[build] Generate workload-dependencies.json

Context: [`Releases.json` loop][0]
Context: dotnet/macios#21779 (comment)

There is a desire to have the .NET Workloads have a machine readable
description of what dependencies they require in order to run, in
order to facilitate tooling that would check for these dependencies.

Add `tools/workload-dependencies`, a new tool which parses a
"Xamarin Manifest" to generate `workload-dependencies.json`.
The "canonical" location for the "Xamarin Manifest" is within
`external/android-platform-support/Feeds/AndroidManifestFeed_d17.12.xml`;
failing that, <https://aka.ms/AndroidManifestFeed/d17-12> can be used.

Output of the tool is a JSON document specifying ther required JDK
and Android SDK packages which the .NET for Android workload requires:

	{
	  "microsoft.net.sdk.android": {
	    "workload": {
	      "alias": [
	        "android"
	      ],
	      "version": "35.0.100"
	    },
	    "jdk": {
	      "version": "[17.0,18.0)",
	      "recommendedVersion": "17.0.12"
	    },
	    "androidsdk": {
	      "packages": [
	        {
	          "desc": "Android SDK Build-Tools 35",
	          "sdkPackage": {
	            "id": "build-tools;*",
	            "version": "[30.0.2,30.0.3,31.0.0,32.0.0,33.0.0,33.0.1,33.0.2,33.0.3,34.0.0,35.0.0]",
	            "recommendedId": "build-tools;35.0.0",
	            "recommendedVersion": "35.0.0"
	          },
	          "optional": "false"
	        },
	        {
	          "desc": "Android SDK Command-line Tools",
	          "sdkPackage": {
	            "id": "cmdline-tools;*",
	            "version": "[5.0,6.0,7.0,8.0,9.0,10.0,11.0,12.0,13.0]",
	            "recommendedId": "cmdline-tools;13.0",
	            "recommendedVersion": "13.0"
	          },
	          "optional": "false"
	        },
	        {
	          "desc": "Android SDK Platform 28",
	          "sdkPackage": {
	            "id": "platforms;android-*",
	            "version": "[1,1,1,2,2,2,2,3,3,3,3,3,3,5,6]",
	            "recommendedId": "platforms;android-28",
	            "recommendedVersion": "6"
	          },
	          "optional": "false"
	        },
	        {
	          "desc": "Android SDK Platform-Tools",
	          "sdkPackage": {
	            "id": "platform-tools",
	            "version": "[33.0.2,33.0.3,34.0.1,34.0.3,34.0.4,34.0.5,35.0.1,35.0.2]",
	            "recommendedId": "platform-tools",
	            "recommendedVersion": "35.0.2"
	          },
	          "optional": "false"
	        },
	        …
	      ]
	    }
	  }
	}

[0]: https://loop.cloud.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%3D?ct=1728330820992&

build-tools/create-packs/Microsoft.NET.Sdk.Android.proj

@@ -43,9 +43,20 @@ about the various Microsoft.Android workloads.
         Replacements="@NET_PREVIOUS_VERSION@=$(AndroidNetPreviousVersion)">
     </ReplaceFileContents>
 
+    <PropertyGroup>
+      <_AndroidPlatformSupportFeed>$(MSBuildThisFileDirectory)/../../external/android-platform-support/Feeds/AndroidManifestFeed_d17.12.xml</_AndroidPlatformSupportFeed>
+      <_Feed Condition=" Exists($(_AndroidPlatformSupportFeed)) ">$(_AndroidPlatformSupportFeed)</_Feed>
+      <_Feed Condition=" '$(_Feed)' == '' ">https://aka.ms/AndroidManifestFeed/d17-12</_Feed>
+      <_Project>$(MSBuildThisFileDirectory)/../../tools/workload-dependencies/workload-dependencies.csproj</_Project>
+      <WorkloadDependenciesPath Condition="'$(WorkloadDependenciesPath)' == ''">$(OutputPath)workload-manifest\workload-dependencies.json</WorkloadDependenciesPath>
+    </PropertyGroup>
+
+    <Exec Command="dotnet run --project &quot;$(_Project)&quot; -- &quot;--feed=$(_Feed)&quot; --workload-version=$(WorkloadVersion) -o &quot;$(WorkloadDependenciesPath)&quot;" />
+
     <ItemGroup>
       <_PackageFiles Include="$(WorkloadManifestJsonPath)" PackagePath="data" />
       <_PackageFiles Include="$(WorkloadManifestTargetsPath)" PackagePath="data" />
+      <_PackageFiles Include="$(WorkloadDependenciesPath)" PackagePath="data" />
     </ItemGroup>
   </Target>
 

