpException(_topLevelFileCompilationException.Message, 
            _topLevelFileCompilationException);
    }

    // Given an exception, attempt to turn it into calls to the CBM callback 
    private void ReportErrorsFromException(Exception e) {
        // If there is no CBM callback, nothing to do 
        if (BuildManager.CBMCallback == null) 
            return;
 
        // Call the CBM callback as appropriate, based on the type of exception

        if (e is HttpCompileException) {
            CompilerResults results = ((HttpCompileException) e).Results; 
            foreach (CompilerError error in results.Errors) {
                BuildManager.CBMCallback.ReportCompilerError(error); 
            } 
        }
        else if (e is HttpParseException) { 
            foreach (ParserError parseError in ((HttpParseException)e).ParserErrors) {
                ReportParseError(parseError);
            }
        } 
    }
 
    // The assemblies produced from the code directories and global.asax, which 
    // every other compilation will linked with.
    private List _topLevelReferencedAssemblies; 
    private List TopLevelReferencedAssemblies { get { return _topLevelReferencedAssemblies; } }

    private Dictionary _topLevelAssembliesIndexTable;
    private IDictionary TopLevelAssembliesIndexTable { get { return _topLevelAssembliesIndexTable; } } 

    private Dictionary _generatedFileTable; 
    internal static Dictionary GenerateFileTable { 
        get {
            if (_theBuildManager._generatedFileTable == null) { 
                _theBuildManager._generatedFileTable = new Dictionary(StringComparer.OrdinalIgnoreCase);
            }

            return _theBuildManager._generatedFileTable; 
        }
    } 
 
    private ArrayList _codeAssemblies;
    public static IList CodeAssemblies { 
        get {
            _theBuildManager.EnsureTopLevelFilesCompiled();
            return _theBuildManager._codeAssemblies;
        } 
    }
 
    private IDictionary _assemblyResolveMapping; 

    private Assembly _appResourcesAssembly; 
    internal static Assembly AppResourcesAssembly { get { return _theBuildManager._appResourcesAssembly; } }

    // Indicates whether the parsers should coninue processing for more errors.
    // This is used in both CBM precompile-web, precompile-page and aspnet_compiler tool. 
    private bool _throwOnFirstParseError = true;
    internal static bool ThrowOnFirstParseError { 
        get { return _theBuildManager._throwOnFirstParseError; } 
        set { _theBuildManager._throwOnFirstParseError = value; }
    } 

    // Marks whether we are in the middle of performing precompilation, which affects how
    // we deal with error handling and batching
    private bool _performingPrecompilation = false; 
    internal static bool PerformingPrecompilation {
        get { return _theBuildManager._performingPrecompilation; } 
        set { _theBuildManager._performingPrecompilation = value; } 
    }
 
    private bool _skipTopLevelCompilationExceptions;
    internal static bool SkipTopLevelCompilationExceptions {
        get { return _theBuildManager._skipTopLevelCompilationExceptions; }
        set { _theBuildManager._skipTopLevelCompilationExceptions = value; } 
    }
 
    /* 
     * Return the list of assemblies that a compilation needs to reference for a given
     * config minus the assemblies indexed later than removeIndex 
     */
    internal static ICollection GetReferencedAssemblies(CompilationSection compConfig, int removeIndex) {

        AssemblySet referencedAssemblies = new AssemblySet(); 

        // Add all the config assemblies to the list 
        foreach (AssemblyInfo a in compConfig.Assemblies) { 
            Assembly[] assemblies = a.AssemblyInternal;
            if (assemblies == null) 
            {
                lock (compConfig)
                {
                    assemblies = a.AssemblyInternal; 
                    if (assemblies == null)
                        assemblies = a.AssemblyInternal = compConfig.LoadAssembly(a); 
                } 
            }
 
            for (int i = 0; i < assemblies.Length; i++)
            {
                if (assemblies[i] != null) {
                    referencedAssemblies.Add(assemblies[i]); 
                }
            } 
        } 

        // Clone the top level referenced assemblies (code + global.asax + etc...), up to the removeIndex 
        for (int i = 0; i < removeIndex; i++) {
            referencedAssemblies.Add(TheBuildManager.TopLevelReferencedAssemblies[i]);
        }
 
        return referencedAssemblies;
    } 
 
    internal static ICollection GetReferencedAssemblies(CompilationSection compConfig) {
 
        // Start by cloning the top level referenced assemblies (code + global.asax + etc...)
        AssemblySet referencedAssemblies = AssemblySet.Create(
            TheBuildManager.TopLevelReferencedAssemblies);
 
        // Add all the config assemblies to the list
        foreach (AssemblyInfo a in compConfig.Assemblies) { 
            Assembly[] assemblies = a.AssemblyInternal; 
            if (assemblies == null)
            { 
                lock (compConfig)
                {
                    assemblies = a.AssemblyInternal;
                    if (assemblies == null) 
                        assemblies = a.AssemblyInternal = compConfig.LoadAssembly(a);
                } 
            } 

            for (int i = 0; i < assemblies.Length; i++) { 
                if (assemblies[i] != null) {
                    referencedAssemblies.Add(assemblies[i]);
                }
            } 
        }
 
        return referencedAssemblies; 
    }
 

    /*
     * Return the list of assemblies that all page compilations need to reference. This includes
     * config assemblies ( section), bin assemblies and assemblies built from the 
     * app App_Code and other top level folders.
     */ 
 
    /// 
    /// Returns the assemblies referenced at the root application level of the current app 
    /// 
    public static ICollection GetReferencedAssemblies() {
        RuntimeConfig appConfig = RuntimeConfig.GetAppConfig();
        CompilationSection compConfig = appConfig.Compilation; 

        _theBuildManager.EnsureTopLevelFilesCompiled(); 
 
        return GetReferencedAssemblies(compConfig);
    } 

    /*
     * Perform initialization work that should only be done once (per app domain).
     */ 
    private void Initialize() {
 
        Debug.Assert(_caches == null); 

        // Register an AssemblyResolve event 
        AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(this.ResolveAssembly);

        _globalAsaxVirtualPath = HttpRuntime.AppDomainAppVirtualPathObject.SimpleCombine(
            HttpApplicationFactory.applicationFileName); 

        _webHashFilePath = Path.Combine(HttpRuntime.CodegenDirInternal, "hash\\hash.web"); 
 
        // Indicate whether we should ignore the top level compilation exceptions.
        // In CBM case, we want to continue processing the page and return partial info even 
        // if the code files fail to compile.
        _skipTopLevelCompilationExceptions = BuildManagerHost.InClientBuildManager;

        // Deal with precompilation if we're in that mode 
        SetPrecompilationInfo(HostingEnvironment.HostingParameters);
 
        // The init code depends on whether we're precompiling or running an app 
        if (_precompTargetPhysicalDir != null) {
 
            // If the app is already precompiled, fail
            FailIfPrecompiledApp();

            PrecompilationModeInitialize(); 
        }
        else { 
            // Check if this application has been precompiled by aspnet_compiler.exe 
            if (IsPrecompiledApp) {
                PrecompiledAppRuntimeModeInitialize(); 
            }
            else {
                RegularAppRuntimeModeInitialize();
            } 
        }
 
        _scriptVirtualDir = Util.GetScriptLocation(); 

        // Top level directories that have a special semantic 
        _excludedTopLevelDirectories = new CaseInsensitiveStringSet();
        _excludedTopLevelDirectories.Add(HttpRuntime.BinDirectoryName);
        _excludedTopLevelDirectories.Add(HttpRuntime.CodeDirectoryName);
        _excludedTopLevelDirectories.Add(HttpRuntime.ResourcesDirectoryName); 
        _excludedTopLevelDirectories.Add(HttpRuntime.LocalResourcesDirectoryName);
        _excludedTopLevelDirectories.Add(HttpRuntime.WebRefDirectoryName); 
        _excludedTopLevelDirectories.Add(HttpRuntime.ThemesDirectoryName); 

        // Top level directories that are not requestable 
        // It's the same as _excludedTopLevelDirectories, except that we allow
        // the bin directory to avoid a v1 breaking change (
        _forbiddenTopLevelDirectories = new CaseInsensitiveStringSet();
        _forbiddenTopLevelDirectories.Add(HttpRuntime.CodeDirectoryName); 
        _forbiddenTopLevelDirectories.Add(HttpRuntime.ResourcesDirectoryName);
        _forbiddenTopLevelDirectories.Add(HttpRuntime.LocalResourcesDirectoryName); 
        _forbiddenTopLevelDirectories.Add(HttpRuntime.WebRefDirectoryName); 
        _forbiddenTopLevelDirectories.Add(HttpRuntime.ThemesDirectoryName);
 
        LoadLicensesAssemblyIfExists();
    }

    /* 
     * Init code used when we are running a non-precompiled app
     */ 
    private void RegularAppRuntimeModeInitialize() { 

        // 
        // Initialize the caches
        //

        // Always try the memory cache first 
        _memoryCache = new MemoryBuildResultCache(HttpRuntime.CacheInternal);
 
        // Use the standard disk cache for regular apps 
        StandardDiskBuildResultCache diskCache = new StandardDiskBuildResultCache(
            HttpRuntime.CodegenDirInternal); 

        _caches = new BuildResultCache[] { _memoryCache, diskCache };

        CheckTopLevelFilesUpToDate(diskCache); 
    }
 
    /* 
     * Init code used when we are running a precompiled app
     */ 
    private void PrecompiledAppRuntimeModeInitialize() {

        //
        // Initialize the caches 
        //
 
        // Always try the memory cache first 
        _memoryCache = new MemoryBuildResultCache(HttpRuntime.CacheInternal);
 
        // Used the precomp cache for precompiled apps
        BuildResultCache preCompCache = new PrecompiledSiteDiskBuildResultCache(
            HttpRuntime.BinDirectoryInternal);
 
        // Also create a regular disk cache so that we can compile and cache additional things.
        // This is useful even in non-updatable precomp, to cache DefaultWsdlHelpGenerator.aspx. 
 
        StandardDiskBuildResultCache diskCache = new StandardDiskBuildResultCache(
            HttpRuntime.CodegenDirInternal); 

        _caches = new BuildResultCache[] { _memoryCache, preCompCache, diskCache };

        CheckTopLevelFilesUpToDate(diskCache); 
    }
 
    /* 
     * Init code used when we are precompiling an app
     */ 
    private void PrecompilationModeInitialize() {

        // We are precompiling an app
 
        // Always try the memory cache first
        _memoryCache = new MemoryBuildResultCache(HttpRuntime.CacheInternal); 
 
        // Create a regular disk cache, to take advantage of the fact that the app
        // may already have been compiled (and to cause it to be if it wasn't) 
        StandardDiskBuildResultCache diskCache = new StandardDiskBuildResultCache(
            HttpRuntime.CodegenDirInternal);

        // Create a special disk cache in the target's bin directory.  Use a slightly different 
        // implementation for the updatable case.
        string targetBinDir = Path.Combine(_precompTargetPhysicalDir, HttpRuntime.BinDirectoryName); 
        BuildResultCache preCompilationCache; 
        if (PrecompilingForUpdatableDeployment) {
            preCompilationCache = new UpdatablePrecompilerDiskBuildResultCache(targetBinDir); 
        }
        else {
            preCompilationCache = new PrecompilerDiskBuildResultCache(targetBinDir);
        } 

        _caches = new BuildResultCache[] { _memoryCache, preCompilationCache, diskCache  }; 
 
        CheckTopLevelFilesUpToDate(diskCache);
    } 

    // Load the licenses assembly from the bin dir if it exists (DevDiv 42149)
    private void LoadLicensesAssemblyIfExists() {
        string licAssemblyPath = Path.Combine(HttpRuntime.BinDirectoryInternal, LicensesAssemblyName + ".dll"); 
        if (File.Exists(licAssemblyPath)) {
            Assembly.Load(LicensesAssemblyName); 
        } 
    }
 
    private void CheckTopLevelFilesUpToDate(StandardDiskBuildResultCache diskCache) {

        bool gotLock = false;
 
        try {
            // Grab the compilation mutex, since this method accesses the codegen files 
            CompilationLock.GetLock(ref gotLock); 

            CheckTopLevelFilesUpToDate2(diskCache); 
        }
        finally {
            // Always release the mutex if we had taken it
            if (gotLock) { 
                CompilationLock.ReleaseLock();
            } 
        } 
    }
 
    /*
     * Check if the top level files are up to date, and cleanup the codegendir
     * if they are not.
     */ 
    private void CheckTopLevelFilesUpToDate2(StandardDiskBuildResultCache diskCache) {
 
        long specialFilesCombinedHash = diskCache.GetPreservedSpecialFilesCombinedHash(); 
        Debug.Trace("BuildManager", "specialFilesCombinedHash=" + specialFilesCombinedHash);
 
        // Delete all the non essential files left over in the codegen dir, unless
        // specialFilesCombinedHash is 0, in which case we delete *everything* further down
        if (specialFilesCombinedHash != 0)
            diskCache.RemoveOldTempFiles(); 

        // Use a HashCodeCombiner object to handle the time stamps of all the 'special' 
        // files and directories that all compilations depend on: 
        // - System.Web.dll (in case there is a newer version of ASP.NET)
        // - ~\Bin directory 
        // - ~\Resource directory
        // - ~\WebReferences directory
        // - ~\Code directory
        // - global.asax 

        HashCodeCombiner specialFilesDateTimeCombiner = new HashCodeCombiner(); 
 
        // Add a
        specialFilesDateTimeCombiner.AddObject(HttpRuntime.AppDomainAppPathInternal); 

        // Process System.Web.dll
        string aspBinaryFileName = typeof(HttpRuntime).Module.FullyQualifiedName;
        specialFilesDateTimeCombiner.AddFile(aspBinaryFileName); 

        // Process machine.config 
        string machineConfigFileName = HttpConfigurationSystem.MachineConfigurationFilePath; 
        specialFilesDateTimeCombiner.AddFile(machineConfigFileName);
 
        // Process root web.config
        string rootWebConfigFileName = HttpConfigurationSystem.RootWebConfigurationFilePath;
        specialFilesDateTimeCombiner.AddFile(rootWebConfigFileName);
 
        // Add a dependency of the bin, resources, webresources and code directories
        string binPhysicalDir = HttpRuntime.BinDirectoryInternal; 
        specialFilesDateTimeCombiner.AddDirectory(binPhysicalDir); 

        // Note that we call AddResourcesDirectory instead of AddDirectory, since we only want 
        // culture neutral files to be taken into account (
        specialFilesDateTimeCombiner.AddResourcesDirectory(HttpRuntime.ResourcesDirectoryVirtualPath.MapPathInternal());

        specialFilesDateTimeCombiner.AddDirectory(HttpRuntime.WebRefDirectoryVirtualPath.MapPathInternal()); 

        specialFilesDateTimeCombiner.AddDirectory(HttpRuntime.CodeDirectoryVirtualPath.MapPathInternal()); 
 
        // Add a dependency on the global asax file.
        specialFilesDateTimeCombiner.AddFile(GlobalAsaxVirtualPath.MapPathInternal()); 

        // Add a dependency on the hash of the app level  section, since it
        // affects all compilations, including the code directory.  It it changes,
        // we may as well, start all over. 
        RuntimeConfig appConfig = RuntimeConfig.GetAppConfig();
        CompilationSection compConfig = appConfig.Compilation; 
        specialFilesDateTimeCombiner.AddObject(compConfig.RecompilationHash); 

        ProfileSection profileSection = appConfig.Profile; 
        specialFilesDateTimeCombiner.AddObject(profileSection.RecompilationHash);

        // Add a dependency on file encoding (DevDiv 4560)
        specialFilesDateTimeCombiner.AddObject(appConfig.Globalization.FileEncoding); 

        // Also add a dependency on the  config section 
        TrustSection casConfig = appConfig.Trust; 
        specialFilesDateTimeCombiner.AddObject(casConfig.Level);
        specialFilesDateTimeCombiner.AddObject(casConfig.OriginUrl); 

        // Add a dependency on whether profile is enabled
        specialFilesDateTimeCombiner.AddObject(ProfileManager.Enabled);
 
        // Add a dependency to the force debug flag.
        specialFilesDateTimeCombiner.AddObject(PrecompilingWithDebugInfo); 
 
        // Store the top level hash
        s_topLevelHash = specialFilesDateTimeCombiner.CombinedHash; 

        if (PrecompilingForCleanBuild || specialFilesDateTimeCombiner.CombinedHash != specialFilesCombinedHash) {
            if (PrecompilingForCleanBuild) {
                Debug.Trace("BuildManager", "Precompiling for clean build."); 
            }
            else { 
                Debug.Trace("BuildManager", "EnsureFirstTimeInit: hash codes don't match.  Old=" + 
                    specialFilesCombinedHash + " New=" + specialFilesDateTimeCombiner.CombinedHash);
            } 

            diskCache.RemoveAllCodegenFiles();
            diskCache.SavePreservedSpecialFilesCombinedHash(specialFilesDateTimeCombiner.CombinedHash);
        } 
        else {
            Debug.Trace("BuildManager", "BuildManager: the special files are up to date"); 
        } 

        Debug.Assert(File.Exists(_webHashFilePath)); 

        //

 
        HttpRuntime.FileChangesMonitor.StartMonitoringFile(_webHashFilePath,
            new FileChangeEventHandler(this.OnWebHashFileChange)); 
    } 

    private void OnWebHashFileChange(Object sender, FileChangeEvent e) { 
        // Shutdown the app domain
        Debug.Trace("BuildManager", _webHashFilePath + " changed - shutting down the app domain");
        Debug.Trace("AppDomainFactory", "Shutting down appdomain because " + _webHashFilePath + " file changed");
 
        HttpRuntime.ShutdownAppDomain(ApplicationShutdownReason.BuildManagerChange, "Change in " + _webHashFilePath);
    } 
 
    /*
     * Check if an assembly name is reserved for a special purpose 
     */
    internal static bool IsReservedAssemblyName(string assemblyName) {

        if (String.Compare(assemblyName, CodeDirectoryAssemblyName, 
                StringComparison.OrdinalIgnoreCase) == 0 ||
            String.Compare(assemblyName, ResourcesDirectoryAssemblyName, 
                StringComparison.OrdinalIgnoreCase) == 0 || 
            String.Compare(assemblyName, WebRefDirectoryAssemblyName,
                StringComparison.OrdinalIgnoreCase) == 0 || 
            String.Compare(assemblyName, GlobalAsaxAssemblyName,
                StringComparison.OrdinalIgnoreCase) == 0) {

            return true; 
        }
 
        return false; 
    }
 
    // excludedSubdirectories contains a list of subdirectory names that should not be
    // recursively included in the compilation (they'll instead be compiled into their
    // own assemblies).
    private Assembly CompileCodeDirectory(VirtualPath virtualDir, CodeDirectoryType dirType, 
        string assemblyName, StringSet excludedSubdirectories) {
 
        Debug.Trace("BuildManager", "CompileCodeDirectory(" + virtualDir.VirtualPathString + ")"); 

        bool isDirectoryAllowed = true; 
        if (IsPrecompiledApp) {
            // Most special dirs are not allowed in precompiled apps.  App_LocalResources is
            // an exception, as it is allowed in updatable precompiled apps.
            if (IsUpdatablePrecompiledAppInternal && dirType == CodeDirectoryType.LocalResources) 
                isDirectoryAllowed = true;
            else 
                isDirectoryAllowed = false; 
        }
 
        // Remember the referenced assemblies based on the current count.
        AssemblyReferenceInfo info = new AssemblyReferenceInfo(_topLevelReferencedAssemblies.Count);
        _topLevelAssembliesIndexTable[virtualDir.VirtualPathString] = info;
 
        Assembly codeAssembly = CodeDirectoryCompiler.GetCodeDirectoryAssembly(
                virtualDir, dirType, assemblyName, excludedSubdirectories, 
                isDirectoryAllowed); 

        if (codeAssembly != null) { 

            // Remember the generated assembly
            info.Assembly = codeAssembly;
 
            // Page resource assemblies are not added to the top level list
            if (dirType != CodeDirectoryType.LocalResources) { 
                _topLevelReferencedAssemblies.Add(codeAssembly); 

                if (dirType == CodeDirectoryType.MainCode || dirType == CodeDirectoryType.SubCode) { 
                    if (_codeAssemblies == null) {
                        _codeAssemblies = new ArrayList();
                    }
 
                    _codeAssemblies.Add(codeAssembly);
                } 
 
                // Add it to the list of assembly name that we resolve, so that users can
                // refer to the assemblies by their fixed name (even though they 
                // random names).  (
                if (_assemblyResolveMapping == null) {
                    _assemblyResolveMapping = new Hashtable(StringComparer.OrdinalIgnoreCase);
                } 
                _assemblyResolveMapping[assemblyName] = codeAssembly;
 
                if (dirType == CodeDirectoryType.MainCode) { 
                    // Profile gets built in the same assembly as the main code dir, so
                    // see whether we can get its type from the assembly. 
                    _profileType = ProfileBuildProvider.GetProfileTypeFromAssembly(
                        codeAssembly, IsPrecompiledApp);

                    // To avoid breaking earlier Whidbey apps, allows the name "__code" 
                    // to be used for the main code assembly.
                    // 
                    _assemblyResolveMapping["__code"] = codeAssembly; 
                }
            } 
        }

        Debug.Trace("BuildManager", "CompileCodeDirectory generated assembly: " +
            (codeAssembly == null ? "None" : codeAssembly.ToString())); 

        return codeAssembly; 
    } 

 
    private void CompileResourcesDirectory() {

        VirtualPath virtualDir = HttpRuntime.ResourcesDirectoryVirtualPath;
 
        Debug.Assert(_appResourcesAssembly == null);
        _appResourcesAssembly = CompileCodeDirectory(virtualDir, CodeDirectoryType.AppResources, 
            ResourcesDirectoryAssemblyName, null /*excludedSubdirectories*/); 
    }
 
    private void CompileWebRefDirectory() {

        CompileCodeDirectory(HttpRuntime.WebRefDirectoryVirtualPath, CodeDirectoryType.WebReferences,
            WebRefDirectoryAssemblyName, null /*excludedSubdirectories*/); 
    }
 
    // Compute the list of subdirectories that should not be compiled with 
    // the top level Code
    private void EnsureExcludedCodeSubDirectoriesComputed() { 

        if (_excludedCodeSubdirectories != null)
            return;
 
        _excludedCodeSubdirectories = new CaseInsensitiveStringSet();
 
        // Get the list of sub directories that will be compiled separately 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();
 
        // Add them to the exclusion list of the top level code directory
        if (codeSubDirectories != null) {
            foreach (CodeSubDirectory entry in codeSubDirectories) {
                _excludedCodeSubdirectories.Add(entry.DirectoryName); 
            }
        } 
    } 

    private void CompileCodeDirectories() { 

        VirtualPath virtualDir = HttpRuntime.CodeDirectoryVirtualPath;

        // Get the list of sub directories that will be compiled separately 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();
 
        if (codeSubDirectories != null) { 

            // Compile all the subdirectory that are listed in config. 

            foreach (CodeSubDirectory entry in codeSubDirectories) {

                // 

 
 
                VirtualPath virtualSubDir = virtualDir.SimpleCombineWithDir(entry.DirectoryName);
 
                string assemblyName = SubCodeDirectoryAssemblyNamePrefix + entry.AssemblyName;

                // Compile the subdirectory tree (no exclusions)
                CompileCodeDirectory(virtualSubDir, CodeDirectoryType.SubCode, assemblyName, 
                    null /*excludedSubdirectories*/);
            } 
        } 

        EnsureExcludedCodeSubDirectoriesComputed(); 

        // Compile the top level Code directory tree, minus the excluded subdirectories
        CompileCodeDirectory(virtualDir, CodeDirectoryType.MainCode,
            CodeDirectoryAssemblyName, _excludedCodeSubdirectories); 
    }
 
    private void CompileGlobalAsax() { 
        _globalAsaxBuildResult = ApplicationBuildProvider.GetGlobalAsaxBuildResult(IsPrecompiledApp);
 
        // Make sure that global.asax notifications are set up (
        HttpApplicationFactory.SetupFileChangeNotifications();

        if (_globalAsaxBuildResult != null) { 

            // We need to add not only the global.asax type, but also its parent types to 
            // the top level assembly list.  This can happen when global.asax has a 'src' 
            // attribute pointing to a source file containing its base type.
            Type type = _globalAsaxBuildResult.ResultType; 
            while (type.Assembly != typeof(HttpRuntime).Assembly) {
                _topLevelReferencedAssemblies.Add(type.Assembly);
                type = type.BaseType;
            } 
        }
    } 
 
    // Call the AppInitialize method in the Code assembly if there is one
    internal static void CallAppInitializeMethod() { 

