Provide a few new features for C# 10 and .NET 6

README.md

@@ -186,7 +186,6 @@ Options:
   exclude-enum-operators                 Bindings for operators over enum types should not be generated. These are largely unnecessary in C# as the operators are available by default.
   exclude-fnptr-codegen                  Generated bindings for latest or preview codegen should not use function pointers.
   exclude-funcs-with-body                Bindings for functions with bodies should not be generated.
-  preview-codegen-nint                   Generated bindings for latest or preview codegen should not use nint or nuint.
   exclude-using-statics-for-enums        Enum usages should be fully qualified and should not include a corresponding 'using static EnumName;'
   explicit-vtbls                         VTBLs should have an explicit type generated with named fields per entry.
   implicit-vtbls                         VTBLs should be implicit to reduce metadata bloat. This is the current default
@@ -195,6 +194,7 @@ Options:
   generate-tests-xunit                   Basic tests validating size, blittability, and associated metadata should be generated for XUnit.
   generate-aggressive-inlining           [MethodImpl(MethodImplOptions.AggressiveInlining)] should be added to generated helper functions.
   generate-cpp-attributes                [CppAttributeList("")] should be generated to document the encountered C++ attributes.
+  generate-file-scoped-namespaces        Namespaces should be scoped to the file to reduce nesting.
   generate-helper-types                  Code files should be generated for various helper attributes and declared transparent structs.
   generate-macro-bindings                Bindings for macro-definitions should be generated. This currently only works with value like macros and not function-like ones.
   generate-marker-interfaces             Bindings for marker interfaces representing native inheritance hierarchies should be generated.

sources/ClangSharp.PInvokeGenerator/Abstractions/EnumDesc.cs

@@ -1,3 +1,4 @@
+using System;
 using ClangSharp.Interop;
 
 namespace ClangSharp.Abstractions
@@ -23,5 +24,7 @@ public bool IsNested
                 Flags = value ? Flags | EnumFlags.Nested : Flags & ~EnumFlags.Nested;
             }
         }
+        public Action<object> WriteCustomAttrs { get; set; }
+        public object CustomAttrGeneratorData { get; set; }
     }
 }

sources/ClangSharp.PInvokeGenerator/Abstractions/FieldDesc.cs

@@ -1,5 +1,6 @@
 // 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 ClangSharp.Interop;
 
 namespace ClangSharp.Abstractions
@@ -11,7 +12,10 @@ internal struct FieldDesc
         public string EscapedName { get; set; }
         public int? Offset { get; set; }
         public bool NeedsNewKeyword { get; set; }
+        public bool HasBody { get; set; }
         public string InheritedFrom { get; set; }
         public CXSourceLocation? Location { get; set; }
+        public Action<object> WriteCustomAttrs { get; set; }
+        public object CustomAttrGeneratorData { get; set; }
     }
 }

sources/ClangSharp.PInvokeGenerator/Abstractions/FunctionOrDelegateDesc.cs

@@ -6,7 +6,7 @@
 
 namespace ClangSharp.Abstractions
 {
-    internal struct FunctionOrDelegateDesc<TCustomAttrGeneratorData>
+    internal struct FunctionOrDelegateDesc
     {
         public AccessSpecifier AccessSpecifier { get; set; }
         public string NativeTypeName { get; set; }
@@ -18,6 +18,7 @@ internal struct FunctionOrDelegateDesc<TCustomAttrGeneratorData>
         public FunctionOrDelegateFlags Flags { get; set; }
         public long? VtblIndex { get; set; }
         public CXSourceLocation? Location { get; set; }
+        public bool HasBody { get; set; }
 
         public bool IsVirtual
         {
@@ -228,7 +229,7 @@ public bool IsCxxConstructor
             }
         }
 
-        public Action<TCustomAttrGeneratorData> WriteCustomAttrs { get; set; }
-        public TCustomAttrGeneratorData CustomAttrGeneratorData { get; set; }
+        public Action<object> WriteCustomAttrs { get; set; }
+        public object CustomAttrGeneratorData { get; set; }
     }
 }

sources/ClangSharp.PInvokeGenerator/Abstractions/IOutputBuilder.VisitDecl.cs

@@ -22,19 +22,19 @@ internal partial interface IOutputBuilder
         void EndValue(in ValueDesc desc);
 
         void BeginEnum(in EnumDesc desc);
-        void EndEnum();
+        void EndEnum(in EnumDesc desc);
 
         void BeginField(in FieldDesc desc);
         void WriteFixedCountField(string typeName, string escapedName, string fixedName, string count);
         void WriteRegularField(string typeName, string escapedName);
-        void EndField(bool isBodyless = true);
+        void EndField(in FieldDesc desc);
 