tools/workload-dependencies/Program.cs

@@ -0,0 +1,290 @@
+using System.Net.Http;
+using System.Xml.Linq;
+
+using Mono.Options;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+const string AppName = "release-json";
+
+var RequiredPackages = new HashSet<string> {
+	"platform-tools",
+	"cmdline-tools",
+	"build-tool",
+	"platform",
+};
+
+var help                = false;
+var feed                = (string?) null;
+var output              = (string?) null;
+int verbosity           = 0;
+var workloadVersion     = (string?) null;
+
+var options = new OptionSet {
+	"Generate `release.json` from Feed XML file.",
+	{ "i|feed=",
+	  "The {PATH} to the Feed XML file.",
+	  v => feed = v },
+	{ "o|output=",
+	  "The {PATH} to the output release.json file.",
+	  v => output = v },
+	{ "workload-version=",
+	  "The {VERSION} of the workload to generate.",
+	  v => workloadVersion = v },
+	{ "v|verbose:",
+	  "Set internal message verbosity",
+	  (int? v) => verbosity = v.HasValue ? v.Value : verbosity + 1 },
+	{ "h|help",
+	  "Show this help message and exit",
+	  v => help = v != null },
+};
+
+XDocument doc;
+
+try {
+	options.Parse (args);
+
+	if (help) {
+		options.WriteOptionDescriptions (Console.Out);
+		return;
+	}
+
+	if (string.IsNullOrEmpty (feed)) {
+		Console.Error.WriteLine ($"{AppName}: --feed is required.");
+		Console.Error.WriteLine ($"{AppName}: Use --help for more information.");
+		return;
+	}
+	doc     = XDocument.Parse (await GetFeedContents (feed));
+	if (doc.Root == null) {
+		throw new InvalidOperationException ("Missing root element in XML feed.");
+	}
+}
+catch (OptionException e) {
+	Console.Error.WriteLine ($"{AppName}: {e.Message}");
+	if (verbosity > 0) {
+		Console.Error.WriteLine (e.ToString ());
+	}
+	return;
+}
+catch (System.Xml.XmlException e) {
+	Console.Error.WriteLine ($"{AppName}: invalid `--feed=PATH` value.  {e.Message}");
+	if (verbosity > 0) {
+		Console.Error.WriteLine (e.ToString ());
+	}
+	return;
+}
+
+var PackageCreators = new Dictionary<string, Func<XDocument, IEnumerable<JObject>>> {
+	["extra"]       = CreateExtraPackageEntries,
+	["addon"]       = CreateAddonPackageEntries,
+	["licenses"]    = doc => Array.Empty<JObject> (),
+	["jdk"]         = doc => Array.Empty<JObject> (),
+};
+
+var release = new JObject {
+	new JProperty ("microsoft.net.sdk.android", new JObject {
+		CreateWorkloadProperty (doc),
+		CreateJdkProperty (doc),
+		new JProperty ("androidsdk", new JObject {
+			new JProperty ("packages", CreatePackagesArray (doc)),
+		}),
+	}),
+};
+
+using var writer = CreateWriter ();
+release.WriteTo (writer);
+writer.Flush ();
+
+async Task<string> GetFeedContents (string feed)
+{
+	if (File.Exists (feed)) {
+		return File.ReadAllText (feed);
+	}
+	if (Uri.TryCreate (feed, UriKind.Absolute, out var uri)) {
+		return await GetFeedContentsFromUri (uri);
+	}
+	throw new NotSupportedException ($"Don't know what to do with --feed={feed}");
+}
+
+async Task<string> GetFeedContentsFromUri (Uri feed)
+{
+	using var client = new HttpClient ();
+	var response = await client.GetAsync (feed);
+	return await response.Content.ReadAsStringAsync ();
+}
+
+JsonWriter CreateWriter ()
+{
+	var w = string.IsNullOrEmpty (output)
+		? new JsonTextWriter (Console.Out) { CloseOutput = false}
+		: new JsonTextWriter (File.CreateText (output)) { CloseOutput = true };
+	w.Formatting = Formatting.Indented;
+	return w;
+}
+
+JProperty CreateWorkloadProperty (XDocument doc)
+{
+	var contents = new JObject (
+		new JProperty ("alias", new JArray ("android")));
+	if (!string.IsNullOrEmpty (workloadVersion))
+		contents.Add (new JProperty ("version", workloadVersion));
+	return new JProperty ("workload", contents);
+}
+
+JProperty CreateJdkProperty (XDocument doc)
+{
+	var latestRevision  = GetLatestRevision (doc, "jdk");
+	var contents        = new JObject (
+		new JProperty ("version", "[17.0,18.0)"));
+	if (!string.IsNullOrEmpty (latestRevision))
+		contents.Add (new JProperty ("recommendedVersion", latestRevision));
+	return new JProperty ("jdk", contents);
+}
+
+IEnumerable<XElement> GetSupportedElements (XDocument doc, string element)
+{
+	if (doc.Root == null) {
+		return Array.Empty<XElement> ();
+	}
+	return doc.Root.Elements (element)
+		.Where (e =>
+			string.Equals ("False", e.ReqAttr ("obsolete"), StringComparison.OrdinalIgnoreCase) &&
+			string.Equals ("False", e.ReqAttr ("preview"), StringComparison.OrdinalIgnoreCase));
+}
+
+IEnumerable<(XElement Element, string Revision)> GetByRevisions (XDocument doc, string element)
+{
+	return GetSupportedElements (doc, element)
+		.OrderByRevision ();
+}
+
+string? GetLatestRevision (XDocument doc, string element)
