Fix wixlib, msm, msi incremental build

Simplify and improves the tracking of input and intermediate files
to fix incremental build issues for wixlibs, merge modules and MSI
databases.

18 files changed, 311 insertions, 62 deletions

diff --git a/src/api/wix/WixToolset.Extensibility/BaseLibrarianExtension.cs b/src/api/wix/WixToolset.Extensibility/BaseLibrarianExtension.cs
index cbc9e4ba..ff5edae3 100644
--- a/src/api/wix/WixToolset.Extensibility/BaseLibrarianExtension.cs
+++ b/src/api/wix/WixToolset.Extensibility/BaseLibrarianExtension.cs
@@ -48,8 +48,8 @@ namespace WixToolset.Extensibility
         /// <summary>
         /// Called at the end of combining.
         /// </summary>
-        /// <param name="library">Combined library intermediate.</param>
-        public virtual void PostCombine(Intermediate library)
+        /// <param name="result">Combined library result.</param>
+        public virtual void PostCombine(ILibraryResult result)
         {
         }
 
diff --git a/src/api/wix/WixToolset.Extensibility/Data/ILibraryResult.cs b/src/api/wix/WixToolset.Extensibility/Data/ILibraryResult.cs
new file mode 100644
index 00000000..6974e265
--- /dev/null
+++ b/src/api/wix/WixToolset.Extensibility/Data/ILibraryResult.cs
@@ -0,0 +1,25 @@
+// 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.Extensibility.Data
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Threading;
+    using WixToolset.Data;
+
+    /// <summary>
+    /// Result of a library combine operation.
+    /// </summary>
+    public interface ILibraryResult
+    {
+        /// <summary>
+        /// Collection of files tracked when binding files into the library.
+        /// </summary>
+        IReadOnlyCollection<ITrackedFile> TrackedFiles { get; set; }
+
+        /// <summary>
+        /// Output of librarian.
+        /// </summary>
+        Intermediate Library { get; set; }
+    }
+}
diff --git a/src/api/wix/WixToolset.Extensibility/ILibrarianExtension.cs b/src/api/wix/WixToolset.Extensibility/ILibrarianExtension.cs
index d9b04cd2..d25da5e4 100644
--- a/src/api/wix/WixToolset.Extensibility/ILibrarianExtension.cs
+++ b/src/api/wix/WixToolset.Extensibility/ILibrarianExtension.cs
@@ -5,13 +5,30 @@ namespace WixToolset.Extensibility
     using WixToolset.Data;
     using WixToolset.Extensibility.Data;
 
-#pragma warning disable 1591 // TODO: add documentation
+    /// <summary>
+    /// Interface all librarian extensions implement.
+    /// </summary>
     public interface ILibrarianExtension
     {
+        /// <summary>
+        /// Called at the beginning of combining.
+        /// </summary>
+        /// <param name="context">Librarian context.</param>
         void PreCombine(ILibraryContext context);
 
+        /// <summary>
+        /// Resolves a path to a file path on disk.
+        /// </summary>
+        /// <param name="sourceLineNumber">Source line number for the path to resolve.</param>
+        /// <param name="symbolDefinition">Symbol related to the path to resolve.</param>
+        /// <param name="path">Path to resolve.</param>
+        /// <returns>Optional resolved file result.</returns>
         IResolveFileResult ResolveFile(SourceLineNumber sourceLineNumber, IntermediateSymbolDefinition symbolDefinition, string path);
 
-        void PostCombine(Intermediate library);
+        /// <summary>
+        /// Called at the end of combining.
+        /// </summary>
+        /// <param name="result">Combined library result.</param>
+        void PostCombine(ILibraryResult result);
     }
 }
diff --git a/src/test/wix/TestData/WixprojModuleCsprojWinFormsNetFx/WixprojModuleCsprojWinFormsNetFx.wixproj b/src/test/wix/TestData/WixprojModuleCsprojWinFormsNetFx/WixprojModuleCsprojWinFormsNetFx.wixproj
index 07e42b08..6009460c 100644
--- a/src/test/wix/TestData/WixprojModuleCsprojWinFormsNetFx/WixprojModuleCsprojWinFormsNetFx.wixproj
+++ b/src/test/wix/TestData/WixprojModuleCsprojWinFormsNetFx/WixprojModuleCsprojWinFormsNetFx.wixproj
@@ -1,19 +1,11 @@
 <!-- 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. -->
+
  <Project Sdk='WixToolset.Sdk'> 
-<!--<Project>
-  <Import Sdk="WixToolset.Sdk" Project='D:\src\wix4\build\wix\Debug\netcoreapp3.1\Sdk\Sdk.props' />-->
   <PropertyGroup>
     <OutputType>Module</OutputType>
   </PropertyGroup>
 
