[X] report diagnostice on ambiguous type

Author: StephaneDelcroix

src/Controls/src/SourceGen/AnalyzerReleases.Unshipped.md

@@ -6,3 +6,4 @@
 Rule ID | Category | Severity | Notes
 --------|----------|----------|-------
 MAUIG1001 | XamlParsing | Error | XamlParsingFailed
+MAUIG1002 | XamlParsing | Error | AmbiguousType

src/Controls/src/SourceGen/CodeBehindGenerator.cs

@@ -369,7 +369,7 @@ static void GenerateXamlCodeBehind(XamlProjectItem? xamlItem, Compilation compil
 		}
 
 		var uid = Crc64.ComputeHashString($"{compilation.AssemblyName}.{itemName}");
-		if (!TryParseXaml(xamlItem, uid, compilation, xmlnsCache, typeCache, context.CancellationToken, out var accessModifier, out var rootType, out var rootClrNamespace, out var generateDefaultCtor, out var addXamlCompilationAttribute, out var hideFromIntellisense, out var XamlResourceIdOnly, out var baseType, out var namedFields))
+		if (!TryParseXaml(xamlItem, uid, compilation, xmlnsCache, typeCache, context.CancellationToken, context.ReportDiagnostic, out var accessModifier, out var rootType, out var rootClrNamespace, out var generateDefaultCtor, out var addXamlCompilationAttribute, out var hideFromIntellisense, out var XamlResourceIdOnly, out var baseType, out var namedFields))
 		{
 			return;
 		}
@@ -472,7 +472,7 @@ static void GenerateXamlCodeBehind(XamlProjectItem? xamlItem, Compilation compil
 		context.AddSource(hintName, SourceText.From(sb.ToString(), Encoding.UTF8));
 	}
 
-	static bool TryParseXaml(XamlProjectItem parseResult, string uid, Compilation compilation, AssemblyCaches xmlnsCache, IDictionary<XmlType, string> typeCache, CancellationToken cancellationToken, out string? accessModifier, out string? rootType, out string? rootClrNamespace, out bool generateDefaultCtor, out bool addXamlCompilationAttribute, out bool hideFromIntellisense, out bool xamlResourceIdOnly, out string? baseType, out IEnumerable<(string, string?, string)>? namedFields)
+	static bool TryParseXaml(XamlProjectItem parseResult, string uid, Compilation compilation, AssemblyCaches xmlnsCache, IDictionary<XmlType, string> typeCache, CancellationToken cancellationToken, Action<Diagnostic> reportDiagnostic, out string? accessModifier, out string? rootType, out string? rootClrNamespace, out bool generateDefaultCtor, out bool addXamlCompilationAttribute, out bool hideFromIntellisense, out bool xamlResourceIdOnly, out string? baseType, out IEnumerable<(string, string?, string)>? namedFields)
 	{
 		accessModifier = null;
 		rootType = null;
@@ -522,9 +522,9 @@ static bool TryParseXaml(XamlProjectItem parseResult, string uid, Compilation co
 			return true;
 		}
 
-		namedFields = GetNamedFields(root, nsmgr, compilation, xmlnsCache, typeCache, cancellationToken);
+		namedFields = GetNamedFields(root, nsmgr, compilation, xmlnsCache, typeCache, cancellationToken, reportDiagnostic);
 		var typeArguments = GetAttributeValue(root, "TypeArguments", XamlParser.X2006Uri, XamlParser.X2009Uri);
-		baseType = GetTypeName(new XmlType(root.NamespaceURI, root.LocalName, typeArguments != null ? TypeArgumentsParser.ParseExpression(typeArguments, nsmgr, null) : null), compilation, xmlnsCache, typeCache);
+		baseType = GetTypeName(new XmlType(root.NamespaceURI, root.LocalName, typeArguments != null ? TypeArgumentsParser.ParseExpression(typeArguments, nsmgr, null) : null), compilation, xmlnsCache, typeCache, reportDiagnostic);
 		if (baseType == null)
 			return false;
 
@@ -554,7 +554,7 @@ static bool GetXamlCompilationProcessingInstruction(XmlDocument xmlDoc)
 		return true;
 	}
 
