Support implicit standard directory reference and "3264" platform folders

Completes wixtoolset/issues#5798 and wixtoolset/issues#5835

17 files changed, 437 insertions, 72 deletions

diff --git a/src/WixToolset.Core.WindowsInstaller/Bind/AddRequiredStandardDirectories.cs b/src/WixToolset.Core.WindowsInstaller/Bind/AddRequiredStandardDirectories.cs
new file mode 100644
index 00000000..4597639b
--- /dev/null
+++ b/src/WixToolset.Core.WindowsInstaller/Bind/AddRequiredStandardDirectories.cs
@@ -0,0 +1,95 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Core.WindowsInstaller.Bind
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using WixToolset.Data;
+    using WixToolset.Data.Symbols;
+    using WixToolset.Data.WindowsInstaller;
+
+    /// <summary>
+    /// Add referenced standard directory symbols, if not already present.
+    /// </summary>
+    internal class AddRequiredStandardDirectories
+    {
+        internal AddRequiredStandardDirectories(IntermediateSection section, Platform platform)
+        {
+            this.Section = section;
+            this.Platform = platform;
+        }
+
+        private IntermediateSection Section { get; }
+
+        private Platform Platform { get; }
+
+        public void Execute()
+        {
+            var directories = this.Section.Symbols.OfType<DirectorySymbol>().ToList();
+            var directoriesById = directories.ToDictionary(d => d.Id.Id);
+
+            foreach (var directory in directories)
+            {
+                var parentDirectoryId = directory.ParentDirectoryRef;
+
+                if (String.IsNullOrEmpty(parentDirectoryId))
+                {
+                    if (directory.Id.Id != "TARGETDIR")
+                    {
+                        directory.ParentDirectoryRef = "TARGETDIR";
+                    }
+                }
+                else
+                {
+                    this.EnsureStandardDirectoryAdded(directoriesById, parentDirectoryId, directory.SourceLineNumbers);
+                }
+            }
+
+            if (!directoriesById.ContainsKey("TARGETDIR") && WindowsInstallerStandard.TryGetStandardDirectory("TARGETDIR", out var targetDir))
+            {
+                directoriesById.Add(targetDir.Id.Id, targetDir);
+                this.Section.AddSymbol(targetDir);
+            }
+        }
+
+        private void EnsureStandardDirectoryAdded(Dictionary<string, DirectorySymbol> directoriesById, string directoryId, SourceLineNumber sourceLineNumbers)
+        {
+            if (!directoriesById.ContainsKey(directoryId) && WindowsInstallerStandard.TryGetStandardDirectory(directoryId, out var standardDirectory))
+            {
+                var parentDirectoryId = this.GetStandardDirectoryParent(directoryId);
+
+                var directory = new DirectorySymbol(sourceLineNumbers, standardDirectory.Id)
+                {
+                    Name = standardDirectory.Name,
+                    ParentDirectoryRef = parentDirectoryId,
+                };
+
+                directoriesById.Add(directory.Id.Id, directory);
+                this.Section.AddSymbol(directory);
+
+                if (!String.IsNullOrEmpty(parentDirectoryId))
+                {
+                    this.EnsureStandardDirectoryAdded(directoriesById, parentDirectoryId, sourceLineNumbers);
+                }
+            }
+        }
+
+        private string GetStandardDirectoryParent(string directoryId)
+        {
+            switch (directoryId)
+            {
+                case "TARGETDIR":
+                    return null;
+
+                case "CommonFiles6432Folder":
+                case "ProgramFiles6432Folder":
+                case "System6432Folder":
+                    return WindowsInstallerStandard.GetPlatformSpecificDirectoryId(directoryId, this.Platform);
+
+                default:
+                    return "TARGETDIR";
+            }
+        }
+    }
+}
diff --git a/src/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs b/src/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
index 950fe1c1..93c617d9 100644
--- a/src/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
+++ b/src/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
@@ -133,6 +133,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             bool compressed;
             bool longNames;
             int installerVersion;
+            Platform platform;
             string modularizationSuffix;
             {
                 var command = new BindSummaryInfoCommand(section);
@@ -141,6 +142,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 compressed = command.Compressed;
                 longNames = command.LongNames;
                 installerVersion = command.InstallerVersion;
+                platform = command.Platform;
                 modularizationSuffix = command.ModularizationSuffix;
             }
 
@@ -194,6 +196,11 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             }
 
