[XSG] Use absolute file paths when generating #line

src/Controls/src/SourceGen/CodeBehindGenerator.cs

@@ -96,12 +96,11 @@ public void Initialize(IncrementalGeneratorInitializationContext initContext)
 		initContext.RegisterSourceOutput(xamlSourceProviderForCB, static (sourceProductionContext, provider) =>
 		{
 			var (xamlItem, xmlnsCache, typeCache, compilation) = provider;
-			var fileName = $"{(string.IsNullOrEmpty(Path.GetDirectoryName(xamlItem!.ProjectItem!.TargetPath)) ? "" : Path.GetDirectoryName(xamlItem.ProjectItem.TargetPath) + Path.DirectorySeparatorChar)}{Path.GetFileNameWithoutExtension(xamlItem.ProjectItem.TargetPath)}.{xamlItem.ProjectItem.Kind.ToLowerInvariant()}.sg.cs".Replace(Path.DirectorySeparatorChar, '_');
 
 			try
 			{
 				var code = CodeBehindCodeWriter.GenerateXamlCodeBehind(xamlItem, compilation, sourceProductionContext.ReportDiagnostic, sourceProductionContext.CancellationToken, xmlnsCache, typeCache);
-				sourceProductionContext.AddSource(fileName, code);
+				sourceProductionContext.AddSource(GetHintName(xamlItem?.ProjectItem, "sg"), code);
 			}
 			catch (Exception e)
 			{
@@ -115,7 +114,10 @@ public void Initialize(IncrementalGeneratorInitializationContext initContext)
 		{
 			var (xamlItem, xmlnsCache, typeCache, compilation) = provider;
 
-			var fileName = $"{(string.IsNullOrEmpty(Path.GetDirectoryName(xamlItem!.ProjectItem!.TargetPath)) ? "" : Path.GetDirectoryName(xamlItem.ProjectItem.TargetPath) + Path.DirectorySeparatorChar)}{Path.GetFileNameWithoutExtension(xamlItem.ProjectItem.TargetPath)}.{xamlItem.ProjectItem.Kind.ToLowerInvariant()}.xsg.cs".Replace(Path.DirectorySeparatorChar, '_');
+			if (xamlItem?.ProjectItem?.RelativePath is not string relativePath)
+			{
+				throw new InvalidOperationException("Xaml item or target path is null");
+			}
 
 			if (!ShouldGenerateSourceGenInitializeComponent(xamlItem, xmlnsCache, compilation))
 				return;
@@ -125,7 +127,7 @@ public void Initialize(IncrementalGeneratorInitializationContext initContext)
 				if (xamlItem != null && xamlItem.Exception != null)
 				{
 					var lineInfo = xamlItem.Exception is XamlParseException xpe ? xpe.XmlInfo : new XmlLineInfo();
-					var location = LocationCreate(fileName, lineInfo, string.Empty);
+					var location = LocationCreate(relativePath, lineInfo, string.Empty);
 					sourceProductionContext.ReportDiagnostic(Diagnostic.Create(Descriptors.XamlParserError, location, xamlItem.Exception.Message));
 				}
 				return;
@@ -137,14 +139,13 @@ public void Initialize(IncrementalGeneratorInitializationContext initContext)
 					return;
 
 				var code = InitializeComponentCodeWriter.GenerateInitializeComponent(xamlItem, compilation, sourceProductionContext, xmlnsCache, typeCache);
-				sourceProductionContext.AddSource(fileName, code);
+				sourceProductionContext.AddSource(GetHintName(xamlItem.ProjectItem, "xsg"), code);
 			}
 			catch (Exception e)
 			{
 				var location = xamlItem?.ProjectItem?.RelativePath is not null ? Location.Create(xamlItem.ProjectItem.RelativePath, new TextSpan(), new LinePositionSpan()) : null;
 				sourceProductionContext.ReportDiagnostic(Diagnostic.Create(Descriptors.XamlParserError, location, e.Message));
 			}
-
 		});
 
 		// Register the CSS pipeline
@@ -184,6 +185,19 @@ public void Initialize(IncrementalGeneratorInitializationContext initContext)
 		});
 	}
 