        // Make sure the code directory has been processed
        _theBuildManager.EnsureTopLevelFilesCompiled();
 
        CodeDirectoryCompiler.CallAppInitializeMethod();
    } 
 
    internal void EnsureTopLevelFilesCompiled() {
 
        // This should never get executed in non-hosted appdomains
        Debug.Assert(HostingEnvironment.IsHosted);

        // If we already tried and got an exception, just rethrow it 
        if (_topLevelFileCompilationException != null && !SkipTopLevelCompilationExceptions) {
            ReportTopLevelCompilationException(); 
        } 

        if(_topLevelFilesCompiledStarted) 
            return;

        // Set impersonation to hosting identity (process or UNC)
        using (new ApplicationImpersonationContext()) { 
            bool gotLock = false;
            _parseErrorReported = false; 
 
            try {
                // Grab the compilation mutex, since this method accesses the codegen files 
                CompilationLock.GetLock(ref gotLock);

                // Check again if there is an exception
                if (_topLevelFileCompilationException != null && !SkipTopLevelCompilationExceptions) { 
                    ReportTopLevelCompilationException();
                } 
 
                // Check again if we're done
                if(_topLevelFilesCompiledStarted) 
                    return;

                _topLevelFilesCompiledStarted = true;
                _topLevelReferencedAssemblies = new List(); 
                _topLevelAssembliesIndexTable =
                    new Dictionary(StringComparer.OrdinalIgnoreCase); 
 
                //
                _topLevelReferencedAssemblies.Add(typeof(HttpRuntime).Assembly); 
                _topLevelReferencedAssemblies.Add(typeof(System.ComponentModel.Component).Assembly);

                _compilationStage = CompilationStage.TopLevelFiles;
 
                CompileResourcesDirectory();
                CompileWebRefDirectory(); 
                CompileCodeDirectories(); 

                _compilationStage = CompilationStage.GlobalAsax; 

                CompileGlobalAsax();

                _compilationStage = CompilationStage.BrowserCapabilities; 

                // Call GetBrowserCapabilitiesType() to make sure browserCap directory is compiled 
                // early on.  This avoids getting into potential deadlock situations later ( 

                BrowserCapabilitiesCompiler.GetBrowserCapabilitiesType(); 
                IFilterResolutionService dummy = HttpCapabilitiesBase.EmptyHttpCapabilitiesBase;

                _compilationStage = CompilationStage.AfterTopLevelFiles;
            } 
            catch (Exception e) {
                // Remember the exception, and rethrow it 
                _topLevelFileCompilationException = e; 

                // Do not rethrow the exception since so CBM can still provide partial support 
                if (!SkipTopLevelCompilationExceptions) {

                    if (!_parseErrorReported) {
                        // Report the error if this is not a CompileException. CompileExceptions are handled 
                        // directly by the AssemblyBuilder already.
                        if (!(e is HttpCompileException)) { 
                            ReportTopLevelCompilationException(); 
                        }
                    } 

                    throw;
                }
            } 
            finally {
                _topLevelFilesCompiledCompleted = true; 
 
                // Always release the mutex if we had taken it
                if (gotLock) { 
                    CompilationLock.ReleaseLock();
                }
            }
        } 
    }
 
    // Generate a random file name with 8 characters 
    private static string GenerateRandomFileName() {
        // Generate random bytes 
        byte[] data = new byte[6];

        lock (_rng) {
            _rng.GetBytes(data); 
        }
 
        // Turn them into a string containing only characters valid in file names/url 
        string s = Convert.ToBase64String(data).ToLower(CultureInfo.InvariantCulture);
        s = s.Replace('/', '-'); 
        s = s.Replace('+', '_');

        return s;
    } 

    // Generate a random name for an assembly, starting with the passed in prefix 
    internal static string GenerateRandomAssemblyName(string baseName) { 

        // Start with the passed in base name 
        string assemblyName = baseName;

        // Append a random token to it.  However, don't do this when precompiling for
        // deployment since, we want the name to be more predictable (DevDiv 36625) 
        if (!PrecompilingForDeployment) {
            baseName += "." + GenerateRandomFileName(); 
        } 

        return baseName; 
    }

    private static string GetGeneratedAssemblyBaseName(VirtualPath virtualPath) {
 
        // Name the assembly using the same scheme as cache keys
        return GetCacheKeyFromVirtualPath(virtualPath); 
    } 

    /* 
     * Look for a type by name in the top level and config assemblies
     */
    public static Type GetType(string typeName, bool throwOnError) {
        return GetType(typeName, throwOnError, false); 
    }
 
    /* 
     * Look for a type by name in the top level and config assemblies
     */ 
    public static Type GetType(string typeName, bool throwOnError, bool ignoreCase) {
        // If it contains an assembly name, just call Type.GetType().  Do this before even trying
        // to initialize the BuildManager, so that if InitializeBuildManager has errors, it doesn't
        // affect us when the type string can be resolved via Type.GetType(). 
        Type type = null;
        if (Util.TypeNameContainsAssembly(typeName)) { 
            type = Type.GetType(typeName, throwOnError, ignoreCase); 

            if (type != null) { 
                    return type;
            }
        }
 
        // Make sure the build manager is initialized.  If it fails to initialize for any reason,
        // don't attempt to use the fancy GetType logic.  Just call Type.GetType instead ( 
        if (!InitializeBuildManager()) { 
            return Type.GetType(typeName, throwOnError, ignoreCase);
        } 

        // First, always try System.Web.dll
        try {
            type = typeof(BuildManager).Assembly.GetType(typeName, 
                false /*throwOnError*/, ignoreCase);
        } 
        catch (ArgumentException e) { 
            // Even though we pass false to throwOnError, GetType can throw if the
            // assembly name is malformed.  In that case, throw our own error instead 
            // of the cryptic ArgumentException (
            throw new HttpException(
                SR.GetString(SR.Invalid_type, typeName), e);
        } 

        if (type != null) return type; 
 
        _theBuildManager.EnsureTopLevelFilesCompiled();
 
        // Otherwise, look for the type in the top level assemblies
        type = Util.GetTypeFromAssemblies(TheBuildManager.TopLevelReferencedAssemblies,
            typeName, ignoreCase);
        if (type != null) return type; 

        // Otherwise, look for the type in the config assemblies 
        AssemblyCollection configAssemblies = CompilationUtil.GetAssembliesForAppLevel(); 
        if (configAssemblies != null) {
            Type t = CompilationUtil.GetTypeFromAssemblies(configAssemblies, typeName, ignoreCase); 
            if (t != null) {
                // If we had already found a different one, it's an ambiguous type reference
                if (type != null && t != type) {
                    throw new HttpException(SR.GetString( 
                        SR.Ambiguous_type, typeName, Util.GetAssemblySafePathFromType(type),
                        Util.GetAssemblySafePathFromType(t))); 
                } 

                type = t; 
            }
        }

        if (type == null && throwOnError) { 
            throw new HttpException(
                SR.GetString(SR.Invalid_type, typeName)); 
        } 

        return type; 
    }

    /*
     * Gets a type from one of the code assemblies 
     */
    internal static Type GetTypeFromCodeAssembly(string typeName, bool ignoreCase) { 
 
        // No code assembly: return
        if (CodeAssemblies == null) 
            return null;

        return Util.GetTypeFromAssemblies(CodeAssemblies, typeName, ignoreCase);
    } 

    internal static BuildProvider CreateBuildProvider(VirtualPath virtualPath, 
        CompilationSection compConfig, ICollection referencedAssemblies, 
        bool failIfUnknown) {
 
        return CreateBuildProvider(virtualPath, BuildProviderAppliesTo.Web,
            compConfig, referencedAssemblies, failIfUnknown);
    }
 
    internal static BuildProvider CreateBuildProvider(VirtualPath virtualPath,
        BuildProviderAppliesTo neededFor, 
        CompilationSection compConfig, ICollection referencedAssemblies, 
        bool failIfUnknown) {
 
        string extension = virtualPath.Extension;

        Type buildProviderType = CompilationUtil.GetBuildProviderTypeFromExtension(compConfig,
            extension, neededFor, failIfUnknown); 
        if (buildProviderType == null)
            return null; 
 
        object o = HttpRuntime.CreatePublicInstance(buildProviderType);
 
        BuildProvider buildProvider = (BuildProvider) o;

        buildProvider.SetVirtualPath(virtualPath);
        buildProvider.SetReferencedAssemblies(referencedAssemblies); 

        return buildProvider; 
    } 

    internal static void ValidateCodeFileVirtualPath(VirtualPath virtualPath) { 
        _theBuildManager.ValidateVirtualPathInternal(virtualPath, false /*allowCrossApp*/, true /*codeFile*/);
    }

    private void ValidateVirtualPathInternal(VirtualPath virtualPath, bool allowCrossApp, bool codeFile) { 

        if (!allowCrossApp) { 
            virtualPath.FailIfNotWithinAppRoot(); 
        }
        else { 
            // If cross app is allowed, and the path is in a different app, nothing more to
            if (!virtualPath.IsWithinAppRoot)
                return;
        } 

        // 
        // Now, detect if it's under a special directory (e.g. 'code', 'resources', 'themes') 
        //
 
        // If it's exactly the app root, it's fine
        if (HttpRuntime.AppDomainAppVirtualPathObject == virtualPath)
            return;
 
        int appPathLen = HttpRuntime.AppDomainAppVirtualPathString.Length;
 
        string virtualPathString = virtualPath.VirtualPathString; 

        // This could happen if the vpath is "/app" (while the app vpath is "/app/") 
        if (virtualPathString.Length < appPathLen)
            return;

        // If no slash after the approot (e.g. "/app/foo.aspx"), it's valid 
        int slashIndex = virtualPathString.IndexOf('/', appPathLen);
        if (slashIndex < 0) 
            return; 

        // Get the name of the first directory under the app root (e.g. "/app/aaa/bbb/foo.aspx" -> "aaa") 
        string dir = virtualPathString.Substring(appPathLen, slashIndex - appPathLen);

        // If it's a forbidden directory, fail
        if (_forbiddenTopLevelDirectories.Contains(dir)) { 
            throw new HttpException(SR.GetString(
                SR.Illegal_special_dir, virtualPathString, dir)); 
        } 
    }
 
    /*
     * Returns a single hash code that represents the state of the built object for
     * the passed in virtualPath.  If it isn't already built, don't build it, but just
     * return 0.  This can be used to determine the validity of output cache that 
     * has been persisted to disk.
     */ 
    internal static long GetBuildResultHashCodeIfCached( 
        HttpContext context, string virtualPath) {
 
        BuildResult result = GetVPathBuildResult(context, VirtualPath.Create(virtualPath),
            true /*noBuild*/, false /*allowCrossApp*/);

        // If it's not cached, return 0 
        if (result == null)
            return 0; 
 
        // Return a single hash code based on both of the BuildResult's hash codes
        string dependenciesHash = result.VirtualPathDependenciesHash; 
        Debug.Assert(result.DependenciesHashComputed);
        return result.ComputeHashCode(s_topLevelHash, StringUtil.GetStringHashCode(dependenciesHash));
    }
 
    internal static BuildResult GetVPathBuildResult(VirtualPath virtualPath) {
 
        return GetVPathBuildResult(null /*context*/, virtualPath, 
            false /*noBuild*/, false /*allowCrossApp*/, false /*allowBuiltInPrecompile*/);
    } 

    internal static BuildResult GetVPathBuildResult(HttpContext context, VirtualPath virtualPath) {

        return GetVPathBuildResult(context, virtualPath, false /*noBuild*/, false /*allowCrossApp*/, false /*allowBuiltInPrecompile*/); 
    }
 
    internal static BuildResult GetVPathBuildResult(HttpContext context, VirtualPath virtualPath, 
        bool noBuild, bool allowCrossApp) {
 
        return GetVPathBuildResult(context, virtualPath, noBuild, allowCrossApp, false /*allowBuiltInPrecompile*/);
    }

    /* 
     * Calls either GetVPathBuildResultWithNoAssert or GetVPathBuildResultWithAssert,
     * depending on whether there is any point in assertting. 
     */ 
    internal static BuildResult GetVPathBuildResult(HttpContext context, VirtualPath virtualPath,
        bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 

        // Could be called with user code on the stack, so need to assertt here (

 
        if (HttpRuntime.IsFullTrust) {
            return GetVPathBuildResultWithNoAssert(context, virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile); 
        } 
        else {
            return GetVPathBuildResultWithAssert(context, virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile); 
        }
    }

    /* 
     * Same as GetVPathBuildResultWithNoAssert, but with an Unrestricted Assert.
     */ 
    [PermissionSet(SecurityAction.Assert, Unrestricted=true)] 
    internal static BuildResult GetVPathBuildResultWithAssert(
        HttpContext context, VirtualPath virtualPath, bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 

        return GetVPathBuildResultWithNoAssert(context, virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile);
    }
 
    internal static BuildResult GetVPathBuildResultWithNoAssert(
        HttpContext context, VirtualPath virtualPath, bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 
 
        using (new ApplicationImpersonationContext()) {
            return _theBuildManager.GetVPathBuildResultInternal(virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile); 
        }
    }

    // name of the slot in call context 
    private const String CircularReferenceCheckerSlotName = "CircRefChk";
 
    private BuildResult GetVPathBuildResultInternal(VirtualPath virtualPath, bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 

        Debug.Trace("BuildManager", "GetBuildResult(" + virtualPath + ")"); 

        // This should never be called while building top level files (
        if (_compilationStage == CompilationStage.TopLevelFiles) {
            throw new HttpException(SR.GetString(SR.Too_early_for_webfile, virtualPath)); 
        }
 
        // Make sure the path is not relative 
        Debug.Assert(!virtualPath.IsRelative);
 
        // Try the cache first before getting the mutex
        BuildResult result = GetVPathBuildResultFromCacheInternal(virtualPath);
        if (result != null)
            return result; 

        // If we were only checking the cache and it wasn't there, return null. 
        if (noBuild) 
            return null;
 
        // Check if it's trying to go cross app, or points to a special directory.
        // It's important to do this before checkin existence, to avoid revealing information
        // about other apps (
        ValidateVirtualPathInternal(virtualPath, allowCrossApp, false /*codeFile*/); 

        // Before grabbing the lock, make sure the file at least exists (ASURT 46465) 
        Util.CheckVirtualFileExists(virtualPath); 

        // If this is a precompiled app, complain if we couldn't find it in the cache 
        if (IsNonUpdatablePrecompiledApp && !allowBuildInPrecompile) {
            throw new HttpException(
                SR.GetString(SR.Cant_update_precompiled_app, virtualPath));
        } 

        bool gotLock = false; 
 
        try {
            // Grab the compilation mutex 
            CompilationLock.GetLock(ref gotLock);

            // Check the cache a second time after getting the mutex
            result = GetVPathBuildResultFromCacheInternal(virtualPath); 
            if (result != null)
                return result; 
 
            // Get the circular reference checker (create it if needed)
            VirtualPathSet circularReferenceChecker; 
            circularReferenceChecker = CallContext.GetData(CircularReferenceCheckerSlotName)
                as VirtualPathSet;
            if (circularReferenceChecker == null) {
                circularReferenceChecker = new VirtualPathSet(); 

                // Create it and save it in the CallContext 
                CallContext.SetData(CircularReferenceCheckerSlotName, circularReferenceChecker); 
            }
 
            // If a circular reference is detected, throw an error
            if (circularReferenceChecker.Contains(virtualPath)) {
                throw new HttpException(
                    SR.GetString(SR.Circular_include)); 
            }
 
            // Add the current virtualPath to the circular reference checker 
            circularReferenceChecker.Add(virtualPath);
 
            try {
                //
                EnsureTopLevelFilesCompiled();
                result = CompileWebFile(virtualPath); 
            }
            finally { 
                // Remove the current virtualPath from the circular reference checker 
                Debug.Assert(circularReferenceChecker.Contains(virtualPath));
                circularReferenceChecker.Remove(virtualPath); 
            }
        }
        finally {
            // Always release the mutex if we had taken it 
            if (gotLock) {
                CompilationLock.ReleaseLock(); 
            } 
        }
 
        return result;
    }

    private BuildResult CompileWebFile(VirtualPath virtualPath) { 

        BuildResult result = null; 
 
        if (_topLevelFilesCompiledCompleted) {
 
            VirtualPath parentPath = virtualPath.Parent;

            // First, try to batch the directory if enabled
            if (IsBatchEnabledForDirectory(parentPath)) { 
                BatchCompileWebDirectory(null, parentPath, true /*ignoreErrors*/);
 
                // If successful, it would have been cached to memory 
                string cacheKey = GetCacheKeyFromVirtualPath(virtualPath);
                result = _memoryCache.GetBuildResult(cacheKey); 

                if (result != null) {
                    // If what we found in the cache is a CompileError, rethrow the exception
                    if (result is BuildResultCompileError) { 
                        throw ((BuildResultCompileError)result).CompileException;
                    } 
 
                    return result;
                } 
            }
        }

 
        DateTime utcStart = DateTime.UtcNow;
 
        // Name the assembly based on the virtual path, in order to get a recognizable name 
        string outputAssemblyName = BuildManager.WebAssemblyNamePrefix +
            BuildManager.GenerateRandomAssemblyName( 
            GetGeneratedAssemblyBaseName(virtualPath));

        BuildProvidersCompiler bpc = new BuildProvidersCompiler(virtualPath /*configPath*/, outputAssemblyName);
 
        // Create a BuildProvider based on the virtual path
        BuildProvider buildProvider = CreateBuildProvider(virtualPath, bpc.CompConfig, 
            bpc.ReferencedAssemblies, true /*failIfUnknown*/); 

        // Set the BuildProvider using a single item collection 
        bpc.SetBuildProviders(new SingleObjectCollection(buildProvider));

        // Compile it
        CompilerResults results; 

        try { 
            results = bpc.PerformBuild(); 
            result = buildProvider.GetBuildResult(results);
        } 
        catch (HttpCompileException e) {

            // If we're not supposed to cache the exception, just rethrow it
            if (e.DontCache) 
                throw;
 
            result = new BuildResultCompileError(virtualPath, e); 

            // Add the dependencies to the compile error build provider, so that 
            // we will retry compilation when a dependency changes
            buildProvider.SetBuildResultDependencies(result);

            // Remember the virtualpath dependencies, so that we will correctly 
            // invalidate buildresult when depdency changes.
            e.VirtualPathDependencies = buildProvider.VirtualPathDependencies; 
 
            // Cache it for next time
            CacheVPathBuildResultInternal(virtualPath, result, utcStart); 

            // Set the DontCache flag, so that the exception will not be incorrectly
            // cached again lower down the stack (
            e.DontCache = true; 

            throw; 
        } 

        if (result == null) 
            return null;

        // Cache it for next time
        CacheVPathBuildResultInternal(virtualPath, result, utcStart); 

        return result; 
    } 

    // Hashtbale to remember the local resources assembly for each directory (or null 
    // if there isn't one). Hashtable
    private Hashtable _localResourcesAssemblies = new Hashtable();

    private void EnsureFirstTimeDirectoryInit(VirtualPath virtualDir) { 

        // Don't process local resources when precompiling for updatable deployment. 
        // Instead, we deploy the App_LocalResources folder as is. 
        if (PrecompilingForUpdatableDeployment)
            return; 

        if (virtualDir == null)
            return;
 
        // Only do this once per directory
        if (_localResourcesAssemblies.Contains(virtualDir)) 
            return; 

        // Don't do anything if it's outside the app root 
        if (!virtualDir.IsWithinAppRoot)
            return;

        Debug.Trace("BuildManager", "EnsureFirstTimeDirectoryInit(" + virtualDir + ")"); 

        // Get the virtual path to the LocalResources subdirectory for this directory 
        VirtualPath localResDir = virtualDir.SimpleCombineWithDir(HttpRuntime.LocalResourcesDirectoryName); 

        bool dirExists; 
        try {
            dirExists = localResDir.DirectoryExists();
        }
        catch { 
            // If an exception happens, the directory may be outside the application,
            // in which case we should skip this logic, and act is if there are no 
            // local resources ( 

            _localResourcesAssemblies[virtualDir] = null; 
            return;
        }

        Debug.Trace("BuildManager", "EnsureFirstTimeDirectoryInit: dirExists=" + dirExists); 

        try { 
            // Monitor changes to it so the appdomain can shut down when it changes 
            HttpRuntime.StartListeningToLocalResourcesDirectory(localResDir);
        } 
        catch {
            // could fail for long directory names
            if (dirExists) {
                throw; 
            }
        } 
 
        Assembly resourceAssembly = null;
 
        // If it exists, build it
        if (dirExists) {

            string localResAssemblyName = GetLocalResourcesAssemblyName(virtualDir); 

            bool gotLock = false; 
 
            try {
                // Grab the compilation mutex, since this method accesses the codegen files 
                CompilationLock.GetLock(ref gotLock);

                resourceAssembly = CompileCodeDirectory(localResDir, CodeDirectoryType.LocalResources,
                    localResAssemblyName, null /*excludedSubdirectories*/); 
            }
            finally { 
                // Always release the mutex if we had taken it 
                if (gotLock) {
                    CompilationLock.ReleaseLock(); 
                }
            }
        }
 
        // Cache it whether it's null or not
        _localResourcesAssemblies[virtualDir] = resourceAssembly; 
    } 

    // 
    private void EnsureFirstTimeDirectoryInitForDependencies(ICollection dependencies) {
        foreach (String dependency in dependencies) {
            VirtualPath dependencyPath = VirtualPath.Create(dependency);
            VirtualPath dir = dependencyPath.Parent; 
            EnsureFirstTimeDirectoryInit(dir);
        } 
    } 

 
    // Retrieve a cached local resources assembly (could be null)
    internal static Assembly GetLocalResourcesAssembly(VirtualPath virtualDir) {
        return (Assembly) _theBuildManager._localResourcesAssemblies[virtualDir];
    } 

    internal static string GetLocalResourcesAssemblyName(VirtualPath virtualDir) { 
        return LocalResourcesDirectoryAssemblyName + "." + GetGeneratedAssemblyBaseName(virtualDir); 
    }
 
    // name of the slot in call context
    private const String BatchCompilationSlotName = "BatchCompileChk";

    // Check if batching is enabled for directory specified by virtualDir 
    private bool IsBatchEnabledForDirectory(VirtualPath virtualDir) {
        // False if compile for fixed name 
        if (CompileWithFixedAssemblyNames) { 
            return false;
        } 

        // Always enable batching for deployement
        if (PrecompilingForDeployment) {
            return true; 
        }
 
        // If it's called by other non-precompile CBM methods, always disable batching 
        if (BuildManagerHost.InClientBuildManager && !PerformingPrecompilation) {
            return false; 
        }

        // Check the config
        return CompilationUtil.IsBatchingEnabled(virtualDir.VirtualPathString); 
    }
 
    private bool BatchCompileWebDirectory(VirtualDirectory vdir, VirtualPath virtualDir, bool ignoreErrors) { 

        // Exactly one of vdir and virtualDir should be non-null.  The idea is to avoid calling 
        // VirtualPathProvider.GetDirectory if batching is disabled (

        if (virtualDir == null)
            virtualDir = vdir.VirtualPathObject; 

        if (vdir == null) 
            vdir = HostingEnvironment.VirtualPathProvider.GetDirectory(virtualDir); 

        // Then, 

        CaseInsensitiveStringSet directoryBatchCompilerChecker;
        directoryBatchCompilerChecker = CallContext.GetData(BatchCompilationSlotName)
            as CaseInsensitiveStringSet; 

        if (directoryBatchCompilerChecker == null) { 
            directoryBatchCompilerChecker = new CaseInsensitiveStringSet(); 

            // Create it and save it in the CallContext 
            CallContext.SetData(BatchCompilationSlotName, directoryBatchCompilerChecker);
        }

        // If we've already tried batch compiling this directory, don't do anything 
        if (directoryBatchCompilerChecker.Contains(vdir.VirtualPath))
            return false; 
 
        // Add the current virtualDir to the batch compiler checker
        directoryBatchCompilerChecker.Add(vdir.VirtualPath); 

        // If we're in the process of precompiling an app, never ignore errors.
        if (_precompilingApp)
            ignoreErrors = false; 

        return BatchCompileWebDirectoryInternal(vdir, ignoreErrors); 
    } 

    private bool BatchCompileWebDirectoryInternal(VirtualDirectory vdir, bool ignoreErrors) { 

        WebDirectoryBatchCompiler sdc = new WebDirectoryBatchCompiler(vdir);

        // Just ignore build providers that have errors 
        if (ignoreErrors) {
            sdc.SetIgnoreErrors(); 
 
