Add C-Style casts support (#26)

* initialized cstyle casts * added integration and accessExpressionBuilder tests * added explicit cast to as cast adapter * Simplify inserting conditional access * Add integration tests --------- Co-authored-by: Simon Rozsival <[email protected]>
simonrozsival · Apr 30, 2024 · a573668 · a573668
1 parent d411076
commit a573668
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Showing 8 changed files with 551 additions and 123 deletions.
diff --git a/src/Controls/src/BindingSourceGen/BindingCodeWriter.cs b/src/Controls/src/BindingSourceGen/BindingCodeWriter.cs
@@ -287,25 +287,37 @@ private void AppendHandlersArray(TypeDescription sourceType, EquatableArray<IPat
 			Indent();
 
 			string nextExpression = "source";
+			bool forceConditonalAccessToNextPart = false;
 			foreach (var part in path)
 			{
-				var expression = nextExpression;
-				nextExpression = AccessExpressionBuilder.Build(nextExpression, part);
+				var previousExpression = nextExpression;
+				nextExpression = AccessExpressionBuilder.Build(previousExpression, MaybeWrapInConditionalAccess(part, forceConditonalAccessToNextPart));
+				forceConditonalAccessToNextPart = part is Cast;
 
 				// Some parts don't have a property name, so we can't generate a handler for them (for example casts)
-				var propertyName = part.PropertyName;
-				if (propertyName is null)
+				if (part.PropertyName is string propertyName)
 				{
-					continue;
+					AppendLine($"new(static source => {previousExpression}, \"{propertyName}\"),");
 				}
-
-				Append("new(static source => ");
-				Append(expression);
-				AppendLine($", \"{part.PropertyName}\"),");
 			}
 			Unindent();
 
 			Append('}');
+
+			static IPathPart MaybeWrapInConditionalAccess(IPathPart part, bool forceConditonalAccess)
+			{
+				if (!forceConditonalAccess)
+				{
+					return part;
+				}
+
+				return part switch
+				{
+					MemberAccess memberAccess => new ConditionalAccess(memberAccess),
+					IndexAccess indexAccess => new ConditionalAccess(indexAccess),
+					_ => part,
+				};
+			}
 		}
 
 		public void Dispose()

diff --git a/src/Controls/src/BindingSourceGen/BindingSourceGenerator.cs b/src/Controls/src/BindingSourceGen/BindingSourceGenerator.cs
@@ -1,7 +1,6 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
-using Microsoft.CodeAnalysis.Text;
 
 namespace Microsoft.Maui.Controls.BindingSourceGen;
 
@@ -90,7 +89,7 @@ static BindingDiagnosticsWrapper GetBindingForGeneration(GeneratorSyntaxContext
 			return ReportDiagnostic(DiagnosticsFactory.UnableToResolvePath(lambdaBody.GetLocation()));
 		}
 