+	private static string GetHintName(ProjectItem? projectItem, string suffix)
+	{
+		if (projectItem?.RelativePath is not string relativePath)
+		{
+			throw new InvalidOperationException("Project item or target path is null");
+		}
+
+		var prefix = Path.GetDirectoryName(relativePath).Replace(Path.DirectorySeparatorChar, '_').Replace(':', '_');
+		var fileNameNoExtension = Path.GetFileNameWithoutExtension(relativePath);
+		var kind = projectItem.Kind.ToLowerInvariant() ?? "unknown-kind";
+		return $"{prefix}{fileNameNoExtension}.{kind}.{suffix}.cs";
+	}
+
 	private static string? GenerateGlobalXmlns(SourceProductionContext sourceProductionContext, AssemblyCaches xmlnsCache)
 	{
 		if (xmlnsCache.GlobalGeneratedXmlnsDefinitions.Count == 0)

src/Controls/src/SourceGen/PrePost.cs

@@ -15,15 +15,19 @@ class PrePost : IDisposable
 	/// <param name="iXmlLineInfo"></param>
 	/// <param name="fileName"></param>
 	/// <returns></returns>
-	public static PrePost NewLineInfo(IndentedTextWriter codeWriter, IXmlLineInfo iXmlLineInfo, string? fileName)
+	public static PrePost NewLineInfo(IndentedTextWriter codeWriter, IXmlLineInfo iXmlLineInfo, ProjectItem? projectItem)
 	{
-		static void LineInfo(IndentedTextWriter codeWriter, IXmlLineInfo iXmlLineInfo, string? fileName)
-			=> codeWriter.WriteLineNoTabs($"#line {(iXmlLineInfo.LineNumber != -1 ? iXmlLineInfo.LineNumber : 1)} \"{fileName}\"");
+		// Emit #line with an absolute path since relative paths have undefined behavior (https://github.com/dotnet/roslyn/issues/71202#issuecomment-1874649780)
+		static void LineInfo(IndentedTextWriter codeWriter, IXmlLineInfo iXmlLineInfo, ProjectItem? projectItem)
+		{
+			var lineNumber = iXmlLineInfo.LineNumber != -1 ? iXmlLineInfo.LineNumber : 1;
+			codeWriter.WriteLineNoTabs($"#line {lineNumber} \"{projectItem?.TargetPath}\"");
+		}
 
 		static void LineDefault(IndentedTextWriter codeWriter, IXmlLineInfo iXmlLineInfo)
 			=> codeWriter.WriteLineNoTabs("#line default");
 
-		return new(() => LineInfo(codeWriter, iXmlLineInfo, fileName), () => LineDefault(codeWriter, iXmlLineInfo));
+		return new(() => LineInfo(codeWriter, iXmlLineInfo, projectItem), () => LineDefault(codeWriter, iXmlLineInfo));
 	}
 
 	public static PrePost NoBlock() =>

src/Controls/src/SourceGen/ProjectItem.cs

@@ -7,6 +7,8 @@
 namespace Microsoft.Maui.Controls.SourceGen;
 record ProjectItem(AdditionalText AdditionalText, AnalyzerConfigOptions Options)
 {
+	private readonly AdditionalText _additionalText = AdditionalText;
+
 	public string Configuration
 		=> Options.GetValueOrDefault("build_property.Configuration", "Debug");
 
@@ -66,5 +68,5 @@ public string? TargetFramework
 		=> Options.GetValueOrNull("build_property.targetFramework");
 
 	public string? TargetPath
-		=> Options.GetValueOrDefault("build_metadata.additionalfiles.TargetPath", AdditionalText.Path);
+		=> Options.GetValueOrDefault("build_metadata.additionalfiles.TargetPath", _additionalText.Path);
 }

src/Controls/src/SourceGen/Visitors/SetPropertiesVisitor.cs

@@ -474,14 +474,14 @@ static void Set(IndentedTextWriter writer, LocalVariable parentVar, string local
 