            // Don't propagate errors that happen during batch compilation
            try { 
                sdc.Process();
            }
            catch {
                return false; 
            }
        } 
        else { 
            sdc.Process();
        } 

        return true;
    }
 
    internal static Type GetGlobalAsaxType() {
        return _theBuildManager.GetGlobalAsaxTypeInternal(); 
    } 

    private Type GetGlobalAsaxTypeInternal() { 
        EnsureTopLevelFilesCompiled();

        if (_globalAsaxBuildResult == null)
            return typeof(HttpApplication); 

        return _globalAsaxBuildResult.ResultType; 
    } 

    internal static BuildResultCompiledGlobalAsaxType GetGlobalAsaxBuildResult() { 
        return _theBuildManager.GetGlobalAsaxBuildResultInternal();
    }

    private BuildResultCompiledGlobalAsaxType GetGlobalAsaxBuildResultInternal() { 
        EnsureTopLevelFilesCompiled();
 
        return _globalAsaxBuildResult; 
    }
 
    internal string[] GetCodeDirectories() {

        VirtualPath virtualDir = HttpRuntime.CodeDirectoryVirtualPath;
 
        // If there is no Code directory, return an empty array
        if (!virtualDir.DirectoryExists()) 
            return new string[0]; 

        // Get the list of code sub directories that will be compiled separately 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();

        // Compute the number of code dirs, including the root one
        int numOfCodeDirs = 1; 
        if (codeSubDirectories != null)
            numOfCodeDirs += codeSubDirectories.Count; 
 
        string[] codeDirs = new string[numOfCodeDirs];
        int current = 0; 

        if (codeSubDirectories != null) {
            foreach (CodeSubDirectory entry in codeSubDirectories) {
 
                VirtualPath virtualSubDir = virtualDir.SimpleCombineWithDir(entry.DirectoryName);
                codeDirs[current++] = virtualSubDir.VirtualPathString; 
            } 
        }
 
        // Add the root code dir at the end of the list (since it's compiled last)
        codeDirs[current++] = virtualDir.VirtualPathString;

        return codeDirs; 
    }
 
    internal void GetCodeDirectoryInformation(VirtualPath virtualCodeDir, 
        out Type codeDomProviderType, out CompilerParameters compilerParameters,
        out string generatedFilesDir) { 

        // Backup the compilation stage, since the call will modify it
        CompilationStage savedCompilationStage = _compilationStage;
 
        try {
            GetCodeDirectoryInformationInternal(virtualCodeDir, out codeDomProviderType, 
                out compilerParameters, out generatedFilesDir); 
        }
        finally { 
            // Restore the compilation stage
            _compilationStage = savedCompilationStage;
        }
    } 

    private void GetCodeDirectoryInformationInternal(VirtualPath virtualCodeDir, 
        out Type codeDomProviderType, out CompilerParameters compilerParameters, 
        out string generatedFilesDir) {
 
        StringSet excludedSubdirectories = null;

        CodeDirectoryType dirType;
 
        // Get the DirectoryType based on the path
        if (virtualCodeDir == HttpRuntime.CodeDirectoryVirtualPath) { 
 
            // If it's the top level code directory, make sure we exclude any
            // subdirectories that are compiled separately 
            EnsureExcludedCodeSubDirectoriesComputed();

            excludedSubdirectories = _excludedCodeSubdirectories;
 
            dirType = CodeDirectoryType.MainCode;
 
            _compilationStage = CompilationStage.TopLevelFiles; 
        }
        else if (virtualCodeDir == HttpRuntime.ResourcesDirectoryVirtualPath) { 

            dirType = CodeDirectoryType.AppResources;

            _compilationStage = CompilationStage.TopLevelFiles; 
        }
        // If virtualCodeDir is a subdir of WebReference virtual path. 
        else if (String.Compare(virtualCodeDir.VirtualPathString, 0, 
            HttpRuntime.WebRefDirectoryVirtualPath.VirtualPathString, 0, HttpRuntime.WebRefDirectoryVirtualPath.VirtualPathString.Length,
            StringComparison.OrdinalIgnoreCase) == 0) { 

            // Use the top WebReference directory info for its sub directories.
            virtualCodeDir = HttpRuntime.WebRefDirectoryVirtualPath;
            dirType = CodeDirectoryType.WebReferences; 

            _compilationStage = CompilationStage.TopLevelFiles; 
        } 
        else if (String.Compare(virtualCodeDir.FileName, HttpRuntime.LocalResourcesDirectoryName,
            StringComparison.OrdinalIgnoreCase) == 0) { 

            dirType = CodeDirectoryType.LocalResources;

            // LocalResources are compiled *after* top level files 
            _compilationStage = CompilationStage.AfterTopLevelFiles;
        } 
        else { 
            // If all else fails, treat it as a sub directory
            // 
            dirType = CodeDirectoryType.SubCode;

            // Sub-code dirs are compiled *before* the main code dir
            _compilationStage = CompilationStage.TopLevelFiles; 
        }
 
        Debug.Assert(virtualCodeDir.HasTrailingSlash); 
        AssemblyReferenceInfo info = TheBuildManager.TopLevelAssembliesIndexTable[virtualCodeDir.VirtualPathString];
        if (info == null) { 
            throw new InvalidOperationException(
                SR.GetString(SR.Invalid_CodeSubDirectory_Not_Exist, virtualCodeDir));
        }
 
        // Get the info we need for this code directory
        CodeDirectoryCompiler.GetCodeDirectoryInformation( 
            virtualCodeDir, dirType, excludedSubdirectories, info.ReferenceIndex, 
            out codeDomProviderType, out compilerParameters,
            out generatedFilesDir); 

        Assembly resultAssembly = info.Assembly;

        if (resultAssembly != null) { 
            // Use the runtime generated assembly location.
            compilerParameters.OutputAssembly = resultAssembly.Location; 
        } 
    }
 
    internal static Type GetProfileType() {
        return _theBuildManager.GetProfileTypeInternal();
    }
 
    private Type GetProfileTypeInternal() {
        EnsureTopLevelFilesCompiled(); 
        return _profileType; 
    }
 

    //
    // Caching related code
    // 

 
    public static ICollection GetVirtualPathDependencies(string virtualPath) { 

        CompilationSection compConfig = RuntimeConfig.GetRootWebConfig().Compilation; 

        // Create a BuildProvider based on the virtual path
        BuildProvider buildProvider = CreateBuildProvider(VirtualPath.Create(virtualPath), compConfig,
            null, false /*failIfUnknown*/); 

        if (buildProvider == null) 
            return null; 

        // Get its dependencies 
        //
        return buildProvider.GetBuildResultVirtualPathDependencies();
    }
 
#if OLD
    /* 
     * Rewrite the virtualPath if appropriate, in order to support ghosting 
     */
    private static void GetGhostedVirtualPath(ref string virtualPath) { 

        VirtualPathProvider virtualPathProvider = HostingEnvironment.VirtualPathProvider;

        string ghostedVirtualPath = virtualPathProvider.GetGhostedVirtualPath(virtualPath); 

        // If the file is not ghosted, don't change the path 
        if (ghostedVirtualPath == null) 
            return;
 
        //


        // Get the list of virtual paths that it depends on (e.g. user controls) 
        ICollection virtualPathDependencies = GetVirtualPathDependencies(virtualPath);
 
        // If there aren't any, return the ghosted path 
        if (virtualPathDependencies == null) {
            virtualPath = ghostedVirtualPath; 
            return;
        }

        // Go through all the dependencies, and if we find any that is *not* ghosted 
        // (i.e. for which GetGhostedVirtualPath returns null), we treat the whole request
        // as unghosted (and hence we return without modifying the virtualPath). 
 
        foreach (string virtualDependency in virtualPathDependencies) {
            string ghostedVirtualDependencyPath = virtualPathProvider.GetGhostedVirtualPath( 
                virtualDependency);
            if (ghostedVirtualDependencyPath == null)
                return;
        } 

        // All the dependencies are ghosted, so we can safely use the ghosted path, 
        // which can then be shared for all fully ghosted requests. 
        virtualPath = ghostedVirtualPath;
    } 
#endif

    internal static string GetCacheKeyFromVirtualPath(VirtualPath virtualPath) {
        bool keyFromVPP; 
        return GetCacheKeyFromVirtualPath(virtualPath, out keyFromVPP);
    } 
 
    /*
     * Same as GetCacheKeyFromVirtualPathInternal, but caches the cache keys 
     * for performance, since creating them is expensive (
*/
    static SimpleRecyclingCache _keyCache = new SimpleRecyclingCache();
    private static string GetCacheKeyFromVirtualPath(VirtualPath virtualPath, out bool keyFromVPP) { 

        // Check if the VirtualPathProvider needs to use a non-default cache key 
        string key = virtualPath.GetCacheKey(); 

        // If so, just return it 
        if (key != null) {
            keyFromVPP = true;
            return key.ToLowerInvariant();
        } 

        // The VPP didn't return a key, so use our standard key algorithm 
        keyFromVPP = false; 

        // Check if the key for this virtual path is already cached 
        key = _keyCache[virtualPath.VirtualPathString] as string;
        if (key != null) return key;

        // Compute the key 
        key = GetCacheKeyFromVirtualPathInternal(virtualPath);
 
        // The key should always be lower case 
        Debug.Assert(key == key.ToLowerInvariant());
 
        // Cache it for next time
        _keyCache[virtualPath.VirtualPathString] = key;

        return key; 
    }
 
    /* 
     * Generate a unique cache key from a virtual path.  e.g. for "/approot/sub1/sub2/foo.aspx"
     * the key could be "foo.aspx.ccdf220e", where ccdf220e is a hash code from 
     * the dir "sub1/sub2".
     */
    private static string GetCacheKeyFromVirtualPathInternal(VirtualPath virtualPath) {
 
        // We want the key to be app independent (for precompilation), so we
        // change the virtual path to be app relative 
 
        /* Disable asserttion since global theme needs to compile theme files in different vroot.
        Debug.Assert(StringUtil.VirtualPathStartsWithAppPath(virtualPath), 
            String.Format("VPath {0} is outside the application: {1}", virtualPath, HttpRuntime.AppDomainAppVirtualPath));
        */
        string virtualPathString = virtualPath.AppRelativeVirtualPathString.ToLowerInvariant();
        virtualPathString = UrlPath.RemoveSlashFromPathIfNeeded(virtualPathString); 

        // Split the path into the directory and the name 
        int slashIndex = virtualPathString.LastIndexOf('/'); 
        Debug.Assert(slashIndex >= 0 || virtualPathString == "~");
 
        if (virtualPathString == "~")
            return "root";

        Debug.Assert(slashIndex != virtualPathString.Length - 1); 
        string name = virtualPathString.Substring(slashIndex + 1);
        string dir; 
        if (slashIndex <= 0) 
            dir = "/";
        else { 
            dir = virtualPathString.Substring(0, slashIndex);
        }

        return name + "." + StringUtil.GetStringHashCode(dir).ToString("x", CultureInfo.InvariantCulture); 
    }
 
    internal static BuildResult GetVPathBuildResultFromCache(VirtualPath virtualPath) { 

        return TheBuildManager.GetVPathBuildResultFromCacheInternal(virtualPath); 
    }

    private BuildResult GetVPathBuildResultFromCacheInternal(VirtualPath virtualPath) {
 
        bool keyFromVPP;
        string cacheKey = GetCacheKeyFromVirtualPath(virtualPath, out keyFromVPP); 
        return GetBuildResultFromCacheInternal(cacheKey, keyFromVPP, virtualPath, 0 /*hashCode*/); 
    }
 
    internal static BuildResult GetBuildResultFromCache(string cacheKey) {
        return _theBuildManager.GetBuildResultFromCacheInternal(cacheKey, false /*keyFromVPP*/, null /*virtualPath*/,
            0 /*hashCode*/);
    } 

    internal static BuildResult GetBuildResultFromCache(string cacheKey, VirtualPath virtualPath) { 
        return _theBuildManager.GetBuildResultFromCacheInternal(cacheKey, false /*keyFromVPP*/, virtualPath, 
            0 /*hashCode*/);
    } 

    private BuildResult GetBuildResultFromCacheInternal(string cacheKey, bool keyFromVPP,
        VirtualPath virtualPath, long hashCode) {
 
        BuildResult result = null;
 
        // Allow the possibility that BuildManager was not initialized due to 
        // a very early failure (e.g. see
 
        if (!_theBuildManagerInitialized)
            return null;

        // The first cache should always be memory 
        Debug.Assert(_caches[0] == _memoryCache);
 
        // Try to get it from the memeory cache before taking any locks (for perf reasons) 
        result = _memoryCache.GetBuildResult(cacheKey, virtualPath, hashCode);
        if (result != null) { 
            return PostProcessFoundBuildResult(result, keyFromVPP, virtualPath);
        }

        Debug.Trace("BuildManager", "Didn't find '" + virtualPath + "' in memory cache before lock"); 

        lock (this) { 
            // Try to get the BuildResult from the cheapest to most expensive cache 
            int i;
            for (i = 0; i < _caches.Length; i++) { 
                result = _caches[i].GetBuildResult(cacheKey, virtualPath, hashCode);

                // There might be changes in local resources for dependencies,
                // so we need to make sure EnsureFirstTimeDirectoryInit gets called 
                // for them even when we already have a cache result.
                // 
 
                if (result != null) {
                    if (result.VirtualPathDependencies != null) { 
                        EnsureFirstTimeDirectoryInitForDependencies(result.VirtualPathDependencies);
                    }

                    break; 
                }
 
                // If we didn't find it in the memory cache, perform the per directory 
                // initialization.  This is a good place to do this, because we don't
                // affect the memory cache code path, but we do the init as soon as 
                // something is not found in the memory cache.
                if (i == 0 && virtualPath != null) {
                    VirtualPath virtualDir = virtualPath.Parent;
                    EnsureFirstTimeDirectoryInit(virtualDir); 
                }
            } 
 

            if (result == null) 
                return null;

            result = PostProcessFoundBuildResult(result, keyFromVPP, virtualPath);
            if (result == null) 
                return null;
 
            Debug.Assert(_memoryCache != null); 

            // If we found it in a cache, cache it in all the caches that come before 
            // the one where we found it.  If we found it in the memory cache, this is a no op.
            for (int j = 0; j < i; j++)
                _caches[j].CacheBuildResult(cacheKey, result, DateTime.UtcNow);
 
            Debug.Trace("BuildManager", "Found '" + virtualPath + "' in " + _caches[i]);
 
            return result; 
        }
    } 

    private BuildResult PostProcessFoundBuildResult(BuildResult result, bool keyFromVPP, VirtualPath virtualPath) {

        // Check that the virtual path in the result matches the passed in 
        // virtualPath (
 
        if (!keyFromVPP) { 
            if (virtualPath != null && virtualPath != result.VirtualPath) {
                Debug.Assert(false); 
                return null;
            }
        }
 
        // If what we found in the cache is a CompileError, rethrow the exception
        if (result is BuildResultCompileError) { 
            // Report the cached error from Callback interface. 
            HttpCompileException compileException = ((BuildResultCompileError)result).CompileException;
 
            // But don't report it if we're doing precompilation, as that would cause it to be
            // reported twice because we always try to compile everything that has failed
            // before (
            if (!PerformingPrecompilation) { 
                ReportErrorsFromException(compileException);
            } 
 
            throw compileException;
        } 

        return result;
    }
 
    internal static bool CacheVPathBuildResult(VirtualPath virtualPath,
        BuildResult result, DateTime utcStart) { 
 
        return _theBuildManager.CacheVPathBuildResultInternal(virtualPath, result, utcStart);
    } 

    private bool CacheVPathBuildResultInternal(VirtualPath virtualPath,
        BuildResult result, DateTime utcStart) {
 
        string cacheKey = GetCacheKeyFromVirtualPath(virtualPath);
        return CacheBuildResult(cacheKey, result, utcStart); 
    } 

    internal static bool CacheBuildResult(string cacheKey, BuildResult result, DateTime utcStart) { 
        return _theBuildManager.CacheBuildResultInternal(cacheKey, result, 0 /*hashCode*/, utcStart);
    }

    private bool CacheBuildResultInternal(string cacheKey, BuildResult result, 
        long hashCode, DateTime utcStart) {
 
        // Before caching it, make sure the hash has been computed 
        result.EnsureVirtualPathDependenciesHashComputed();
 
        for (int i = 0; i < _caches.Length; i++) {
            _caches[i].CacheBuildResult(cacheKey, result, hashCode, utcStart);
        }
 
        // If we find that it's no longer valid after caching it, remove it from the cache (
        if (!TimeStampChecker.CheckFilesStillValid(cacheKey, result.VirtualPathDependencies)) { 
            _memoryCache.RemoveAssemblyAndCleanupDependencies(result as BuildResultCompiledAssemblyBase); 
            return false;
        } 

        return true;
    }
 

    // 
    // Precompilation related code 
    //
 
    internal void SetPrecompilationInfo(HostingEnvironmentParameters hostingParameters) {

        if (hostingParameters == null || hostingParameters.ClientBuildManagerParameter == null)
            return; 

        _precompilationFlags = hostingParameters.ClientBuildManagerParameter.PrecompilationFlags; 
 
        _strongNameKeyFile = hostingParameters.ClientBuildManagerParameter.StrongNameKeyFile;
        _strongNameKeyContainer = hostingParameters.ClientBuildManagerParameter.StrongNameKeyContainer; 

        // Check if we're precompiling to a target directory
        _precompTargetPhysicalDir = hostingParameters.PrecompilationTargetPhysicalDirectory;
        if (_precompTargetPhysicalDir == null) 
            return;
 
        // Check if the target dir already exists and is not empty 
        if (Util.IsNonEmptyDirectory(_precompTargetPhysicalDir)) {
 
            // If it's not empty and OverwriteTarget is off, fail
            if ((_precompilationFlags & PrecompilationFlags.OverwriteTarget) == 0) {
                throw new HttpException(SR.GetString(SR.Dir_not_empty));
            } 

            // Does it contain the precomp marker file 
            bool updatable; 
            bool precompiled = ReadPrecompMarkerFile(_precompTargetPhysicalDir, out updatable);
 
            // If not, refuse to delete the directory, even if OverwriteTarget is on (
            if (!precompiled) {
                throw new HttpException(SR.GetString(SR.Dir_not_empty_not_precomp));
            } 

            // The OverwriteTarget flag was specified, so delete the directory 
            if (!DeletePrecompTargetDirectory()) { 
                // If we failed to delete it, sleep 250 ms and try again, in case there is
                // an appdomain in the process of shutting down (the shut down would 
                // have been triggered by the first delete attempt)
                Debug.Trace("BuildManager", "Failed to delete " + _precompTargetPhysicalDir + ".  Sleeping and trying once more...");
                Thread.Sleep(250);
 
                if (!DeletePrecompTargetDirectory()) {
                    Debug.Trace("BuildManager", "Failed to delete " + _precompTargetPhysicalDir + ".  Sleeping and trying once more..."); 
                    // Try again after 1 second. 
                    Thread.Sleep(1000);
 
                    // If we still couldn't delete it, fail
                    if (!DeletePrecompTargetDirectory()) {
                        throw new HttpException(SR.GetString(SR.Cant_delete_dir));
                    } 
                }
            } 
        } 

        // Create a marker file to mark the fact that this is a precompiled app 
        CreatePrecompMarkerFile();
    }

    private bool DeletePrecompTargetDirectory() { 
        try {
            if (_precompTargetPhysicalDir != null) { 
                // Go through all the files in the directory and delete them. 
                foreach (FileData fileData in FileEnumerator.Create(_precompTargetPhysicalDir)) {
 
                    if (fileData.IsDirectory) {
                        Directory.Delete(fileData.FullName, true /*recursive*/);
                    }
                    else { 
                        Util.DeleteFileNoException(fileData.FullName);
                    } 
                } 
            }
        } 
#if DEBUG
        catch (Exception e) {
            Debug.Trace("BuildManager", "DeletePrecompTargetDirectory failed: " + e.Message);
        } 
#else
        catch {} 
#endif 
        return !Util.IsNonEmptyDirectory(_precompTargetPhysicalDir);
    } 

    private void FailIfPrecompiledApp() {

        if (IsPrecompiledApp) { 
            throw new HttpException(SR.GetString(SR.Already_precomp));
        } 
    } 

    internal void PrecompileApp(ClientBuildManagerCallback callback) { 

        // Remember the original setting
        bool skipTopLevelExceptions = SkipTopLevelCompilationExceptions;
 
        try {
            _cbmCallback = callback; 
 
            // Don't stop on the first parse errors, process as many errors as possible.
            ThrowOnFirstParseError = false; 

            // Don't skip top level compilation exceptions even called by CBM.
            SkipTopLevelCompilationExceptions = false;
 
            PrecompileApp(HttpRuntime.AppDomainAppVirtualPathObject);
        } 
        finally { 
            // Revert to original setting
            SkipTopLevelCompilationExceptions = skipTopLevelExceptions; 
            ThrowOnFirstParseError = true;

            _cbmCallback = null;
        } 
    }
 
    private void PrecompileApp(VirtualPath startingVirtualDir) { 
        using (new ApplicationImpersonationContext()) {
            try { 
                PerformingPrecompilation = true;

                PrecompileAppInternal(startingVirtualDir);
            } 
            catch {
                // If anything fails during precompilation, wipe out the target to avoid 
                // leaving it in a random state ( 
                DeletePrecompTargetDirectory();
 
                throw;
            }
            finally {
                PerformingPrecompilation = false; 
            }
        } 
    } 

    private void PrecompileAppInternal(VirtualPath startingVirtualDir) { 

        // If the app is already precompiled, fail
        FailIfPrecompiledApp();
 
        VirtualDirectory appVdir = startingVirtualDir.GetDirectory();
 
        EnsureTopLevelFilesCompiled(); 

        try { 
            // Clear the parseError flag first
            _parseErrorReported = false;

            PrecompileWebDirectoriesRecursive(appVdir, true /*topLevel*/); 
            PrecompileThemeDirectories();
        } 
        catch (HttpParseException parseException) { 
            // if nothing calls callback.reportparseerror yet, report the parse error.
            if (!_parseErrorReported) { 
                ReportErrorsFromException(parseException);
            }

            throw; 
        }
 
        // Copy all the DLL's we compiled into the destination's bin directory (if any) 
        if (_precompTargetPhysicalDir != null) {
            string targetBinDir = Path.Combine(_precompTargetPhysicalDir, HttpRuntime.BinDirectoryName); 
            CopyCompiledAssembliesToDestinationBin(HttpRuntime.CodegenDirInternal, targetBinDir);
        }

        // Copy all the static files to the destination directory (if any).  We treat anything we 
        // don't compile as a static file.  It's better to do this at the end of the precompilation,
        // this way if any pages has errors (parse or compile), we never get to this step. 
        if (_precompTargetPhysicalDir != null) { 
            CopyStaticFilesRecursive(appVdir, _precompTargetPhysicalDir, true /*topLevel*/);
        } 
    }

    // Create a small file that marks that app as being precompiled
    private void CreatePrecompMarkerFile() { 

        Debug.Assert(PrecompilingForDeployment); 
 
        Directory.CreateDirectory(_precompTargetPhysicalDir);
        string precompMarkerFile = Path.Combine(_precompTargetPhysicalDir, precompMarkerFileName); 

        using (StreamWriter writer = new StreamWriter(precompMarkerFile, false /*append*/, Encoding.UTF8)) {
            writer.Write("");
        }
    }
 
    private static bool ReadPrecompMarkerFile(string appRoot, out bool updatable) {
 
        updatable = false; 

        // Get the full physical path to the precompilation market file 
        string precompMarkerFile = Path.Combine(appRoot, precompMarkerFileName);

        // If the file doesn't exist at all, it's not a precompiled app
        if (!File.Exists(precompMarkerFile)) 
            return false;
 
        XmlDocument doc = new XmlDocument(); 
        try {
            doc.Load(precompMarkerFile); 
        }
        catch {
            // If we fail to read it for any reason, ignore it.
            return false; 
        }
 
        // Get the root element, and make sure it's what we expect 
        XmlNode root = doc.DocumentElement;
        Debug.Assert(root != null && root.Name == "precompiledApp"); 
        if (root == null || root.Name != "precompiledApp")
            return false;