-  <!--<PropertyGroup>
-    <WixBinDir>D:\src\wix4\build\wix\Debug\publish\WixToolset.Sdk\tools\net461\x86\</WixBinDir>
-    <WixBinDir64>D:\src\wix4\build\wix\Debug\publish\WixToolset.Sdk\tools\net461\x64\</WixBinDir64>
-  </PropertyGroup>-->
-
   <ItemGroup>
     <ProjectReference Include="..\CsprojWindowsFormsNetFx\CsprojWindowsFormsNetFx.csproj" />
   </ItemGroup>
-
-  <!--<Import Sdk="WixToolset.Sdk" Project='D:\src\wix4\build\wix\Debug\netcoreapp3.1\Sdk\Sdk.targets' />-->
 </Project>
diff --git a/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.ja-jp.wxl b/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.ja-jp.wxl
index 52e1871e..0f902c8d 100644
--- a/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.ja-jp.wxl
+++ b/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.ja-jp.wxl
@@ -5,7 +5,7 @@ This file contains the declaration of all the localizable strings.
 -->
 <WixLocalization xmlns="http://wixtoolset.org/schemas/v4/wxl" Culture="ja-JP">
 
-  <String Id="PackageName">WixprojPackageVcxprojWindowsApp, eh?</String>
+  <String Id="PackageName">WixprojPackageVcxprojWindowsApp-jp</String>
   <String Id="FeatureTitle">The First Feature in my Prooooduct, eh?</String>
 
 </WixLocalization>
diff --git a/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.wxs b/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.wxs
index fe849608..508d4721 100644
--- a/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.wxs
+++ b/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/Package.wxs
@@ -1,5 +1,7 @@
-<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs">
+<Wix xmlns="http://wixtoolset.org/schemas/v4/wxs"
+     xmlns:ui="http://wixtoolset.org/schemas/v4/wxs/ui">
   <Package Name='!(loc.PackageName)' Manufacturer='WiX Toolset' Version='0.0.1' UpgradeCode='41a2c17e-1976-465b-bcde-eae03516ca68'>
+    <SoftwareTag Regid='wixtoolset.org' InstallDirectory='ApplicationFolder' />
 
     <StandardDirectory Id='ProgramFiles6432Folder'>
       <Directory Id='ApplicationFolder' Name='Test App'>
@@ -16,5 +18,7 @@
 
       <MergeRef Id='WinFormsModule' />
     </Feature>
+
+    <ui:WixUI Id="WixUI_Minimal" />
   </Package>
 </Wix>
diff --git a/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/WixprojPackageVcxprojWindowsApp.wixproj b/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/WixprojPackageVcxprojWindowsApp.wixproj
index 7dc26a2d..bbd39870 100644
--- a/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/WixprojPackageVcxprojWindowsApp.wixproj
+++ b/src/test/wix/TestData/WixprojPackageVcxprojWindowsApp/WixprojPackageVcxprojWindowsApp.wixproj
@@ -5,5 +5,7 @@
     <ProjectReference Include="..\VcxprojWindowsApp\VcxprojWindowsApp.vcxproj" />
     <ProjectReference Include="..\WixprojLibraryVcxprojDll\WixprojLibraryVcxprojDll.wixproj" />
     <ProjectReference Include="..\WixprojModuleCsprojWinFormsNetFx\WixprojModuleCsprojWinFormsNetFx.wixproj" />
+
+    <PackageReference Include="Wixtoolset.UI.wixext" Version="4.0.0-preview.1-build.205" />
   </ItemGroup>
 </Project>
diff --git a/src/test/wix/WixE2E/WixE2EFixture.cs b/src/test/wix/WixE2E/WixE2EFixture.cs
index 89762f72..b1c6b2de 100644
--- a/src/test/wix/WixE2E/WixE2EFixture.cs
+++ b/src/test/wix/WixE2E/WixE2EFixture.cs
@@ -2,7 +2,12 @@
 
 namespace WixE2E
 {
+    using System;
     using System.IO;
+    using System.Linq;
+    using System.Security.Cryptography;
+    using System.Text;
+    using System.Threading;
     using WixBuildTools.TestSupport;
     using Xunit;
 
@@ -52,6 +57,93 @@ namespace WixE2E
             result.AssertSuccess();
         }
 
