Function pointer support

documentation/for-contributors/generators/symbol-layer/symbols/README.md

@@ -19,18 +19,19 @@ Parent Symbols (Unlisted, abstract):
 | TypeSymbol | |
 | MethodSymbol |
 
-| Name                       | Symbol Layer File                                                                              | Symbol Layer Tests                                                                                                  | Emitter Tests                                                                                    |
-| -------------------------- | ---------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ |
-| ClassSymbol                | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/ClassSymbol.cs)                | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/ClassSymbolTests.cs)                | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/ClassSymbolTests.cs)                |
-| ExternalTypeReference      | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/ExternalTypeReference.cs)      | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/ExternalTypeReferenceTests.cs)      | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/ExternalTypeReferenceTests.cs)      |
-| FieldSymbol                | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/FieldSymbol.cs)                | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/FieldTests.cs)                      | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/EmitterFieldTests.cs)               |
-| IdentifierSymbol           | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/IdentifierSymbol.cs)           | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/IdentifierTests.cs)                 | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/IdentifierSymbolTests.cs)           |
-| InternalTypeReference      | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/InternalTypeReference.cs)      | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/InternalTypeReferenceTests.cs)      | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/InternalTypeReferenceTests.cs)      |
-| NamespaceSymbol            | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/NamespaceSymbol.cs)            | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/NamespaceTests.cs)                  | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/EmitterNamespaceTests.cs)           |
-| PointerTypeReference       | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/PointerTypeReference.cs)       | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/PointerTypeReferenceTests.cs)       | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/PointerTypeReferenceTests.cs)       |
-| StaticExternalMethodSymbol | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/StaticExternalMethodSymbol.cs) | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/StaticExternalMethodSymbolTests.cs) | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/StaticExternalMethodSymbolTests.cs) |
-| StructSymbol               | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/StructSymbol.cs)               | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/StructTests.cs)                     | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/EmitterStructTests.cs)              |
-| UnresolvedTypeReference    | [here](src/generators/Silk.NET.SilkTouch.Symbols/UnresolvedTypeReference.cs)                   | [here](tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/UnresolvedTypeReferenceTests.cs)                   | -                                                                                                |
+| Name                         | Symbol Layer File                                                                                | Symbol Layer Tests                                                                                                    | Emitter Tests                                                                                      |
+| ---------------------------- | ------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------- |
+| ClassSymbol                  | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/ClassSymbol.cs)                  | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/ClassSymbolTests.cs)                  | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/ClassSymbolTests.cs)                  |
+| ExternalTypeReference        | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/ExternalTypeReference.cs)        | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/ExternalTypeReferenceTests.cs)        | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/ExternalTypeReferenceTests.cs)        |
+| FunctionPointerTypeReference | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/FunctionPointerTypeReference.cs) | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/FunctionPointerTypeReferenceTests.cs) | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/FunctionPointerTypeReferenceTests.cs) |
+| FieldSymbol                  | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/FieldSymbol.cs)                  | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/FieldTests.cs)                        | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/EmitterFieldTests.cs)                 |
+| IdentifierSymbol             | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/IdentifierSymbol.cs)             | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/IdentifierTests.cs)                   | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/IdentifierSymbolTests.cs)             |
+| InternalTypeReference        | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/InternalTypeReference.cs)        | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/InternalTypeReferenceTests.cs)        | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/InternalTypeReferenceTests.cs)        |
+| NamespaceSymbol              | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/NamespaceSymbol.cs)              | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/NamespaceTests.cs)                    | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/EmitterNamespaceTests.cs)             |
+| PointerTypeReference         | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/PointerTypeReference.cs)         | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/PointerTypeReferenceTests.cs)         | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/PointerTypeReferenceTests.cs)         |
+| StaticExternalMethodSymbol   | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/StaticExternalMethodSymbol.cs)   | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/StaticExternalMethodSymbolTests.cs)   | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/StaticExternalMethodSymbolTests.cs)   |
+| StructSymbol                 | [here](../../../../../src/generators/Silk.NET.SilkTouch.Symbols/StructSymbol.cs)                 | [here](../../../../../tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/StructTests.cs)                       | [here](../../../../../tests/Silk.NET.SilkTouch.Emitter.Tests/EmitterStructTests.cs)                |
+| UnresolvedTypeReference      | [here](src/generators/Silk.NET.SilkTouch.Symbols/UnresolvedTypeReference.cs)                     | [here](tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/UnresolvedTypeReferenceTests.cs)                     | -                                                                                                  |
 
