Add `Files` file harvesting.

Implements https://github.com/wixtoolset/issues/issues/7857.

Like [naked files](https://github.com/wixtoolset/issues/issues/7696),
`Files` elements can appear where `Component` elements do in WiX v4. The
optimizer enumerates files and directories, generating single-file
components as it goes. MSBuild-like wildcards (including `**`) are
supported. `Excludes` child elements lets you exclude files that would
otherwise be captured by wildcards.

4 files changed, 91 insertions, 1 deletions

diff --git a/src/api/wix/WixToolset.Data/ErrorMessages.cs b/src/api/wix/WixToolset.Data/ErrorMessages.cs
index 79b835cd..d604e94f 100644
--- a/src/api/wix/WixToolset.Data/ErrorMessages.cs
+++ b/src/api/wix/WixToolset.Data/ErrorMessages.cs
@@ -368,6 +368,11 @@ namespace WixToolset.Data
             return Message(sourceLineNumbers, Ids.ExpectedAttribute, "The {0}/@{1} attribute was not found; it is required unless the attribute {2} has a value of '{3}'.", elementName, attributeName, otherAttributeName, otherAttributeValue, otherAttributeValueUnless);
         }
 
+        public static Message ExpectedAttributeInElementOrParent(SourceLineNumber sourceLineNumbers, string elementName, string attributeName)
+        {
+            return Message(sourceLineNumbers, Ids.ExpectedAttributeInElementOrParent, "The {0}/@{1} attribute was not found or empty; it is required unless it is specified in the parent element.", elementName, attributeName);
+        }
+
         public static Message ExpectedAttributeInElementOrParent(SourceLineNumber sourceLineNumbers, string elementName, string attributeName, string parentElementName)
         {
             return Message(sourceLineNumbers, Ids.ExpectedAttributeInElementOrParent, "The {0}/@{1} attribute was not found or empty; it is required, or it can be specified in the parent {2} element.", elementName, attributeName, parentElementName);
diff --git a/src/api/wix/WixToolset.Data/Symbols/HarvestFilesSymbol.cs b/src/api/wix/WixToolset.Data/Symbols/HarvestFilesSymbol.cs
new file mode 100644
index 00000000..a3123fc1
--- /dev/null
+++ b/src/api/wix/WixToolset.Data/Symbols/HarvestFilesSymbol.cs
@@ -0,0 +1,84 @@
+// 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.Data
+{
+    using WixToolset.Data.Symbols;
+
+    public static partial class SymbolDefinitions
+    {
+        public static readonly IntermediateSymbolDefinition HarvestFiles = new IntermediateSymbolDefinition(
+            SymbolDefinitionType.HarvestFiles,
+            new[]
+            {
+                new IntermediateFieldDefinition(nameof(HarvestFilesSymbolFields.DirectoryRef), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestFilesSymbolFields.Inclusions), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestFilesSymbolFields.Exclusions), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestFilesSymbolFields.ComplexReferenceParentType), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestFilesSymbolFields.ParentId), IntermediateFieldType.String),
+                new IntermediateFieldDefinition(nameof(HarvestFilesSymbolFields.SourcePath), IntermediateFieldType.String),
+            },
+            typeof(HarvestFilesSymbol));
+    }
+}
+
+namespace WixToolset.Data.Symbols
+{
+    public enum HarvestFilesSymbolFields
+    {
+        DirectoryRef,
+        Inclusions,
+        Exclusions,
+        ComplexReferenceParentType,
+        ParentId,
+        SourcePath,
+    }
+
+    public class HarvestFilesSymbol : IntermediateSymbol
+    {
+        public HarvestFilesSymbol() : base(SymbolDefinitions.HarvestFiles, null, null)
+        {
+        }
+
+        public HarvestFilesSymbol(SourceLineNumber sourceLineNumber, Identifier id = null) : base(SymbolDefinitions.HarvestFiles, sourceLineNumber, id)
+        {
+        }
+
+        public IntermediateField this[HarvestFilesSymbolFields index] => this.Fields[(int)index];
+
+        public string DirectoryRef
+        {
+            get => (string)this.Fields[(int)HarvestFilesSymbolFields.DirectoryRef];
+            set => this.Set((int)HarvestFilesSymbolFields.DirectoryRef, value);
+        }
+
+        public string Inclusions
+        {
+            get => (string)this.Fields[(int)HarvestFilesSymbolFields.Inclusions];
+            set => this.Set((int)HarvestFilesSymbolFields.Inclusions, value);
+        }
+
+        public string Exclusions
+        {
+            get => (string)this.Fields[(int)HarvestFilesSymbolFields.Exclusions];
+            set => this.Set((int)HarvestFilesSymbolFields.Exclusions, value);
+        }
+
+        public string ComplexReferenceParentType
+        {
+            get => (string)this.Fields[(int)HarvestFilesSymbolFields.ComplexReferenceParentType];
+            set => this.Set((int)HarvestFilesSymbolFields.ComplexReferenceParentType, value);
+        }
+
+        public string ParentId
+        {
+            get => (string)this.Fields[(int)HarvestFilesSymbolFields.ParentId];
+            set => this.Set((int)HarvestFilesSymbolFields.ParentId, value);
+        }
+
+        public string SourcePath
+        {
+            get => (string)this.Fields[(int)HarvestFilesSymbolFields.SourcePath];
+            set => this.Set((int)HarvestFilesSymbolFields.SourcePath, value);
+        }
+    }
+}
diff --git a/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs b/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs
index 3b545a71..67c00431 100644
--- a/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs
+++ b/src/api/wix/WixToolset.Data/Symbols/SymbolDefinitions.cs
@@ -40,6 +40,7 @@ namespace WixToolset.Data
         FeatureComponents,
         File,
         FileSFPCatalog,
+        HarvestFiles,
         Icon,
         ImageFamilies,
         IniFile,
diff --git a/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs b/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs
index 3c20c14b..e7856c7c 100644
--- a/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs
+++ b/src/api/wix/WixToolset.Extensibility/Services/IParseHelper.cs
@@ -11,7 +11,7 @@ namespace WixToolset.Extensibility.Services
     using WixToolset.Extensibility.Data;
 
     /// <summary>
-    /// Interface provided to help compiler extensions parse.
+    /// Interface provided to help compiler and optimizer extensions parse.
     /// </summary>
     public interface IParseHelper
     {