             {
+                var command = new AddRequiredStandardDirectories(section, platform);
+                command.Execute();
+            }
+
+            {
                 var command = new CreateSpecialPropertiesCommand(section);
                 command.Execute();
             }
@@ -332,7 +339,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
             // Set generated component guids.
             {
-                var command = new CalculateComponentGuids(this.Messaging, this.BackendHelper, this.PathResolver, section);
+                var command = new CalculateComponentGuids(this.Messaging, this.BackendHelper, this.PathResolver, section, platform);
                 command.Execute();
             }
 
diff --git a/src/WixToolset.Core.WindowsInstaller/Bind/BindSummaryInfoCommand.cs b/src/WixToolset.Core.WindowsInstaller/Bind/BindSummaryInfoCommand.cs
index 82688edf..63691016 100644
--- a/src/WixToolset.Core.WindowsInstaller/Bind/BindSummaryInfoCommand.cs
+++ b/src/WixToolset.Core.WindowsInstaller/Bind/BindSummaryInfoCommand.cs
@@ -32,6 +32,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         public int InstallerVersion { get; private set; }
 
+        public Platform Platform { get; private set; }
+
         /// <summary>
         /// Modularization guid, or null if the output is not a module.
         /// </summary>
@@ -66,6 +68,10 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                             summaryInformationSymbol.Value = Common.GetValidCodePage(codepage, false, false, summaryInformationSymbol.SourceLineNumbers).ToString(CultureInfo.InvariantCulture);
                         }
                         break;
+                    case SummaryInformationType.PlatformAndLanguage:
+                        this.Platform = GetPlatformFromSummaryInformation(summaryInformationSymbol.Value);
+                        break;
+
                     case SummaryInformationType.PackageCode: // PID_REVNUMBER
                         var packageCode = summaryInformationSymbol.Value;
 
@@ -137,5 +143,30 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 });
             }
         }
+
+        private static Platform GetPlatformFromSummaryInformation(string value)
+        {
+            var separatorIndex = value.IndexOf(';');
+            var platformValue = separatorIndex > 0 ? value.Substring(0, separatorIndex) : value;
+
+            switch (platformValue)
+            {
+                case "x64":
+                    return Platform.X64;
+
+                case "Arm":
+                    return Platform.ARM;
+
+                case "Arm64":
+                    return Platform.ARM64;
+
+                case "Intel64":
+                    return Platform.IA64;
+
+                case "Intel":
+                default:
+                    return Platform.X86;
+            }
+        }
     }
 }
diff --git a/src/WixToolset.Core.WindowsInstaller/Bind/CalculateComponentGuids.cs b/src/WixToolset.Core.WindowsInstaller/Bind/CalculateComponentGuids.cs
index a1e3ac83..02336cae 100644
--- a/src/WixToolset.Core.WindowsInstaller/Bind/CalculateComponentGuids.cs
+++ b/src/WixToolset.Core.WindowsInstaller/Bind/CalculateComponentGuids.cs
@@ -16,12 +16,13 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     /// </summary>
     internal class CalculateComponentGuids
     {
-        internal CalculateComponentGuids(IMessaging messaging, IBackendHelper helper, IPathResolver pathResolver, IntermediateSection section)
+        internal CalculateComponentGuids(IMessaging messaging, IBackendHelper helper, IPathResolver pathResolver, IntermediateSection section, Platform platform)
         {
             this.Messaging = messaging;
             this.BackendHelper = helper;
             this.PathResolver = pathResolver;
             this.Section = section;
+            this.Platform = platform;
         }
 
         private IMessaging Messaging { get; }
@@ -32,6 +33,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IntermediateSection Section { get; }
 
+        private Platform Platform { get; }
+
         public void Execute()
         {
             Dictionary<string, RegistrySymbol> registryKeyRows = null;
@@ -42,7 +45,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             // Find components with generatable guids.
             foreach (var componentSymbol in this.Section.Symbols.OfType<ComponentSymbol>())
             {
-                // Skip components that do not specify generate guid.
+                // Skip components that do not specify generate guid. 
                 if (componentSymbol.ComponentId != "*")
                 {
                     continue;
@@ -135,7 +138,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                         if (fileRow.Id.Id == componentSymbol.KeyPath)
                         {
                             // calculate the key file's canonical target path
-                            string directoryPath = this.PathResolver.GetDirectoryPath(targetPathsByDirectoryId, componentIdGenSeeds, componentSymbol.DirectoryRef, true);
+                            string directoryPath = this.PathResolver.GetCanonicalDirectoryPath(targetPathsByDirectoryId, componentIdGenSeeds, componentSymbol.DirectoryRef, this.Platform);
                             string fileName = Common.GetName(fileRow.Name, false, true).ToLowerInvariant();
                             path = Path.Combine(directoryPath, fileName);
 
diff --git a/src/WixToolset.Core.WindowsInstaller/Bind/SequenceActionsCommand.cs b/src/WixToolset.Core.WindowsInstaller/Bind/SequenceActionsCommand.cs
index 7f43da9a..93e25878 100644
--- a/src/WixToolset.Core.WindowsInstaller/Bind/SequenceActionsCommand.cs
+++ b/src/WixToolset.Core.WindowsInstaller/Bind/SequenceActionsCommand.cs
@@ -34,25 +34,25 @@ namespace WixToolset.Core.WindowsInstaller.Bind
         {
             var requiredActionSymbols = new Dictionary<string, WixActionSymbol>();
 