-	static IEnumerable<(string name, string? type, string accessModifier)> GetNamedFields(XmlNode root, XmlNamespaceManager nsmgr, Compilation compilation, AssemblyCaches xmlnsCache, IDictionary<XmlType, string> typeCache, CancellationToken cancellationToken)
+	static IEnumerable<(string name, string? type, string accessModifier)> GetNamedFields(XmlNode root, XmlNamespaceManager nsmgr, Compilation compilation, AssemblyCaches xmlnsCache, IDictionary<XmlType, string> typeCache, CancellationToken cancellationToken, Action<Diagnostic> reportDiagnostic) 
 	{
 		var xPrefix = nsmgr.LookupPrefix(XamlParser.X2006Uri) ?? nsmgr.LookupPrefix(XamlParser.X2009Uri);
 		if (xPrefix == null)
@@ -586,11 +586,11 @@ static bool GetXamlCompilationProcessingInstruction(XmlDocument xmlDoc)
 				accessModifier = "private";
 			}
 
-			yield return (name ?? "", GetTypeName(xmlType, compilation, xmlnsCache, typeCache), accessModifier);
+			yield return (name ?? "", GetTypeName(xmlType, compilation, xmlnsCache, typeCache, reportDiagnostic), accessModifier);
 		}
 	}
 
-	static string? GetTypeName(XmlType xmlType, Compilation compilation, AssemblyCaches xmlnsCache, IDictionary<XmlType, string> typeCache)
+	static string? GetTypeName(XmlType xmlType, Compilation compilation, AssemblyCaches xmlnsCache, IDictionary<XmlType, string> typeCache, Action<Diagnostic> reportDiagnostic)
 	{
 		if (typeCache.TryGetValue(xmlType, out string returnType))
 		{
@@ -605,12 +605,12 @@ static bool GetXamlCompilationProcessingInstruction(XmlDocument xmlDoc)
 		else
 		{
 			// It's an external, non-built-in namespace URL.
-			returnType = GetTypeNameFromCustomNamespace(xmlType, compilation, xmlnsCache);
+			returnType = GetTypeNameFromCustomNamespace(xmlType, compilation, xmlnsCache, reportDiagnostic);
 		}
 
 		if (xmlType.TypeArguments != null)
 		{
-			returnType = $"{returnType}<{string.Join(", ", xmlType.TypeArguments.Select(typeArg => GetTypeName(typeArg, compilation, xmlnsCache, typeCache)))}>";
+			returnType = $"{returnType}<{string.Join(", ", xmlType.TypeArguments.Select(typeArg => GetTypeName(typeArg, compilation, xmlnsCache, typeCache, reportDiagnostic)))}>";
 		}
 
 		if (returnType == null)
@@ -640,10 +640,10 @@ static bool GetXamlCompilationProcessingInstruction(XmlDocument xmlDoc)
 		return XmlnsHelper.ParseNamespaceFromXmlns(namespaceuri);
 	}
 
-	static string GetTypeNameFromCustomNamespace(XmlType xmlType, Compilation compilation, AssemblyCaches xmlnsCache)
+	static string GetTypeNameFromCustomNamespace(XmlType xmlType, Compilation compilation, AssemblyCaches xmlnsCache, Action<Diagnostic> reportDiagnostic)
 	{
 #nullable disable
-		string typeName = xmlType.GetTypeReference<string>(xmlnsCache.XmlnsDefinitions, null,
+		IEnumerable<string> typeNames = xmlType.GetTypeReferences<string>(xmlnsCache.XmlnsDefinitions, null,
 			(typeInfo) =>
 			{
 				string typeName = typeInfo.typeName.Replace('+', '/'); //Nested types
@@ -679,7 +679,13 @@ static string GetTypeNameFromCustomNamespace(XmlType xmlType, Compilation compil
 				return null;
 			});
 
-		return typeName;
+		if (typeNames.Distinct().Skip(1).Any())
+		{
+			reportDiagnostic(Diagnostic.Create(Descriptors.AmbiguousType, Location.None,
+				new[] { xmlType.Name, xmlType.NamespaceUri }.ToArray()));
+
+		}
+		return typeNames.FirstOrDefault();
 #nullable enable
 	}
 