+        [Fact]
+        public void CanIncrementalBuildPackageWithNativeWindowsAppWithNoEdits()
+        {
+            var projectDirectory = TestData.Get("TestData", "WixprojPackageVcxprojWindowsApp");
+            var projectPath = Path.Combine(projectDirectory, "WixprojPackageVcxprojWindowsApp.wixproj");
+            var projectBinPath = Path.Combine(projectDirectory, "bin");
+
+            CleanEverything();
+
+            var result = RestoreAndBuild(projectPath);
+            result.AssertSuccess();
+
+            var firstBuiltFiles = Directory.GetFiles(projectBinPath, "*.*", SearchOption.AllDirectories).ToArray();
+            var firstHashes = firstBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')} with hash: {GetFileHash(s)}").ToArray();
+
+            // This should be an incremental build and not do any work.
+            //
+            result = RestoreAndBuild(projectPath);
+            result.AssertSuccess();
+
+            var secondBuiltFiles = Directory.GetFiles(projectBinPath, "*.*", SearchOption.AllDirectories).ToArray();
+            var secondHashes = secondBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')} with hash: {GetFileHash(s)}").ToArray();
+
+            WixAssert.CompareLineByLine(firstHashes, secondHashes);
+        }
+
+        [Fact]
+        public void CanIncrementalBuildPackageWithNativeWindowsAppWithEdits()
+        {
+            var projectDirectory = TestData.Get("TestData", "WixprojPackageVcxprojWindowsApp");
+            var projectPath = Path.Combine(projectDirectory, "WixprojPackageVcxprojWindowsApp.wixproj");
+            var projectBinPath = Path.Combine(projectDirectory, "bin");
+
+            CleanEverything();
+
+            var result = RestoreAndBuild(projectPath);
+            result.AssertSuccess();
+
+            var firstBuiltFiles = Directory.GetFiles(projectBinPath, "*.*", SearchOption.AllDirectories).ToArray();
+            var firstRelativePaths = firstBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')}").ToArray();
+            var firstHashes = firstBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')} with hash: {GetFileHash(s)}").ToArray();
+
+            var packageWxsPath = Path.Combine(projectDirectory, "Package.wxs");
+            File.SetLastWriteTime(packageWxsPath, DateTime.Now);
+
+            // This should be an incremental build that does work because a file was updated.
+            //
+            result = RestoreAndBuild(projectPath);
+            result.AssertSuccess();
+
+            var secondBuiltFiles = Directory.GetFiles(projectBinPath, "*.*", SearchOption.AllDirectories).ToArray();
+            var secondRelativePaths = secondBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')}").ToArray();
+            var secondHashes = secondBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')} with hash: {GetFileHash(s)}").ToArray();
+
+            WixAssert.CompareLineByLine(firstRelativePaths, secondRelativePaths);
+            Assert.NotEqual(firstHashes, secondHashes);
+        }
+
+        [Fact(Skip = "Investigate if .NET Core WebApplications can be incrementally built")]
+        public void CanIncrementalBuildPackageWithNetCoreWebAppWithoutEdits()
+        {
+            var projectDirectory = TestData.Get("TestData", "WixprojPackageCsprojWebApplicationNetCore");
+            var projectPath = Path.Combine(projectDirectory, "WixprojPackageCsprojWebApplicationNetCore.wixproj");
+            var projectBinPath = Path.Combine(projectDirectory, "bin");
+
+            CleanEverything();
+
+            var result = RestoreAndBuild(projectPath);
+            result.AssertSuccess();
+
+            var firstBuiltFiles = Directory.GetFiles(projectBinPath, "*.*", SearchOption.AllDirectories).ToArray();
+            var firstHashes = firstBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')} with hash: {GetFileHash(s)}").ToArray();
+
+            //var packageWxsPath = Path.Combine(projectDirectory, "Package.wxs");
+            //File.SetLastWriteTime(packageWxsPath, DateTime.Now);
+
+            // This should be an incremental build that does work because a file was updated.
+            //
+            result = RestoreAndBuild(projectPath);
+            result.AssertSuccess();
+
+            var secondBuiltFiles = Directory.GetFiles(projectBinPath, "*.*", SearchOption.AllDirectories).ToArray();
+            var secondHashes = secondBuiltFiles.Select(s => $"{s.Substring(projectBinPath.Length).TrimStart('\\')} with hash: {GetFileHash(s)}").ToArray();
+
+            WixAssert.CompareLineByLine(firstHashes, secondHashes);
+        }
+
         private static void CleanEverything()
         {
             var rootFolder = TestData.Get("TestData");
@@ -71,6 +163,23 @@ namespace WixE2E
             }
         }
 
+        private static string GetFileHash(string path)
+        {
+            using (var sha2 = SHA256.Create())
+            {
+                var bytes = File.ReadAllBytes(path);
+                var hashBytes = sha2.ComputeHash(bytes);
+
+                var sb = new StringBuilder();
+                foreach (var hash in hashBytes)
+                {
+                    sb.AppendFormat("{0:X}", hash);
+                }
+
+                return sb.ToString();
+            }
+        }
+
         private static MsbuildRunnerResult RestoreAndBuild(string projectPath, bool x64 = true)
         {
             return MsbuildRunner.Execute(projectPath, new[] { "-Restore", "-v:m", "-bl" }, x64);
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
index ab471702..c3dbcfce 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/BindDatabaseCommand.cs
@@ -244,6 +244,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                     command.Execute();
 
                     fileFacades.AddRange(command.MergeModulesFileFacades);
+                    trackedFiles.AddRange(command.TrackedFiles);
                 }
             }
 