-            // Get the standard actions required based on symbols in the section.
-            var overridableActionSymbols = this.GetRequiredStandardActions();
-
             // Index all the action symbols and look for collisions.
             foreach (var actionSymbol in this.Section.Symbols.OfType<WixActionSymbol>())
             {
                 if (actionSymbol.Overridable) // overridable action
                 {
-                    if (overridableActionSymbols.TryGetValue(actionSymbol.Id.Id, out var collidingActionSymbol))
+                    if (requiredActionSymbols.TryGetValue(actionSymbol.Id.Id, out var collidingActionSymbol))
                     {
-                        this.Messaging.Write(ErrorMessages.OverridableActionCollision(actionSymbol.SourceLineNumbers, actionSymbol.SequenceTable.ToString(), actionSymbol.Action));
-                        if (null != collidingActionSymbol.SourceLineNumbers)
+                        if (collidingActionSymbol.Overridable)
                         {
-                            this.Messaging.Write(ErrorMessages.OverridableActionCollision2(collidingActionSymbol.SourceLineNumbers));
+                            this.Messaging.Write(ErrorMessages.OverridableActionCollision(actionSymbol.SourceLineNumbers, actionSymbol.SequenceTable.ToString(), actionSymbol.Action));
+                            if (null != collidingActionSymbol.SourceLineNumbers)
+                            {
+                                this.Messaging.Write(ErrorMessages.OverridableActionCollision2(collidingActionSymbol.SourceLineNumbers));
+                            }
                         }
                     }
                     else
                     {
-                        overridableActionSymbols.Add(actionSymbol.Id.Id, actionSymbol);
+                        requiredActionSymbols.Add(actionSymbol.Id.Id, actionSymbol);
                     }
                 }
                 else // unsequenced or sequenced action.
@@ -71,7 +71,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                         }
                     }
 
-                    if (requiredActionSymbols.TryGetValue(actionSymbol.Id.Id, out var collidingActionSymbol))
+                    if (requiredActionSymbols.TryGetValue(actionSymbol.Id.Id, out var collidingActionSymbol) && !collidingActionSymbol.Overridable)
                     {
                         this.Messaging.Write(ErrorMessages.ActionCollision(actionSymbol.SourceLineNumbers, actionSymbol.SequenceTable.ToString(), actionSymbol.Action));
                         if (null != collidingActionSymbol.SourceLineNumbers)
@@ -81,13 +81,16 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                     }
                     else
                     {
-                        requiredActionSymbols.Add(actionSymbol.Id.Id, actionSymbol);
+                        requiredActionSymbols[actionSymbol.Id.Id] = actionSymbol;
                     }
                 }
             }
 
+            // Get the standard actions required based on symbols in the section.
+            var requiredStandardActions = this.GetRequiredStandardActions();
+
             // Add the overridable action symbols that are not overridden to the required action symbols.
-            foreach (var actionSymbol in overridableActionSymbols.Values)
+            foreach (var actionSymbol in requiredStandardActions.Values)
             {
                 if (!requiredActionSymbols.ContainsKey(actionSymbol.Id.Id))
                 {
@@ -557,17 +560,6 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             return set;
         }
 
-        private IEnumerable<WixActionSymbol> GetActions(SequenceTable sequence, string[] actionNames)
-        {
-            foreach (var action in WindowsInstallerStandard.StandardActions())
-            {
-                if (action.SequenceTable == sequence && actionNames.Contains(action.Action))
-                {
-                    yield return action;
-                }
-            }
-        }
-
         /// <summary>
         /// Sequence an action before or after a standard action.
         /// </summary>
diff --git a/src/WixToolset.Core/Compiler.cs b/src/WixToolset.Core/Compiler.cs
index c504e96f..c641bceb 100644
--- a/src/WixToolset.Core/Compiler.cs
+++ b/src/WixToolset.Core/Compiler.cs
@@ -4279,8 +4279,7 @@ namespace WixToolset.Core
                     this.Core.AddInlineDirectoryId(inlineSyntax, id.Id);
                 }
             }
-
-            if ("TARGETDIR".Equals(id.Id, StringComparison.Ordinal) && !("SourceDir".Equals(name, StringComparison.Ordinal) && shortName == null && shortSourceName == null && sourceName == null))
+            else if ("TARGETDIR".Equals(id.Id, StringComparison.Ordinal) && !("SourceDir".Equals(name, StringComparison.Ordinal) && shortName == null && shortSourceName == null && sourceName == null))
             {
                 this.Core.Write(ErrorMessages.IllegalTargetDirDefaultDir(sourceLineNumbers, name));
             }
diff --git a/src/WixToolset.Core/ExtensibilityServices/PathResolver.cs b/src/WixToolset.Core/ExtensibilityServices/PathResolver.cs
index 15cd4fc9..72be2bcb 100644
--- a/src/WixToolset.Core/ExtensibilityServices/PathResolver.cs
+++ b/src/WixToolset.Core/ExtensibilityServices/PathResolver.cs
@@ -12,7 +12,7 @@ namespace WixToolset.Core.ExtensibilityServices
 