        // Check the updatable flag 
        HandlerBase.GetAndRemoveBooleanAttribute(root, "updatable", ref updatable);
 
        return true; 
    }
 
    /*
     * Are we precompiling the app for deployment (as opposed to in-place)
     */
    internal static bool PrecompilingForDeployment { 
        get {
            return (_theBuildManager._precompTargetPhysicalDir != null); 
        } 
    }
 
    internal static bool PrecompilingForUpdatableDeployment {
        get {
            // The updatebale mode only applies in deployment precompilation mode
            if (!PrecompilingForDeployment) 
                return false;
 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.Updatable) != 0; 
        }
    } 

    private static bool PrecompilingForCleanBuild {
        get {
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.Clean) != 0; 
        }
    } 
 
    internal static bool PrecompilingWithDebugInfo {
        get { 
            // The ForceDebug flag only applies in deployment precompilation mode
            if (!PrecompilingForDeployment)
                return false;
 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.ForceDebug) != 0;
        } 
    } 

    internal static bool PrecompilingWithCodeAnalysisSymbol { 
        get {
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.CodeAnalysis) != 0;
        }
    } 

    private static bool CompileWithFixedAssemblyNames { 
        get { 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.FixedNames) != 0;
        } 
    }

    internal static bool CompileWithAllowPartiallyTrustedCallersAttribute {
        get { 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.AllowPartiallyTrustedCallers) != 0;
        } 
    } 

    internal static bool CompileWithDelaySignAttribute { 
        get {
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.DelaySign) != 0;
        }
    } 

    internal static string StrongNameKeyFile { 
        get { 
            return _theBuildManager._strongNameKeyFile;
        } 
    }

    internal static string StrongNameKeyContainer {
        get { 
            return _theBuildManager._strongNameKeyContainer;
        } 
    } 

    // If we're in the process of precompiling for updatable deployment, this returns 
    // a writer to the target file specified by the virtual path.  This is used when the
    // deployed file needs to be different from the original (as is the case for aspx files).
    internal static TextWriter GetUpdatableDeploymentTargetWriter(VirtualPath virtualPath, Encoding fileEncoding) {
 
        Debug.Assert(fileEncoding != null);
 
        if (!PrecompilingForUpdatableDeployment) 
            return null;
 
        Debug.Assert(!virtualPath.IsRelative);

        string path = virtualPath.AppRelativeVirtualPathString;
 
        // Skip the "~/" to be left with the relative path
        path = path.Substring(2); 
 
        // Combine it with the precomp target dir to get the full path
        string physicalPath = Path.Combine(_theBuildManager._precompTargetPhysicalDir, path); 

        // Before trying to create the file, make sure the directory exists
        string physicalDir = Path.GetDirectoryName(physicalPath);
        Directory.CreateDirectory(physicalDir); 

        return new StreamWriter(physicalPath, false /*append*/, fileEncoding); 
    } 

    private bool IsPrecompiledAppInternal { 
        get {
            if (!_isPrecompiledAppComputed) {
                _isPrecompiledApp = ReadPrecompMarkerFile(HttpRuntime.AppDomainAppPathInternal,
                    out _isUpdatablePrecompiledApp); 

                _isPrecompiledAppComputed = true; 
            } 

            return _isPrecompiledApp; 
        }
    }

    internal static bool IsPrecompiledApp { 
        get {
            return _theBuildManager.IsPrecompiledAppInternal; 
        } 
    }
 
    private bool IsUpdatablePrecompiledAppInternal {
        get {
            return IsPrecompiledApp && _isUpdatablePrecompiledApp;
        } 
    }
 
    internal static bool IsUpdatablePrecompiledApp { 
        get {
            return _theBuildManager.IsUpdatablePrecompiledAppInternal; 
        }
    }

    private bool IsNonUpdatablePrecompiledApp { 
        get {
            return IsPrecompiledApp && !_isUpdatablePrecompiledApp; 
        } 
    }
 
    private void PrecompileWebDirectoriesRecursive(VirtualDirectory vdir, bool topLevel) {

        // Precompile the children directory
 
        foreach (VirtualDirectory childVdir in vdir.Directories) {
 
            if (topLevel && _excludedTopLevelDirectories.Contains(childVdir.Name)) 
                continue;
 
            // Exclude the special FrontPage directory (
            if (childVdir.Name == "_vti_cnf")
                continue;
 
            PrecompileWebDirectoriesRecursive(childVdir, false /*topLevel*/);
        } 
 
        // Precompile this directory
        try { 
            // Set a flag to remember that we're in the process of precompiling.  This
            // way, if BatchCompileWebDirectory ends up getting called again recursively
            // via CompileWebFile, we know that we cannot ignore errors.
            _precompilingApp = true; 

            if (IsBatchEnabledForDirectory(vdir.VirtualPathObject)) { 
                // batch everything if enabled 
                BatchCompileWebDirectory(vdir, null, false /*ignoreErrors*/);
            } 
            else {
                // if batching is disabled, compile each web file individually.
                NonBatchDirectoryCompiler dirCompiler = new NonBatchDirectoryCompiler(vdir);
                dirCompiler.Process(); 
            }
        } 
        finally { 
            // Always restore the flag to false when we're done.
            _precompilingApp = false; 
        }
    }

    private void PrecompileThemeDirectories() { 
        string appPhysicalDir = Path.Combine(HttpRuntime.AppDomainAppPathInternal, HttpRuntime.ThemesDirectoryName);
 
        if (Directory.Exists(appPhysicalDir)) { 
            string[] themeDirs = Directory.GetDirectories(appPhysicalDir);
 
            foreach (string themeDirPath in themeDirs) {
                string themeDirName = Path.GetFileName(themeDirPath);
                ThemeDirectoryCompiler.GetThemeBuildResultType(null /*context*/, themeDirName);
            } 
        }
    } 
 
    /*
     * Recursively copy all the static files from the source directory to the 
     * target directory of the precompilation
     */
    private void CopyStaticFilesRecursive(VirtualDirectory sourceVdir, string destPhysicalDir,
        bool topLevel) { 

        // Make sure the target physical dir has no relation with the source.  It's important to 
        // 

        string sourcePhysicalDir = HostingEnvironment.MapPathInternal(sourceVdir.VirtualPath); 
        VerifyUnrelatedSourceAndDest(sourcePhysicalDir, destPhysicalDir);

        bool directoryCreationAttempted = false;
 
        foreach (VirtualFileBase child in sourceVdir.Children) {
 
            string destPhysicalSubDir = Path.Combine(destPhysicalDir, child.Name); 

            if (child.IsDirectory) { 

                // Skip the special top level directories, since they never contain relevant
                // static files.  Note that we don't skip Themes, which does contain static files.
                if (topLevel && 
                    (StringUtil.EqualsIgnoreCase(child.Name, HttpRuntime.CodeDirectoryName) ||
                    StringUtil.EqualsIgnoreCase(child.Name, HttpRuntime.ResourcesDirectoryName) || 
                    StringUtil.EqualsIgnoreCase(child.Name, HttpRuntime.WebRefDirectoryName))) { 

                    continue; 
                }

                // Also, skip the LocalResources directory at any level, except when precompiling
                // for updatable deployment (in which case, we deploy the local resources file) 
                if (!PrecompilingForUpdatableDeployment && StringUtil.EqualsIgnoreCase(child.Name,
                    HttpRuntime.LocalResourcesDirectoryName)) { 
                    continue; 
                }
 
                CopyStaticFilesRecursive(child as VirtualDirectory, destPhysicalSubDir, false /*topLevel*/);
                continue;
            }
 
            // Create the destination directory if needed
            if (!directoryCreationAttempted) { 
                directoryCreationAttempted = true; 
                Directory.CreateDirectory(destPhysicalDir);
            } 

            // Copy the file as appropriate based on its extension
            CopyPrecompiledFile(child as VirtualFile, destPhysicalSubDir);
        } 
    }
 
    /* 
     * Copy all the assemblies from the codegen dir into the bin directory of the
     * target precompiled app. 
     */
    private void CopyCompiledAssembliesToDestinationBin(string fromDir, string toDir) {

        bool createdDirectory = false; 

        foreach (FileData fileData in FileEnumerator.Create(fromDir)) { 
            // Windows OS Bug 1981578 
            // Create a new directory only if there is something in the directory.
            if (!createdDirectory) 
                Directory.CreateDirectory(toDir);
            createdDirectory = true;

            // Recurse on subdirectories.if they contain culture files 
            if (fileData.IsDirectory) {
 
                if (Util.IsCultureName(fileData.Name)) { 
                    string fromSubDir = Path.Combine(fromDir, fileData.Name);
                    string toSubDir = Path.Combine(toDir, fileData.Name); 
                    CopyCompiledAssembliesToDestinationBin(fromSubDir, toSubDir);
                }

                continue; 
            }
 
            // Only process DLL's and PDB's 
            string extension = Path.GetExtension(fileData.Name);
            if (extension != ".dll" && extension != ".pdb") 
                continue;

            string sourcePhysicalPath = Path.Combine(fromDir, fileData.Name);
            string destPhysicalPath = Path.Combine(toDir, fileData.Name); 

            // Copy the file to the destination 
            // 
            File.Copy(sourcePhysicalPath, destPhysicalPath, true /*overwrite*/);
        } 
    }

    // Copy one file from the source app to the precompiled app
    private void CopyPrecompiledFile(VirtualFile vfile, string destPhysicalPath) { 

        bool createStub; 
 
        if (CompilationUtil.NeedToCopyFile(vfile.VirtualPathObject, PrecompilingForUpdatableDeployment,
            out createStub)) { 

            //
            string sourcePhysicalPath = HostingEnvironment.MapPathInternal(vfile.VirtualPath);
 
            // The file could already exist with updatable precompilation, since we would create the modified file
            // earlier during processing of a code beside page. 
            if (File.Exists(destPhysicalPath)) { 

                // In that case, we still need to fix it up to insert the correct type string in the 
                // inherits attribute (

                // First, get the just-compiled BuildResult.  It should always exist
                BuildResultCompiledType result = GetVPathBuildResult(null, vfile.VirtualPathObject, 
                    true /*noBuild*/, false /*allowCrossApp*/) as BuildResultCompiledType;
                Debug.Assert(result != null); 
 
                //
 
                Encoding encoding = Util.GetEncodingFromConfigPath(vfile.VirtualPathObject);

                // Read in the file
                string newAspxFile = Util.StringFromFile(destPhysicalPath, ref encoding); 

                // Replace the placeholder token by the true type with the assembly 
                newAspxFile = newAspxFile.Replace(UpdatableInheritReplacementToken, 
                    Util.GetAssemblyQualifiedTypeName(result.ResultType));
 
                // Write the modified file back with the correct inherits type string
                StreamWriter writer = new StreamWriter(destPhysicalPath, false /* append */, encoding);
                writer.Write(newAspxFile);
                writer.Close(); 
            }
            else { 
                // Just copy the file to the destination 
                File.Copy(sourcePhysicalPath, destPhysicalPath, false /*overwrite*/);
            } 

            // If it has a readonly attribute, clear it on the destination (
            Util.ClearReadOnlyAttribute(destPhysicalPath);
        } 
        else {
            if (createStub) { 
                // Create the stub file, with a helpful static message 
                StreamWriter writer = new StreamWriter(destPhysicalPath);
                writer.Write(SR.GetString(SR.Precomp_stub_file)); 
                writer.Close();
            }
        }
    } 

    // Make sure the target physical dir has no relation with the source 
    internal static void VerifyUnrelatedSourceAndDest(string sourcePhysicalDir, string destPhysicalDir) { 

        // Make sure they're normalized and end with a '\' before comparing ( 
        sourcePhysicalDir = FileUtil.FixUpPhysicalDirectory(sourcePhysicalDir);
        destPhysicalDir = FileUtil.FixUpPhysicalDirectory(destPhysicalDir);

        if (StringUtil.StringStartsWithIgnoreCase(sourcePhysicalDir, destPhysicalDir) || 
            StringUtil.StringStartsWithIgnoreCase(destPhysicalDir, sourcePhysicalDir)) {
            throw new HttpException(SR.GetString( 
                SR.Illegal_precomp_dir, destPhysicalDir, sourcePhysicalDir)); 
        }
    } 

    internal static void ReportDirectoryCompilationProgress(VirtualPath virtualDir) {

        // Nothing to do if there is no CBM callback 
        if (CBMCallback == null)
            return; 
 
        // Don't report anything if the directory doesn't exist
        if (!virtualDir.DirectoryExists()) 
            return;

        string message = SR.GetString(SR.Directory_progress, virtualDir.VirtualPathString);
        CBMCallback.ReportProgress(message); 
    }
 
 
    //
    // Public methods 
    //


    ///  
    ///     Compiles a file given its virtual path, using the appropriate BuildProvider (based
    ///     on the file's extension).  The compiled type is returned. 
    ///     This methods performs both memory and disk caching of the compiled Type. 
    /// 
    public static Type GetCompiledType(string virtualPath) { 
        if (virtualPath == null) {
            throw new ArgumentNullException("virtualPath");
        }
 
        return GetCompiledType(VirtualPath.Create(virtualPath));
    } 
 
    // This method is called by BuildManagerHost thru CBM
    internal static Type GetCompiledType(VirtualPath virtualPath, ClientBuildManagerCallback callback) { 
        // Remember the original setting
        bool skipTopLevelExceptions = SkipTopLevelCompilationExceptions;
        bool throwOnFirstParseError = ThrowOnFirstParseError;
 
        try {
            // Don't skip top level compilation exceptions even called by CBM. 
            SkipTopLevelCompilationExceptions = false; 

            // Don't stop on the first parse error, process as many errors as possible. 
            ThrowOnFirstParseError = false;

            _theBuildManager._cbmCallback = callback;
            return GetCompiledType(virtualPath); 
        }
        finally { 
            _theBuildManager._cbmCallback = null; 

            // Revert to original setting 
            SkipTopLevelCompilationExceptions = skipTopLevelExceptions;

            ThrowOnFirstParseError = throwOnFirstParseError;
        } 
    }
 
    internal static Type GetCompiledType(VirtualPath virtualPath) { 
        ITypedWebObjectFactory factory = GetVirtualPathObjectFactory(virtualPath,
            null /*context*/, false /*allowCrossApp*/, false /*noAssert*/); 

        BuildResultCompiledType resultType = factory as BuildResultCompiledType;
        if (resultType == null) return null;
 
        return resultType.ResultType;
    } 
 
    /// Process a file based on its virtual path, and instantiate the result.  This API works for both
    /// compiled and no compile pages.  requiredBaseType specifies a type from which the resulting 
    /// object must derive.  If it doesn't, the API fails without instantiating the object.
    public static object CreateInstanceFromVirtualPath(string virtualPath, Type requiredBaseType) {
        VirtualPath virtualPathObject = VirtualPath.CreateNonRelative(virtualPath);
        return CreateInstanceFromVirtualPath(virtualPathObject, requiredBaseType, 
            null /*context*/, false /*allowCrossApp*/, false /*noAssert*/);
    } 
 
    /// 
    ///     Process a file given its virtual path, using the appropriate BuildProvider (based 
    ///     on the file's extension).  The result is then instantiated and returned.
    /// 
    internal static object CreateInstanceFromVirtualPath(VirtualPath virtualPath,
        Type requiredBaseType, HttpContext context, bool allowCrossApp, bool noAssert) { 

        ITypedWebObjectFactory objectFactory = GetVirtualPathObjectFactory(virtualPath, context, allowCrossApp, noAssert); 
        if (objectFactory == null) return null; 

        // Make sure it has the required base type ( 
        Util.CheckAssignableType(requiredBaseType, objectFactory.InstantiatedType);

        // impersonate client while executing page ctor (see ASURT 89712)
        // (compilation is done while not impersonating client) 

        Object instance; 
        using (new ClientImpersonationContext(context)) { 
            instance = objectFactory.CreateInstance();
        } 

        return instance;
    }
 

    ///  
    ///     Process a file given its virtual path, using the appropriate BuildProvider (based 
    ///     on the file's extension).  The ITypedWebObjectFactory is returned.
    ///     This methods performs both memory and disk caching of the compiled Type. 
    /// 
    private static ITypedWebObjectFactory GetVirtualPathObjectFactory(VirtualPath virtualPath,
        HttpContext context, bool allowCrossApp, bool noAssert) {
 
        if (virtualPath == null)
            throw new ArgumentNullException("virtualPath"); 
 
        // Throw here immediately if top level exception exists.
        // This is because EnsureTopLevelFilesCompiled (where the exception is thrown) 
        // might not be called.
        if (_theBuildManager._topLevelFileCompilationException != null) {
            _theBuildManager.ReportTopLevelCompilationException();
        } 

        ITypedWebObjectFactory objectFactory; 
        BuildResult buildResult; 

        // We need to assertt here since there may be user code on the stack, 
        // and code may demand UnmanagedCode permission.  But if we're in full trust,
        // or noAssert is true, skip the assertt for perf reasons (
        if (HttpRuntime.IsFullTrust || noAssert) {
            buildResult = GetVPathBuildResultWithNoAssert( 
                context, virtualPath, false /*noBuild*/, allowCrossApp, false /*allowBuildInPrecompile*/);
        } 
        else { 
            buildResult = GetVPathBuildResultWithAssert(
                context, virtualPath, false /*noBuild*/, allowCrossApp, false /*allowBuildInPrecompile*/); 
        }

        // DevDiv 67952
        // The returned build result may not always be castable to ITypedWebObjectFactory. 
        objectFactory = buildResult as ITypedWebObjectFactory;
 
        return objectFactory; 
    }
 
    /// 
    ///     Compiles a file given its virtual path, using the appropriate BuildProvider (based
    ///     on the file's extension).  The compiled assembly is returned.
    ///     This methods performs both memory and disk caching of the compiled assembly. 
    /// 
    public static Assembly GetCompiledAssembly(string virtualPath) { 
 
        BuildResult result = GetVPathBuildResult(VirtualPath.Create(virtualPath));
        if (result == null) return null; 

        BuildResultCompiledAssemblyBase resultAssembly = result as BuildResultCompiledAssemblyBase;
        if (resultAssembly == null) return null;
 
        return resultAssembly.ResultAssembly;
    } 
 

    ///  
    ///     Compiles a file given its virtual path, using the appropriate BuildProvider (based
    ///     on the file's extension).  If the BuildProvider chose to persist a custom
    ///     string, the string is returned.
    ///     This methods performs both memory and disk caching. 
    /// 
    public static string GetCompiledCustomString(string virtualPath) { 
 
        BuildResult result = GetVPathBuildResult(VirtualPath.Create(virtualPath));
        if (result == null) return null; 

        BuildResultCustomString resultCustomString = result as BuildResultCustomString;
        if (resultCustomString == null) return null;
 
        return resultCustomString.CustomString;
    } 
 
    /// 
    ///     Returns the BuildDependencySet for the passed in virtualPath, assuming 
    ///     that information is cached.  Otherwise, return null.
    /// 
    public static BuildDependencySet GetCachedBuildDependencySet(
        HttpContext context, string virtualPath) { 

        BuildResult result = GetVPathBuildResult(context, VirtualPath.Create(virtualPath), 
            true /*noBuild*/, false /*allowCrossApp*/); 

        // If it's not cached, return null 
        if (result == null)
            return null;

        // We found it in the cache.  Wrap it with a BuildDependencySet object. 
        return new BuildDependencySet(result);
    } 
 
    private Assembly ResolveAssembly(object sender, ResolveEventArgs e) {
 
        if (_assemblyResolveMapping == null)
            return null;

        string name = e.Name; 
        Assembly assembly = (Assembly)_assemblyResolveMapping[name];
 
        // Return the assembly if we have it in our mapping ( 
        if (assembly != null) {
            return assembly; 
        }

        // Get the normalized assembly name from random name (
        String normalizedName = GetNormalizedCodeAssemblyName(name); 
        if (normalizedName != null) {
            return (Assembly)_assemblyResolveMapping[normalizedName]; 
        } 

        return null; 
    }

    internal static string GetNormalizedCodeAssemblyName(string assemblyName) {
        // Return the main code assembly. 
        if (assemblyName.StartsWith(CodeDirectoryAssemblyName, StringComparison.Ordinal)) {
            return CodeDirectoryAssemblyName; 
        } 

        // Check the sub code directories. 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();
        foreach (CodeSubDirectory directory in codeSubDirectories) {
            if (assemblyName.StartsWith(SubCodeDirectoryAssemblyNamePrefix + directory.AssemblyName + ".", StringComparison.Ordinal)) {
                return directory.AssemblyName; 
            }
        } 
 
        return null;
    } 

    internal static string GetNormalizedTypeName(Type t) {
        string assemblyFullName = t.Assembly.FullName;
        string normalizedCodeAssemblyName = GetNormalizedCodeAssemblyName(assemblyFullName); 
        if (normalizedCodeAssemblyName == null) {
            return t.AssemblyQualifiedName; 
        } 

        string normalizedTypeName = t.FullName + ", " + normalizedCodeAssemblyName; 
        return normalizedTypeName;
    }
}
 
internal enum CompilationStage {
    PreTopLevelFiles = 0,       // Before EnsureTopLevelFilesCompiled() is called 
    TopLevelFiles = 1,          // In EnsureTopLevelFilesCompiled() but before building global.asax 
    GlobalAsax = 2,             // While building global.asax
    BrowserCapabilities = 3,    // While building browserCap 
    AfterTopLevelFiles = 4      // After EnsureTopLevelFilesCompiled() is called
}

internal class AssemblyReferenceInfo { 
    internal Assembly Assembly;
    internal int ReferenceIndex; 
 
    internal AssemblyReferenceInfo(int referenceIndex) {
        ReferenceIndex = referenceIndex; 
    }
}
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
//------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/************************************************************************************************************/ 
 

 
namespace System.Web.Compilation {

using System;
using System.IO; 
using System.Collections;
using System.Collections.Generic; 
using System.Collections.Specialized; 
using System.Reflection;
using System.Runtime.Remoting.Messaging; 
using System.Text;
using System.Xml;
using System.Globalization;
using System.Resources; 
using System.CodeDom;
using System.CodeDom.Compiler; 
using System.Configuration; 
using System.Web.Configuration;
using System.Web.Util; 
using System.Web.Caching;
using System.Web.UI;
#if ORCAS
using System.Web.UI.Imaging; 
#endif
using System.Web.Hosting; 
using System.Web.Profile; 
using System.Web.Security;
using System.Threading; 
using System.Security.Permissions;
using System.Web.Management;

 
/// 
///     
///       IProvider compilation related services 
///    
///  
[AspNetHostingPermission(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Medium)]
public sealed class BuildManager {

    /// Contants relating to generated assembly names 

    // All generated assemblies start with this prefix 
    internal const string AssemblyNamePrefix = "App_"; 

    // Web assemblies are the assemblies generated from web files (aspx, ascx, ...) 
    internal const string WebAssemblyNamePrefix = AssemblyNamePrefix + "Web_";

    internal const string AppThemeAssemblyNamePrefix = AssemblyNamePrefix + "Theme_";
    internal const string GlobalThemeAssemblyNamePrefix = AssemblyNamePrefix + "GlobalTheme_"; 
    internal const string AppBrowserCapAssemblyNamePrefix = AssemblyNamePrefix + "Browsers";
 
    private const string CodeDirectoryAssemblyName = AssemblyNamePrefix + "Code"; 
    internal const string SubCodeDirectoryAssemblyNamePrefix = AssemblyNamePrefix + "SubCode_";
    private const string ResourcesDirectoryAssemblyName = AssemblyNamePrefix + "GlobalResources"; 
    private const string LocalResourcesDirectoryAssemblyName = AssemblyNamePrefix + "LocalResources";
    private const string WebRefDirectoryAssemblyName = AssemblyNamePrefix + "WebReferences";
    internal const string GlobalAsaxAssemblyName = AssemblyNamePrefix + HttpApplicationFactory.applicationFileName;
 
    private const string LicensesAssemblyName = AssemblyNamePrefix + "Licenses";
 
    internal const string UpdatableInheritReplacementToken = "__ASPNET_INHERITS"; 

    private static System.Security.Cryptography.RNGCryptoServiceProvider _rng = new System.Security.Cryptography.RNGCryptoServiceProvider(); 
    private static bool _theBuildManagerInitialized;
    private static Exception _initializeException;
    private static BuildManager _theBuildManager = new BuildManager();  // single instance of the class
    private static long s_topLevelHash; 
    internal static BuildManager TheBuildManager { get { return _theBuildManager; } }
 
    // Precompilation related fields 
    private const string precompMarkerFileName = "PrecompiledApp.config";
    private string _precompTargetPhysicalDir; 
    private PrecompilationFlags _precompilationFlags;
    private bool _isPrecompiledApp;
    private bool _isPrecompiledAppComputed;
    private bool _isUpdatablePrecompiledApp; 
    private bool _precompilingApp;  // we're in the process of precompiling an app
 
    private string _strongNameKeyFile; 
    private string _strongNameKeyContainer;
 