@@ -260,8 +261,10 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
                 if (softwareTags.Any())
                 {
-                    var command = new ProcessPackageSoftwareTagsCommand(section, softwareTags, this.IntermediateFolder);
+                    var command = new ProcessPackageSoftwareTagsCommand(section, this.WindowsInstallerBackendHelper, softwareTags, this.IntermediateFolder);
                     command.Execute();
+
+                    trackedFiles.AddRange(command.TrackedFiles);
                 }
             }
 
@@ -483,8 +486,10 @@ namespace WixToolset.Core.WindowsInstaller.Bind
             {
                 this.Messaging.Write(VerboseMessages.MergingModules());
 
-                var command = new MergeModulesCommand(this.Messaging, fileFacades, section, suppressedTableNames, this.OutputPath, this.IntermediateFolder);
+                var command = new MergeModulesCommand(this.Messaging, this.WindowsInstallerBackendHelper, fileFacades, section, suppressedTableNames, this.OutputPath, this.IntermediateFolder);
                 command.Execute();
+
+                trackedFiles.AddRange(command.TrackedFiles);
             }
 
             if (this.Messaging.EncounteredError)
@@ -508,8 +513,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 trackedFiles.AddRange(command.TrackedFiles);
             }
 
-            // TODO: this is not sufficient to collect all Input files (for example, it misses Binary and Icon tables).
-            trackedFiles.AddRange(fileFacades.Select(f => this.WindowsInstallerBackendHelper.TrackFile(f.SourcePath, TrackedFileType.Input, f.SourceLineNumber)));
+            var trackedInputFiles = this.TrackInputFiles(data, trackedFiles);
+            trackedFiles.AddRange(trackedInputFiles);
 
             var result = this.ServiceProvider.GetService<IBindResult>();
             result.FileTransfers = fileTransfers;
@@ -613,5 +618,26 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
             return layout;
         }
+
+        private IEnumerable<ITrackedFile> TrackInputFiles(WindowsInstallerData data, List<ITrackedFile> trackedFiles)
+        {
+            var trackedInputFiles = new List<ITrackedFile>();
+            var intermediateAndTemporaryPaths = new HashSet<string>(trackedFiles.Where(t => t.Type == TrackedFileType.Intermediate || t.Type == TrackedFileType.Temporary).Select(t => t.Path), StringComparer.OrdinalIgnoreCase);
+
+            foreach (var row in data.Tables.SelectMany(t => t.Rows))
+            {
+                foreach (var field in row.Fields.Where(f => f.Column.Type == ColumnType.Object))
+                {
+                    var path = field.AsString();
+
+                    if (!intermediateAndTemporaryPaths.Contains(path))
+                    {
+                        trackedInputFiles.Add(this.WindowsInstallerBackendHelper.TrackFile(path, TrackedFileType.Input, row.SourceLineNumbers));
+                    }
+                }
+            }
+
+            return trackedInputFiles;
+        }
     }
 }
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/ExtractMergeModuleFilesCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/ExtractMergeModuleFilesCommand.cs
index aac4dd4f..06168727 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/ExtractMergeModuleFilesCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/ExtractMergeModuleFilesCommand.cs
@@ -49,9 +49,12 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         public IEnumerable<IFileFacade> MergeModulesFileFacades { get; private set; }
 
+        public IReadOnlyList<ITrackedFile> TrackedFiles { get; private set; }
+
         public void Execute()
         {
             var mergeModulesFileFacades = new List<IFileFacade>();
+            var trackedFiles = new List<ITrackedFile>();
 
             var merge = MsmInterop.GetMsmMerge();
 
@@ -66,21 +69,23 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
             foreach (var wixMergeRow in this.WixMergeSymbols)
             {
-                var containsFiles = this.CreateFacadesForMergeModuleFiles(wixMergeRow, mergeModulesFileFacades, indexedFileFacades);
+                var modulesTrackedFiles = this.CreateFacadesForMergeModuleFiles(wixMergeRow, mergeModulesFileFacades, indexedFileFacades);
 
                 // If the module has files and creating layout
-                if (containsFiles && !this.SuppressLayout)
+                if (modulesTrackedFiles.Count > 0 && !this.SuppressLayout)
                 {
                     this.ExtractFilesFromMergeModule(merge, wixMergeRow);
+                    trackedFiles.AddRange(modulesTrackedFiles);
                 }
             }
 
             this.MergeModulesFileFacades = mergeModulesFileFacades;
+            this.TrackedFiles = trackedFiles;
         }
 