     internal class PathResolver : IPathResolver
     {
-        public string GetDirectoryPath(Dictionary<string, IResolvedDirectory> directories, Dictionary<string, string> componentIdGenSeeds, string directory, bool canonicalize)
+        public string GetCanonicalDirectoryPath(Dictionary<string, IResolvedDirectory> directories, Dictionary<string, string> componentIdGenSeeds, string directory, Platform platform)
         {
             if (!directories.TryGetValue(directory, out var resolvedDirectory))
             {
@@ -25,19 +25,13 @@ namespace WixToolset.Core.ExtensibilityServices
                 {
                     resolvedDirectory.Path = componentIdGenSeeds[directory];
                 }
-                else if (canonicalize && WindowsInstallerStandard.IsStandardDirectory(directory))
+                else if (WindowsInstallerStandard.IsStandardDirectory(directory))
                 {
-                    // when canonicalization is on, standard directories are treated equally
-                    resolvedDirectory.Path = directory;
+                    resolvedDirectory.Path = WindowsInstallerStandard.GetPlatformSpecificDirectoryId(directory, platform);
                 }
                 else
                 {
-                    string name = resolvedDirectory.Name;
-
-                    if (canonicalize)
-                    {
-                        name = name?.ToLowerInvariant();
-                    }
+                    var name = resolvedDirectory.Name?.ToLowerInvariant();
 
                     if (String.IsNullOrEmpty(resolvedDirectory.DirectoryParent))
                     {
@@ -45,7 +39,7 @@ namespace WixToolset.Core.ExtensibilityServices
                     }
                     else
                     {
-                        var parentPath = this.GetDirectoryPath(directories, componentIdGenSeeds, resolvedDirectory.DirectoryParent, canonicalize);
+                        var parentPath = this.GetCanonicalDirectoryPath(directories, componentIdGenSeeds, resolvedDirectory.DirectoryParent, platform);
 
                         if (null != resolvedDirectory.Name)
                         {
@@ -62,6 +56,39 @@ namespace WixToolset.Core.ExtensibilityServices
             return resolvedDirectory.Path;
         }
 
+        public string GetDirectoryPath(Dictionary<string, IResolvedDirectory> directories, string directory)
+        {
+            if (!directories.TryGetValue(directory, out var resolvedDirectory))
+            {
+                throw new WixException(ErrorMessages.ExpectedDirectory(directory));
+            }
+
+            if (null == resolvedDirectory.Path)
+            {
+                var name = resolvedDirectory.Name;
+
+                if (String.IsNullOrEmpty(resolvedDirectory.DirectoryParent))
+                {
+                    resolvedDirectory.Path = name;
+                }
+                else
+                {
+                    var parentPath = this.GetDirectoryPath(directories, resolvedDirectory.DirectoryParent);
+
+                    if (null != resolvedDirectory.Name)
+                    {
+                        resolvedDirectory.Path = Path.Combine(parentPath, name);
+                    }
+                    else
+                    {
+                        resolvedDirectory.Path = parentPath;
+                    }
+                }
+            }
+
+            return resolvedDirectory.Path;
+        }
+
         public string GetFileSourcePath(Dictionary<string, IResolvedDirectory> directories, string directoryId, string fileName, bool compressed, bool useLongName)
         {
             var fileSourcePath = Common.GetName(fileName, true, useLongName);
@@ -75,7 +102,7 @@ namespace WixToolset.Core.ExtensibilityServices
             {
                 // Get the relative path of where we want the file to be layed out as specified
                 // in the Directory table.
-                var directoryPath = this.GetDirectoryPath(directories, null, directoryId, false);
+                var directoryPath = this.GetDirectoryPath(directories, directoryId);
                 fileSourcePath = Path.Combine(directoryPath, fileSourcePath);
             }
 
diff --git a/src/WixToolset.Core/Link/ResolveReferencesCommand.cs b/src/WixToolset.Core/Link/ResolveReferencesCommand.cs
index d2be0699..90b61e8b 100644
--- a/src/WixToolset.Core/Link/ResolveReferencesCommand.cs
+++ b/src/WixToolset.Core/Link/ResolveReferencesCommand.cs
@@ -72,27 +72,22 @@ namespace WixToolset.Core.Link
                     continue;
                 }
 