    // filepath to the generated web.hash file, This file should only be re-created when
    // the appdomain is restarted and the top-level generated assemblies need to be recompiled.
    private string _webHashFilePath;
    internal static String WebHashFilePath { 
        get { return _theBuildManager._webHashFilePath; }
    } 
 
    private BuildResultCache[] _caches;
    private MemoryBuildResultCache _memoryCache; 

    private bool _topLevelFilesCompiledStarted;
    private bool _topLevelFilesCompiledCompleted;
    private Exception _topLevelFileCompilationException; 

    private BuildResultCompiledGlobalAsaxType _globalAsaxBuildResult; 
    private Type _profileType; 

    // Special top level directories that are treated differently from regular web directories 
    // during precompilation (e.g. App_Code)
    private StringSet _excludedTopLevelDirectories;

    // Directories that are not requestable 
    private StringSet _forbiddenTopLevelDirectories;
 
    private StringSet _excludedCodeSubdirectories; 

    private CompilationStage _compilationStage = CompilationStage.PreTopLevelFiles; 
    internal static CompilationStage CompilationStage { get { return _theBuildManager._compilationStage; } }

    private VirtualPath _scriptVirtualDir;
    private VirtualPath _globalAsaxVirtualPath; 
    internal static VirtualPath ScriptVirtualDir { get { return _theBuildManager._scriptVirtualDir; } }
    internal static VirtualPath GlobalAsaxVirtualPath { get { return _theBuildManager._globalAsaxVirtualPath; } } 
 
    private BuildManager() { }
 
    internal static bool InitializeBuildManager() {

        // If we already tried and got an exception, just rethrow it
        if (_initializeException != null) { 
            // We need to wrap it in a new exception, otherwise we lose the original stack.
            throw new HttpException(_initializeException.Message, _initializeException); 
        } 

        if (!_theBuildManagerInitialized) { 

            // If Fusion was not yet initialized, skip the init.
            // This can happen when there is a very early failure (e.g. see
            Debug.Trace("BuildManager", "InitializeBuildManager " + HttpRuntime.FusionInited); 
            if (!HttpRuntime.FusionInited)
                return false; 
 
            // Likewise, if the trust level has not yet been determined, skip the init (
            if (HttpRuntime.TrustLevel == null) 
                return false;

            _theBuildManagerInitialized = true;
            try { 
                _theBuildManager.Initialize();
            } 
            catch (Exception e) { 
                _theBuildManagerInitialized = false;
                _initializeException = e; 
                throw;
            }
        }
 
        return true;
    } 
 
    private ClientBuildManagerCallback _cbmCallback;
    internal static ClientBuildManagerCallback CBMCallback { get { return _theBuildManager._cbmCallback; } } 

    private static bool _parseErrorReported;
    internal static void ReportParseError(ParserError parseError) {
        // If there is a CBM callback, inform it of the error 
        if (BuildManager.CBMCallback != null) {
            _parseErrorReported = true; 
            BuildManager.CBMCallback.ReportParseError(parseError); 
        }
    } 

    private void ReportTopLevelCompilationException() {
        Debug.Assert(_topLevelFileCompilationException != null);
 
        // Try to report the cached error to the CBM callback
        ReportErrorsFromException(_topLevelFileCompilationException); 
 
        // We need to wrap it in a new exception, otherwise we lose the original stack.
        throw new HttpException(_topLevelFileCompilationException.Message, 
            _topLevelFileCompilationException);
    }

    // Given an exception, attempt to turn it into calls to the CBM callback 
    private void ReportErrorsFromException(Exception e) {
        // If there is no CBM callback, nothing to do 
        if (BuildManager.CBMCallback == null) 
            return;
 
        // Call the CBM callback as appropriate, based on the type of exception

        if (e is HttpCompileException) {
            CompilerResults results = ((HttpCompileException) e).Results; 
            foreach (CompilerError error in results.Errors) {
                BuildManager.CBMCallback.ReportCompilerError(error); 
            } 
        }
        else if (e is HttpParseException) { 
            foreach (ParserError parseError in ((HttpParseException)e).ParserErrors) {
                ReportParseError(parseError);
            }
        } 
    }
 
    // The assemblies produced from the code directories and global.asax, which 
    // every other compilation will linked with.
    private List _topLevelReferencedAssemblies; 
    private List TopLevelReferencedAssemblies { get { return _topLevelReferencedAssemblies; } }

    private Dictionary _topLevelAssembliesIndexTable;
    private IDictionary TopLevelAssembliesIndexTable { get { return _topLevelAssembliesIndexTable; } } 

    private Dictionary _generatedFileTable; 
    internal static Dictionary GenerateFileTable { 
        get {
            if (_theBuildManager._generatedFileTable == null) { 
                _theBuildManager._generatedFileTable = new Dictionary(StringComparer.OrdinalIgnoreCase);
            }

            return _theBuildManager._generatedFileTable; 
        }
    } 
 
    private ArrayList _codeAssemblies;
    public static IList CodeAssemblies { 
        get {
            _theBuildManager.EnsureTopLevelFilesCompiled();
            return _theBuildManager._codeAssemblies;
        } 
    }
 
    private IDictionary _assemblyResolveMapping; 

    private Assembly _appResourcesAssembly; 
    internal static Assembly AppResourcesAssembly { get { return _theBuildManager._appResourcesAssembly; } }

    // Indicates whether the parsers should coninue processing for more errors.
    // This is used in both CBM precompile-web, precompile-page and aspnet_compiler tool. 
    private bool _throwOnFirstParseError = true;
    internal static bool ThrowOnFirstParseError { 
        get { return _theBuildManager._throwOnFirstParseError; } 
        set { _theBuildManager._throwOnFirstParseError = value; }
    } 

    // Marks whether we are in the middle of performing precompilation, which affects how
    // we deal with error handling and batching
    private bool _performingPrecompilation = false; 
    internal static bool PerformingPrecompilation {
        get { return _theBuildManager._performingPrecompilation; } 
        set { _theBuildManager._performingPrecompilation = value; } 
    }
 
    private bool _skipTopLevelCompilationExceptions;
    internal static bool SkipTopLevelCompilationExceptions {
        get { return _theBuildManager._skipTopLevelCompilationExceptions; }
        set { _theBuildManager._skipTopLevelCompilationExceptions = value; } 
    }
 
    /* 
     * Return the list of assemblies that a compilation needs to reference for a given
     * config minus the assemblies indexed later than removeIndex 
     */
    internal static ICollection GetReferencedAssemblies(CompilationSection compConfig, int removeIndex) {

        AssemblySet referencedAssemblies = new AssemblySet(); 

        // Add all the config assemblies to the list 
        foreach (AssemblyInfo a in compConfig.Assemblies) { 
            Assembly[] assemblies = a.AssemblyInternal;
            if (assemblies == null) 
            {
                lock (compConfig)
                {
                    assemblies = a.AssemblyInternal; 
                    if (assemblies == null)
                        assemblies = a.AssemblyInternal = compConfig.LoadAssembly(a); 
                } 
            }
 
            for (int i = 0; i < assemblies.Length; i++)
            {
                if (assemblies[i] != null) {
                    referencedAssemblies.Add(assemblies[i]); 
                }
            } 
        } 

        // Clone the top level referenced assemblies (code + global.asax + etc...), up to the removeIndex 
        for (int i = 0; i < removeIndex; i++) {
            referencedAssemblies.Add(TheBuildManager.TopLevelReferencedAssemblies[i]);
        }
 
        return referencedAssemblies;
    } 
 
    internal static ICollection GetReferencedAssemblies(CompilationSection compConfig) {
 
        // Start by cloning the top level referenced assemblies (code + global.asax + etc...)
        AssemblySet referencedAssemblies = AssemblySet.Create(
            TheBuildManager.TopLevelReferencedAssemblies);
 
        // Add all the config assemblies to the list
        foreach (AssemblyInfo a in compConfig.Assemblies) { 
            Assembly[] assemblies = a.AssemblyInternal; 
            if (assemblies == null)
            { 
                lock (compConfig)
                {
                    assemblies = a.AssemblyInternal;
                    if (assemblies == null) 
                        assemblies = a.AssemblyInternal = compConfig.LoadAssembly(a);
                } 
            } 

            for (int i = 0; i < assemblies.Length; i++) { 
                if (assemblies[i] != null) {
                    referencedAssemblies.Add(assemblies[i]);
                }
            } 
        }
 
        return referencedAssemblies; 
    }
 

    /*
     * Return the list of assemblies that all page compilations need to reference. This includes
     * config assemblies ( section), bin assemblies and assemblies built from the 
     * app App_Code and other top level folders.
     */ 
 
    /// 
    /// Returns the assemblies referenced at the root application level of the current app 
    /// 
    public static ICollection GetReferencedAssemblies() {
        RuntimeConfig appConfig = RuntimeConfig.GetAppConfig();
        CompilationSection compConfig = appConfig.Compilation; 

        _theBuildManager.EnsureTopLevelFilesCompiled(); 
 
        return GetReferencedAssemblies(compConfig);
    } 

    /*
     * Perform initialization work that should only be done once (per app domain).
     */ 
    private void Initialize() {
 
        Debug.Assert(_caches == null); 

        // Register an AssemblyResolve event 
        AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(this.ResolveAssembly);

        _globalAsaxVirtualPath = HttpRuntime.AppDomainAppVirtualPathObject.SimpleCombine(
            HttpApplicationFactory.applicationFileName); 

        _webHashFilePath = Path.Combine(HttpRuntime.CodegenDirInternal, "hash\\hash.web"); 
 
        // Indicate whether we should ignore the top level compilation exceptions.
        // In CBM case, we want to continue processing the page and return partial info even 
        // if the code files fail to compile.
        _skipTopLevelCompilationExceptions = BuildManagerHost.InClientBuildManager;

        // Deal with precompilation if we're in that mode 
        SetPrecompilationInfo(HostingEnvironment.HostingParameters);
 
        // The init code depends on whether we're precompiling or running an app 
        if (_precompTargetPhysicalDir != null) {
 
            // If the app is already precompiled, fail
            FailIfPrecompiledApp();

            PrecompilationModeInitialize(); 
        }
        else { 
            // Check if this application has been precompiled by aspnet_compiler.exe 
            if (IsPrecompiledApp) {
                PrecompiledAppRuntimeModeInitialize(); 
            }
            else {
                RegularAppRuntimeModeInitialize();
            } 
        }
 
        _scriptVirtualDir = Util.GetScriptLocation(); 

        // Top level directories that have a special semantic 
        _excludedTopLevelDirectories = new CaseInsensitiveStringSet();
        _excludedTopLevelDirectories.Add(HttpRuntime.BinDirectoryName);
        _excludedTopLevelDirectories.Add(HttpRuntime.CodeDirectoryName);
        _excludedTopLevelDirectories.Add(HttpRuntime.ResourcesDirectoryName); 
        _excludedTopLevelDirectories.Add(HttpRuntime.LocalResourcesDirectoryName);
        _excludedTopLevelDirectories.Add(HttpRuntime.WebRefDirectoryName); 
        _excludedTopLevelDirectories.Add(HttpRuntime.ThemesDirectoryName); 

        // Top level directories that are not requestable 
        // It's the same as _excludedTopLevelDirectories, except that we allow
        // the bin directory to avoid a v1 breaking change (
        _forbiddenTopLevelDirectories = new CaseInsensitiveStringSet();
        _forbiddenTopLevelDirectories.Add(HttpRuntime.CodeDirectoryName); 
        _forbiddenTopLevelDirectories.Add(HttpRuntime.ResourcesDirectoryName);
        _forbiddenTopLevelDirectories.Add(HttpRuntime.LocalResourcesDirectoryName); 
        _forbiddenTopLevelDirectories.Add(HttpRuntime.WebRefDirectoryName); 
        _forbiddenTopLevelDirectories.Add(HttpRuntime.ThemesDirectoryName);
 
        LoadLicensesAssemblyIfExists();
    }

    /* 
     * Init code used when we are running a non-precompiled app
     */ 
    private void RegularAppRuntimeModeInitialize() { 

        // 
        // Initialize the caches
        //

        // Always try the memory cache first 
        _memoryCache = new MemoryBuildResultCache(HttpRuntime.CacheInternal);
 
        // Use the standard disk cache for regular apps 
        StandardDiskBuildResultCache diskCache = new StandardDiskBuildResultCache(
            HttpRuntime.CodegenDirInternal); 

        _caches = new BuildResultCache[] { _memoryCache, diskCache };

        CheckTopLevelFilesUpToDate(diskCache); 
    }
 
    /* 
     * Init code used when we are running a precompiled app
     */ 
    private void PrecompiledAppRuntimeModeInitialize() {

        //
        // Initialize the caches 
        //
 
        // Always try the memory cache first 
        _memoryCache = new MemoryBuildResultCache(HttpRuntime.CacheInternal);
 
        // Used the precomp cache for precompiled apps
        BuildResultCache preCompCache = new PrecompiledSiteDiskBuildResultCache(
            HttpRuntime.BinDirectoryInternal);
 
        // Also create a regular disk cache so that we can compile and cache additional things.
        // This is useful even in non-updatable precomp, to cache DefaultWsdlHelpGenerator.aspx. 
 
        StandardDiskBuildResultCache diskCache = new StandardDiskBuildResultCache(
            HttpRuntime.CodegenDirInternal); 

        _caches = new BuildResultCache[] { _memoryCache, preCompCache, diskCache };

        CheckTopLevelFilesUpToDate(diskCache); 
    }
 
    /* 
     * Init code used when we are precompiling an app
     */ 
    private void PrecompilationModeInitialize() {

        // We are precompiling an app
 
        // Always try the memory cache first
        _memoryCache = new MemoryBuildResultCache(HttpRuntime.CacheInternal); 
 
        // Create a regular disk cache, to take advantage of the fact that the app
        // may already have been compiled (and to cause it to be if it wasn't) 
        StandardDiskBuildResultCache diskCache = new StandardDiskBuildResultCache(
            HttpRuntime.CodegenDirInternal);

        // Create a special disk cache in the target's bin directory.  Use a slightly different 
        // implementation for the updatable case.
        string targetBinDir = Path.Combine(_precompTargetPhysicalDir, HttpRuntime.BinDirectoryName); 
        BuildResultCache preCompilationCache; 
        if (PrecompilingForUpdatableDeployment) {
            preCompilationCache = new UpdatablePrecompilerDiskBuildResultCache(targetBinDir); 
        }
        else {
            preCompilationCache = new PrecompilerDiskBuildResultCache(targetBinDir);
        } 

        _caches = new BuildResultCache[] { _memoryCache, preCompilationCache, diskCache  }; 
 
        CheckTopLevelFilesUpToDate(diskCache);
    } 

    // Load the licenses assembly from the bin dir if it exists (DevDiv 42149)
    private void LoadLicensesAssemblyIfExists() {
        string licAssemblyPath = Path.Combine(HttpRuntime.BinDirectoryInternal, LicensesAssemblyName + ".dll"); 
        if (File.Exists(licAssemblyPath)) {
            Assembly.Load(LicensesAssemblyName); 
        } 
    }
 
    private void CheckTopLevelFilesUpToDate(StandardDiskBuildResultCache diskCache) {

        bool gotLock = false;
 
        try {
            // Grab the compilation mutex, since this method accesses the codegen files 
            CompilationLock.GetLock(ref gotLock); 

            CheckTopLevelFilesUpToDate2(diskCache); 
        }
        finally {
            // Always release the mutex if we had taken it
            if (gotLock) { 
                CompilationLock.ReleaseLock();
            } 
        } 
    }
 
    /*
     * Check if the top level files are up to date, and cleanup the codegendir
     * if they are not.
     */ 
    private void CheckTopLevelFilesUpToDate2(StandardDiskBuildResultCache diskCache) {
 
        long specialFilesCombinedHash = diskCache.GetPreservedSpecialFilesCombinedHash(); 
        Debug.Trace("BuildManager", "specialFilesCombinedHash=" + specialFilesCombinedHash);
 
        // Delete all the non essential files left over in the codegen dir, unless
        // specialFilesCombinedHash is 0, in which case we delete *everything* further down
        if (specialFilesCombinedHash != 0)
            diskCache.RemoveOldTempFiles(); 

        // Use a HashCodeCombiner object to handle the time stamps of all the 'special' 
        // files and directories that all compilations depend on: 
        // - System.Web.dll (in case there is a newer version of ASP.NET)
        // - ~\Bin directory 
        // - ~\Resource directory
        // - ~\WebReferences directory
        // - ~\Code directory
        // - global.asax 

        HashCodeCombiner specialFilesDateTimeCombiner = new HashCodeCombiner(); 
 
        // Add a
        specialFilesDateTimeCombiner.AddObject(HttpRuntime.AppDomainAppPathInternal); 

        // Process System.Web.dll
        string aspBinaryFileName = typeof(HttpRuntime).Module.FullyQualifiedName;
        specialFilesDateTimeCombiner.AddFile(aspBinaryFileName); 

        // Process machine.config 
        string machineConfigFileName = HttpConfigurationSystem.MachineConfigurationFilePath; 
        specialFilesDateTimeCombiner.AddFile(machineConfigFileName);
 
        // Process root web.config
        string rootWebConfigFileName = HttpConfigurationSystem.RootWebConfigurationFilePath;
        specialFilesDateTimeCombiner.AddFile(rootWebConfigFileName);
 
        // Add a dependency of the bin, resources, webresources and code directories
        string binPhysicalDir = HttpRuntime.BinDirectoryInternal; 
        specialFilesDateTimeCombiner.AddDirectory(binPhysicalDir); 

        // Note that we call AddResourcesDirectory instead of AddDirectory, since we only want 
        // culture neutral files to be taken into account (
        specialFilesDateTimeCombiner.AddResourcesDirectory(HttpRuntime.ResourcesDirectoryVirtualPath.MapPathInternal());

        specialFilesDateTimeCombiner.AddDirectory(HttpRuntime.WebRefDirectoryVirtualPath.MapPathInternal()); 

        specialFilesDateTimeCombiner.AddDirectory(HttpRuntime.CodeDirectoryVirtualPath.MapPathInternal()); 
 
        // Add a dependency on the global asax file.
        specialFilesDateTimeCombiner.AddFile(GlobalAsaxVirtualPath.MapPathInternal()); 

        // Add a dependency on the hash of the app level  section, since it
        // affects all compilations, including the code directory.  It it changes,
        // we may as well, start all over. 
        RuntimeConfig appConfig = RuntimeConfig.GetAppConfig();
        CompilationSection compConfig = appConfig.Compilation; 
        specialFilesDateTimeCombiner.AddObject(compConfig.RecompilationHash); 

        ProfileSection profileSection = appConfig.Profile; 
        specialFilesDateTimeCombiner.AddObject(profileSection.RecompilationHash);

        // Add a dependency on file encoding (DevDiv 4560)
        specialFilesDateTimeCombiner.AddObject(appConfig.Globalization.FileEncoding); 

        // Also add a dependency on the  config section 
        TrustSection casConfig = appConfig.Trust; 
        specialFilesDateTimeCombiner.AddObject(casConfig.Level);
        specialFilesDateTimeCombiner.AddObject(casConfig.OriginUrl); 

        // Add a dependency on whether profile is enabled
        specialFilesDateTimeCombiner.AddObject(ProfileManager.Enabled);
 
        // Add a dependency to the force debug flag.
        specialFilesDateTimeCombiner.AddObject(PrecompilingWithDebugInfo); 
 
        // Store the top level hash
        s_topLevelHash = specialFilesDateTimeCombiner.CombinedHash; 

        if (PrecompilingForCleanBuild || specialFilesDateTimeCombiner.CombinedHash != specialFilesCombinedHash) {
            if (PrecompilingForCleanBuild) {
                Debug.Trace("BuildManager", "Precompiling for clean build."); 
            }
            else { 
                Debug.Trace("BuildManager", "EnsureFirstTimeInit: hash codes don't match.  Old=" + 
                    specialFilesCombinedHash + " New=" + specialFilesDateTimeCombiner.CombinedHash);
            } 

            diskCache.RemoveAllCodegenFiles();
            diskCache.SavePreservedSpecialFilesCombinedHash(specialFilesDateTimeCombiner.CombinedHash);
        } 
        else {
            Debug.Trace("BuildManager", "BuildManager: the special files are up to date"); 
        } 

        Debug.Assert(File.Exists(_webHashFilePath)); 

        //

 
        HttpRuntime.FileChangesMonitor.StartMonitoringFile(_webHashFilePath,
            new FileChangeEventHandler(this.OnWebHashFileChange)); 
    } 

    private void OnWebHashFileChange(Object sender, FileChangeEvent e) { 
        // Shutdown the app domain
        Debug.Trace("BuildManager", _webHashFilePath + " changed - shutting down the app domain");
        Debug.Trace("AppDomainFactory", "Shutting down appdomain because " + _webHashFilePath + " file changed");
 
        HttpRuntime.ShutdownAppDomain(ApplicationShutdownReason.BuildManagerChange, "Change in " + _webHashFilePath);
    } 
 
    /*
     * Check if an assembly name is reserved for a special purpose 
     */
    internal static bool IsReservedAssemblyName(string assemblyName) {

        if (String.Compare(assemblyName, CodeDirectoryAssemblyName, 
                StringComparison.OrdinalIgnoreCase) == 0 ||
            String.Compare(assemblyName, ResourcesDirectoryAssemblyName, 
                StringComparison.OrdinalIgnoreCase) == 0 || 
            String.Compare(assemblyName, WebRefDirectoryAssemblyName,
                StringComparison.OrdinalIgnoreCase) == 0 || 
            String.Compare(assemblyName, GlobalAsaxAssemblyName,
                StringComparison.OrdinalIgnoreCase) == 0) {

            return true; 
        }
 
        return false; 
    }
 
    // excludedSubdirectories contains a list of subdirectory names that should not be
    // recursively included in the compilation (they'll instead be compiled into their
    // own assemblies).
    private Assembly CompileCodeDirectory(VirtualPath virtualDir, CodeDirectoryType dirType, 
        string assemblyName, StringSet excludedSubdirectories) {
 
        Debug.Trace("BuildManager", "CompileCodeDirectory(" + virtualDir.VirtualPathString + ")"); 

        bool isDirectoryAllowed = true; 
        if (IsPrecompiledApp) {
            // Most special dirs are not allowed in precompiled apps.  App_LocalResources is
            // an exception, as it is allowed in updatable precompiled apps.
            if (IsUpdatablePrecompiledAppInternal && dirType == CodeDirectoryType.LocalResources) 
                isDirectoryAllowed = true;
            else 
                isDirectoryAllowed = false; 
        }
 
        // Remember the referenced assemblies based on the current count.
        AssemblyReferenceInfo info = new AssemblyReferenceInfo(_topLevelReferencedAssemblies.Count);
        _topLevelAssembliesIndexTable[virtualDir.VirtualPathString] = info;
 
        Assembly codeAssembly = CodeDirectoryCompiler.GetCodeDirectoryAssembly(
                virtualDir, dirType, assemblyName, excludedSubdirectories, 
                isDirectoryAllowed); 

        if (codeAssembly != null) { 

            // Remember the generated assembly
            info.Assembly = codeAssembly;
 
            // Page resource assemblies are not added to the top level list
            if (dirType != CodeDirectoryType.LocalResources) { 
                _topLevelReferencedAssemblies.Add(codeAssembly); 

                if (dirType == CodeDirectoryType.MainCode || dirType == CodeDirectoryType.SubCode) { 
                    if (_codeAssemblies == null) {
                        _codeAssemblies = new ArrayList();
                    }
 
                    _codeAssemblies.Add(codeAssembly);
                } 
 
                // Add it to the list of assembly name that we resolve, so that users can
                // refer to the assemblies by their fixed name (even though they 
                // random names).  (
                if (_assemblyResolveMapping == null) {
                    _assemblyResolveMapping = new Hashtable(StringComparer.OrdinalIgnoreCase);
                } 
                _assemblyResolveMapping[assemblyName] = codeAssembly;
 
                if (dirType == CodeDirectoryType.MainCode) { 
                    // Profile gets built in the same assembly as the main code dir, so
                    // see whether we can get its type from the assembly. 
                    _profileType = ProfileBuildProvider.GetProfileTypeFromAssembly(
                        codeAssembly, IsPrecompiledApp);

                    // To avoid breaking earlier Whidbey apps, allows the name "__code" 
                    // to be used for the main code assembly.
                    // 
                    _assemblyResolveMapping["__code"] = codeAssembly; 
                }
            } 
        }

        Debug.Trace("BuildManager", "CompileCodeDirectory generated assembly: " +
            (codeAssembly == null ? "None" : codeAssembly.ToString())); 

        return codeAssembly; 
    } 

 
    private void CompileResourcesDirectory() {

        VirtualPath virtualDir = HttpRuntime.ResourcesDirectoryVirtualPath;
 