-        private bool CreateFacadesForMergeModuleFiles(WixMergeSymbol wixMergeRow, List<IFileFacade> mergeModulesFileFacades, Dictionary<string, IFileFacade> indexedFileFacades)
+        private IReadOnlyCollection<ITrackedFile> CreateFacadesForMergeModuleFiles(WixMergeSymbol wixMergeRow, List<IFileFacade> mergeModulesFileFacades, Dictionary<string, IFileFacade> indexedFileFacades)
         {
-            var containsFiles = false;
+            var trackedFiles = new List<ITrackedFile>();
 
             try
             {
@@ -125,12 +130,13 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                                 {
                                     mergeModulesFileFacades.Add(mergeModuleFileFacade);
 
-                                    // Keep updating the indexes as new rows are added.
+                                    // Keep updating the indexes as new facades are added.
                                     indexedFileFacades.Add(mergeModuleFileFacade.Id, mergeModuleFileFacade);
                                     uniqueModuleFileIdentifiers.Add(mergeModuleFileFacade.Id, mergeModuleFileFacade);
-                                }
 
-                                containsFiles = true;
+                                    // Track where file will be extracted.
+                                    trackedFiles.Add(this.BackendHelper.TrackFile(mergeModuleFileFacade.SourcePath, TrackedFileType.Intermediate, mergeModuleFileFacade.SourceLineNumber));
+                                }
                             }
                         }
                     }
@@ -164,7 +170,7 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                 throw new WixException(ErrorMessages.CannotOpenMergeModule(wixMergeRow.SourceLineNumbers, wixMergeRow.Id.Id, wixMergeRow.SourceFile));
             }
 
-            return containsFiles;
+            return trackedFiles;
         }
 
         private void ExtractFilesFromMergeModule(IMsmMerge2 merge, WixMergeSymbol wixMergeRow)
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs
index 6446692e..96b7866c 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/MergeModulesCommand.cs
@@ -22,9 +22,10 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     /// </summary>
     internal class MergeModulesCommand
     {
-        public MergeModulesCommand(IMessaging messaging, IEnumerable<IFileFacade> fileFacades, IntermediateSection section, IEnumerable<string> suppressedTableNames, string outputPath, string intermediateFolder)
+        public MergeModulesCommand(IMessaging messaging, IBackendHelper backendHelper, IEnumerable<IFileFacade> fileFacades, IntermediateSection section, IEnumerable<string> suppressedTableNames, string outputPath, string intermediateFolder)
         {
             this.Messaging = messaging;
+            this.BackendHelper = backendHelper;
             this.FileFacades = fileFacades;
             this.Section = section;
             this.SuppressedTableNames = suppressedTableNames ?? Array.Empty<string>();
@@ -34,6 +35,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IMessaging Messaging { get; }
 
+        private IBackendHelper BackendHelper { get; }
+
         private IEnumerable<IFileFacade> FileFacades { get; }
 
         private IntermediateSection Section { get; }
@@ -44,8 +47,12 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private string IntermediateFolder { get; }
 
+        public IReadOnlyList<ITrackedFile> TrackedFiles { get; private set; }
+
         public void Execute()
         {
+            var trackedFiles = new List<ITrackedFile>();
+
             var wixMergeSymbols = this.Section.Symbols.OfType<WixMergeSymbol>().ToList();
             if (!wixMergeSymbols.Any())
             {
@@ -93,6 +100,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                         merge.OpenModule(wixMergeRow.SourceFile, mergeLanguage);
                         moduleOpen = true;
 
+                        trackedFiles.Add(this.BackendHelper.TrackFile(wixMergeRow.SourceFile, TrackedFileType.Input, wixMergeRow.SourceLineNumbers));
+
                         // If there is merge configuration data, create a callback object to contain it all.
                         ConfigurationCallback callback = null;
                         if (!String.IsNullOrEmpty(wixMergeRow.ConfigurationData))
@@ -326,6 +335,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
                 db.Commit();
             }
+
+            this.TrackedFiles = trackedFiles;
         }
     }
 }
diff --git a/src/wix/WixToolset.Core.WindowsInstaller/Bind/ProcessPackageSoftwareTagsCommand.cs b/src/wix/WixToolset.Core.WindowsInstaller/Bind/ProcessPackageSoftwareTagsCommand.cs
index 9a068603..68e11790 100644
--- a/src/wix/WixToolset.Core.WindowsInstaller/Bind/ProcessPackageSoftwareTagsCommand.cs
+++ b/src/wix/WixToolset.Core.WindowsInstaller/Bind/ProcessPackageSoftwareTagsCommand.cs
@@ -9,12 +9,15 @@ namespace WixToolset.Core.WindowsInstaller.Bind
     using System.Xml;
     using WixToolset.Data;
     using WixToolset.Data.Symbols;
+    using WixToolset.Extensibility.Data;
+    using WixToolset.Extensibility.Services;
 