-                if (!this.symbolsWithSections.TryGetValue(wixSimpleReferenceRow.SymbolicName, out var symbolWithSection))
-                {
-                    this.Messaging.Write(ErrorMessages.UnresolvedReference(wixSimpleReferenceRow.SourceLineNumbers, wixSimpleReferenceRow.SymbolicName));
-                }
-                else // see if the symbol (and any of its duplicates) are appropriately accessible.
+                // See if the symbol (and any of its duplicates) are appropriately accessible.
+                if (this.symbolsWithSections.TryGetValue(wixSimpleReferenceRow.SymbolicName, out var symbolWithSection))
                 {
                     var accessible = this.DetermineAccessibleSymbols(section, symbolWithSection);
-                    if (!accessible.Any())
-                    {
-                        this.Messaging.Write(ErrorMessages.UnresolvedReference(wixSimpleReferenceRow.SourceLineNumbers, wixSimpleReferenceRow.SymbolicName, symbolWithSection.Access));
-                    }
-                    else if (1 == accessible.Count)
+                    if (accessible.Count == 1)
                     {
                         var accessibleSymbol = accessible[0];
-                        this.referencedSymbols.Add(accessibleSymbol);
-
-                        if (null != accessibleSymbol.Section)
+                        if (this.referencedSymbols.Add(accessibleSymbol) && null != accessibleSymbol.Section)
                         {
                             this.RecursivelyResolveReferences(accessibleSymbol.Section);
                         }
                     }
+                    else if (accessible.Count == 0)
+                    {
+                        this.Messaging.Write(ErrorMessages.UnresolvedReference(wixSimpleReferenceRow.SourceLineNumbers, wixSimpleReferenceRow.SymbolicName, symbolWithSection.Access));
+                    }
                     else // display errors for the duplicate symbols.
                     {
                         var accessibleSymbol = accessible[0];
@@ -113,6 +108,10 @@ namespace WixToolset.Core.Link
                         }
                     }
                 }
+                else
+                {
+                    this.Messaging.Write(ErrorMessages.UnresolvedReference(wixSimpleReferenceRow.SourceLineNumbers, wixSimpleReferenceRow.SymbolicName));
+                }
             }
         }
 
diff --git a/src/WixToolset.Core/Link/SymbolWithSection.cs b/src/WixToolset.Core/Link/SymbolWithSection.cs
new file mode 100644
index 00000000..c8934d0f
--- /dev/null
+++ b/src/WixToolset.Core/Link/SymbolWithSection.cs
@@ -0,0 +1,91 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Core.Link
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Symbol with section representing a single unique symbol.
+    /// </summary>
+    internal class SymbolWithSection
+    {
+        private HashSet<SymbolWithSection> possibleConflicts;
+        private HashSet<SymbolWithSection> redundants;
+
+        /// <summary>
+        /// Creates a symbol for a symbol.
+        /// </summary>
+        /// <param name="symbol">Symbol for the symbol</param>
+        public SymbolWithSection(IntermediateSection section, IntermediateSymbol symbol)
+        {
+            this.Symbol = symbol;
+            this.Section = section;
+            this.Name = String.Concat(this.Symbol.Definition.Name, ":", this.Symbol.Id.Id);
+        }
+
+        /// <summary>
+        /// Gets the accessibility of the symbol which is a direct reflection of the accessibility of the row's accessibility.
+        /// </summary>
+        /// <value>Accessbility of the symbol.</value>
+        public AccessModifier Access => this.Symbol.Id.Access;
+
+        /// <summary>
+        /// Gets the name of the symbol.
+        /// </summary>
+        /// <value>Name of the symbol.</value>
+        public string Name { get; }
+
+        /// <summary>
+        /// Gets the symbol for this symbol.
+        /// </summary>
+        /// <value>Symbol for this symbol.</value>
+        public IntermediateSymbol Symbol { get; }
+
+        /// <summary>
+        /// Gets the section for the symbol.
+        /// </summary>
+        /// <value>Section for the symbol.</value>
+        public IntermediateSection Section { get; }
+
+        /// <summary>
+        /// Gets any duplicates of this symbol with sections that are possible conflicts.
+        /// </summary>
+        public IEnumerable<SymbolWithSection> PossiblyConflicts => this.possibleConflicts ?? Enumerable.Empty<SymbolWithSection>();
+
+        /// <summary>
+        /// Gets any duplicates of this symbol with sections that are redundant.
+        /// </summary>
+        public IEnumerable<SymbolWithSection> Redundants => this.redundants ?? Enumerable.Empty<SymbolWithSection>();
+
+        /// <summary>
+        /// Adds a duplicate symbol with sections that is a possible conflict.
+        /// </summary>
+        /// <param name="symbolWithSection">Symbol with section that is a possible conflict of this symbol.</param>
+        public void AddPossibleConflict(SymbolWithSection symbolWithSection)
+        {
+            if (null == this.possibleConflicts)
+            {
+                this.possibleConflicts = new HashSet<SymbolWithSection>();
+            }
+
+            this.possibleConflicts.Add(symbolWithSection);
+        }
+
+        /// <summary>
+        /// Adds a duplicate symbol that is redundant.
+        /// </summary>
+        /// <param name="symbolWithSection">Symbol with section that is redundant of this symbol.</param>
+        public void AddRedundant(SymbolWithSection symbolWithSection)
+        {
+            if (null == this.redundants)
+            {
+                this.redundants = new HashSet<SymbolWithSection>();
+            }
+
+            this.redundants.Add(symbolWithSection);
+        }
+    }
+}
diff --git a/src/WixToolset.Core/Linker.cs b/src/WixToolset.Core/Linker.cs
index cdefa5c7..1cfd085d 100644
--- a/src/WixToolset.Core/Linker.cs
+++ b/src/WixToolset.Core/Linker.cs
@@ -149,13 +149,12 @@ namespace WixToolset.Core
                     throw new WixException(ErrorMessages.MissingEntrySection(this.Context.ExpectedOutputType.ToString()));
                 }
 