@@ -893,9 +899,6 @@ public bool Equals(Compilation x, Compilation y)
 			return x.ExternalReferences.OfType<PortableExecutableReference>().SequenceEqual(y.ExternalReferences.OfType<PortableExecutableReference>());
 		}
 
-		public int GetHashCode(Compilation obj)
-		{
-			return obj.References.GetHashCode();
-		}
+		public int GetHashCode(Compilation obj) => obj.References.GetHashCode();
 	}
 }

src/Controls/src/SourceGen/Descriptors.cs

@@ -12,6 +12,14 @@ public static class Descriptors
 			category: "XamlParsing",
 			defaultSeverity: DiagnosticSeverity.Error,
 			isEnabledByDefault: true);
+
+		public static DiagnosticDescriptor AmbiguousType = new DiagnosticDescriptor(
+			id: "MAUIG1002",
+			title: new LocalizableResourceString(nameof(MauiGResources.AmbiguousTypeTitle), MauiGResources.ResourceManager, typeof(MauiGResources)),
+			messageFormat: new LocalizableResourceString(nameof(MauiGResources.AmbiguousTypeMessage), MauiGResources.ResourceManager, typeof(MauiGResources)),
+			category: "XamlParsing",
+			defaultSeverity: DiagnosticSeverity.Error,
+			isEnabledByDefault: true);
 	}
 }
 

src/Controls/src/SourceGen/MauiGResources.Designer.cs

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
+  <!--  
     Microsoft ResX Schema 
     
     Version 2.0
@@ -123,4 +123,12 @@
   <data name="XamlParsingFailed" xml:space="preserve">
     <value>XAML parsing failed</value>
   </data>
-</root>
+  <data name="AmbiguousTypeTitle" xml:space="preserve">
+    <value>Ambiguous Type</value>
+    <comment>/</comment>
+  </data>
+  <data name="AmbiguousTypeMessage" xml:space="preserve">
+    <value>Multiple names found in the current xml namespace. use a more specific prefix.</value>
+    <comment>/</comment>
+  </data>
+</root>

src/Controls/src/SourceGen/MauiGResources.resx

@@ -275,4 +275,46 @@ public void TestCodeBehindGenerator_NotXaml()
 
 		Assert.That(result.Results.Single().GeneratedSources.Where(gs => gs.HintName.EndsWith(".sg.cs", StringComparison.OrdinalIgnoreCase)), Is.Empty);
 	}
+
+		[Test]
+	public void TestCodeBehindGenerator_ConflictingNames()
+	{
+		var code =
+"""
+using Microsoft.Maui.Controls;
+[assembly: XmlnsDefinition("http://schemas.microsoft.com/dotnet/maui/global", "http://schemas.microsoft.com/dotnet/2021/maui")]
+[assembly: XmlnsDefinition("http://schemas.microsoft.com/dotnet/maui/global", "Ns1")]
+[assembly: XmlnsDefinition("http://schemas.microsoft.com/dotnet/maui/global", "Ns2")]
+
+namespace Ns1
+{
+	public class Conflicting : Label { }
+}
+
+namespace Ns2
+{
+	public class Conflicting : Label { }
+}
+""";
+
+		var xaml =
+"""
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage
+	xmlns="http://schemas.microsoft.com/dotnet/maui/global"
+	xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+	x:Class="Test.TestPage">
+		<Conflicting x:Name="conflicting" Text="Hello MAUI!" />
+</ContentPage>
+""";
+
+		var compilation = SourceGeneratorDriver.CreateMauiCompilation();
+		compilation = compilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(code));
+
+		var result = SourceGeneratorDriver.RunGenerator<CodeBehindGenerator>(compilation, new AdditionalXamlFile("Test.xaml", xaml));
+
+		Assert.IsTrue(result.Diagnostics.Any());
+
+		//var generated = result.Results.Single().GeneratedSources.Single().SourceText.ToString();
+	}
 }