 		if (node is ValueNode valueNode)
 		{
-			using (context.ProjectItem.EnableLineInfo ? PrePost.NewLineInfo(writer, (IXmlLineInfo)node, context.ProjectItem.RelativePath) : PrePost.NoBlock())
+			using (context.ProjectItem.EnableLineInfo ? PrePost.NewLineInfo(writer, (IXmlLineInfo)node, context.ProjectItem) : PrePost.NoBlock())
 			{
 				var valueString = valueNode.ConvertTo(property, context, parentVar);
 				writer.WriteLine($"{parentVar.Name}.{EscapeIdentifier(localName)} = {valueString};");
 			}
 		}
 		else if (node is ElementNode elementNode)
-			using (context.ProjectItem.EnableLineInfo ? PrePost.NewLineInfo(writer, (IXmlLineInfo)node, context.ProjectItem.RelativePath) : PrePost.NoBlock())
+			using (context.ProjectItem.EnableLineInfo ? PrePost.NewLineInfo(writer, (IXmlLineInfo)node, context.ProjectItem) : PrePost.NoBlock())
 				writer.WriteLine($"{parentVar.Name}.{EscapeIdentifier(localName)} = ({property.Type.ToFQDisplayString()}){(HasDoubleImplicitConversion(context.Variables[elementNode].Type, property.Type, context, out var conv) ? "(" + conv!.ReturnType.ToFQDisplayString() + ")" : string.Empty)}{context.Variables[elementNode].Name};");
 	}
 
@@ -610,7 +610,7 @@ static void Add(IndentedTextWriter writer, LocalVariable parentVar, XmlName prop
 		if (HasDoubleImplicitConversion(context.Variables[valueNode].Type, itemType, context, out var conv))
 			cast = "(" + conv!.ReturnType.ToFQDisplayString() + ")";
 
-		using (context.ProjectItem.EnableLineInfo ? PrePost.NewLineInfo(writer, (IXmlLineInfo)valueNode, context.ProjectItem.RelativePath) : PrePost.NoBlock())
+		using (context.ProjectItem.EnableLineInfo ? PrePost.NewLineInfo(writer, (IXmlLineInfo)valueNode, context.ProjectItem) : PrePost.NoBlock())
 			writer.WriteLine($"{parentObj}.Add(({itemType.ToFQDisplayString()}){cast}{context.Variables[valueNode].Name});");
 	}
 

src/Controls/tests/SourceGen.UnitTests/InitializeComponent/CompiledBindings.cs

@@ -1,3 +1,5 @@
+using System;
+using System.IO;
 using System.Linq;
 using NUnit.Framework;
 
@@ -50,9 +52,8 @@ public struct Bar
 	public string Title { get; set; } = "Title";
 }
 """;
-
-		var expected =
-"""
+		var testXamlFilePath = Path.Combine(Environment.CurrentDirectory, "Test.xaml");
+		var expected = $$"""
 
 //------------------------------------------------------------------------------
 // <auto-generated>
@@ -81,7 +82,7 @@ private partial void InitializeComponent()
 #if !_MAUIXAML_SG_NAMESCOPE_DISABLE
 		global::Microsoft.Maui.Controls.Internals.NameScope.SetNameScope(__root, iNameScope);
 #endif
-#line 1 "Test.xaml"
+#line 1 "{{testXamlFilePath}}"
 		bindingExtension.Path = "Foo.Bar.Title";
 #line default
 		var bindingBase = CreateTypedBindingFrom_bindingExtension(bindingExtension);

src/Controls/tests/SourceGen.UnitTests/InitializeComponent/LineInfoTests.cs

@@ -0,0 +1,36 @@
+using System;
+using System.IO;
+using System.Linq;
+using NUnit.Framework;
+
+namespace Microsoft.Maui.Controls.SourceGen.UnitTests.InitializeComponent;
+
+public class LineInfoTests : SourceGenXamlInitializeComponentTestBase
+{
+    [Test]
+    public void DiagnosticShowsLocationInInputXamlFile()
+    {
+        var xaml =
+"""
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentPage
+    xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    x:Class="Test.TestPage">
+    <ContentPage.Resources>
+        <ResourceDictionary>
+            <ResourceDictionary.MergedDictionaries>
+                <ResourceDictionary Source="Resources/Styles\Colors.xaml" />
+            </ResourceDictionary.MergedDictionaries>
+        </ResourceDictionary>
+    </ContentPage.Resources>
+</ContentPage>
+""";
+
+        var (result, _) = RunGenerator(xaml, string.Empty);
+
+        var generatedCode = result.GeneratedTrees.Single(tree => Path.GetFileName(tree.FilePath) == "Test.xaml.xsg.cs").ToString();
+        var expectedFilePath = Path.Combine(Environment.CurrentDirectory, "Test.xaml");
+        Assert.IsTrue(generatedCode.Contains(@$"#line 9 ""{expectedFilePath}""", StringComparison.Ordinal));
+    }
+}

src/Controls/tests/SourceGen.UnitTests/InitializeComponent/SetBinding.cs

@@ -1,3 +1,5 @@
+using System;
+using System.IO;
 using System.Linq;
 using NUnit.Framework;
 
