Android manifest almost finished (protobuf missing) + native bits

Beginnings of support for reading ELF binaries, needed for typemaps and friends

Author: grendello

tools/apput/src/Android/ARSCHeader.cs

@@ -28,7 +28,7 @@ public ARSCHeader (Stream data, AndroidManifestChunkType? expectedType = null)
 		}
 
 		// Data in AXML is little-endian, which is fortuitous as that's the only format BinaryReader understands.
-		using BinaryReader reader = Utilities.GetReaderAndRewindStream (data);
+		using BinaryReader reader = Utilities.GetReaderAndRewindStream (data, rewindStream: false);
 
 		// ushort: type
 		// ushort: header_size

tools/apput/src/Android/AXMLParser.cs

@@ -108,7 +108,7 @@ public AXMLParser (Stream data)
 	{
 		valid = true;
 
-		XmlDocument ret = new XmlDocument ();
+		var ret = new XmlDocument ();
 		XmlDeclaration declaration = ret.CreateXmlDeclaration ("1.0", stringPool.IsUTF8 ? "UTF-8" : "UTF-16", null);
 		ret.InsertBefore (declaration, ret.DocumentElement);
 

tools/apput/src/Android/AndroidManifest.cs

@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Xml;
 
 namespace ApplicationUtility;
 
@@ -8,6 +9,7 @@ public class AndroidManifest : IAspect
 	public string Description { get; }
 
 	AXMLParser? binaryParser;
+	XmlDocument? xmlDoc;
 
 	AndroidManifest (AXMLParser binaryParser, string? description)
 	{
@@ -35,6 +37,7 @@ public static IAspect LoadAspect (Stream stream, IAspectState state, string? des
 
 	public static IAspectState ProbeAspect (Stream stream, string? description)
 	{
+		Log.Debug ($"Checking if '{description}' is an Android binary XML document.");
 		try {
 			stream.Seek (0, SeekOrigin.Begin);
 
@@ -44,15 +47,48 @@ public static IAspectState ProbeAspect (Stream stream, string? description)
 			// We leave parsing of the data to `LoadAspect`, here we only detect the format
 			return new AndroidManifestAspectState (binaryParser);
 		} catch (Exception ex) {
-			Log.Debug ($"Failed to instantiate AXML binary parser for '{description}'", ex);
+			Log.Debug ($"Failed to instantiate AXML binary parser for '{description}'. Exception thrown:", ex);
 		}
 
-		// TODO: detect plain XML
-		throw new NotImplementedException ();
+		Log.Debug ($"Checking if '{description}' is an plain XML document.");
+		try {
+			return new AndroidManifestAspectState (ParsePlainXML (stream));
+		} catch (Exception ex) {
+			Log.Debug ($"Failed to parse '{description}' as XML document. Exception thrown:", ex);
+		}
+
+		// TODO: AndroidManifest.xml in AAB files is actually a protobuf data dump. Attempt to
+		//       deserialize it here.
+		return new BasicAspectState (success: false);
 	}
 
 	void Read ()
 	{
-		throw new NotImplementedException ();
+		if (binaryParser == null) {
+			throw new NotImplementedException ();
+		}
+
+		xmlDoc = binaryParser.Parse ();
+		if (xmlDoc == null || !binaryParser.IsValid) {
+			Log.Debug ($"AXML parser didn't render a valid document for '{Description}'");
+			return;
+		}
+		Log.Debug ($"'{Description}' loaded and parsed correctly.");
+	}
+
+	static XmlDocument ParsePlainXML (Stream stream)
+	{
+		stream.Seek (0, SeekOrigin.Begin);
+		var settings = new XmlReaderSettings {
+			IgnoreComments = true,
+			IgnoreProcessingInstructions = true,
+			IgnoreWhitespace = true,
+		};
+
+		using var reader = XmlReader.Create (stream, settings);
+		var doc = new XmlDocument ();
+		doc.Load (reader);
+
+		return doc;
 	}
 }

tools/apput/src/Android/AndroidManifestAspectState.cs

@@ -1,12 +1,20 @@
+using System.Xml;
+
 namespace ApplicationUtility;
 
 class AndroidManifestAspectState : IAspectState
 {
 	public bool Success => true;
 	public AXMLParser? BinaryParser { get; }
+	public XmlDocument? Xml { get; }
 
 	public AndroidManifestAspectState (AXMLParser? binaryParser)
 	{
 		BinaryParser = binaryParser;
 	}
+
+	public AndroidManifestAspectState (XmlDocument? xmlDoc)
+	{
+		Xml = xmlDoc;
+	}
 }

tools/apput/src/Common/Utilities.cs

@@ -33,9 +33,12 @@ public static void CloseAndDeleteFile (FileStream stream, bool quiet = true)
 		DeleteFile (path);
 	}
 
-	public static BinaryReader GetReaderAndRewindStream (Stream stream)
+	public static BinaryReader GetReaderAndRewindStream (Stream stream, bool rewindStream = false)
 	{
-		stream.Seek (0, SeekOrigin.Begin);
+		if (rewindStream) {
+			stream.Seek (0, SeekOrigin.Begin);
+		}
+
 		return new BinaryReader (stream, Encoding.UTF8, leaveOpen: true);
 	}
 
@@ -44,4 +47,6 @@ public static BasicAspectState GetFailureAspectState (string message)
 		Log.Debug (message);
 		return new BasicAspectState (false);
 	}
+
+	public static string ToStringOrNull<T> (T? reference) => reference == null ? "<NULL>" : reference.ToString () ?? "[unknown]";
 }