Use ForAttributeWithMetadataName whenever possible

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/INotifyPropertyChangedGenerator.cs

@@ -23,7 +23,7 @@ public sealed class INotifyPropertyChangedGenerator : TransitiveMembersGenerator
     /// Initializes a new instance of the <see cref="INotifyPropertyChangedGenerator"/> class.
     /// </summary>
     public INotifyPropertyChangedGenerator()
-        : base("global::CommunityToolkit.Mvvm.ComponentModel.INotifyPropertyChangedAttribute")
+        : base("CommunityToolkit.Mvvm.ComponentModel.INotifyPropertyChangedAttribute")
     {
     }
 

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableObjectGenerator.cs

@@ -22,7 +22,7 @@ public sealed class ObservableObjectGenerator : TransitiveMembersGenerator<objec
     /// Initializes a new instance of the <see cref="ObservableObjectGenerator"/> class.
     /// </summary>
     public ObservableObjectGenerator()
-        : base("global::CommunityToolkit.Mvvm.ComponentModel.ObservableObjectAttribute")
+        : base("CommunityToolkit.Mvvm.ComponentModel.ObservableObjectAttribute")
     {
     }
 

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservablePropertyGenerator.cs

@@ -27,7 +27,8 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         // Gather info for all annotated fields
         IncrementalValuesProvider<(HierarchyInfo Hierarchy, Result<PropertyInfo?> Info)> propertyInfoWithErrors =
             context.SyntaxProvider
-            .CreateSyntaxProvider(
+            .ForAttributeWithMetadataName(
+                "CommunityToolkit.Mvvm.ComponentModel.ObservablePropertyAttribute",
                 static (node, _) => node is VariableDeclaratorSyntax { Parent: VariableDeclarationSyntax { Parent: FieldDeclarationSyntax { Parent: ClassDeclarationSyntax or RecordDeclarationSyntax, AttributeLists.Count: > 0 } } },
                 static (context, token) =>
                 {
@@ -36,13 +37,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
                         return default;
                     }
 
-                    IFieldSymbol fieldSymbol = (IFieldSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node, token)!;
-
-                    // Filter the fields using [ObservableProperty]
-                    if (!fieldSymbol.HasAttributeWithFullyQualifiedName("global::CommunityToolkit.Mvvm.ComponentModel.ObservablePropertyAttribute"))
-                    {
-                        return default;
-                    }
+                    IFieldSymbol fieldSymbol = (IFieldSymbol)context.TargetSymbol;
 
                     // Produce the incremental models
                     HierarchyInfo hierarchy = HierarchyInfo.From(fieldSymbol.ContainingType);

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/ObservableRecipientGenerator.cs

@@ -25,7 +25,7 @@ public sealed class ObservableRecipientGenerator : TransitiveMembersGenerator<Ob
     /// Initializes a new instance of the <see cref="ObservableRecipientGenerator"/> class.
     /// </summary>
     public ObservableRecipientGenerator()
-        : base("global::CommunityToolkit.Mvvm.ComponentModel.ObservableRecipientAttribute")
+        : base("CommunityToolkit.Mvvm.ComponentModel.ObservableRecipientAttribute")
     {
     }
 

CommunityToolkit.Mvvm.SourceGenerators/ComponentModel/TransitiveMembersGenerator.cs

@@ -21,9 +21,9 @@ namespace CommunityToolkit.Mvvm.SourceGenerators;
 public abstract partial class TransitiveMembersGenerator<TInfo> : IIncrementalGenerator
 {
     /// <summary>
-    /// The fully qualified name of the attribute type to look for.
+    /// The fully qualified metadata name of the attribute type to look for.
     /// </summary>
-    private readonly string attributeType;
+    private readonly string fullyQualifiedAttributeMetadataName;
 
     /// <summary>
     /// An <see cref="IEqualityComparer{T}"/> instance to compare intermediate models.
@@ -51,13 +51,13 @@ public abstract partial class TransitiveMembersGenerator<TInfo> : IIncrementalGe
     /// <summary>
     /// Initializes a new instance of the <see cref="TransitiveMembersGenerator{TInfo}"/> class.
     /// </summary>
-    /// <param name="attributeType">The fully qualified name of the attribute type to look for.</param>
+    /// <param name="fullyQualifiedAttributeMetadataName">The fully qualified metadata name of the attribute type to look for.</param>
     /// <param name="comparer">An <see cref="IEqualityComparer{T}"/> instance to compare intermediate models.</param>
-    private protected TransitiveMembersGenerator(string attributeType, IEqualityComparer<TInfo>? comparer = null)
+    private protected TransitiveMembersGenerator(string fullyQualifiedAttributeMetadataName, IEqualityComparer<TInfo>? comparer = null)
     {
-        this.attributeType = attributeType;
+        this.fullyQualifiedAttributeMetadataName = fullyQualifiedAttributeMetadataName;
         this.comparer = comparer ?? EqualityComparer<TInfo>.Default;
-        this.classDeclaration = Execute.LoadClassDeclaration(attributeType);
+        this.classDeclaration = Execute.LoadClassDeclaration(fullyQualifiedAttributeMetadataName);
 
