Ensure SAL/C++ attributes on fields generate a CppAttributeList

sources/ClangSharp.PInvokeGenerator/Abstractions/FieldDesc.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation and Contributors. All Rights Reserved. Licensed under the MIT License (MIT). See License.md in the repository root for more information.
 
 using System;
+using System.Collections.Generic;
 using ClangSharp.Interop;
 
 namespace ClangSharp.Abstractions;
@@ -9,6 +10,7 @@ internal struct FieldDesc
 {
     public AccessSpecifier AccessSpecifier { get; set; }
     public string? NativeTypeName { get; set; }
+    public IEnumerable<string>? CppAttributes { get; set; }
     public string EscapedName { get; set; }
     public string ParentName { get; set; }
     public int? Offset { get; set; }

sources/ClangSharp.PInvokeGenerator/CSharp/CSharpOutputBuilder.VisitDecl.cs

@@ -308,6 +308,11 @@ public void BeginField(in FieldDesc desc)
             AddNativeTypeNameAttribute(desc.NativeTypeName);
         }
 
+        if (desc.CppAttributes is not null)
+        {
+            AddCppAttributes(desc.CppAttributes);
+        }
+
         if (desc.Location is { } location)
         {
             WriteSourceLocation(location, false);

sources/ClangSharp.PInvokeGenerator/PInvokeGenerator.VisitDecl.cs

@@ -449,6 +449,9 @@ private void VisitFieldDecl(FieldDecl fieldDecl)
         var desc = new FieldDesc {
             AccessSpecifier = accessSpecifier,
             NativeTypeName = nativeTypeName,
+            CppAttributes = _config.GenerateCppAttributes
+                ? fieldDecl.Attrs.Select(x => EscapeString(x.Spelling))
+                : null,
             EscapedName = escapedName,
             ParentName = GetRemappedCursorName(parent),
             Offset = offset,

tests/ClangSharp.PInvokeGenerator.UnitTests/SalFieldAttributeTest.cs

@@ -0,0 +1,49 @@
+// Copyright (c) .NET Foundation and Contributors. All Rights Reserved. Licensed under the MIT License (MIT). See License.md in the repository root for more information.
+
+using System.Threading.Tasks;
+using NUnit.Framework;
+
+namespace ClangSharp.UnitTests;
+
+/// <summary>
+/// Regression test for https://github.com/dotnet/ClangSharp/issues/444.
+/// Under <c>generate-cpp-attributes</c>, a C++ attribute (e.g. a SAL <c>_Field_size_full_</c>
+/// annotation surfaced as an <c>annotate</c> attribute) on a struct field was not emitted as a
+/// <c>[CppAttributeList("...")]</c>, even though the same attribute on a parameter was. Fields now
+/// emit the attribute the same way parameters do.
+/// </summary>
+[Platform("win")]
+public sealed class SalFieldAttributeTest : PInvokeGeneratorTest
+{
+    private const string InputContents = @"#define _Field_size_full_(x) __attribute__((annotate(""_Field_size_full_("" #x "")"")))
+
+struct MyStruct
+{
+    int count;
+    _Field_size_full_(count) int* data;
+};
+";
+
+    [Test]
+    public Task FieldSalAnnotationGeneratesCppAttributeList()
+    {
+        var expectedOutputContents = @"namespace ClangSharp.Test
+{
+    public unsafe partial struct MyStruct
+    {
+        public int count;
+
+        [CppAttributeList(""_Field_size_full_(count)"")]
+        [NativeAnnotation(""_Field_size_full_(count)"")]
+        public int* data;
+    }
+}
+";
+
+        var expectedDiagnostics = new[] {
+            new Diagnostic(DiagnosticLevel.Warning, "Function like macro definition records are not supported: '_Field_size_full_'. Generated bindings may be incomplete.", "Line 1, Column 9 in ClangUnsavedFile.h")
+        };
+
+        return ValidateGeneratedCSharpLatestWindowsBindingsAsync(InputContents, expectedOutputContents, additionalConfigOptions: PInvokeGeneratorConfigurationOptions.GenerateCppAttributes, expectedDiagnostics: expectedDiagnostics);
+    }
+}