+{
+	return GetByRevisions (doc, element)
+		.LastOrDefault ()
+		.Revision;
+}
+
+IEnumerable<JObject> CreateExtraPackageEntries (XDocument doc)
+{
+	var allExtras   = GetByRevisions (doc, "extra").ToList ();
+	var paths       = allExtras
+		.Select (e => e.Element.ReqAttr ("path"))
+		.Distinct ();
+	foreach (var path in paths) {
+		var extras  = allExtras
+			.Where (e => e.Element.ReqAttr ("path") == path);
+		var version = string.Join (",", extras.Select (e => e.Revision));
+		var latest  = extras.Last ();
+		var entry   = new JObject {
+			new JProperty ("desc",                        latest.Element.ReqAttr ("description")),
+			new JProperty ("sdkPackage", new JObject {
+				new JProperty ("id",                  path),
+				new JProperty ("version",             "[" + version + "]"),
+				new JProperty ("recommendedId",       latest.Element.ReqAttr ("path")),
+				new JProperty ("recommendedVersion",  latest.Revision),
+			}),
+			new JProperty ("optional",                    "true"),
+		};
+		yield return entry;
+	}
+}
+
+IEnumerable<JObject> CreateAddonPackageEntries (XDocument doc)
+{
+	var allAddons   = GetSupportedElements (doc, "addon").ToList ()
+		.OrderBy (e => e.ReqAttr ("path"));
+	var paths       = allAddons
+		.Select (e => GetEntryId (e))
+		.Distinct ();
+	foreach (var path in paths) {
+		var addons  = allAddons
+			.Where (e => GetEntryId (e) == path);
+		var version = string.Join (",", addons.Select (e => e.ReqAttr ("revision")));
+		var latest  = addons.Last ();
+		var entry   = new JObject {
+			new JProperty ("desc",                        latest.ReqAttr ("description")),
+			new JProperty ("sdkPackage", new JObject {
+				new JProperty ("id",                  path),
+				new JProperty ("version",             "[" + version + "]"),
+				new JProperty ("recommendedId",       latest.ReqAttr ("path")),
+				new JProperty ("recommendedVersion",  latest.ReqAttr ("revision")),
+			}),
+			new JProperty ("optional",                    "true"),
+		};
+		yield return entry;
+	}
+}
+
+JArray CreatePackagesArray (XDocument doc)
+{
+	var packages    = new JArray ();
+	var names       = doc.Root!.Elements ()
+		.Select (e => e.Name.LocalName)
+		.Distinct ()
+		.OrderBy (e => e);
+	foreach (var name in names) {
+		if (PackageCreators.TryGetValue (name, out var creator)) {
+			foreach (var e in creator (doc)) {
+				packages.Add (e);
+			}
+			continue;
+		}
+		var items       = GetSupportedElements (doc, name)
+			.OrderBy (e => e.ReqAttr ("path"));
+		if (!items.Any ()) {
+			continue;
+		}
+		var version     = string.Join (",", items.Select (e => e.ReqAttr ("revision")));
+		var latest      = items.Last ();
+
+		var entry   = new JObject {
+			new JProperty ("desc",                            latest.ReqAttr ("description")),
+			new JProperty ("sdkPackage", new JObject {
+				new JProperty ("id",                          GetEntryId (latest)),
+				new JProperty ("version",                     "[" + version + "]"),
+				new JProperty ("recommendedId",               latest.ReqAttr ("path")),
+				new JProperty ("recommendedVersion",          latest.ReqAttr ("revision")),
+			}),
+			new JProperty ("optional", (!RequiredPackages.Contains (name)).ToString ().ToLowerInvariant ()),
+		};
+
+		packages.Add (entry);
+	}
+	return packages;
+}
+
+string GetEntryId (XElement entry)
+{
+	var path    = entry.ReqAttr ("path");
+	var semic   = path.LastIndexOf (';');
+	if (semic < 0) {
+		return path;
+	}
+	var hyphen  = path.LastIndexOf ('-');
+	if (hyphen < 0) {
+		return path.Substring (0, semic+1) + "*";
+	}
+	return path.Substring (0, Math.Max (hyphen, semic)+1) + "*";
+}
+
+static class Extensions
+{
+	public static string ReqAttr (this XElement e, string attribute)
+	{
+		var v = (string?) e.Attribute (attribute);
+		if (v == null) {
+			throw new InvalidOperationException ($"Missing required attribute `{attribute}` in: `{e}");
+		}
+		return v;
+	}
+
+	public static IEnumerable<(XElement Element, string Revision)> OrderByRevision (this IEnumerable<XElement> elements)
+	{
+		return from e in elements
+			let     revision    = e.ReqAttr ("revision")
+			let     version     = new Version (revision.Contains (".") ? revision : revision + ".0")
+			orderby version
+			select (e, revision);
+	}
+}

tools/workload-dependencies/workload-dependencies.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <RootNamespace>release_json</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Mono.Options" Version="$(MonoOptionsVersion)" />
+    <PackageReference Include="Newtonsoft.Json" Version="$(NewtonsoftJsonPackageVersion)" />
+  </ItemGroup>
+</Project>