        Debug.Assert(_appResourcesAssembly == null);
        _appResourcesAssembly = CompileCodeDirectory(virtualDir, CodeDirectoryType.AppResources, 
            ResourcesDirectoryAssemblyName, null /*excludedSubdirectories*/); 
    }
 
    private void CompileWebRefDirectory() {

        CompileCodeDirectory(HttpRuntime.WebRefDirectoryVirtualPath, CodeDirectoryType.WebReferences,
            WebRefDirectoryAssemblyName, null /*excludedSubdirectories*/); 
    }
 
    // Compute the list of subdirectories that should not be compiled with 
    // the top level Code
    private void EnsureExcludedCodeSubDirectoriesComputed() { 

        if (_excludedCodeSubdirectories != null)
            return;
 
        _excludedCodeSubdirectories = new CaseInsensitiveStringSet();
 
        // Get the list of sub directories that will be compiled separately 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();
 
        // Add them to the exclusion list of the top level code directory
        if (codeSubDirectories != null) {
            foreach (CodeSubDirectory entry in codeSubDirectories) {
                _excludedCodeSubdirectories.Add(entry.DirectoryName); 
            }
        } 
    } 

    private void CompileCodeDirectories() { 

        VirtualPath virtualDir = HttpRuntime.CodeDirectoryVirtualPath;

        // Get the list of sub directories that will be compiled separately 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();
 
        if (codeSubDirectories != null) { 

            // Compile all the subdirectory that are listed in config. 

            foreach (CodeSubDirectory entry in codeSubDirectories) {

                // 

 
 
                VirtualPath virtualSubDir = virtualDir.SimpleCombineWithDir(entry.DirectoryName);
 
                string assemblyName = SubCodeDirectoryAssemblyNamePrefix + entry.AssemblyName;

                // Compile the subdirectory tree (no exclusions)
                CompileCodeDirectory(virtualSubDir, CodeDirectoryType.SubCode, assemblyName, 
                    null /*excludedSubdirectories*/);
            } 
        } 

        EnsureExcludedCodeSubDirectoriesComputed(); 

        // Compile the top level Code directory tree, minus the excluded subdirectories
        CompileCodeDirectory(virtualDir, CodeDirectoryType.MainCode,
            CodeDirectoryAssemblyName, _excludedCodeSubdirectories); 
    }
 
    private void CompileGlobalAsax() { 
        _globalAsaxBuildResult = ApplicationBuildProvider.GetGlobalAsaxBuildResult(IsPrecompiledApp);
 
        // Make sure that global.asax notifications are set up (
        HttpApplicationFactory.SetupFileChangeNotifications();

        if (_globalAsaxBuildResult != null) { 

            // We need to add not only the global.asax type, but also its parent types to 
            // the top level assembly list.  This can happen when global.asax has a 'src' 
            // attribute pointing to a source file containing its base type.
            Type type = _globalAsaxBuildResult.ResultType; 
            while (type.Assembly != typeof(HttpRuntime).Assembly) {
                _topLevelReferencedAssemblies.Add(type.Assembly);
                type = type.BaseType;
            } 
        }
    } 
 
    // Call the AppInitialize method in the Code assembly if there is one
    internal static void CallAppInitializeMethod() { 

        // Make sure the code directory has been processed
        _theBuildManager.EnsureTopLevelFilesCompiled();
 
        CodeDirectoryCompiler.CallAppInitializeMethod();
    } 
 
    internal void EnsureTopLevelFilesCompiled() {
 
        // This should never get executed in non-hosted appdomains
        Debug.Assert(HostingEnvironment.IsHosted);

        // If we already tried and got an exception, just rethrow it 
        if (_topLevelFileCompilationException != null && !SkipTopLevelCompilationExceptions) {
            ReportTopLevelCompilationException(); 
        } 

        if(_topLevelFilesCompiledStarted) 
            return;

        // Set impersonation to hosting identity (process or UNC)
        using (new ApplicationImpersonationContext()) { 
            bool gotLock = false;
            _parseErrorReported = false; 
 
            try {
                // Grab the compilation mutex, since this method accesses the codegen files 
                CompilationLock.GetLock(ref gotLock);

                // Check again if there is an exception
                if (_topLevelFileCompilationException != null && !SkipTopLevelCompilationExceptions) { 
                    ReportTopLevelCompilationException();
                } 
 
                // Check again if we're done
                if(_topLevelFilesCompiledStarted) 
                    return;

                _topLevelFilesCompiledStarted = true;
                _topLevelReferencedAssemblies = new List(); 
                _topLevelAssembliesIndexTable =
                    new Dictionary(StringComparer.OrdinalIgnoreCase); 
 
                //
                _topLevelReferencedAssemblies.Add(typeof(HttpRuntime).Assembly); 
                _topLevelReferencedAssemblies.Add(typeof(System.ComponentModel.Component).Assembly);

                _compilationStage = CompilationStage.TopLevelFiles;
 
                CompileResourcesDirectory();
                CompileWebRefDirectory(); 
                CompileCodeDirectories(); 

                _compilationStage = CompilationStage.GlobalAsax; 

                CompileGlobalAsax();

                _compilationStage = CompilationStage.BrowserCapabilities; 

                // Call GetBrowserCapabilitiesType() to make sure browserCap directory is compiled 
                // early on.  This avoids getting into potential deadlock situations later ( 

                BrowserCapabilitiesCompiler.GetBrowserCapabilitiesType(); 
                IFilterResolutionService dummy = HttpCapabilitiesBase.EmptyHttpCapabilitiesBase;

                _compilationStage = CompilationStage.AfterTopLevelFiles;
            } 
            catch (Exception e) {
                // Remember the exception, and rethrow it 
                _topLevelFileCompilationException = e; 

                // Do not rethrow the exception since so CBM can still provide partial support 
                if (!SkipTopLevelCompilationExceptions) {

                    if (!_parseErrorReported) {
                        // Report the error if this is not a CompileException. CompileExceptions are handled 
                        // directly by the AssemblyBuilder already.
                        if (!(e is HttpCompileException)) { 
                            ReportTopLevelCompilationException(); 
                        }
                    } 

                    throw;
                }
            } 
            finally {
                _topLevelFilesCompiledCompleted = true; 
 
                // Always release the mutex if we had taken it
                if (gotLock) { 
                    CompilationLock.ReleaseLock();
                }
            }
        } 
    }
 
    // Generate a random file name with 8 characters 
    private static string GenerateRandomFileName() {
        // Generate random bytes 
        byte[] data = new byte[6];

        lock (_rng) {
            _rng.GetBytes(data); 
        }
 
        // Turn them into a string containing only characters valid in file names/url 
        string s = Convert.ToBase64String(data).ToLower(CultureInfo.InvariantCulture);
        s = s.Replace('/', '-'); 
        s = s.Replace('+', '_');

        return s;
    } 

    // Generate a random name for an assembly, starting with the passed in prefix 
    internal static string GenerateRandomAssemblyName(string baseName) { 

        // Start with the passed in base name 
        string assemblyName = baseName;

        // Append a random token to it.  However, don't do this when precompiling for
        // deployment since, we want the name to be more predictable (DevDiv 36625) 
        if (!PrecompilingForDeployment) {
            baseName += "." + GenerateRandomFileName(); 
        } 

        return baseName; 
    }

    private static string GetGeneratedAssemblyBaseName(VirtualPath virtualPath) {
 
        // Name the assembly using the same scheme as cache keys
        return GetCacheKeyFromVirtualPath(virtualPath); 
    } 

    /* 
     * Look for a type by name in the top level and config assemblies
     */
    public static Type GetType(string typeName, bool throwOnError) {
        return GetType(typeName, throwOnError, false); 
    }
 
    /* 
     * Look for a type by name in the top level and config assemblies
     */ 
    public static Type GetType(string typeName, bool throwOnError, bool ignoreCase) {
        // If it contains an assembly name, just call Type.GetType().  Do this before even trying
        // to initialize the BuildManager, so that if InitializeBuildManager has errors, it doesn't
        // affect us when the type string can be resolved via Type.GetType(). 
        Type type = null;
        if (Util.TypeNameContainsAssembly(typeName)) { 
            type = Type.GetType(typeName, throwOnError, ignoreCase); 

            if (type != null) { 
                    return type;
            }
        }
 
        // Make sure the build manager is initialized.  If it fails to initialize for any reason,
        // don't attempt to use the fancy GetType logic.  Just call Type.GetType instead ( 
        if (!InitializeBuildManager()) { 
            return Type.GetType(typeName, throwOnError, ignoreCase);
        } 

        // First, always try System.Web.dll
        try {
            type = typeof(BuildManager).Assembly.GetType(typeName, 
                false /*throwOnError*/, ignoreCase);
        } 
        catch (ArgumentException e) { 
            // Even though we pass false to throwOnError, GetType can throw if the
            // assembly name is malformed.  In that case, throw our own error instead 
            // of the cryptic ArgumentException (
            throw new HttpException(
                SR.GetString(SR.Invalid_type, typeName), e);
        } 

        if (type != null) return type; 
 
        _theBuildManager.EnsureTopLevelFilesCompiled();
 
        // Otherwise, look for the type in the top level assemblies
        type = Util.GetTypeFromAssemblies(TheBuildManager.TopLevelReferencedAssemblies,
            typeName, ignoreCase);
        if (type != null) return type; 

        // Otherwise, look for the type in the config assemblies 
        AssemblyCollection configAssemblies = CompilationUtil.GetAssembliesForAppLevel(); 
        if (configAssemblies != null) {
            Type t = CompilationUtil.GetTypeFromAssemblies(configAssemblies, typeName, ignoreCase); 
            if (t != null) {
                // If we had already found a different one, it's an ambiguous type reference
                if (type != null && t != type) {
                    throw new HttpException(SR.GetString( 
                        SR.Ambiguous_type, typeName, Util.GetAssemblySafePathFromType(type),
                        Util.GetAssemblySafePathFromType(t))); 
                } 

                type = t; 
            }
        }

        if (type == null && throwOnError) { 
            throw new HttpException(
                SR.GetString(SR.Invalid_type, typeName)); 
        } 

        return type; 
    }

    /*
     * Gets a type from one of the code assemblies 
     */
    internal static Type GetTypeFromCodeAssembly(string typeName, bool ignoreCase) { 
 
        // No code assembly: return
        if (CodeAssemblies == null) 
            return null;

        return Util.GetTypeFromAssemblies(CodeAssemblies, typeName, ignoreCase);
    } 

    internal static BuildProvider CreateBuildProvider(VirtualPath virtualPath, 
        CompilationSection compConfig, ICollection referencedAssemblies, 
        bool failIfUnknown) {
 
        return CreateBuildProvider(virtualPath, BuildProviderAppliesTo.Web,
            compConfig, referencedAssemblies, failIfUnknown);
    }
 
    internal static BuildProvider CreateBuildProvider(VirtualPath virtualPath,
        BuildProviderAppliesTo neededFor, 
        CompilationSection compConfig, ICollection referencedAssemblies, 
        bool failIfUnknown) {
 
        string extension = virtualPath.Extension;

        Type buildProviderType = CompilationUtil.GetBuildProviderTypeFromExtension(compConfig,
            extension, neededFor, failIfUnknown); 
        if (buildProviderType == null)
            return null; 
 
        object o = HttpRuntime.CreatePublicInstance(buildProviderType);
 
        BuildProvider buildProvider = (BuildProvider) o;

        buildProvider.SetVirtualPath(virtualPath);
        buildProvider.SetReferencedAssemblies(referencedAssemblies); 

        return buildProvider; 
    } 

    internal static void ValidateCodeFileVirtualPath(VirtualPath virtualPath) { 
        _theBuildManager.ValidateVirtualPathInternal(virtualPath, false /*allowCrossApp*/, true /*codeFile*/);
    }

    private void ValidateVirtualPathInternal(VirtualPath virtualPath, bool allowCrossApp, bool codeFile) { 

        if (!allowCrossApp) { 
            virtualPath.FailIfNotWithinAppRoot(); 
        }
        else { 
            // If cross app is allowed, and the path is in a different app, nothing more to
            if (!virtualPath.IsWithinAppRoot)
                return;
        } 

        // 
        // Now, detect if it's under a special directory (e.g. 'code', 'resources', 'themes') 
        //
 
        // If it's exactly the app root, it's fine
        if (HttpRuntime.AppDomainAppVirtualPathObject == virtualPath)
            return;
 
        int appPathLen = HttpRuntime.AppDomainAppVirtualPathString.Length;
 
        string virtualPathString = virtualPath.VirtualPathString; 

        // This could happen if the vpath is "/app" (while the app vpath is "/app/") 
        if (virtualPathString.Length < appPathLen)
            return;

        // If no slash after the approot (e.g. "/app/foo.aspx"), it's valid 
        int slashIndex = virtualPathString.IndexOf('/', appPathLen);
        if (slashIndex < 0) 
            return; 

        // Get the name of the first directory under the app root (e.g. "/app/aaa/bbb/foo.aspx" -> "aaa") 
        string dir = virtualPathString.Substring(appPathLen, slashIndex - appPathLen);

        // If it's a forbidden directory, fail
        if (_forbiddenTopLevelDirectories.Contains(dir)) { 
            throw new HttpException(SR.GetString(
                SR.Illegal_special_dir, virtualPathString, dir)); 
        } 
    }
 
    /*
     * Returns a single hash code that represents the state of the built object for
     * the passed in virtualPath.  If it isn't already built, don't build it, but just
     * return 0.  This can be used to determine the validity of output cache that 
     * has been persisted to disk.
     */ 
    internal static long GetBuildResultHashCodeIfCached( 
        HttpContext context, string virtualPath) {
 
        BuildResult result = GetVPathBuildResult(context, VirtualPath.Create(virtualPath),
            true /*noBuild*/, false /*allowCrossApp*/);

        // If it's not cached, return 0 
        if (result == null)
            return 0; 
 
        // Return a single hash code based on both of the BuildResult's hash codes
        string dependenciesHash = result.VirtualPathDependenciesHash; 
        Debug.Assert(result.DependenciesHashComputed);
        return result.ComputeHashCode(s_topLevelHash, StringUtil.GetStringHashCode(dependenciesHash));
    }
 
    internal static BuildResult GetVPathBuildResult(VirtualPath virtualPath) {
 
        return GetVPathBuildResult(null /*context*/, virtualPath, 
            false /*noBuild*/, false /*allowCrossApp*/, false /*allowBuiltInPrecompile*/);
    } 

    internal static BuildResult GetVPathBuildResult(HttpContext context, VirtualPath virtualPath) {

        return GetVPathBuildResult(context, virtualPath, false /*noBuild*/, false /*allowCrossApp*/, false /*allowBuiltInPrecompile*/); 
    }
 
    internal static BuildResult GetVPathBuildResult(HttpContext context, VirtualPath virtualPath, 
        bool noBuild, bool allowCrossApp) {
 
        return GetVPathBuildResult(context, virtualPath, noBuild, allowCrossApp, false /*allowBuiltInPrecompile*/);
    }

    /* 
     * Calls either GetVPathBuildResultWithNoAssert or GetVPathBuildResultWithAssert,
     * depending on whether there is any point in assertting. 
     */ 
    internal static BuildResult GetVPathBuildResult(HttpContext context, VirtualPath virtualPath,
        bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 

        // Could be called with user code on the stack, so need to assertt here (

 
        if (HttpRuntime.IsFullTrust) {
            return GetVPathBuildResultWithNoAssert(context, virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile); 
        } 
        else {
            return GetVPathBuildResultWithAssert(context, virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile); 
        }
    }

    /* 
     * Same as GetVPathBuildResultWithNoAssert, but with an Unrestricted Assert.
     */ 
    [PermissionSet(SecurityAction.Assert, Unrestricted=true)] 
    internal static BuildResult GetVPathBuildResultWithAssert(
        HttpContext context, VirtualPath virtualPath, bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 

        return GetVPathBuildResultWithNoAssert(context, virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile);
    }
 
    internal static BuildResult GetVPathBuildResultWithNoAssert(
        HttpContext context, VirtualPath virtualPath, bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 
 
        using (new ApplicationImpersonationContext()) {
            return _theBuildManager.GetVPathBuildResultInternal(virtualPath, noBuild, allowCrossApp, allowBuildInPrecompile); 
        }
    }

    // name of the slot in call context 
    private const String CircularReferenceCheckerSlotName = "CircRefChk";
 
    private BuildResult GetVPathBuildResultInternal(VirtualPath virtualPath, bool noBuild, bool allowCrossApp, bool allowBuildInPrecompile) { 

        Debug.Trace("BuildManager", "GetBuildResult(" + virtualPath + ")"); 

        // This should never be called while building top level files (
        if (_compilationStage == CompilationStage.TopLevelFiles) {
            throw new HttpException(SR.GetString(SR.Too_early_for_webfile, virtualPath)); 
        }
 
        // Make sure the path is not relative 
        Debug.Assert(!virtualPath.IsRelative);
 
        // Try the cache first before getting the mutex
        BuildResult result = GetVPathBuildResultFromCacheInternal(virtualPath);
        if (result != null)
            return result; 

        // If we were only checking the cache and it wasn't there, return null. 
        if (noBuild) 
            return null;
 
        // Check if it's trying to go cross app, or points to a special directory.
        // It's important to do this before checkin existence, to avoid revealing information
        // about other apps (
        ValidateVirtualPathInternal(virtualPath, allowCrossApp, false /*codeFile*/); 

        // Before grabbing the lock, make sure the file at least exists (ASURT 46465) 
        Util.CheckVirtualFileExists(virtualPath); 

        // If this is a precompiled app, complain if we couldn't find it in the cache 
        if (IsNonUpdatablePrecompiledApp && !allowBuildInPrecompile) {
            throw new HttpException(
                SR.GetString(SR.Cant_update_precompiled_app, virtualPath));
        } 

        bool gotLock = false; 
 
        try {
            // Grab the compilation mutex 
            CompilationLock.GetLock(ref gotLock);

            // Check the cache a second time after getting the mutex
            result = GetVPathBuildResultFromCacheInternal(virtualPath); 
            if (result != null)
                return result; 
 
            // Get the circular reference checker (create it if needed)
            VirtualPathSet circularReferenceChecker; 
            circularReferenceChecker = CallContext.GetData(CircularReferenceCheckerSlotName)
                as VirtualPathSet;
            if (circularReferenceChecker == null) {
                circularReferenceChecker = new VirtualPathSet(); 

                // Create it and save it in the CallContext 
                CallContext.SetData(CircularReferenceCheckerSlotName, circularReferenceChecker); 
            }
 
            // If a circular reference is detected, throw an error
            if (circularReferenceChecker.Contains(virtualPath)) {
                throw new HttpException(
                    SR.GetString(SR.Circular_include)); 
            }
 
            // Add the current virtualPath to the circular reference checker 
            circularReferenceChecker.Add(virtualPath);
 
            try {
                //
                EnsureTopLevelFilesCompiled();
                result = CompileWebFile(virtualPath); 
            }
            finally { 
                // Remove the current virtualPath from the circular reference checker 
                Debug.Assert(circularReferenceChecker.Contains(virtualPath));
                circularReferenceChecker.Remove(virtualPath); 
            }
        }
        finally {
            // Always release the mutex if we had taken it 
            if (gotLock) {
                CompilationLock.ReleaseLock(); 
            } 
        }
 
        return result;
    }

    private BuildResult CompileWebFile(VirtualPath virtualPath) { 

        BuildResult result = null; 
 
        if (_topLevelFilesCompiledCompleted) {
 
            VirtualPath parentPath = virtualPath.Parent;

            // First, try to batch the directory if enabled
            if (IsBatchEnabledForDirectory(parentPath)) { 
                BatchCompileWebDirectory(null, parentPath, true /*ignoreErrors*/);
 
                // If successful, it would have been cached to memory 
                string cacheKey = GetCacheKeyFromVirtualPath(virtualPath);
                result = _memoryCache.GetBuildResult(cacheKey); 

                if (result != null) {
                    // If what we found in the cache is a CompileError, rethrow the exception
                    if (result is BuildResultCompileError) { 
                        throw ((BuildResultCompileError)result).CompileException;
                    } 
 
                    return result;
                } 
            }
        }

 
        DateTime utcStart = DateTime.UtcNow;
 
        // Name the assembly based on the virtual path, in order to get a recognizable name 
        string outputAssemblyName = BuildManager.WebAssemblyNamePrefix +
            BuildManager.GenerateRandomAssemblyName( 
            GetGeneratedAssemblyBaseName(virtualPath));

        BuildProvidersCompiler bpc = new BuildProvidersCompiler(virtualPath /*configPath*/, outputAssemblyName);
 
        // Create a BuildProvider based on the virtual path
        BuildProvider buildProvider = CreateBuildProvider(virtualPath, bpc.CompConfig, 
            bpc.ReferencedAssemblies, true /*failIfUnknown*/); 

        // Set the BuildProvider using a single item collection 
        bpc.SetBuildProviders(new SingleObjectCollection(buildProvider));

        // Compile it
        CompilerResults results; 

        try { 
            results = bpc.PerformBuild(); 
            result = buildProvider.GetBuildResult(results);
        } 
        catch (HttpCompileException e) {

            // If we're not supposed to cache the exception, just rethrow it
            if (e.DontCache) 
                throw;
 
            result = new BuildResultCompileError(virtualPath, e); 

            // Add the dependencies to the compile error build provider, so that 
            // we will retry compilation when a dependency changes
            buildProvider.SetBuildResultDependencies(result);

            // Remember the virtualpath dependencies, so that we will correctly 
            // invalidate buildresult when depdency changes.
            e.VirtualPathDependencies = buildProvider.VirtualPathDependencies; 
 
            // Cache it for next time
            CacheVPathBuildResultInternal(virtualPath, result, utcStart); 

            // Set the DontCache flag, so that the exception will not be incorrectly
            // cached again lower down the stack (
            e.DontCache = true; 

            throw; 
        } 

        if (result == null) 
            return null;

        // Cache it for next time
        CacheVPathBuildResultInternal(virtualPath, result, utcStart); 

        return result; 
    } 

    // Hashtbale to remember the local resources assembly for each directory (or null 
    // if there isn't one). Hashtable
    private Hashtable _localResourcesAssemblies = new Hashtable();

    private void EnsureFirstTimeDirectoryInit(VirtualPath virtualDir) { 

        // Don't process local resources when precompiling for updatable deployment. 
        // Instead, we deploy the App_LocalResources folder as is. 
        if (PrecompilingForUpdatableDeployment)
            return; 

        if (virtualDir == null)
            return;
 
        // Only do this once per directory
        if (_localResourcesAssemblies.Contains(virtualDir)) 
            return; 

        // Don't do anything if it's outside the app root 
        if (!virtualDir.IsWithinAppRoot)
            return;

        Debug.Trace("BuildManager", "EnsureFirstTimeDirectoryInit(" + virtualDir + ")"); 

        // Get the virtual path to the LocalResources subdirectory for this directory 
        VirtualPath localResDir = virtualDir.SimpleCombineWithDir(HttpRuntime.LocalResourcesDirectoryName); 

        bool dirExists; 
        try {
            dirExists = localResDir.DirectoryExists();
        }
        catch { 
            // If an exception happens, the directory may be outside the application,
            // in which case we should skip this logic, and act is if there are no 
            // local resources ( 

            _localResourcesAssemblies[virtualDir] = null; 
            return;
        }

        Debug.Trace("BuildManager", "EnsureFirstTimeDirectoryInit: dirExists=" + dirExists); 

        try { 
            // Monitor changes to it so the appdomain can shut down when it changes 
            HttpRuntime.StartListeningToLocalResourcesDirectory(localResDir);
        } 
        catch {
            // could fail for long directory names
            if (dirExists) {
                throw; 
            }
        } 
 
        Assembly resourceAssembly = null;
 
        // If it exists, build it
        if (dirExists) {

            string localResAssemblyName = GetLocalResourcesAssemblyName(virtualDir); 

            bool gotLock = false; 
 
            try {
                // Grab the compilation mutex, since this method accesses the codegen files 
                CompilationLock.GetLock(ref gotLock);

                resourceAssembly = CompileCodeDirectory(localResDir, CodeDirectoryType.LocalResources,
                    localResAssemblyName, null /*excludedSubdirectories*/); 
            }
            finally { 
                // Always release the mutex if we had taken it 
                if (gotLock) {
                    CompilationLock.ReleaseLock(); 
                }
            }
        }
 
        // Cache it whether it's null or not
        _localResourcesAssemblies[virtualDir] = resourceAssembly; 
    } 