 ## How to create a symbol
 

src/generators/Silk.NET.SilkTouch.DotnetTool/Program.cs

@@ -342,6 +342,11 @@ private static IEnumerable<Symbol> ProcessSymbols
                 visitors.Add(ActivatorUtilities.CreateInstance<PointerTypeResolver>(serviceProvider, typeStore));
             }
 
+            if ((usedSymbolVisitors & AvailableSymbolVisitors.FunctionPointerTypeResolver) != 0)
+            {
+                visitors.Add(ActivatorUtilities.CreateInstance<FunctionPointerTypeResolver>(serviceProvider, typeStore));
+            }
+
             if ((usedSymbolVisitors & AvailableSymbolVisitors.InternalTypeResolver) != 0)
             {
                 var typeScopeSymbolVisitor = ActivatorUtilities.CreateInstance<TypeScopeSymbolVisitor>
@@ -518,7 +523,8 @@ private enum AvailableSymbolVisitors
             PointerTypeResolver = 1 << 1,
             InternalTypeResolver = 1 << 2,
             PrimitiveTypeResolver = 1 << 3,
-            AllTypeResolvers = PointerTypeResolver | InternalTypeResolver | PrimitiveTypeResolver,
+            FunctionPointerTypeResolver = 1 << 4,
+            AllTypeResolvers = PointerTypeResolver | InternalTypeResolver | PrimitiveTypeResolver | FunctionPointerTypeResolver,
         }
     }
 }

src/generators/Silk.NET.SilkTouch.Emitter/CSharpEmitter.cs

@@ -236,6 +236,45 @@ protected override PointerTypeReference VisitPointerTypeReference(PointerTypeRef
             return pointerTypeReference;
         }
 
+        protected override FunctionPointerTypeReference VisitFunctionPointerTypeReference
+            (FunctionPointerTypeReference functionPointerTypeReference)
+        {
+            AssertClearState();
+
+            var paramList = functionPointerTypeReference.ParameterTypes
+                .Append(functionPointerTypeReference.ReturnType)
+                .Select
+                (
+                    (x, i) =>
+                    {
+                        VisitTypeReference(x);
+                        if (_syntax is not TypeSyntax typeSyntax)
+                            throw new InvalidOperationException("TypeReference did not return TypeSyntax");
+                        ClearState();
+
+                        if (i == 0 || i > functionPointerTypeReference.ParameterTypes.Length)
+                            return typeSyntax;
+                        else
+                            return typeSyntax.WithLeadingTrivia(Space); // not ideal, but the easiest way to do this
+                    }
+                )
+                .Select(FunctionPointerParameter)
+                .ToImmutableArray();
+
+            _syntax = FunctionPointerType
+            (
+                Token(SyntaxKind.DelegateKeyword),
+                Token(SyntaxKind.AsteriskToken),
+                FunctionPointerCallingConvention(Token(SyntaxKind.UnmanagedKeyword)).WithLeadingTrivia(Space),
+                FunctionPointerParameterList
+                (
+                    SeparatedList(paramList)
+                )
+            );
+
+            return functionPointerTypeReference;
+        }
+
         protected override ExternalTypeReference VisitExternalTypeReference(ExternalTypeReference typeReference)
         {
             AssertClearState();

src/generators/Silk.NET.SilkTouch.Symbols/FunctionPointerTypeReference.cs

@@ -0,0 +1,13 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Immutable;
+
+namespace Silk.NET.SilkTouch.Symbols;
+
+/// <summary>
+/// A <see cref="TypeReference"/> representing a function pointer.
+/// </summary>
+public sealed record FunctionPointerTypeReference(TypeReference ReturnType, ImmutableArray<TypeReference> ParameterTypes) : TypeReference
+{
+}

src/generators/Silk.NET.SilkTouch.Symbols/SymbolVisitor.cs

@@ -120,6 +120,7 @@ protected virtual TypeReference VisitTypeReference(TypeReference typeReference)
         if (typeReference is InternalTypeReference itr) return VisitInternalTypeReference(itr);
         if (typeReference is UnresolvedTypeReference utr) UnresolvedTypeReference.ThrowInvalidSymbol();
         if (typeReference is PointerTypeReference ptr) return VisitPointerTypeReference(ptr);
+        if (typeReference is FunctionPointerTypeReference fptr) return VisitFunctionPointerTypeReference(fptr);
         return ThrowUnknownSymbol<TypeReference>(typeReference);
     }
 