-		var pathParser = new PathParser(context);
+		var pathParser = new PathParser(context, enabledNullable);
 		var (pathDiagnostics, parts) = pathParser.ParsePath(lambdaBody);
 		if (pathDiagnostics.Length > 0)
 		{
@@ -179,6 +178,7 @@ private static SetterOptions DeriveSetterOptions(ExpressionSyntax? lambdaBodyExp
 			ConditionalAccessExpressionSyntax conditionalAccess => conditionalAccess.WhenNotNull,
 			MemberBindingExpressionSyntax memberBinding => memberBinding.Name,
 			BinaryExpressionSyntax binary when binary.Kind() == SyntaxKind.AsExpression => binary.Left,
+			CastExpressionSyntax cast => cast.Expression,
 			ParenthesizedExpressionSyntax parenthesized => parenthesized.Expression,
 			_ => null,
 		};
@@ -205,99 +205,3 @@ static bool AcceptsNullValue(ISymbol? symbol, bool enabledNullable)
 	private static BindingDiagnosticsWrapper ReportDiagnostics(EquatableArray<DiagnosticInfo> diagnostics) => new(null, diagnostics);
 	private static BindingDiagnosticsWrapper ReportDiagnostic(DiagnosticInfo diagnostic) => new(null, new EquatableArray<DiagnosticInfo>([diagnostic]));
 }
-
-public class TrackingNames
-{
-	public const string BindingsWithDiagnostics = nameof(BindingsWithDiagnostics);
-	public const string Bindings = nameof(Bindings);
-}
-
-public sealed record BindingDiagnosticsWrapper(
-	CodeWriterBinding? Binding,
-	EquatableArray<DiagnosticInfo> Diagnostics);
-
-public sealed record CodeWriterBinding(
-	InterceptorLocation Location,
-	TypeDescription SourceType,
-	TypeDescription PropertyType,
-	EquatableArray<IPathPart> Path,
-	SetterOptions SetterOptions);
-
-public sealed record SourceCodeLocation(string FilePath, TextSpan TextSpan, LinePositionSpan LineSpan)
-{
-	public static SourceCodeLocation? CreateFrom(Location location)
-		=> location.SourceTree is null
-			? null
-			: new SourceCodeLocation(location.SourceTree.FilePath, location.SourceSpan, location.GetLineSpan().Span);
-
-	public Location ToLocation()
-	{
-		return Location.Create(FilePath, TextSpan, LineSpan);
-	}
-
-	public InterceptorLocation ToInterceptorLocation()
-	{
-		return new InterceptorLocation(FilePath, LineSpan.Start.Line + 1, LineSpan.Start.Character + 1);
-	}
-}
-
-public sealed record InterceptorLocation(string FilePath, int Line, int Column);
-
-public sealed record TypeDescription(
-	string GlobalName,
-	bool IsValueType = false,
-	bool IsNullable = false,
-	bool IsGenericParameter = false)
-{
-	public override string ToString()
-		=> IsNullable
-			? $"{GlobalName}?"
-			: GlobalName;
-}
-
-public sealed record SetterOptions(bool IsWritable, bool AcceptsNullValue = false);
-
-public sealed record MemberAccess(string MemberName) : IPathPart
-{
-	public string? PropertyName => MemberName;
-
-	public bool Equals(IPathPart other)
-	{
-		return other is MemberAccess memberAccess && MemberName == memberAccess.MemberName;
-	}
-}
-
-public sealed record IndexAccess(string DefaultMemberName, object Index) : IPathPart
-{
-	public string? PropertyName => $"{DefaultMemberName}[{Index}]";
-
-	public bool Equals(IPathPart other)
-	{
-		return other is IndexAccess indexAccess && DefaultMemberName == indexAccess.DefaultMemberName && Index.Equals(indexAccess.Index);
-	}
-}
-
-public sealed record ConditionalAccess(IPathPart Part) : IPathPart
-{
-	public string? PropertyName => Part.PropertyName;
-
-	public bool Equals(IPathPart other)
-	{
-		return other is ConditionalAccess conditionalAccess && Part.Equals(conditionalAccess.Part);
-	}
-}
-
-public sealed record Cast(TypeDescription TargetType) : IPathPart
-{
-	public string? PropertyName => null;
-
-	public bool Equals(IPathPart other)
-	{
-		return other is Cast cast && TargetType.Equals(cast.TargetType);
-	}
-}
-
-public interface IPathPart : IEquatable<IPathPart>
-{
-	public string? PropertyName { get; }
-}
diff --git a/src/Controls/src/BindingSourceGen/BindingSourceGeneratorUtilities.cs b/src/Controls/src/BindingSourceGen/BindingSourceGeneratorUtilities.cs
@@ -31,7 +31,19 @@ internal static TypeDescription CreateTypeNameFromITypeSymbol(ITypeSymbol typeSy
             IsValueType: typeSymbol.IsValueType);
     }
 
-    internal static TypeDescription CreateTypeDescriptionForCast(ITypeSymbol typeSymbol)
+    internal static TypeDescription CreateTypeDescriptionForExplicitCast(ITypeSymbol typeSymbol, bool enabledNullable)
+    {
+        var isNullable = IsTypeNullable(typeSymbol, enabledNullable);
+        var name = GetGlobalName(typeSymbol, isNullable, typeSymbol.IsValueType);
+
+        return new TypeDescription(
+            GlobalName: name,
+            IsNullable: isNullable,
+            IsGenericParameter: typeSymbol.Kind == SymbolKind.TypeParameter,
+            IsValueType: typeSymbol.IsValueType);
+    }
+
+    internal static TypeDescription CreateTypeDescriptionForAsCast(ITypeSymbol typeSymbol)
     {
         // We can cast to nullable value type or non-nullable reference type
         var name = typeSymbol.IsValueType ?