    // 
    private void EnsureFirstTimeDirectoryInitForDependencies(ICollection dependencies) {
        foreach (String dependency in dependencies) {
            VirtualPath dependencyPath = VirtualPath.Create(dependency);
            VirtualPath dir = dependencyPath.Parent; 
            EnsureFirstTimeDirectoryInit(dir);
        } 
    } 

 
    // Retrieve a cached local resources assembly (could be null)
    internal static Assembly GetLocalResourcesAssembly(VirtualPath virtualDir) {
        return (Assembly) _theBuildManager._localResourcesAssemblies[virtualDir];
    } 

    internal static string GetLocalResourcesAssemblyName(VirtualPath virtualDir) { 
        return LocalResourcesDirectoryAssemblyName + "." + GetGeneratedAssemblyBaseName(virtualDir); 
    }
 
    // name of the slot in call context
    private const String BatchCompilationSlotName = "BatchCompileChk";

    // Check if batching is enabled for directory specified by virtualDir 
    private bool IsBatchEnabledForDirectory(VirtualPath virtualDir) {
        // False if compile for fixed name 
        if (CompileWithFixedAssemblyNames) { 
            return false;
        } 

        // Always enable batching for deployement
        if (PrecompilingForDeployment) {
            return true; 
        }
 
        // If it's called by other non-precompile CBM methods, always disable batching 
        if (BuildManagerHost.InClientBuildManager && !PerformingPrecompilation) {
            return false; 
        }

        // Check the config
        return CompilationUtil.IsBatchingEnabled(virtualDir.VirtualPathString); 
    }
 
    private bool BatchCompileWebDirectory(VirtualDirectory vdir, VirtualPath virtualDir, bool ignoreErrors) { 

        // Exactly one of vdir and virtualDir should be non-null.  The idea is to avoid calling 
        // VirtualPathProvider.GetDirectory if batching is disabled (

        if (virtualDir == null)
            virtualDir = vdir.VirtualPathObject; 

        if (vdir == null) 
            vdir = HostingEnvironment.VirtualPathProvider.GetDirectory(virtualDir); 

        // Then, 

        CaseInsensitiveStringSet directoryBatchCompilerChecker;
        directoryBatchCompilerChecker = CallContext.GetData(BatchCompilationSlotName)
            as CaseInsensitiveStringSet; 

        if (directoryBatchCompilerChecker == null) { 
            directoryBatchCompilerChecker = new CaseInsensitiveStringSet(); 

            // Create it and save it in the CallContext 
            CallContext.SetData(BatchCompilationSlotName, directoryBatchCompilerChecker);
        }

        // If we've already tried batch compiling this directory, don't do anything 
        if (directoryBatchCompilerChecker.Contains(vdir.VirtualPath))
            return false; 
 
        // Add the current virtualDir to the batch compiler checker
        directoryBatchCompilerChecker.Add(vdir.VirtualPath); 

        // If we're in the process of precompiling an app, never ignore errors.
        if (_precompilingApp)
            ignoreErrors = false; 

        return BatchCompileWebDirectoryInternal(vdir, ignoreErrors); 
    } 

    private bool BatchCompileWebDirectoryInternal(VirtualDirectory vdir, bool ignoreErrors) { 

        WebDirectoryBatchCompiler sdc = new WebDirectoryBatchCompiler(vdir);

        // Just ignore build providers that have errors 
        if (ignoreErrors) {
            sdc.SetIgnoreErrors(); 
 
            // Don't propagate errors that happen during batch compilation
            try { 
                sdc.Process();
            }
            catch {
                return false; 
            }
        } 
        else { 
            sdc.Process();
        } 

        return true;
    }
 
    internal static Type GetGlobalAsaxType() {
        return _theBuildManager.GetGlobalAsaxTypeInternal(); 
    } 

    private Type GetGlobalAsaxTypeInternal() { 
        EnsureTopLevelFilesCompiled();

        if (_globalAsaxBuildResult == null)
            return typeof(HttpApplication); 

        return _globalAsaxBuildResult.ResultType; 
    } 

    internal static BuildResultCompiledGlobalAsaxType GetGlobalAsaxBuildResult() { 
        return _theBuildManager.GetGlobalAsaxBuildResultInternal();
    }

    private BuildResultCompiledGlobalAsaxType GetGlobalAsaxBuildResultInternal() { 
        EnsureTopLevelFilesCompiled();
 
        return _globalAsaxBuildResult; 
    }
 
    internal string[] GetCodeDirectories() {

        VirtualPath virtualDir = HttpRuntime.CodeDirectoryVirtualPath;
 
        // If there is no Code directory, return an empty array
        if (!virtualDir.DirectoryExists()) 
            return new string[0]; 

        // Get the list of code sub directories that will be compiled separately 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();

        // Compute the number of code dirs, including the root one
        int numOfCodeDirs = 1; 
        if (codeSubDirectories != null)
            numOfCodeDirs += codeSubDirectories.Count; 
 
        string[] codeDirs = new string[numOfCodeDirs];
        int current = 0; 

        if (codeSubDirectories != null) {
            foreach (CodeSubDirectory entry in codeSubDirectories) {
 
                VirtualPath virtualSubDir = virtualDir.SimpleCombineWithDir(entry.DirectoryName);
                codeDirs[current++] = virtualSubDir.VirtualPathString; 
            } 
        }
 
        // Add the root code dir at the end of the list (since it's compiled last)
        codeDirs[current++] = virtualDir.VirtualPathString;

        return codeDirs; 
    }
 
    internal void GetCodeDirectoryInformation(VirtualPath virtualCodeDir, 
        out Type codeDomProviderType, out CompilerParameters compilerParameters,
        out string generatedFilesDir) { 

        // Backup the compilation stage, since the call will modify it
        CompilationStage savedCompilationStage = _compilationStage;
 
        try {
            GetCodeDirectoryInformationInternal(virtualCodeDir, out codeDomProviderType, 
                out compilerParameters, out generatedFilesDir); 
        }
        finally { 
            // Restore the compilation stage
            _compilationStage = savedCompilationStage;
        }
    } 

    private void GetCodeDirectoryInformationInternal(VirtualPath virtualCodeDir, 
        out Type codeDomProviderType, out CompilerParameters compilerParameters, 
        out string generatedFilesDir) {
 
        StringSet excludedSubdirectories = null;

        CodeDirectoryType dirType;
 
        // Get the DirectoryType based on the path
        if (virtualCodeDir == HttpRuntime.CodeDirectoryVirtualPath) { 
 
            // If it's the top level code directory, make sure we exclude any
            // subdirectories that are compiled separately 
            EnsureExcludedCodeSubDirectoriesComputed();

            excludedSubdirectories = _excludedCodeSubdirectories;
 
            dirType = CodeDirectoryType.MainCode;
 
            _compilationStage = CompilationStage.TopLevelFiles; 
        }
        else if (virtualCodeDir == HttpRuntime.ResourcesDirectoryVirtualPath) { 

            dirType = CodeDirectoryType.AppResources;

            _compilationStage = CompilationStage.TopLevelFiles; 
        }
        // If virtualCodeDir is a subdir of WebReference virtual path. 
        else if (String.Compare(virtualCodeDir.VirtualPathString, 0, 
            HttpRuntime.WebRefDirectoryVirtualPath.VirtualPathString, 0, HttpRuntime.WebRefDirectoryVirtualPath.VirtualPathString.Length,
            StringComparison.OrdinalIgnoreCase) == 0) { 

            // Use the top WebReference directory info for its sub directories.
            virtualCodeDir = HttpRuntime.WebRefDirectoryVirtualPath;
            dirType = CodeDirectoryType.WebReferences; 

            _compilationStage = CompilationStage.TopLevelFiles; 
        } 
        else if (String.Compare(virtualCodeDir.FileName, HttpRuntime.LocalResourcesDirectoryName,
            StringComparison.OrdinalIgnoreCase) == 0) { 

            dirType = CodeDirectoryType.LocalResources;

            // LocalResources are compiled *after* top level files 
            _compilationStage = CompilationStage.AfterTopLevelFiles;
        } 
        else { 
            // If all else fails, treat it as a sub directory
            // 
            dirType = CodeDirectoryType.SubCode;

            // Sub-code dirs are compiled *before* the main code dir
            _compilationStage = CompilationStage.TopLevelFiles; 
        }
 
        Debug.Assert(virtualCodeDir.HasTrailingSlash); 
        AssemblyReferenceInfo info = TheBuildManager.TopLevelAssembliesIndexTable[virtualCodeDir.VirtualPathString];
        if (info == null) { 
            throw new InvalidOperationException(
                SR.GetString(SR.Invalid_CodeSubDirectory_Not_Exist, virtualCodeDir));
        }
 
        // Get the info we need for this code directory
        CodeDirectoryCompiler.GetCodeDirectoryInformation( 
            virtualCodeDir, dirType, excludedSubdirectories, info.ReferenceIndex, 
            out codeDomProviderType, out compilerParameters,
            out generatedFilesDir); 

        Assembly resultAssembly = info.Assembly;

        if (resultAssembly != null) { 
            // Use the runtime generated assembly location.
            compilerParameters.OutputAssembly = resultAssembly.Location; 
        } 
    }
 
    internal static Type GetProfileType() {
        return _theBuildManager.GetProfileTypeInternal();
    }
 
    private Type GetProfileTypeInternal() {
        EnsureTopLevelFilesCompiled(); 
        return _profileType; 
    }
 

    //
    // Caching related code
    // 

 
    public static ICollection GetVirtualPathDependencies(string virtualPath) { 

        CompilationSection compConfig = RuntimeConfig.GetRootWebConfig().Compilation; 

        // Create a BuildProvider based on the virtual path
        BuildProvider buildProvider = CreateBuildProvider(VirtualPath.Create(virtualPath), compConfig,
            null, false /*failIfUnknown*/); 

        if (buildProvider == null) 
            return null; 

        // Get its dependencies 
        //
        return buildProvider.GetBuildResultVirtualPathDependencies();
    }
 
#if OLD
    /* 
     * Rewrite the virtualPath if appropriate, in order to support ghosting 
     */
    private static void GetGhostedVirtualPath(ref string virtualPath) { 

        VirtualPathProvider virtualPathProvider = HostingEnvironment.VirtualPathProvider;

        string ghostedVirtualPath = virtualPathProvider.GetGhostedVirtualPath(virtualPath); 

        // If the file is not ghosted, don't change the path 
        if (ghostedVirtualPath == null) 
            return;
 
        //


        // Get the list of virtual paths that it depends on (e.g. user controls) 
        ICollection virtualPathDependencies = GetVirtualPathDependencies(virtualPath);
 
        // If there aren't any, return the ghosted path 
        if (virtualPathDependencies == null) {
            virtualPath = ghostedVirtualPath; 
            return;
        }

        // Go through all the dependencies, and if we find any that is *not* ghosted 
        // (i.e. for which GetGhostedVirtualPath returns null), we treat the whole request
        // as unghosted (and hence we return without modifying the virtualPath). 
 
        foreach (string virtualDependency in virtualPathDependencies) {
            string ghostedVirtualDependencyPath = virtualPathProvider.GetGhostedVirtualPath( 
                virtualDependency);
            if (ghostedVirtualDependencyPath == null)
                return;
        } 

        // All the dependencies are ghosted, so we can safely use the ghosted path, 
        // which can then be shared for all fully ghosted requests. 
        virtualPath = ghostedVirtualPath;
    } 
#endif

    internal static string GetCacheKeyFromVirtualPath(VirtualPath virtualPath) {
        bool keyFromVPP; 
        return GetCacheKeyFromVirtualPath(virtualPath, out keyFromVPP);
    } 
 
    /*
     * Same as GetCacheKeyFromVirtualPathInternal, but caches the cache keys 
     * for performance, since creating them is expensive (
*/
    static SimpleRecyclingCache _keyCache = new SimpleRecyclingCache();
    private static string GetCacheKeyFromVirtualPath(VirtualPath virtualPath, out bool keyFromVPP) { 

        // Check if the VirtualPathProvider needs to use a non-default cache key 
        string key = virtualPath.GetCacheKey(); 

        // If so, just return it 
        if (key != null) {
            keyFromVPP = true;
            return key.ToLowerInvariant();
        } 

        // The VPP didn't return a key, so use our standard key algorithm 
        keyFromVPP = false; 

        // Check if the key for this virtual path is already cached 
        key = _keyCache[virtualPath.VirtualPathString] as string;
        if (key != null) return key;

        // Compute the key 
        key = GetCacheKeyFromVirtualPathInternal(virtualPath);
 
        // The key should always be lower case 
        Debug.Assert(key == key.ToLowerInvariant());
 
        // Cache it for next time
        _keyCache[virtualPath.VirtualPathString] = key;

        return key; 
    }
 
    /* 
     * Generate a unique cache key from a virtual path.  e.g. for "/approot/sub1/sub2/foo.aspx"
     * the key could be "foo.aspx.ccdf220e", where ccdf220e is a hash code from 
     * the dir "sub1/sub2".
     */
    private static string GetCacheKeyFromVirtualPathInternal(VirtualPath virtualPath) {
 
        // We want the key to be app independent (for precompilation), so we
        // change the virtual path to be app relative 
 
        /* Disable asserttion since global theme needs to compile theme files in different vroot.
        Debug.Assert(StringUtil.VirtualPathStartsWithAppPath(virtualPath), 
            String.Format("VPath {0} is outside the application: {1}", virtualPath, HttpRuntime.AppDomainAppVirtualPath));
        */
        string virtualPathString = virtualPath.AppRelativeVirtualPathString.ToLowerInvariant();
        virtualPathString = UrlPath.RemoveSlashFromPathIfNeeded(virtualPathString); 

        // Split the path into the directory and the name 
        int slashIndex = virtualPathString.LastIndexOf('/'); 
        Debug.Assert(slashIndex >= 0 || virtualPathString == "~");
 
        if (virtualPathString == "~")
            return "root";

        Debug.Assert(slashIndex != virtualPathString.Length - 1); 
        string name = virtualPathString.Substring(slashIndex + 1);
        string dir; 
        if (slashIndex <= 0) 
            dir = "/";
        else { 
            dir = virtualPathString.Substring(0, slashIndex);
        }

        return name + "." + StringUtil.GetStringHashCode(dir).ToString("x", CultureInfo.InvariantCulture); 
    }
 
    internal static BuildResult GetVPathBuildResultFromCache(VirtualPath virtualPath) { 

        return TheBuildManager.GetVPathBuildResultFromCacheInternal(virtualPath); 
    }

    private BuildResult GetVPathBuildResultFromCacheInternal(VirtualPath virtualPath) {
 
        bool keyFromVPP;
        string cacheKey = GetCacheKeyFromVirtualPath(virtualPath, out keyFromVPP); 
        return GetBuildResultFromCacheInternal(cacheKey, keyFromVPP, virtualPath, 0 /*hashCode*/); 
    }
 
    internal static BuildResult GetBuildResultFromCache(string cacheKey) {
        return _theBuildManager.GetBuildResultFromCacheInternal(cacheKey, false /*keyFromVPP*/, null /*virtualPath*/,
            0 /*hashCode*/);
    } 

    internal static BuildResult GetBuildResultFromCache(string cacheKey, VirtualPath virtualPath) { 
        return _theBuildManager.GetBuildResultFromCacheInternal(cacheKey, false /*keyFromVPP*/, virtualPath, 
            0 /*hashCode*/);
    } 

    private BuildResult GetBuildResultFromCacheInternal(string cacheKey, bool keyFromVPP,
        VirtualPath virtualPath, long hashCode) {
 
        BuildResult result = null;
 
        // Allow the possibility that BuildManager was not initialized due to 
        // a very early failure (e.g. see
 
        if (!_theBuildManagerInitialized)
            return null;

        // The first cache should always be memory 
        Debug.Assert(_caches[0] == _memoryCache);
 
        // Try to get it from the memeory cache before taking any locks (for perf reasons) 
        result = _memoryCache.GetBuildResult(cacheKey, virtualPath, hashCode);
        if (result != null) { 
            return PostProcessFoundBuildResult(result, keyFromVPP, virtualPath);
        }

        Debug.Trace("BuildManager", "Didn't find '" + virtualPath + "' in memory cache before lock"); 

        lock (this) { 
            // Try to get the BuildResult from the cheapest to most expensive cache 
            int i;
            for (i = 0; i < _caches.Length; i++) { 
                result = _caches[i].GetBuildResult(cacheKey, virtualPath, hashCode);

                // There might be changes in local resources for dependencies,
                // so we need to make sure EnsureFirstTimeDirectoryInit gets called 
                // for them even when we already have a cache result.
                // 
 
                if (result != null) {
                    if (result.VirtualPathDependencies != null) { 
                        EnsureFirstTimeDirectoryInitForDependencies(result.VirtualPathDependencies);
                    }

                    break; 
                }
 
                // If we didn't find it in the memory cache, perform the per directory 
                // initialization.  This is a good place to do this, because we don't
                // affect the memory cache code path, but we do the init as soon as 
                // something is not found in the memory cache.
                if (i == 0 && virtualPath != null) {
                    VirtualPath virtualDir = virtualPath.Parent;
                    EnsureFirstTimeDirectoryInit(virtualDir); 
                }
            } 
 

            if (result == null) 
                return null;

            result = PostProcessFoundBuildResult(result, keyFromVPP, virtualPath);
            if (result == null) 
                return null;
 
            Debug.Assert(_memoryCache != null); 

            // If we found it in a cache, cache it in all the caches that come before 
            // the one where we found it.  If we found it in the memory cache, this is a no op.
            for (int j = 0; j < i; j++)
                _caches[j].CacheBuildResult(cacheKey, result, DateTime.UtcNow);
 
            Debug.Trace("BuildManager", "Found '" + virtualPath + "' in " + _caches[i]);
 
            return result; 
        }
    } 

    private BuildResult PostProcessFoundBuildResult(BuildResult result, bool keyFromVPP, VirtualPath virtualPath) {

        // Check that the virtual path in the result matches the passed in 
        // virtualPath (
 
        if (!keyFromVPP) { 
            if (virtualPath != null && virtualPath != result.VirtualPath) {
                Debug.Assert(false); 
                return null;
            }
        }
 
        // If what we found in the cache is a CompileError, rethrow the exception
        if (result is BuildResultCompileError) { 
            // Report the cached error from Callback interface. 
            HttpCompileException compileException = ((BuildResultCompileError)result).CompileException;
 
            // But don't report it if we're doing precompilation, as that would cause it to be
            // reported twice because we always try to compile everything that has failed
            // before (
            if (!PerformingPrecompilation) { 
                ReportErrorsFromException(compileException);
            } 
 
            throw compileException;
        } 

        return result;
    }
 
    internal static bool CacheVPathBuildResult(VirtualPath virtualPath,
        BuildResult result, DateTime utcStart) { 
 
        return _theBuildManager.CacheVPathBuildResultInternal(virtualPath, result, utcStart);
    } 

    private bool CacheVPathBuildResultInternal(VirtualPath virtualPath,
        BuildResult result, DateTime utcStart) {
 
        string cacheKey = GetCacheKeyFromVirtualPath(virtualPath);
        return CacheBuildResult(cacheKey, result, utcStart); 
    } 

    internal static bool CacheBuildResult(string cacheKey, BuildResult result, DateTime utcStart) { 
        return _theBuildManager.CacheBuildResultInternal(cacheKey, result, 0 /*hashCode*/, utcStart);
    }

    private bool CacheBuildResultInternal(string cacheKey, BuildResult result, 
        long hashCode, DateTime utcStart) {
 
        // Before caching it, make sure the hash has been computed 
        result.EnsureVirtualPathDependenciesHashComputed();
 
        for (int i = 0; i < _caches.Length; i++) {
            _caches[i].CacheBuildResult(cacheKey, result, hashCode, utcStart);
        }
 
        // If we find that it's no longer valid after caching it, remove it from the cache (
        if (!TimeStampChecker.CheckFilesStillValid(cacheKey, result.VirtualPathDependencies)) { 
            _memoryCache.RemoveAssemblyAndCleanupDependencies(result as BuildResultCompiledAssemblyBase); 
            return false;
        } 

        return true;
    }
 

    // 
    // Precompilation related code 
    //
 
    internal void SetPrecompilationInfo(HostingEnvironmentParameters hostingParameters) {

        if (hostingParameters == null || hostingParameters.ClientBuildManagerParameter == null)
            return; 

        _precompilationFlags = hostingParameters.ClientBuildManagerParameter.PrecompilationFlags; 
 
        _strongNameKeyFile = hostingParameters.ClientBuildManagerParameter.StrongNameKeyFile;
        _strongNameKeyContainer = hostingParameters.ClientBuildManagerParameter.StrongNameKeyContainer; 

        // Check if we're precompiling to a target directory
        _precompTargetPhysicalDir = hostingParameters.PrecompilationTargetPhysicalDirectory;
        if (_precompTargetPhysicalDir == null) 
            return;
 
        // Check if the target dir already exists and is not empty 
        if (Util.IsNonEmptyDirectory(_precompTargetPhysicalDir)) {
 
            // If it's not empty and OverwriteTarget is off, fail
            if ((_precompilationFlags & PrecompilationFlags.OverwriteTarget) == 0) {
                throw new HttpException(SR.GetString(SR.Dir_not_empty));
            } 

            // Does it contain the precomp marker file 
            bool updatable; 
            bool precompiled = ReadPrecompMarkerFile(_precompTargetPhysicalDir, out updatable);
 
            // If not, refuse to delete the directory, even if OverwriteTarget is on (
            if (!precompiled) {
                throw new HttpException(SR.GetString(SR.Dir_not_empty_not_precomp));
            } 

            // The OverwriteTarget flag was specified, so delete the directory 
            if (!DeletePrecompTargetDirectory()) { 
                // If we failed to delete it, sleep 250 ms and try again, in case there is
                // an appdomain in the process of shutting down (the shut down would 
                // have been triggered by the first delete attempt)
                Debug.Trace("BuildManager", "Failed to delete " + _precompTargetPhysicalDir + ".  Sleeping and trying once more...");
                Thread.Sleep(250);
 
                if (!DeletePrecompTargetDirectory()) {
                    Debug.Trace("BuildManager", "Failed to delete " + _precompTargetPhysicalDir + ".  Sleeping and trying once more..."); 
                    // Try again after 1 second. 
                    Thread.Sleep(1000);
 
                    // If we still couldn't delete it, fail
                    if (!DeletePrecompTargetDirectory()) {
                        throw new HttpException(SR.GetString(SR.Cant_delete_dir));
                    } 
                }
            } 
        } 

        // Create a marker file to mark the fact that this is a precompiled app 
        CreatePrecompMarkerFile();
    }

    private bool DeletePrecompTargetDirectory() { 
        try {
            if (_precompTargetPhysicalDir != null) { 
                // Go through all the files in the directory and delete them. 
                foreach (FileData fileData in FileEnumerator.Create(_precompTargetPhysicalDir)) {
 
                    if (fileData.IsDirectory) {
                        Directory.Delete(fileData.FullName, true /*recursive*/);
                    }
                    else { 
                        Util.DeleteFileNoException(fileData.FullName);
                    } 
                } 
            }
        } 
#if DEBUG
        catch (Exception e) {
            Debug.Trace("BuildManager", "DeletePrecompTargetDirectory failed: " + e.Message);
        } 
#else
        catch {} 
#endif 
        return !Util.IsNonEmptyDirectory(_precompTargetPhysicalDir);
    } 

    private void FailIfPrecompiledApp() {

        if (IsPrecompiledApp) { 
            throw new HttpException(SR.GetString(SR.Already_precomp));
        } 
    } 

    internal void PrecompileApp(ClientBuildManagerCallback callback) { 

        // Remember the original setting
        bool skipTopLevelExceptions = SkipTopLevelCompilationExceptions;
 
        try {
            _cbmCallback = callback; 
 
            // Don't stop on the first parse errors, process as many errors as possible.
            ThrowOnFirstParseError = false; 

            // Don't skip top level compilation exceptions even called by CBM.
            SkipTopLevelCompilationExceptions = false;
 
            PrecompileApp(HttpRuntime.AppDomainAppVirtualPathObject);
        } 
        finally { 
            // Revert to original setting
            SkipTopLevelCompilationExceptions = skipTopLevelExceptions; 
            ThrowOnFirstParseError = true;

            _cbmCallback = null;
        } 
    }
 
    private void PrecompileApp(VirtualPath startingVirtualDir) { 
        using (new ApplicationImpersonationContext()) {
            try { 
                PerformingPrecompilation = true;

                PrecompileAppInternal(startingVirtualDir);
            } 
            catch {
                // If anything fails during precompilation, wipe out the target to avoid 
                // leaving it in a random state ( 
                DeletePrecompTargetDirectory();
 
                throw;
            }
            finally {
                PerformingPrecompilation = false; 
            }
        } 
    } 

    private void PrecompileAppInternal(VirtualPath startingVirtualDir) { 

        // If the app is already precompiled, fail
        FailIfPrecompiledApp();
 