-                // Add the missing standard action symbols.
-                this.LoadStandardActions(find.EntrySection, find.SymbolsByName);
+                // Add the missing standard action and directory symbols.
+                this.LoadStandardSymbols(find.SymbolsByName);
 
                 // Resolve the symbol references to find the set of sections we care about for linking.
                 // Of course, we start with the entry section (that's how it got its name after all).
                 var resolve = new ResolveReferencesCommand(this.Messaging, find.EntrySection, find.SymbolsByName);
-
                 resolve.Execute();
 
                 if (this.Messaging.EncounteredError)
@@ -732,14 +731,14 @@ namespace WixToolset.Core
 #endif
 
         /// <summary>
-        /// Load the standard action symbols.
+        /// Load the standard action and directory symbols.
         /// </summary>
         /// <param name="symbolsByName">Collection of symbols.</param>
-        private void LoadStandardActions(IntermediateSection section, IDictionary<string, SymbolWithSection> symbolsByName)
+        private void LoadStandardSymbols(IDictionary<string, SymbolWithSection> symbolsByName)
         {
             foreach (var actionSymbol in WindowsInstallerStandard.StandardActions())
             {
-                var symbolWithSection = new SymbolWithSection(section, actionSymbol);
+                var symbolWithSection = new SymbolWithSection(null, actionSymbol);
 
                 // If the action's symbol has not already been defined (i.e. overriden by the user), add it now.
                 if (!symbolsByName.ContainsKey(symbolWithSection.Name))
@@ -747,6 +746,17 @@ namespace WixToolset.Core
                     symbolsByName.Add(symbolWithSection.Name, symbolWithSection);
                 }
             }
+
+            foreach (var directorySymbol in WindowsInstallerStandard.StandardDirectories())
+            {
+                var symbolWithSection = new SymbolWithSection(null, directorySymbol);
+
+                // If the directory's symbol has not already been defined (i.e. overriden by the user), add it now.
+                if (!symbolsByName.ContainsKey(symbolWithSection.Name))
+                {
+                    symbolsByName.Add(symbolWithSection.Name, symbolWithSection);
+                }
+            }
         }
 