@@ -36,8 +38,8 @@ public TestPage()
 }
 """;
 
-		var expected =
-"""
+		var testXamlFilePath = Path.Combine(Environment.CurrentDirectory, "Test.xaml");
+		var expected = $$"""
 
 //------------------------------------------------------------------------------
 // <auto-generated>
@@ -66,7 +68,7 @@ private partial void InitializeComponent()
 #if !_MAUIXAML_SG_NAMESCOPE_DISABLE
 		global::Microsoft.Maui.Controls.Internals.NameScope.SetNameScope(__root, iNameScope);
 #endif
-#line 1 "Test.xaml"
+#line 1 "{{testXamlFilePath}}"
 		bindingExtension.Path = "Title";
 #line default
 		var bindingBase = new global::Microsoft.Maui.Controls.Binding(bindingExtension.Path, bindingExtension.Mode, bindingExtension.Converter, bindingExtension.ConverterParameter, bindingExtension.StringFormat, bindingExtension.Source) { UpdateSourceEventName = bindingExtension.UpdateSourceEventName, FallbackValue = bindingExtension.FallbackValue, TargetNullValue = bindingExtension.TargetNullValue };

src/Controls/tests/SourceGen.UnitTests/InitializeComponent/SimplifyOnPlatform.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using System.Linq;
 using NUnit.Framework;
 
@@ -43,8 +44,8 @@ public TestPage()
 }
 """;
 
-var expected =
-"""
+		var testXamlFilePath = Path.Combine(Environment.CurrentDirectory, "Test.xaml");
+		var expected = $$"""
 
 //------------------------------------------------------------------------------
 // <auto-generated>
@@ -97,7 +98,7 @@ private partial void InitializeComponent()
 #if !_MAUIXAML_SG_NAMESCOPE_DISABLE
 		global::Microsoft.Maui.Controls.Internals.INameScope iNameScope2 = new global::Microsoft.Maui.Controls.Internals.NameScope();
 #endif
-#line 8 "Test.xaml"
+#line 8 "{{testXamlFilePath}}"
 		var xamlServiceProvider1 = new global::Microsoft.Maui.Controls.Xaml.Internals.XamlServiceProvider(this);
 		var iProvideValueTarget1 = new global::Microsoft.Maui.Controls.Xaml.Internals.SimpleValueTargetProvider(
 			new object?[] {setter, style1, __root},
@@ -118,16 +119,16 @@ private partial void InitializeComponent()
 		xamlServiceProvider1.Add(typeof(global::Microsoft.Maui.Controls.Xaml.IXamlTypeResolver), new global::Microsoft.Maui.Controls.Xaml.Internals.XamlTypeResolver(xmlNamespaceResolver1, typeof(global::Test.TestPage).Assembly));
 		setter.Property = ((global::Microsoft.Maui.Controls.IExtendedTypeConverter)new global::Microsoft.Maui.Controls.BindablePropertyConverter()).ConvertFromInvariantString("TextColor", xamlServiceProvider1) as global::Microsoft.Maui.Controls.BindableProperty;
 #line default
-#line 8 "Test.xaml"
+#line 8 "{{testXamlFilePath}}"
 		setter.Value = "Pink";
 #line default
 		var setter2 = new global::Microsoft.Maui.Controls.Setter {Property = global::Microsoft.Maui.Controls.Label.TextColorProperty, Value = global::Microsoft.Maui.Graphics.Color.Parse("Pink")};
 		if (global::Microsoft.Maui.VisualDiagnostics.GetSourceInfo(setter2!) == null)
 			global::Microsoft.Maui.VisualDiagnostics.RegisterSourceInfo(setter2!, new global::System.Uri(@"Test.xaml;assembly=SourceGeneratorDriver.Generated", global::System.UriKind.Relative), 8, 14);
-#line 8 "Test.xaml"
+#line 8 "{{testXamlFilePath}}"
 		((global::System.Collections.Generic.ICollection<global::Microsoft.Maui.Controls.Setter>)style1.Setters).Add((global::Microsoft.Maui.Controls.Setter)setter2);
 #line default
-#line 9 "Test.xaml"
+#line 9 "{{testXamlFilePath}}"
 		var xamlServiceProvider2 = new global::Microsoft.Maui.Controls.Xaml.Internals.XamlServiceProvider(this);
 		var iProvideValueTarget2 = new global::Microsoft.Maui.Controls.Xaml.Internals.SimpleValueTargetProvider(
 			new object?[] {setter1, style1, __root},
@@ -148,13 +149,13 @@ private partial void InitializeComponent()
 		xamlServiceProvider2.Add(typeof(global::Microsoft.Maui.Controls.Xaml.IXamlTypeResolver), new global::Microsoft.Maui.Controls.Xaml.Internals.XamlTypeResolver(xmlNamespaceResolver2, typeof(global::Test.TestPage).Assembly));
 		setter1.Property = ((global::Microsoft.Maui.Controls.IExtendedTypeConverter)new global::Microsoft.Maui.Controls.BindablePropertyConverter()).ConvertFromInvariantString("IsVisible", xamlServiceProvider2) as global::Microsoft.Maui.Controls.BindableProperty;
 #line default
-#line 1 "Test.xaml"
+#line 1 "{{testXamlFilePath}}"
 		setter1.Value = "True";
 #line default
 		var setter3 = new global::Microsoft.Maui.Controls.Setter {Property = global::Microsoft.Maui.Controls.VisualElement.IsVisibleProperty, Value = (bool)new global::Microsoft.Maui.Controls.VisualElement.VisibilityConverter().ConvertFromInvariantString("True")!};
 		if (global::Microsoft.Maui.VisualDiagnostics.GetSourceInfo(setter3!) == null)
 			global::Microsoft.Maui.VisualDiagnostics.RegisterSourceInfo(setter3!, new global::System.Uri(@"Test.xaml;assembly=SourceGeneratorDriver.Generated", global::System.UriKind.Relative), 9, 14);
-#line 9 "Test.xaml"
+#line 9 "{{testXamlFilePath}}"
 		((global::System.Collections.Generic.ICollection<global::Microsoft.Maui.Controls.Setter>)style1.Setters).Add((global::Microsoft.Maui.Controls.Setter)setter3);
 #line default
 		var resourceDictionary = __root.Resources;