     internal class ProcessPackageSoftwareTagsCommand
     {
-        public ProcessPackageSoftwareTagsCommand(IntermediateSection section, IEnumerable<WixProductTagSymbol> softwareTags, string intermediateFolder)
+        public ProcessPackageSoftwareTagsCommand(IntermediateSection section, IBackendHelper backendHelper, IEnumerable<WixProductTagSymbol> softwareTags, string intermediateFolder)
         {
             this.Section = section;
+            this.BackendHelper = backendHelper;
             this.SoftwareTags = softwareTags;
             this.IntermediateFolder = intermediateFolder;
         }
@@ -23,10 +26,16 @@ namespace WixToolset.Core.WindowsInstaller.Bind
 
         private IntermediateSection Section { get; }
 
+        private IBackendHelper BackendHelper { get; }
+
         private IEnumerable<WixProductTagSymbol> SoftwareTags { get; }
 
+        public IReadOnlyCollection<ITrackedFile> TrackedFiles { get; private set; }
+
         public void Execute()
         {
+            var trackedFiles = new List<ITrackedFile>();
+
             string productName = null;
             string productVersion = null;
             string manufacturer = null;
@@ -70,6 +79,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                     // Write the tag file.
                     fileSymbol.Source = new IntermediateFieldPathValue { Path = Path.Combine(workingFolder, fileSymbol.Name) };
 
+                    trackedFiles.Add(this.BackendHelper.TrackFile(fileSymbol.Source.Path, TrackedFileType.Intermediate, tagRow.SourceLineNumbers));
+
                     using (var fs = new FileStream(fileSymbol.Source.Path, FileMode.Create))
                     {
                         CreateTagFile(fs, uniqueId, productName, productVersion, tagRow.Regid, manufacturer, persistentId);
@@ -86,6 +97,8 @@ namespace WixToolset.Core.WindowsInstaller.Bind
                     });
                 }
             }
+
+            this.TrackedFiles = trackedFiles;
         }
 
         private static string NormalizeGuid(string guidString)
diff --git a/src/wix/WixToolset.Core/Bind/ExtractEmbeddedFilesCommand.cs b/src/wix/WixToolset.Core/Bind/ExtractEmbeddedFilesCommand.cs
index ec2d8896..5d984d53 100644
--- a/src/wix/WixToolset.Core/Bind/ExtractEmbeddedFilesCommand.cs
+++ b/src/wix/WixToolset.Core/Bind/ExtractEmbeddedFilesCommand.cs
@@ -31,6 +31,7 @@ namespace WixToolset.Core.Bind
             foreach (var expectedEmbeddedFileByUri in group)
             {
                 var baseUri = expectedEmbeddedFileByUri.Key;
+                trackedFiles.Add(this.BackendHelper.TrackFile(baseUri.LocalPath, TrackedFileType.Input));
 
                 using (var wixout = WixOutput.Read(baseUri))
                 {
@@ -41,7 +42,7 @@ namespace WixToolset.Core.Bind
                         if (uniqueIds.Add(embeddedFile.EmbeddedFileId))
                         {
                             wixout.ExtractEmbeddedFile(embeddedFile.EmbeddedFileId, embeddedFile.OutputPath);
-                            trackedFiles.Add(this.BackendHelper.TrackFile(embeddedFile.OutputPath, TrackedFileType.Temporary));
+                            trackedFiles.Add(this.BackendHelper.TrackFile(embeddedFile.OutputPath, TrackedFileType.Intermediate));
                         }
                     }
                 }
diff --git a/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs b/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
index d289b557..67d2876d 100644
--- a/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
+++ b/src/wix/WixToolset.Core/CommandLine/BuildCommand.cs
@@ -132,12 +132,7 @@ namespace WixToolset.Core.CommandLine
             {
                 using (new IntermediateFieldContext("wix.lib"))
                 {
-                    var wixlib = this.LibraryPhase(wixobjs, wxls, this.commandLine.BindFiles, this.commandLine.BindPaths, cancellationToken);
-
-                    if (!this.Messaging.EncounteredError)
-                    {
-                        wixlib.Save(this.OutputFile);
-                    }
+                    this.LibraryPhase(wixobjs, wxls, this.commandLine.BindFiles, this.commandLine.BindPaths, cancellationToken);
                 }
             }
             else
@@ -260,7 +255,7 @@ namespace WixToolset.Core.CommandLine
             return intermediates;
         }
 