         /// <summary>
diff --git a/src/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs b/src/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs
new file mode 100644
index 00000000..83f2f2bb
--- /dev/null
+++ b/src/test/WixToolsetTest.CoreIntegration/DirectoryFixture.cs
@@ -0,0 +1,89 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolsetTest.CoreIntegration
+{
+    using System.IO;
+    using System.Linq;
+    using WixBuildTools.TestSupport;
+    using WixToolset.Core.TestPackage;
+    using WixToolset.Data;
+    using Xunit;
+
+    public class DirectoryFixture
+    {
+        [Fact]
+        public void CanGet32bitProgramFiles6432Folder()
+        {
+            var folder = TestData.Get(@"TestData");
+
+            using (var fs = new DisposableFileSystem())
+            {
+                var baseFolder = fs.GetFolder();
+                var intermediateFolder = Path.Combine(baseFolder, "obj");
+                var msiPath = Path.Combine(baseFolder, @"bin\test.msi");
+
+                var result = WixRunner.Execute(new[]
+                {
+                    "build",
+                    Path.Combine(folder, "Directory", "Empty.wxs"),
+                    Path.Combine(folder, "ProductWithComponentGroupRef", "Product.wxs"),
+                    "-bindpath", Path.Combine(folder, "SingleFile", "data"),
+                    "-intermediateFolder", intermediateFolder,
+                    "-o", msiPath
+                });
+
+                result.AssertSuccess();
+
+                var intermediate = Intermediate.Load(Path.Combine(baseFolder, @"bin\test.wixpdb"));
+                var section = intermediate.Sections.Single();
+
+                var dirSymbols = section.Symbols.OfType<WixToolset.Data.Symbols.DirectorySymbol>().ToList();
+                Assert.Equal(new[]
+                {
+                    "INSTALLFOLDER",
+                    "ProgramFiles6432Folder",
+                    "ProgramFilesFolder",
+                    "TARGETDIR"
+                }, dirSymbols.Select(d => d.Id.Id).ToArray());
+            }
+        }
+
+        [Fact]
+        public void CanGet64bitProgramFiles6432Folder()
+        {
+            var folder = TestData.Get(@"TestData");
+
+            using (var fs = new DisposableFileSystem())
+            {
+                var baseFolder = fs.GetFolder();
+                var intermediateFolder = Path.Combine(baseFolder, "obj");
+                var msiPath = Path.Combine(baseFolder, @"bin\test.msi");
+
+                var result = WixRunner.Execute(new[]
+                {
+                    "build",
+                    "-arch", "x64",
+                    Path.Combine(folder, "Directory", "Empty.wxs"),
+                    Path.Combine(folder, "ProductWithComponentGroupRef", "Product.wxs"),
+                    "-bindpath", Path.Combine(folder, "SingleFile", "data"),
+                    "-intermediateFolder", intermediateFolder,
+                    "-o", msiPath
+                });
+
+                result.AssertSuccess();
+
+                var intermediate = Intermediate.Load(Path.Combine(baseFolder, @"bin\test.wixpdb"));
+                var section = intermediate.Sections.Single();
+
+                var dirSymbols = section.Symbols.OfType<WixToolset.Data.Symbols.DirectorySymbol>().ToList();
+                Assert.Equal(new[]
+                {
+                    "INSTALLFOLDER",
+                    "ProgramFiles6432Folder",
+                    "ProgramFiles64Folder",
+                    "TARGETDIR"
+                }, dirSymbols.Select(d => d.Id.Id).ToArray());
+            }
+        }
+    }
+}
diff --git a/src/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs b/src/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs
index 3ab218d1..4ff7f5f6 100644
--- a/src/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs
+++ b/src/test/WixToolsetTest.CoreIntegration/MsiQueryFixture.cs
@@ -365,14 +365,15 @@ namespace WixToolsetTest.CoreIntegration
 