src/Controls/tests/SourceGen.UnitTests/InitializeComponent/SourceGenXamlInitializeComponentTests.cs

@@ -1,3 +1,5 @@
+using System;
+using System.IO;
 using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
@@ -16,7 +18,9 @@ protected record AdditionalXamlFile(string Path, string Content, string? Relativ
 	{
 		var compilation = CreateMauiCompilation();
 		compilation = compilation.AddSyntaxTrees(CSharpSyntaxTree.ParseText(code));
-		var result = RunGenerator<CodeBehindGenerator>(compilation, new AdditionalXamlFile("Test.xaml", xaml, TargetFramework: targetFramework, NoWarn: noWarn));
+		var workingDirectory = Environment.CurrentDirectory;
+		var xamlFile = new AdditionalXamlFile(Path.Combine(workingDirectory, "Test.xaml"), xaml, RelativePath: "Test.xaml", TargetFramework: targetFramework, NoWarn: noWarn);
+		var result = RunGenerator<CodeBehindGenerator>(compilation, xamlFile);
 		var generated = result.Results.SingleOrDefault().GeneratedSources.SingleOrDefault(gs => gs.HintName.EndsWith(".xsg.cs")).SourceText?.ToString();
 
 		return (result, generated);

src/Controls/tests/SourceGen.UnitTests/SourceGeneratorDriver.cs

@@ -94,6 +94,7 @@ private static MetadataReference[] GetMauiReferences()
 				MetadataReference.CreateFromFile(Path.Combine(dotNetAssemblyPath, "System.Private.CoreLib.dll")),
 				MetadataReference.CreateFromFile(Path.Combine(dotNetAssemblyPath, "System.Runtime.dll")),
 				MetadataReference.CreateFromFile(Path.Combine(dotNetAssemblyPath, "System.ObjectModel.dll")),
+				MetadataReference.CreateFromFile(typeof(Uri).Assembly.Location),						//System.Private.Uri
 				MetadataReference.CreateFromFile(typeof(Color).Assembly.Location),						//Graphics
 				MetadataReference.CreateFromFile(typeof(Button).Assembly.Location),						//Controls
 				MetadataReference.CreateFromFile(typeof(BindingExtension).Assembly.Location),			//Xaml