-        private Intermediate LibraryPhase(IReadOnlyCollection<Intermediate> intermediates, IReadOnlyCollection<Localization> localizations, bool bindFiles, IReadOnlyCollection<IBindPath> bindPaths, CancellationToken cancellationToken)
+        private void LibraryPhase(IReadOnlyCollection<Intermediate> intermediates, IReadOnlyCollection<Localization> localizations, bool bindFiles, IReadOnlyCollection<IBindPath> bindPaths, CancellationToken cancellationToken)
         {
             var context = this.ServiceProvider.GetService<ILibraryContext>();
             context.BindFiles = bindFiles;
@@ -270,18 +265,22 @@ namespace WixToolset.Core.CommandLine
             context.Intermediates = intermediates;
             context.CancellationToken = cancellationToken;
 
-            Intermediate library = null;
             try
             {
                 var librarian = this.ServiceProvider.GetService<ILibrarian>();
-                library = librarian.Combine(context);
+                var result = librarian.Combine(context);
+
+                if (!this.Messaging.EncounteredError)
+                {
+                    result.Library.Save(this.OutputFile);
+
+                    this.LayoutFiles(this.IntermediateFolder, result.TrackedFiles, null, cancellationToken);
+                }
             }
             catch (WixException e)
             {
                 this.Messaging.Write(e.Error);
             }
-
-            return library;
         }
 
         private Intermediate LinkPhase(IEnumerable<Intermediate> intermediates, IEnumerable<string> libraryFiles, ISymbolDefinitionCreator creator, CancellationToken cancellationToken)
@@ -365,19 +364,7 @@ namespace WixToolset.Core.CommandLine
                     return;
                 }
 
-                {
-                    var context = this.ServiceProvider.GetService<ILayoutContext>();
-                    context.Extensions = this.ExtensionManager.GetServices<ILayoutExtension>();
-                    context.TrackedFiles = bindResult.TrackedFiles;
-                    context.FileTransfers = bindResult.FileTransfers;
-                    context.IntermediateFolder = intermediateFolder;
-                    context.TrackingFile = this.TrackingFile;
-                    context.ResetAcls = this.commandLine.ResetAcls;
-                    context.CancellationToken = cancellationToken;
-
-                    var layout = this.ServiceProvider.GetService<ILayoutCreator>();
-                    layout.Layout(context);
-                }
+                this.LayoutFiles(intermediateFolder, bindResult.TrackedFiles, bindResult.FileTransfers, cancellationToken);
             }
             finally
             {
@@ -385,6 +372,21 @@ namespace WixToolset.Core.CommandLine
             }
         }
 
+        private void LayoutFiles(string intermediateFolder, IReadOnlyCollection<ITrackedFile> trackedFiles, IReadOnlyCollection<IFileTransfer> fileTransfers, CancellationToken cancellationToken)
+        {
+            var context = this.ServiceProvider.GetService<ILayoutContext>();
+            context.Extensions = this.ExtensionManager.GetServices<ILayoutExtension>();
+            context.TrackedFiles = trackedFiles;
+            context.FileTransfers = fileTransfers;
+            context.IntermediateFolder = intermediateFolder;
+            context.TrackingFile = this.TrackingFile;
+            context.ResetAcls = this.commandLine.ResetAcls;
+            context.CancellationToken = cancellationToken;
+
+            var layout = this.ServiceProvider.GetService<ILayoutCreator>();
+            layout.Layout(context);
+        }
+
         private IEnumerable<Intermediate> LoadLibraries(IEnumerable<string> libraryFiles, ISymbolDefinitionCreator creator)
         {
             try
diff --git a/src/wix/WixToolset.Core/ILibrarian.cs b/src/wix/WixToolset.Core/ILibrarian.cs
index 0fcedea5..8f57ca67 100644
--- a/src/wix/WixToolset.Core/ILibrarian.cs
+++ b/src/wix/WixToolset.Core/ILibrarian.cs
@@ -5,9 +5,16 @@ namespace WixToolset.Core
     using WixToolset.Data;
     using WixToolset.Extensibility.Data;
 