diff --git a/src/Controls/src/BindingSourceGen/GeneratorDataModels.cs b/src/Controls/src/BindingSourceGen/GeneratorDataModels.cs
@@ -0,0 +1,101 @@
+
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.Maui.Controls.BindingSourceGen;
+
+public class TrackingNames
+{
+	public const string BindingsWithDiagnostics = nameof(BindingsWithDiagnostics);
+	public const string Bindings = nameof(Bindings);
+}
+
+public sealed record BindingDiagnosticsWrapper(
+	CodeWriterBinding? Binding,
+	EquatableArray<DiagnosticInfo> Diagnostics);
+
+public sealed record CodeWriterBinding(
+	InterceptorLocation Location,
+	TypeDescription SourceType,
+	TypeDescription PropertyType,
+	EquatableArray<IPathPart> Path,
+	SetterOptions SetterOptions);
+
+public sealed record SourceCodeLocation(string FilePath, TextSpan TextSpan, LinePositionSpan LineSpan)
+{
+	public static SourceCodeLocation? CreateFrom(Location location)
+		=> location.SourceTree is null
+			? null
+			: new SourceCodeLocation(location.SourceTree.FilePath, location.SourceSpan, location.GetLineSpan().Span);
+
+	public Location ToLocation()
+	{
+		return Location.Create(FilePath, TextSpan, LineSpan);
+	}
+
+	public InterceptorLocation ToInterceptorLocation()
+	{
+		return new InterceptorLocation(FilePath, LineSpan.Start.Line + 1, LineSpan.Start.Character + 1);
+	}
+}
+
+public sealed record InterceptorLocation(string FilePath, int Line, int Column);
+
+public sealed record TypeDescription(
+	string GlobalName,
+	bool IsValueType = false,
+	bool IsNullable = false,
+	bool IsGenericParameter = false)
+{
+	public override string ToString()
+		=> IsNullable
+			? $"{GlobalName}?"
+			: GlobalName;
+}
+
+public sealed record SetterOptions(bool IsWritable, bool AcceptsNullValue = false);
+
+public sealed record MemberAccess(string MemberName) : IPathPart
+{
+	public string? PropertyName => MemberName;
+
+	public bool Equals(IPathPart other)
+	{
+		return other is MemberAccess memberAccess && MemberName == memberAccess.MemberName;
+	}
+}
+
+public sealed record IndexAccess(string DefaultMemberName, object Index) : IPathPart
+{
+	public string? PropertyName => $"{DefaultMemberName}[{Index}]";
+
+	public bool Equals(IPathPart other)
+	{
+		return other is IndexAccess indexAccess && DefaultMemberName == indexAccess.DefaultMemberName && Index.Equals(indexAccess.Index);
+	}
+}
+
+public sealed record ConditionalAccess(IPathPart Part) : IPathPart
+{
+	public string? PropertyName => Part.PropertyName;
+
+	public bool Equals(IPathPart other)
+	{
+		return other is ConditionalAccess conditionalAccess && Part.Equals(conditionalAccess.Part);
+	}
+}
+
+public sealed record Cast(TypeDescription TargetType) : IPathPart
+{
+	public string? PropertyName => null;
+
+	public bool Equals(IPathPart other)
+	{
+		return other is Cast cast && TargetType.Equals(cast.TargetType);
+	}
+}
+
+public interface IPathPart : IEquatable<IPathPart>
+{
+	public string? PropertyName { get; }
+}
diff --git a/src/Controls/src/BindingSourceGen/PathParser.cs b/src/Controls/src/BindingSourceGen/PathParser.cs
@@ -7,12 +7,14 @@ namespace Microsoft.Maui.Controls.BindingSourceGen;
 
 internal class PathParser
 {
-    internal PathParser(GeneratorSyntaxContext context)
+    internal PathParser(GeneratorSyntaxContext context, bool enabledNullable)
     {
         Context = context;
+        EnabledNullable = enabledNullable;
     }
 
     private GeneratorSyntaxContext Context { get; }
+    private bool EnabledNullable { get; }
 
     internal (EquatableArray<DiagnosticInfo> diagnostics, List<IPathPart> parts) ParsePath(CSharpSyntaxNode? expressionSyntax)
     {
@@ -26,6 +28,7 @@ internal PathParser(GeneratorSyntaxContext context)
             MemberBindingExpressionSyntax memberBinding => HandleMemberBindingExpression(memberBinding),
             ParenthesizedExpressionSyntax parenthesized => ParsePath(parenthesized.Expression),
             BinaryExpressionSyntax asExpression when asExpression.Kind() == SyntaxKind.AsExpression => HandleBinaryExpression(asExpression),
+            CastExpressionSyntax castExpression => HandleCastExpression(castExpression),
             _ => HandleDefaultCase(),
         };
     }
@@ -118,7 +121,25 @@ BinaryExpressionSyntax asExpression when asExpression.Kind() == SyntaxKind.AsExp
             return (new EquatableArray<DiagnosticInfo>([DiagnosticsFactory.UnableToResolvePath(Context.Node.GetLocation())]), new List<IPathPart>());
         };
 
-        parts.Add(new Cast(BindingGenerationUtilities.CreateTypeDescriptionForCast(typeInfo)));
+        parts.Add(new Cast(BindingGenerationUtilities.CreateTypeDescriptionForAsCast(typeInfo)));
+        return (diagnostics, parts);
+    }
+
+    private (EquatableArray<DiagnosticInfo> diagnostics, List<IPathPart> parts) HandleCastExpression(CastExpressionSyntax castExpression)
+    {
+        var (diagnostics, parts) = ParsePath(castExpression.Expression);
+        if (diagnostics.Length > 0)
+        {
+            return (diagnostics, parts);
+        }
+
+        var typeInfo = Context.SemanticModel.GetTypeInfo(castExpression.Type).Type;
+        if (typeInfo == null)
+        {
+            return (new EquatableArray<DiagnosticInfo>([DiagnosticsFactory.UnableToResolvePath(Context.Node.GetLocation())]), new List<IPathPart>());
+        };
+
+        parts.Add(new Cast(BindingGenerationUtilities.CreateTypeDescriptionForExplicitCast(typeInfo, EnabledNullable)));
         return (diagnostics, parts);
     }
 

diff --git a/src/Controls/tests/BindingSourceGen.UnitTests/AccessExpressionBuilderTests.cs b/src/Controls/tests/BindingSourceGen.UnitTests/AccessExpressionBuilderTests.cs
@@ -1,4 +1,3 @@
-using System.Linq;
 using Microsoft.Maui.Controls.BindingSourceGen;
 using Xunit;