-        void BeginFunctionOrDelegate<TCustomAttrGeneratorData>(in FunctionOrDelegateDesc<TCustomAttrGeneratorData> info, ref bool isMethodClassUnsafe);
+        void BeginFunctionOrDelegate(in FunctionOrDelegateDesc info, ref bool isMethodClassUnsafe);
         void BeginFunctionInnerPrototype(string escapedName);
-        void BeginParameter<TCustomAttrGeneratorData>(in ParameterDesc<TCustomAttrGeneratorData> info);
+        void BeginParameter(in ParameterDesc info);
         void BeginParameterDefault();
         void EndParameterDefault();
-        void EndParameter();
+        void EndParameter(in ParameterDesc info);
         void WriteParameterSeparator();
         void EndFunctionInnerPrototype();
         void BeginConstructorInitializer(string memberRefName, string memberInitName);
@@ -45,14 +45,14 @@ internal partial interface IOutputBuilder
         void BeginInnerFunctionBody();
         void EndInnerFunctionBody();
         void EndBody(bool isExpressionBody = false);
-        void EndFunctionOrDelegate(bool isVirtual, bool isBodyless);
+        void EndFunctionOrDelegate(in FunctionOrDelegateDesc info);
 
-        void BeginStruct<TCustomAttrGeneratorData>(in StructDesc<TCustomAttrGeneratorData> info);
+        void BeginStruct(in StructDesc info);
         void BeginMarkerInterface(string[] baseTypeNames);
         void EndMarkerInterface();
         void BeginExplicitVtbl();
         void EndExplicitVtbl();
-        void EndStruct();
+        void EndStruct(in StructDesc info);
 
         void EmitCompatibleCodeSupport();
         void EmitFnPtrSupport();

sources/ClangSharp.PInvokeGenerator/Abstractions/ParameterDesc.cs

@@ -6,14 +6,14 @@
 
 namespace ClangSharp.Abstractions
 {
-    internal struct ParameterDesc<TCustomAttrGeneratorData>
+    internal struct ParameterDesc
     {
         public string Type { get; set; }
         public string Name { get; set; }
         public string NativeTypeName { get; set; }
         public IEnumerable<string> CppAttributes { get; set; }
-        public Action<TCustomAttrGeneratorData> WriteCustomAttrs { get; set; }
-        public TCustomAttrGeneratorData CustomAttrGeneratorData { get; set; }
+        public Action<object> WriteCustomAttrs { get; set; }
+        public object CustomAttrGeneratorData { get; set; }
         public CXSourceLocation? Location { get; set; }
     }
 }

sources/ClangSharp.PInvokeGenerator/Abstractions/StructDesc.cs

@@ -7,7 +7,7 @@
 
 namespace ClangSharp.Abstractions
 {
-    internal struct StructDesc<TCustomAttrGeneratorData>
+    internal struct StructDesc
     {
         public AccessSpecifier AccessSpecifier { get; set; }
         public string EscapedName { get; set; }
@@ -70,8 +70,8 @@ public bool IsUnion
             }
         }
 
-        public Action<TCustomAttrGeneratorData> WriteCustomAttrs { get; set; }
-        public TCustomAttrGeneratorData CustomAttrGeneratorData { get; set; }
+        public Action<object> WriteCustomAttrs { get; set; }
+        public object CustomAttrGeneratorData { get; set; }
 
         public StructLayoutAttribute LayoutAttribute
         {

sources/ClangSharp.PInvokeGenerator/Abstractions/ValueDesc.cs

@@ -1,5 +1,6 @@
 // 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 ClangSharp.Interop;
 
 namespace ClangSharp.Abstractions
@@ -18,5 +19,7 @@ internal struct ValueDesc
         public bool IsArray => Flags.HasFlag(ValueFlags.Array);
         public bool IsConstant => Flags.HasFlag(ValueFlags.Constant);
         public bool IsCopy => Flags.HasFlag(ValueFlags.Copy);
+        public Action<object> WriteCustomAttrs { get; set; }
+        public object CustomAttrGeneratorData { get; set; }
     }
 }

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

@@ -41,6 +41,8 @@ public void BeginValue(in ValueDesc desc)
                 WriteSourceLocation(location, false);
             }
 
+            desc.WriteCustomAttrs?.Invoke(desc.CustomAttrGeneratorData);
+
             var isProperty = false;
             var isExpressionBody = false;
 
@@ -212,6 +214,8 @@ public void BeginEnum(in EnumDesc desc)
                 WriteSourceLocation(location, false);
             }
 
+            desc.WriteCustomAttrs?.Invoke(desc.CustomAttrGeneratorData);
+
             WriteIndented(GetAccessSpecifierString(desc.AccessSpecifier, desc.IsNested));
             Write(" enum ");
             Write(desc.EscapedName);
@@ -226,7 +230,7 @@ public void BeginEnum(in EnumDesc desc)
             WriteBlockStart();
         }
 
-        public void EndEnum() => WriteBlockEnd();
+        public void EndEnum(in EnumDesc desc) => WriteBlockEnd();
 
         public void BeginField(in FieldDesc desc)
         {
@@ -245,6 +249,8 @@ public void BeginField(in FieldDesc desc)
                 WriteSourceLocation(location, false);
             }
 
+            desc.WriteCustomAttrs?.Invoke(desc.CustomAttrGeneratorData);
+
             WriteIndented(GetAccessSpecifierString(desc.AccessSpecifier, isNested: true));
             Write(' ');
 