-#pragma warning disable 1591 // TODO: add documentation
+    /// <summary>
+    /// Create libraries from input intermediates.
+    /// </summary>
     public interface ILibrarian
     {
-        Intermediate Combine(ILibraryContext context);
+        /// <summary>
+        /// Combine intermediates into a single result.
+        /// </summary>
+        /// <param name="context">Library context.</param>
+        /// <returns>Library result.</returns>
+        ILibraryResult Combine(ILibraryContext context);
     }
 }
diff --git a/src/wix/WixToolset.Core/Librarian.cs b/src/wix/WixToolset.Core/Librarian.cs
index 1dd1b44d..2762fb33 100644
--- a/src/wix/WixToolset.Core/Librarian.cs
+++ b/src/wix/WixToolset.Core/Librarian.cs
@@ -21,17 +21,20 @@ namespace WixToolset.Core
             this.ServiceProvider = serviceProvider;
 
             this.Messaging = this.ServiceProvider.GetService<IMessaging>();
+            this.LayoutServices = this.ServiceProvider.GetService<ILayoutServices>();
         }
 
         private IServiceProvider ServiceProvider { get; }
 
         private IMessaging Messaging { get; }
 
+        private ILayoutServices LayoutServices { get; }
+
         /// <summary>
         /// Create a library by combining several intermediates (objects).
         /// </summary>
-        /// <returns>Returns the new library.</returns>
-        public Intermediate Combine(ILibraryContext context)
+        /// <returns>Returns tracked input files and the new library.</returns>
+        public ILibraryResult Combine(ILibraryContext context)
         {
             if (String.IsNullOrEmpty(context.LibraryId))
             {
@@ -43,7 +46,9 @@ namespace WixToolset.Core
                 extension.PreCombine(context);
             }
 
+            ILibraryResult result = this.ServiceProvider.GetService<ILibraryResult>();
             Intermediate library = null;
+            IReadOnlyCollection<ITrackedFile> trackedFiles = null;
             try
             {
                 var sections = context.Intermediates.SelectMany(i => i.Sections).ToList();
@@ -56,7 +61,7 @@ namespace WixToolset.Core
                     return null;
                 }
 
-                this.ResolveFilePathsToEmbed(context, sections);
+                trackedFiles = this.ResolveFilePathsToEmbed(context, sections);
 
                 foreach (var section in sections)
                 {
@@ -71,17 +76,22 @@ namespace WixToolset.Core
             }
             finally
             {
+                result.Library = library;
+                result.TrackedFiles = trackedFiles;
+
                 foreach (var extension in context.Extensions)
                 {
-                    extension.PostCombine(library);
+                    extension.PostCombine(result);
                 }
             }
 
-            return this.Messaging.EncounteredError ? null : library;
+            return result;
         }
 
-        private void ResolveFilePathsToEmbed(ILibraryContext context, IEnumerable<IntermediateSection> sections)
+        private IReadOnlyCollection<ITrackedFile> ResolveFilePathsToEmbed(ILibraryContext context, IEnumerable<IntermediateSection> sections)
         {
+            var trackedFiles = new List<ITrackedFile>();
+
             // Resolve paths to files that are to be embedded in the library.
             if (context.BindFiles)
             {
@@ -105,6 +115,8 @@ namespace WixToolset.Core
                             {
                                 // File was successfully resolved so track the embedded index as the embedded file index.
                                 field.Set(new IntermediateFieldPathValue { Embed = true, Path = file });
+
+                                trackedFiles.Add(this.LayoutServices.TrackFile(file, TrackedFileType.Input, symbol.SourceLineNumbers));
                             }
                             else
                             {
@@ -114,6 +126,8 @@ namespace WixToolset.Core
                     }
                 }
             }
+
+            return trackedFiles;
         }
 
         private void Validate(Intermediate library)
diff --git a/src/wix/WixToolset.Core/LibraryResult.cs b/src/wix/WixToolset.Core/LibraryResult.cs
new file mode 100644
index 00000000..80db2c3a
--- /dev/null
+++ b/src/wix/WixToolset.Core/LibraryResult.cs
@@ -0,0 +1,19 @@
+// 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
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Threading;
+    using WixToolset.Data;
+    using WixToolset.Extensibility;
+    using WixToolset.Extensibility.Data;
+    using WixToolset.Extensibility.Services;
+
+    internal class LibraryResult : ILibraryResult
+    {
+        public IReadOnlyCollection<ITrackedFile> TrackedFiles { get; set; }
+
+        public Intermediate Library { get; set; }
+    }
+}
diff --git a/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs b/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
index 7bbd4075..06dbdfae 100644
--- a/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
+++ b/src/wix/WixToolset.Core/WixToolsetServiceProvider.cs
@@ -35,6 +35,7 @@ namespace WixToolset.Core
             this.AddService<IPreprocessContext>((provider, singletons) => new PreprocessContext(provider));
             this.AddService<ICompileContext>((provider, singletons) => new CompileContext(provider));
             this.AddService<ILibraryContext>((provider, singletons) => new LibraryContext(provider));
+            this.AddService<ILibraryResult>((provider, singletons) => new LibraryResult());
             this.AddService<ILinkContext>((provider, singletons) => new LinkContext(provider));
             this.AddService<IResolveContext>((provider, singletons) => new ResolveContext(provider));
             this.AddService<IBindContext>((provider, singletons) => new BindContext(provider));