        VirtualDirectory appVdir = startingVirtualDir.GetDirectory();
 
        EnsureTopLevelFilesCompiled(); 

        try { 
            // Clear the parseError flag first
            _parseErrorReported = false;

            PrecompileWebDirectoriesRecursive(appVdir, true /*topLevel*/); 
            PrecompileThemeDirectories();
        } 
        catch (HttpParseException parseException) { 
            // if nothing calls callback.reportparseerror yet, report the parse error.
            if (!_parseErrorReported) { 
                ReportErrorsFromException(parseException);
            }

            throw; 
        }
 
        // Copy all the DLL's we compiled into the destination's bin directory (if any) 
        if (_precompTargetPhysicalDir != null) {
            string targetBinDir = Path.Combine(_precompTargetPhysicalDir, HttpRuntime.BinDirectoryName); 
            CopyCompiledAssembliesToDestinationBin(HttpRuntime.CodegenDirInternal, targetBinDir);
        }

        // Copy all the static files to the destination directory (if any).  We treat anything we 
        // don't compile as a static file.  It's better to do this at the end of the precompilation,
        // this way if any pages has errors (parse or compile), we never get to this step. 
        if (_precompTargetPhysicalDir != null) { 
            CopyStaticFilesRecursive(appVdir, _precompTargetPhysicalDir, true /*topLevel*/);
        } 
    }

    // Create a small file that marks that app as being precompiled
    private void CreatePrecompMarkerFile() { 

        Debug.Assert(PrecompilingForDeployment); 
 
        Directory.CreateDirectory(_precompTargetPhysicalDir);
        string precompMarkerFile = Path.Combine(_precompTargetPhysicalDir, precompMarkerFileName); 

        using (StreamWriter writer = new StreamWriter(precompMarkerFile, false /*append*/, Encoding.UTF8)) {
            writer.Write("");
        }
    }
 
    private static bool ReadPrecompMarkerFile(string appRoot, out bool updatable) {
 
        updatable = false; 

        // Get the full physical path to the precompilation market file 
        string precompMarkerFile = Path.Combine(appRoot, precompMarkerFileName);

        // If the file doesn't exist at all, it's not a precompiled app
        if (!File.Exists(precompMarkerFile)) 
            return false;
 
        XmlDocument doc = new XmlDocument(); 
        try {
            doc.Load(precompMarkerFile); 
        }
        catch {
            // If we fail to read it for any reason, ignore it.
            return false; 
        }
 
        // Get the root element, and make sure it's what we expect 
        XmlNode root = doc.DocumentElement;
        Debug.Assert(root != null && root.Name == "precompiledApp"); 
        if (root == null || root.Name != "precompiledApp")
            return false;

        // Check the updatable flag 
        HandlerBase.GetAndRemoveBooleanAttribute(root, "updatable", ref updatable);
 
        return true; 
    }
 
    /*
     * Are we precompiling the app for deployment (as opposed to in-place)
     */
    internal static bool PrecompilingForDeployment { 
        get {
            return (_theBuildManager._precompTargetPhysicalDir != null); 
        } 
    }
 
    internal static bool PrecompilingForUpdatableDeployment {
        get {
            // The updatebale mode only applies in deployment precompilation mode
            if (!PrecompilingForDeployment) 
                return false;
 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.Updatable) != 0; 
        }
    } 

    private static bool PrecompilingForCleanBuild {
        get {
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.Clean) != 0; 
        }
    } 
 
    internal static bool PrecompilingWithDebugInfo {
        get { 
            // The ForceDebug flag only applies in deployment precompilation mode
            if (!PrecompilingForDeployment)
                return false;
 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.ForceDebug) != 0;
        } 
    } 

    internal static bool PrecompilingWithCodeAnalysisSymbol { 
        get {
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.CodeAnalysis) != 0;
        }
    } 

    private static bool CompileWithFixedAssemblyNames { 
        get { 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.FixedNames) != 0;
        } 
    }

    internal static bool CompileWithAllowPartiallyTrustedCallersAttribute {
        get { 
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.AllowPartiallyTrustedCallers) != 0;
        } 
    } 

    internal static bool CompileWithDelaySignAttribute { 
        get {
            return (_theBuildManager._precompilationFlags & PrecompilationFlags.DelaySign) != 0;
        }
    } 

    internal static string StrongNameKeyFile { 
        get { 
            return _theBuildManager._strongNameKeyFile;
        } 
    }

    internal static string StrongNameKeyContainer {
        get { 
            return _theBuildManager._strongNameKeyContainer;
        } 
    } 

    // If we're in the process of precompiling for updatable deployment, this returns 
    // a writer to the target file specified by the virtual path.  This is used when the
    // deployed file needs to be different from the original (as is the case for aspx files).
    internal static TextWriter GetUpdatableDeploymentTargetWriter(VirtualPath virtualPath, Encoding fileEncoding) {
 
        Debug.Assert(fileEncoding != null);
 
        if (!PrecompilingForUpdatableDeployment) 
            return null;
 
        Debug.Assert(!virtualPath.IsRelative);

        string path = virtualPath.AppRelativeVirtualPathString;
 
        // Skip the "~/" to be left with the relative path
        path = path.Substring(2); 
 
        // Combine it with the precomp target dir to get the full path
        string physicalPath = Path.Combine(_theBuildManager._precompTargetPhysicalDir, path); 

        // Before trying to create the file, make sure the directory exists
        string physicalDir = Path.GetDirectoryName(physicalPath);
        Directory.CreateDirectory(physicalDir); 

        return new StreamWriter(physicalPath, false /*append*/, fileEncoding); 
    } 

    private bool IsPrecompiledAppInternal { 
        get {
            if (!_isPrecompiledAppComputed) {
                _isPrecompiledApp = ReadPrecompMarkerFile(HttpRuntime.AppDomainAppPathInternal,
                    out _isUpdatablePrecompiledApp); 

                _isPrecompiledAppComputed = true; 
            } 

            return _isPrecompiledApp; 
        }
    }

    internal static bool IsPrecompiledApp { 
        get {
            return _theBuildManager.IsPrecompiledAppInternal; 
        } 
    }
 
    private bool IsUpdatablePrecompiledAppInternal {
        get {
            return IsPrecompiledApp && _isUpdatablePrecompiledApp;
        } 
    }
 
    internal static bool IsUpdatablePrecompiledApp { 
        get {
            return _theBuildManager.IsUpdatablePrecompiledAppInternal; 
        }
    }

    private bool IsNonUpdatablePrecompiledApp { 
        get {
            return IsPrecompiledApp && !_isUpdatablePrecompiledApp; 
        } 
    }
 
    private void PrecompileWebDirectoriesRecursive(VirtualDirectory vdir, bool topLevel) {

        // Precompile the children directory
 
        foreach (VirtualDirectory childVdir in vdir.Directories) {
 
            if (topLevel && _excludedTopLevelDirectories.Contains(childVdir.Name)) 
                continue;
 
            // Exclude the special FrontPage directory (
            if (childVdir.Name == "_vti_cnf")
                continue;
 
            PrecompileWebDirectoriesRecursive(childVdir, false /*topLevel*/);
        } 
 
        // Precompile this directory
        try { 
            // Set a flag to remember that we're in the process of precompiling.  This
            // way, if BatchCompileWebDirectory ends up getting called again recursively
            // via CompileWebFile, we know that we cannot ignore errors.
            _precompilingApp = true; 

            if (IsBatchEnabledForDirectory(vdir.VirtualPathObject)) { 
                // batch everything if enabled 
                BatchCompileWebDirectory(vdir, null, false /*ignoreErrors*/);
            } 
            else {
                // if batching is disabled, compile each web file individually.
                NonBatchDirectoryCompiler dirCompiler = new NonBatchDirectoryCompiler(vdir);
                dirCompiler.Process(); 
            }
        } 
        finally { 
            // Always restore the flag to false when we're done.
            _precompilingApp = false; 
        }
    }

    private void PrecompileThemeDirectories() { 
        string appPhysicalDir = Path.Combine(HttpRuntime.AppDomainAppPathInternal, HttpRuntime.ThemesDirectoryName);
 
        if (Directory.Exists(appPhysicalDir)) { 
            string[] themeDirs = Directory.GetDirectories(appPhysicalDir);
 
            foreach (string themeDirPath in themeDirs) {
                string themeDirName = Path.GetFileName(themeDirPath);
                ThemeDirectoryCompiler.GetThemeBuildResultType(null /*context*/, themeDirName);
            } 
        }
    } 
 
    /*
     * Recursively copy all the static files from the source directory to the 
     * target directory of the precompilation
     */
    private void CopyStaticFilesRecursive(VirtualDirectory sourceVdir, string destPhysicalDir,
        bool topLevel) { 

        // Make sure the target physical dir has no relation with the source.  It's important to 
        // 

        string sourcePhysicalDir = HostingEnvironment.MapPathInternal(sourceVdir.VirtualPath); 
        VerifyUnrelatedSourceAndDest(sourcePhysicalDir, destPhysicalDir);

        bool directoryCreationAttempted = false;
 
        foreach (VirtualFileBase child in sourceVdir.Children) {
 
            string destPhysicalSubDir = Path.Combine(destPhysicalDir, child.Name); 

            if (child.IsDirectory) { 

                // Skip the special top level directories, since they never contain relevant
                // static files.  Note that we don't skip Themes, which does contain static files.
                if (topLevel && 
                    (StringUtil.EqualsIgnoreCase(child.Name, HttpRuntime.CodeDirectoryName) ||
                    StringUtil.EqualsIgnoreCase(child.Name, HttpRuntime.ResourcesDirectoryName) || 
                    StringUtil.EqualsIgnoreCase(child.Name, HttpRuntime.WebRefDirectoryName))) { 

                    continue; 
                }

                // Also, skip the LocalResources directory at any level, except when precompiling
                // for updatable deployment (in which case, we deploy the local resources file) 
                if (!PrecompilingForUpdatableDeployment && StringUtil.EqualsIgnoreCase(child.Name,
                    HttpRuntime.LocalResourcesDirectoryName)) { 
                    continue; 
                }
 
                CopyStaticFilesRecursive(child as VirtualDirectory, destPhysicalSubDir, false /*topLevel*/);
                continue;
            }
 
            // Create the destination directory if needed
            if (!directoryCreationAttempted) { 
                directoryCreationAttempted = true; 
                Directory.CreateDirectory(destPhysicalDir);
            } 

            // Copy the file as appropriate based on its extension
            CopyPrecompiledFile(child as VirtualFile, destPhysicalSubDir);
        } 
    }
 
    /* 
     * Copy all the assemblies from the codegen dir into the bin directory of the
     * target precompiled app. 
     */
    private void CopyCompiledAssembliesToDestinationBin(string fromDir, string toDir) {

        bool createdDirectory = false; 

        foreach (FileData fileData in FileEnumerator.Create(fromDir)) { 
            // Windows OS Bug 1981578 
            // Create a new directory only if there is something in the directory.
            if (!createdDirectory) 
                Directory.CreateDirectory(toDir);
            createdDirectory = true;

            // Recurse on subdirectories.if they contain culture files 
            if (fileData.IsDirectory) {
 
                if (Util.IsCultureName(fileData.Name)) { 
                    string fromSubDir = Path.Combine(fromDir, fileData.Name);
                    string toSubDir = Path.Combine(toDir, fileData.Name); 
                    CopyCompiledAssembliesToDestinationBin(fromSubDir, toSubDir);
                }

                continue; 
            }
 
            // Only process DLL's and PDB's 
            string extension = Path.GetExtension(fileData.Name);
            if (extension != ".dll" && extension != ".pdb") 
                continue;

            string sourcePhysicalPath = Path.Combine(fromDir, fileData.Name);
            string destPhysicalPath = Path.Combine(toDir, fileData.Name); 

            // Copy the file to the destination 
            // 
            File.Copy(sourcePhysicalPath, destPhysicalPath, true /*overwrite*/);
        } 
    }

    // Copy one file from the source app to the precompiled app
    private void CopyPrecompiledFile(VirtualFile vfile, string destPhysicalPath) { 

        bool createStub; 
 
        if (CompilationUtil.NeedToCopyFile(vfile.VirtualPathObject, PrecompilingForUpdatableDeployment,
            out createStub)) { 

            //
            string sourcePhysicalPath = HostingEnvironment.MapPathInternal(vfile.VirtualPath);
 
            // The file could already exist with updatable precompilation, since we would create the modified file
            // earlier during processing of a code beside page. 
            if (File.Exists(destPhysicalPath)) { 

                // In that case, we still need to fix it up to insert the correct type string in the 
                // inherits attribute (

                // First, get the just-compiled BuildResult.  It should always exist
                BuildResultCompiledType result = GetVPathBuildResult(null, vfile.VirtualPathObject, 
                    true /*noBuild*/, false /*allowCrossApp*/) as BuildResultCompiledType;
                Debug.Assert(result != null); 
 
                //
 
                Encoding encoding = Util.GetEncodingFromConfigPath(vfile.VirtualPathObject);

                // Read in the file
                string newAspxFile = Util.StringFromFile(destPhysicalPath, ref encoding); 

                // Replace the placeholder token by the true type with the assembly 
                newAspxFile = newAspxFile.Replace(UpdatableInheritReplacementToken, 
                    Util.GetAssemblyQualifiedTypeName(result.ResultType));
 
                // Write the modified file back with the correct inherits type string
                StreamWriter writer = new StreamWriter(destPhysicalPath, false /* append */, encoding);
                writer.Write(newAspxFile);
                writer.Close(); 
            }
            else { 
                // Just copy the file to the destination 
                File.Copy(sourcePhysicalPath, destPhysicalPath, false /*overwrite*/);
            } 

            // If it has a readonly attribute, clear it on the destination (
            Util.ClearReadOnlyAttribute(destPhysicalPath);
        } 
        else {
            if (createStub) { 
                // Create the stub file, with a helpful static message 
                StreamWriter writer = new StreamWriter(destPhysicalPath);
                writer.Write(SR.GetString(SR.Precomp_stub_file)); 
                writer.Close();
            }
        }
    } 

    // Make sure the target physical dir has no relation with the source 
    internal static void VerifyUnrelatedSourceAndDest(string sourcePhysicalDir, string destPhysicalDir) { 

        // Make sure they're normalized and end with a '\' before comparing ( 
        sourcePhysicalDir = FileUtil.FixUpPhysicalDirectory(sourcePhysicalDir);
        destPhysicalDir = FileUtil.FixUpPhysicalDirectory(destPhysicalDir);

        if (StringUtil.StringStartsWithIgnoreCase(sourcePhysicalDir, destPhysicalDir) || 
            StringUtil.StringStartsWithIgnoreCase(destPhysicalDir, sourcePhysicalDir)) {
            throw new HttpException(SR.GetString( 
                SR.Illegal_precomp_dir, destPhysicalDir, sourcePhysicalDir)); 
        }
    } 

    internal static void ReportDirectoryCompilationProgress(VirtualPath virtualDir) {

        // Nothing to do if there is no CBM callback 
        if (CBMCallback == null)
            return; 
 
        // Don't report anything if the directory doesn't exist
        if (!virtualDir.DirectoryExists()) 
            return;

        string message = SR.GetString(SR.Directory_progress, virtualDir.VirtualPathString);
        CBMCallback.ReportProgress(message); 
    }
 
 
    //
    // Public methods 
    //


    ///  
    ///     Compiles a file given its virtual path, using the appropriate BuildProvider (based
    ///     on the file's extension).  The compiled type is returned. 
    ///     This methods performs both memory and disk caching of the compiled Type. 
    /// 
    public static Type GetCompiledType(string virtualPath) { 
        if (virtualPath == null) {
            throw new ArgumentNullException("virtualPath");
        }
 
        return GetCompiledType(VirtualPath.Create(virtualPath));
    } 
 
    // This method is called by BuildManagerHost thru CBM
    internal static Type GetCompiledType(VirtualPath virtualPath, ClientBuildManagerCallback callback) { 
        // Remember the original setting
        bool skipTopLevelExceptions = SkipTopLevelCompilationExceptions;
        bool throwOnFirstParseError = ThrowOnFirstParseError;
 
        try {
            // Don't skip top level compilation exceptions even called by CBM. 
            SkipTopLevelCompilationExceptions = false; 

            // Don't stop on the first parse error, process as many errors as possible. 
            ThrowOnFirstParseError = false;

            _theBuildManager._cbmCallback = callback;
            return GetCompiledType(virtualPath); 
        }
        finally { 
            _theBuildManager._cbmCallback = null; 

            // Revert to original setting 
            SkipTopLevelCompilationExceptions = skipTopLevelExceptions;

            ThrowOnFirstParseError = throwOnFirstParseError;
        } 
    }
 
    internal static Type GetCompiledType(VirtualPath virtualPath) { 
        ITypedWebObjectFactory factory = GetVirtualPathObjectFactory(virtualPath,
            null /*context*/, false /*allowCrossApp*/, false /*noAssert*/); 

        BuildResultCompiledType resultType = factory as BuildResultCompiledType;
        if (resultType == null) return null;
 
        return resultType.ResultType;
    } 
 
    /// Process a file based on its virtual path, and instantiate the result.  This API works for both
    /// compiled and no compile pages.  requiredBaseType specifies a type from which the resulting 
    /// object must derive.  If it doesn't, the API fails without instantiating the object.
    public static object CreateInstanceFromVirtualPath(string virtualPath, Type requiredBaseType) {
        VirtualPath virtualPathObject = VirtualPath.CreateNonRelative(virtualPath);
        return CreateInstanceFromVirtualPath(virtualPathObject, requiredBaseType, 
            null /*context*/, false /*allowCrossApp*/, false /*noAssert*/);
    } 
 
    /// 
    ///     Process a file given its virtual path, using the appropriate BuildProvider (based 
    ///     on the file's extension).  The result is then instantiated and returned.
    /// 
    internal static object CreateInstanceFromVirtualPath(VirtualPath virtualPath,
        Type requiredBaseType, HttpContext context, bool allowCrossApp, bool noAssert) { 

        ITypedWebObjectFactory objectFactory = GetVirtualPathObjectFactory(virtualPath, context, allowCrossApp, noAssert); 
        if (objectFactory == null) return null; 

        // Make sure it has the required base type ( 
        Util.CheckAssignableType(requiredBaseType, objectFactory.InstantiatedType);

        // impersonate client while executing page ctor (see ASURT 89712)
        // (compilation is done while not impersonating client) 

        Object instance; 
        using (new ClientImpersonationContext(context)) { 
            instance = objectFactory.CreateInstance();
        } 

        return instance;
    }
 

    ///  
    ///     Process a file given its virtual path, using the appropriate BuildProvider (based 
    ///     on the file's extension).  The ITypedWebObjectFactory is returned.
    ///     This methods performs both memory and disk caching of the compiled Type. 
    /// 
    private static ITypedWebObjectFactory GetVirtualPathObjectFactory(VirtualPath virtualPath,
        HttpContext context, bool allowCrossApp, bool noAssert) {
 
        if (virtualPath == null)
            throw new ArgumentNullException("virtualPath"); 
 
        // Throw here immediately if top level exception exists.
        // This is because EnsureTopLevelFilesCompiled (where the exception is thrown) 
        // might not be called.
        if (_theBuildManager._topLevelFileCompilationException != null) {
            _theBuildManager.ReportTopLevelCompilationException();
        } 

        ITypedWebObjectFactory objectFactory; 
        BuildResult buildResult; 

        // We need to assertt here since there may be user code on the stack, 
        // and code may demand UnmanagedCode permission.  But if we're in full trust,
        // or noAssert is true, skip the assertt for perf reasons (
        if (HttpRuntime.IsFullTrust || noAssert) {
            buildResult = GetVPathBuildResultWithNoAssert( 
                context, virtualPath, false /*noBuild*/, allowCrossApp, false /*allowBuildInPrecompile*/);
        } 
        else { 
            buildResult = GetVPathBuildResultWithAssert(
                context, virtualPath, false /*noBuild*/, allowCrossApp, false /*allowBuildInPrecompile*/); 
        }

        // DevDiv 67952
        // The returned build result may not always be castable to ITypedWebObjectFactory. 
        objectFactory = buildResult as ITypedWebObjectFactory;
 
        return objectFactory; 
    }
 
    /// 
    ///     Compiles a file given its virtual path, using the appropriate BuildProvider (based
    ///     on the file's extension).  The compiled assembly is returned.
    ///     This methods performs both memory and disk caching of the compiled assembly. 
    /// 
    public static Assembly GetCompiledAssembly(string virtualPath) { 
 
        BuildResult result = GetVPathBuildResult(VirtualPath.Create(virtualPath));
        if (result == null) return null; 

        BuildResultCompiledAssemblyBase resultAssembly = result as BuildResultCompiledAssemblyBase;
        if (resultAssembly == null) return null;
 
        return resultAssembly.ResultAssembly;
    } 
 

    ///  
    ///     Compiles a file given its virtual path, using the appropriate BuildProvider (based
    ///     on the file's extension).  If the BuildProvider chose to persist a custom
    ///     string, the string is returned.
    ///     This methods performs both memory and disk caching. 
    /// 
    public static string GetCompiledCustomString(string virtualPath) { 
 
        BuildResult result = GetVPathBuildResult(VirtualPath.Create(virtualPath));
        if (result == null) return null; 

        BuildResultCustomString resultCustomString = result as BuildResultCustomString;
        if (resultCustomString == null) return null;
 
        return resultCustomString.CustomString;
    } 
 
    /// 
    ///     Returns the BuildDependencySet for the passed in virtualPath, assuming 
    ///     that information is cached.  Otherwise, return null.
    /// 
    public static BuildDependencySet GetCachedBuildDependencySet(
        HttpContext context, string virtualPath) { 

        BuildResult result = GetVPathBuildResult(context, VirtualPath.Create(virtualPath), 
            true /*noBuild*/, false /*allowCrossApp*/); 

        // If it's not cached, return null 
        if (result == null)
            return null;

        // We found it in the cache.  Wrap it with a BuildDependencySet object. 
        return new BuildDependencySet(result);
    } 
 
    private Assembly ResolveAssembly(object sender, ResolveEventArgs e) {
 
        if (_assemblyResolveMapping == null)
            return null;

        string name = e.Name; 
        Assembly assembly = (Assembly)_assemblyResolveMapping[name];
 
        // Return the assembly if we have it in our mapping ( 
        if (assembly != null) {
            return assembly; 
        }

        // Get the normalized assembly name from random name (
        String normalizedName = GetNormalizedCodeAssemblyName(name); 
        if (normalizedName != null) {
            return (Assembly)_assemblyResolveMapping[normalizedName]; 
        } 

        return null; 
    }

    internal static string GetNormalizedCodeAssemblyName(string assemblyName) {
        // Return the main code assembly. 
        if (assemblyName.StartsWith(CodeDirectoryAssemblyName, StringComparison.Ordinal)) {
            return CodeDirectoryAssemblyName; 
        } 

        // Check the sub code directories. 
        CodeSubDirectoriesCollection codeSubDirectories = CompilationUtil.GetCodeSubDirectories();
        foreach (CodeSubDirectory directory in codeSubDirectories) {
            if (assemblyName.StartsWith(SubCodeDirectoryAssemblyNamePrefix + directory.AssemblyName + ".", StringComparison.Ordinal)) {
                return directory.AssemblyName; 
            }
        } 
 
        return null;
    } 

    internal static string GetNormalizedTypeName(Type t) {
        string assemblyFullName = t.Assembly.FullName;
        string normalizedCodeAssemblyName = GetNormalizedCodeAssemblyName(assemblyFullName); 
        if (normalizedCodeAssemblyName == null) {
            return t.AssemblyQualifiedName; 
        } 

        string normalizedTypeName = t.FullName + ", " + normalizedCodeAssemblyName; 
        return normalizedTypeName;
    }
}
 
internal enum CompilationStage {
    PreTopLevelFiles = 0,       // Before EnsureTopLevelFilesCompiled() is called 
    TopLevelFiles = 1,          // In EnsureTopLevelFilesCompiled() but before building global.asax 
    GlobalAsax = 2,             // While building global.asax
    BrowserCapabilities = 3,    // While building browserCap 
    AfterTopLevelFiles = 4      // After EnsureTopLevelFilesCompiled() is called
}

internal class AssemblyReferenceInfo { 
    internal Assembly Assembly;
    internal int ReferenceIndex; 
 
    internal AssemblyReferenceInfo(int referenceIndex) {
        ReferenceIndex = referenceIndex; 
    }
}
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

                        

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