@@ -281,20 +287,18 @@ public void WriteRegularField(string typeName, string escapedName)
             Write(escapedName);
         }
 
-        public void EndField(bool isBodyless = true)
+        public void EndField(in FieldDesc desc)
         {
-            if (isBodyless)
+            if (!desc.HasBody)
             {
                 WriteSemicolon();
                 WriteNewline();
                 NeedsNewline = true;
             }
         }
 
-        public void BeginFunctionOrDelegate<TCustomAttrGeneratorData>(in FunctionOrDelegateDesc<TCustomAttrGeneratorData> desc, ref bool isMethodClassUnsafe)
+        public void BeginFunctionOrDelegate(in FunctionOrDelegateDesc desc, ref bool isMethodClassUnsafe)
         {
-            desc.WriteCustomAttrs?.Invoke(desc.CustomAttrGeneratorData);
-
             if (desc.IsVirtual)
             {
                 Debug.Assert(!desc.HasFnPtrCodeGen);
@@ -338,10 +342,12 @@ public void BeginFunctionOrDelegate<TCustomAttrGeneratorData>(in FunctionOrDeleg
                 }
 
                 Write("ExactSpelling = true");
-                if (desc.SetLastError)
+
+                if (desc.SetLastError && !_config.GenerateSetsLastSystemErrorAttribute)
                 {
                     Write(", SetLastError = true");
                 }
+
                 WriteLine(")]");
             }
 
@@ -350,6 +356,12 @@ public void BeginFunctionOrDelegate<TCustomAttrGeneratorData>(in FunctionOrDeleg
                 WriteSourceLocation(location, false);
             }
 
+            if (desc.SetLastError && _config.GenerateSetsLastSystemErrorAttribute)
+            {
+                WriteIndentedLine("[SetsLastSystemError]");
+            }
+            // GenerateSetsLastSystemErrorAttribute
+
             if (desc.IsAggressivelyInlined)
             {
                 AddUsingDirective("System.Runtime.CompilerServices");
@@ -368,6 +380,8 @@ public void BeginFunctionOrDelegate<TCustomAttrGeneratorData>(in FunctionOrDeleg
                 AddNativeTypeNameAttribute(desc.NativeTypeName, attributePrefix: "return: ");
             }
 
+            desc.WriteCustomAttrs?.Invoke(desc.CustomAttrGeneratorData);
+
             if (_isInMarkerInterface)
             {
                 WriteIndentation();
@@ -466,7 +480,7 @@ public void BeginFunctionInnerPrototype(string escapedName)
             Write('(');
         }
 
-        public void BeginParameter<TCustomAttrGeneratorData>(in ParameterDesc<TCustomAttrGeneratorData> info)
+        public void BeginParameter(in ParameterDesc info)
         {
             if (info.NativeTypeName is not null)
             {
@@ -498,7 +512,7 @@ public void EndParameterDefault()
             // nop, used only by XML
         }
 
-        public void EndParameter()
+        public void EndParameter(in ParameterDesc info)
         {
             // nop, used only by XML
         }
@@ -572,9 +586,9 @@ public void EndBody(bool isExpressionBody = false)
             }
         }
 
-        public void EndFunctionOrDelegate(bool isVirtual, bool isBodyless)
+        public void EndFunctionOrDelegate(in FunctionOrDelegateDesc desc)
         {
-            if (isBodyless)
+            if (!desc.HasBody || desc.IsVirtual)
             {
                 WriteSemicolon();
                 WriteNewline();
@@ -583,7 +597,7 @@ public void EndFunctionOrDelegate(bool isVirtual, bool isBodyless)
             NeedsNewline = true;
         }
 
-        public void BeginStruct<TCustomAttrGeneratorData>(in StructDesc<TCustomAttrGeneratorData> desc)
+        public void BeginStruct(in StructDesc desc)
         {
             if (desc.LayoutAttribute is not null)
             {
@@ -624,6 +638,8 @@ public void BeginStruct<TCustomAttrGeneratorData>(in StructDesc<TCustomAttrGener
                 WriteSourceLocation(location, false);
             }
 
+            desc.WriteCustomAttrs?.Invoke(desc.CustomAttrGeneratorData);
+
             WriteIndented(GetAccessSpecifierString(desc.AccessSpecifier, desc.IsNested));
             Write(' ');
 
@@ -685,7 +701,7 @@ public void EmitFnPtrSupport()
 
         public void EmitSystemSupport() => AddUsingDirective("System");
 
-        public void EndStruct() => WriteBlockEnd();
+        public void EndStruct(in StructDesc desc) => WriteBlockEnd();
 
         public void EndMarkerInterface()
         {

sources/ClangSharp.PInvokeGenerator/CSharp/CSharpOutputBuilder.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Text;
 
 namespace ClangSharp.CSharp
@@ -66,11 +67,7 @@ internal sealed partial class CSharpOutputBuilder
 
         public void DecreaseIndentation()
         {
-            if (_indentationLevel == 0)
-            {
-                throw new InvalidOperationException();
-            }
-
+            Debug.Assert(_indentationLevel > 0);
             _indentationLevel--;
         }