         Execute.ProcessMemberDeclarations(
             GetType(),
@@ -72,25 +72,20 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         // Gather all generation info, and any diagnostics
         IncrementalValuesProvider<Result<(HierarchyInfo Hierarchy, bool IsSealed, TInfo? Info)>> generationInfoWithErrors =
             context.SyntaxProvider
-            .CreateSyntaxProvider(
-                static (node, _) => node is ClassDeclarationSyntax { AttributeLists.Count: > 0 },
+            .ForAttributeWithMetadataName(
+                this.fullyQualifiedAttributeMetadataName,
+                static (node, _) => node is ClassDeclarationSyntax classDeclaration && classDeclaration.HasOrPotentiallyHasAttributes(),
                 (context, token) =>
                 {
                     if (!context.SemanticModel.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
                     {
                         return default;
                     }
 
-                    INamedTypeSymbol typeSymbol = (INamedTypeSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node, token)!;
-
-                    // Filter the types with the target attribute
-                    if (!typeSymbol.TryGetAttributeWithFullyQualifiedName(this.attributeType, out AttributeData? attributeData))
-                    {
-                        return default;
-                    }
+                    INamedTypeSymbol typeSymbol = (INamedTypeSymbol)context.TargetSymbol;
 
                     // Gather all generation info, and any diagnostics
-                    TInfo? info = ValidateTargetTypeAndGetInfo(typeSymbol, attributeData, context.SemanticModel.Compilation, out ImmutableArray<Diagnostic> diagnostics);
+                    TInfo? info = ValidateTargetTypeAndGetInfo(typeSymbol, context.Attributes[0], context.SemanticModel.Compilation, out ImmutableArray<Diagnostic> diagnostics);
 
                     // If there are any diagnostics, there's no need to compute the hierarchy info at all, just return them
                     if (diagnostics.Length > 0)

CommunityToolkit.Mvvm.SourceGenerators/Extensions/ISymbolExtensions.cs

@@ -3,7 +3,9 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Immutable;
+#if !ROSLYN_4_3
 using System.Diagnostics.CodeAnalysis;
+#endif
 using Microsoft.CodeAnalysis;
 
 namespace CommunityToolkit.Mvvm.SourceGenerators.Extensions;
@@ -65,6 +67,7 @@ public static bool HasAttributeWithFullyQualifiedName(this ISymbol symbol, strin
         return false;
     }
 
+#if !ROSLYN_4_3
     /// <summary>
     /// Tries to get an attribute with the specified full name.
     /// </summary>
@@ -90,6 +93,7 @@ public static bool TryGetAttributeWithFullyQualifiedName(this ISymbol symbol, st
 
         return false;
     }
+#endif
 
     /// <summary>
     /// Calculates the effective accessibility for a given symbol.

CommunityToolkit.Mvvm.SourceGenerators/Extensions/TypeDeclarationSyntaxExtensions.cs

@@ -38,4 +38,30 @@ public static bool HasOrPotentiallyHasBaseTypes(this TypeDeclarationSyntax typeD
 
         return false;
     }
+
+    /// <summary>
+    /// Checks whether a given <see cref="TypeDeclarationSyntax"/> has or could possibly have any attributes, using only syntax.
+    /// </summary>
+    /// <param name="typeDeclaration">The input <see cref="TypeDeclarationSyntax"/> instance to check.</param>
+    /// <returns>Whether <paramref name="typeDeclaration"/> has or could possibly have any attributes.</returns>
+    public static bool HasOrPotentiallyHasAttributes(this TypeDeclarationSyntax typeDeclaration)
+    {
+        // If the type has any attributes lists, then clearly it can have attributes
+        if (typeDeclaration.AttributeLists.Count > 0)
+        {
+            return true;
+        }
+
+        // If the declaration has no attribute lists, check if the type is partial. If it is, it means
+        // that there could be another partial declaration with some attribute lists over them.
+        foreach (SyntaxToken modifier in typeDeclaration.Modifiers)
+        {
+            if (modifier.IsKind(SyntaxKind.PartialKeyword))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }

CommunityToolkit.Mvvm.SourceGenerators/Input/RelayCommandGenerator.cs

@@ -26,7 +26,8 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         // Gather info for all annotated command methods (starting from method declarations with at least one attribute)
         IncrementalValuesProvider<(HierarchyInfo Hierarchy, Result<CommandInfo?> Info)> commandInfoWithErrors =
             context.SyntaxProvider
-            .CreateSyntaxProvider(
+            .ForAttributeWithMetadataName(
+                "CommunityToolkit.Mvvm.Input.RelayCommandAttribute",
                 static (node, _) => node is MethodDeclarationSyntax { Parent: ClassDeclarationSyntax, AttributeLists.Count: > 0 },
                 static (context, token) =>
                 {
@@ -35,17 +36,11 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
                         return default;
                     }
 
-                    IMethodSymbol methodSymbol = (IMethodSymbol)context.SemanticModel.GetDeclaredSymbol(context.Node, token)!;
-
-                    // Filter the methods using [RelayCommand]
-                    if (!methodSymbol.TryGetAttributeWithFullyQualifiedName("global::CommunityToolkit.Mvvm.Input.RelayCommandAttribute", out AttributeData? attribute))
-                    {
-                        return default;
-                    }
+                    IMethodSymbol methodSymbol = (IMethodSymbol)context.TargetSymbol;
 
                     // Produce the incremental models
                     HierarchyInfo hierarchy = HierarchyInfo.From(methodSymbol.ContainingType);
-                    CommandInfo? commandInfo = Execute.GetInfo(methodSymbol, attribute, out ImmutableArray<Diagnostic> diagnostics);
+                    CommandInfo? commandInfo = Execute.GetInfo(methodSymbol, context.Attributes[0], out ImmutableArray<Diagnostic> diagnostics);
 
                     return (Hierarchy: hierarchy, new Result<CommandInfo?>(commandInfo, diagnostics));
                 })