                 Assert.True(File.Exists(msiPath));
                 var results = Query.QueryDatabase(msiPath, new[] { "Directory" });
-                Assert.Equal(new[]
+                WixAssert.CompareLineByLine(new[]
                 {
                     "Directory:DUPLICATENAMEANDSHORTNAME\tINSTALLFOLDER\tduplicat",
-                    "Directory:INSTALLFOLDER\tProgramFilesFolder\toekcr5lq|MsiPackage",
+                    "Directory:INSTALLFOLDER\tProgramFiles6432Folder\t1egc1laj|MsiPackage",
                     "Directory:NAMEANDSHORTNAME\tINSTALLFOLDER\tSHORTNAM|NameAndShortName",
                     "Directory:NAMEANDSHORTSOURCENAME\tINSTALLFOLDER\tNAMEASSN|NameAndShortSourceName",
                     "Directory:NAMEWITHSHORTVALUE\tINSTALLFOLDER\tSHORTVAL",
-                    "Directory:ProgramFilesFolder\tTARGETDIR\t.",
+                    "Directory:ProgramFiles6432Folder\tProgramFilesFolder\t.",
+                    "Directory:ProgramFilesFolder\tTARGETDIR\tPFiles",
                     "Directory:SHORTNAMEANDLONGSOURCENAME\tINSTALLFOLDER\tSHNALSNM:6ukthv5q|ShortNameAndLongSourceName",
                     "Directory:SHORTNAMEONLY\tINSTALLFOLDER\tSHORTONL",
                     "Directory:SOURCENAME\tINSTALLFOLDER\ts2s5bq-i|NameAndSourceName:dhnqygng|SourceNameWithName",
diff --git a/src/test/WixToolsetTest.CoreIntegration/TestData/CustomAction/SimpleCustomAction.wxs b/src/test/WixToolsetTest.CoreIntegration/TestData/CustomAction/SimpleCustomAction.wxs
new file mode 100644
index 00000000..72d5e4a5
--- /dev/null
+++ b/src/test/WixToolsetTest.CoreIntegration/TestData/CustomAction/SimpleCustomAction.wxs
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+    <Fragment>
+        <ComponentGroup Id="ProductComponents">
+            <ComponentGroupRef Id="MinimalComponentGroup" />
+        </ComponentGroup>
+
+        <Binary Id="Binary1" SourceFile="test.txt" />
+        <CustomAction Id="Action1" BinaryKey="Binary1" DllEntry="EntryPoint1" />
+
+        <InstallExecuteSequence>
+            <Custom Action="Action1" After="InstallFiles" />
+        </InstallExecuteSequence>
+    </Fragment>
+</Wix>
diff --git a/src/test/WixToolsetTest.CoreIntegration/TestData/CustomTable/CustomTable-Expected.wxs b/src/test/WixToolsetTest.CoreIntegration/TestData/CustomTable/CustomTable-Expected.wxs
index 68386612..c55f4ed0 100644
--- a/src/test/WixToolsetTest.CoreIntegration/TestData/CustomTable/CustomTable-Expected.wxs
+++ b/src/test/WixToolsetTest.CoreIntegration/TestData/CustomTable/CustomTable-Expected.wxs
@@ -15,11 +15,13 @@
       </Row>
     </CustomTable>
     <Directory Id="TARGETDIR" Name="SourceDir">
-      <Directory Id="ProgramFilesFolder">
-        <Directory Id="INSTALLFOLDER" Name="MsiPackage" ShortName="oekcr5lq">
-          <Component Id="filcV1yrx0x8wJWj4qMzcH21jwkPko" Guid="{E597A58A-03CB-50D8-93E3-DABA263F233A}" Win64="no">
-            <File Id="filcV1yrx0x8wJWj4qMzcH21jwkPko" Name="test.txt" KeyPath="yes" Source="SourceDir\\MsiPackage\test.txt" />
-          </Component>
+      <Directory Id="ProgramFilesFolder" Name="PFiles">
+        <Directory Id="ProgramFiles6432Folder">
+          <Directory Id="INSTALLFOLDER" Name="MsiPackage" ShortName="1egc1laj">
+            <Component Id="filcV1yrx0x8wJWj4qMzcH21jwkPko" Guid="{E597A58A-03CB-50D8-93E3-DABA263F233A}" Win64="no">
+              <File Id="filcV1yrx0x8wJWj4qMzcH21jwkPko" Name="test.txt" KeyPath="yes" Source="SourceDir\PFiles\\MsiPackage\test.txt" />
+            </Component>
+          </Directory>
         </Directory>
       </Directory>
     </Directory>
diff --git a/src/test/WixToolsetTest.CoreIntegration/TestData/Directory/Empty.wxs b/src/test/WixToolsetTest.CoreIntegration/TestData/Directory/Empty.wxs
new file mode 100644
index 00000000..50cf6850
--- /dev/null
+++ b/src/test/WixToolsetTest.CoreIntegration/TestData/Directory/Empty.wxs
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+    <Fragment>
+        <ComponentGroup Id="ProductComponents" Directory="INSTALLFOLDER" />
+    </Fragment>
+</Wix>
diff --git a/src/test/WixToolsetTest.CoreIntegration/TestData/ProductWithComponentGroupRef/Product.wxs b/src/test/WixToolsetTest.CoreIntegration/TestData/ProductWithComponentGroupRef/Product.wxs
index b2f22b7d..5b26091a 100644
--- a/src/test/WixToolsetTest.CoreIntegration/TestData/ProductWithComponentGroupRef/Product.wxs
+++ b/src/test/WixToolsetTest.CoreIntegration/TestData/ProductWithComponentGroupRef/Product.wxs
@@ -11,10 +11,6 @@
     </Product>
 
     <Fragment>
-        <Directory Id="TARGETDIR" Name="SourceDir">
-            <Directory Id="ProgramFilesFolder">
-                <Directory Id="INSTALLFOLDER" Name="MsiPackage" />
-            </Directory>
-        </Directory>
+        <Directory Id="INSTALLFOLDER" Name="ProgramFiles6432Folder:\MsiPackage" />
     </Fragment>
 </Wix>
diff --git a/src/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj b/src/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj
index 15078b8a..601a66e7 100644
--- a/src/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj
+++ b/src/test/WixToolsetTest.CoreIntegration/WixToolsetTest.CoreIntegration.csproj
@@ -36,6 +36,7 @@
     <Content Include="TestData\Class\IconIndex0.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\Class\OldClassTableDef.msi" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\CopyFile\CopyFile.wxs" CopyToOutputDirectory="PreserveNewest" />
+    <Content Include="TestData\CustomAction\SimpleCustomAction.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\CustomAction\CustomActionCycle.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\CustomAction\UnscheduledCustomAction.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\CustomTable\CustomTable-Expected.wxs" CopyToOutputDirectory="PreserveNewest" />
@@ -48,6 +49,7 @@
     <Content Include="TestData\CustomTable\LocalizedCustomTable.en-us.wxl" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\DefaultDir\DefaultDir.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\DialogsInInstallUISequence\PackageComponents.wxs" CopyToOutputDirectory="PreserveNewest" />
+    <Content Include="TestData\Directory\Empty.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\EnsureTable\EnsureTable.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\Environment\Environment.wxs" CopyToOutputDirectory="PreserveNewest" />
     <Content Include="TestData\ErrorsInUI\data\test.txt" CopyToOutputDirectory="PreserveNewest" />