@@ -135,7 +136,24 @@ protected virtual PointerTypeReference VisitPointerTypeReference(PointerTypeRefe
     {
         return new PointerTypeReference(VisitTypeReference(pointerTypeReference.Underlying));
     }
-
+    /// <summary>
+    /// Visit a <see cref="FunctionPointerTypeReference"/>. Will call the appropriate methods to visit the different parts of the symbol.
+    /// </summary>
+    /// <param name="functionPointerTypeReference">The function pointer type reference to visit</param>
+    /// <returns>The rewritten symbol</returns>
+    /// <remarks>
+    /// The order in which the parts are visited is kept as an implementation detail. Do not rely on this order.
+    /// </remarks>
+    protected virtual FunctionPointerTypeReference VisitFunctionPointerTypeReference
+        (FunctionPointerTypeReference functionPointerTypeReference)
+    {
+        return new FunctionPointerTypeReference
+        (
+            VisitTypeReference(functionPointerTypeReference.ReturnType),
+            functionPointerTypeReference.ParameterTypes.Select(VisitTypeReference).ToImmutableArray()
+        );
+    }
+
     /// <summary>
     /// Visit a <see cref="InternalTypeReference"/>. Will call the appropriate methods to visit the different parts of the symbol.
     /// </summary>

src/generators/Silk.NET.SilkTouch.TypeResolution/FunctionPointerTypeResolver.cs

@@ -0,0 +1,48 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Immutable;
+using System.Text.RegularExpressions;
+using Silk.NET.SilkTouch.Symbols;
+
+namespace Silk.NET.SilkTouch.TypeResolution;
+
+/// <summary>
+/// A <see cref="SimpleTypeResolverBase"/> that resolves strings of standard C# form
+/// </summary>
+public class FunctionPointerTypeResolver : SimpleTypeResolverBase
+{
+    private static readonly Regex _regex = new
+    (/*lang=regex*/
+        @"delegate\*\sunmanaged(\[((?'modifier'.(?=,\s?)?)+)*\])?\<((?'parameter'(.(?=,\s?)+))(,\s?))*(?'return_type'(.)+)\>",
+        RegexOptions.CultureInvariant
+    );
+
+    /// <inheritdoc />
+    public FunctionPointerTypeResolver(TypeStore typeStore) : base(typeStore)
+    {
+    }
+
+    /// <inheritdoc />
+    protected override bool TryResolve(UnresolvedTypeReference utr, out TypeReference? resolved)
+    {
+        if (utr.Text.StartsWith("delegate*"))
+        {
+            var match = _regex.Match(utr.Text);
+            if (match.Success)
+            {
+                var parameters = match.Groups["parameter"]
+                    .Captures.OfType<Capture>()
+                    .Select(x => new UnresolvedTypeReference(x.Value))
+                    .Cast<TypeReference>()
+                    .ToImmutableArray();
+                var returnType = new UnresolvedTypeReference(match.Groups["return_type"].Value);
+
+                resolved = new FunctionPointerTypeReference(returnType, parameters);
+                return true;
+            }
+        }
+        resolved = null;
+        return false;
+    }
+}

tests/Silk.NET.SilkTouch.Emitter.Tests/FunctionPointerTypeReferenceTests.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Immutable;
+using Silk.NET.SilkTouch.Symbols;
+using Xunit;
+
+namespace Silk.NET.SilkTouch.Emitter.Tests;
+
+public class FunctionPointerTypeReferenceTests : EmitterTest
+{
+    [Fact, Trait("Category", "Symbols"),
+     Trait("Target Language", "C#")]
+    public void StringTestNoParams()
+    {
+        var symbol = new FunctionPointerTypeReference
+            (new ExternalTypeReference(null, new IdentifierSymbol("Ret")), ImmutableArray<TypeReference>.Empty);
+
+        var transformed = Transform(symbol);
+
+        Assert.Equal("delegate* unmanaged<Ret>", transformed.ToFullString());
+    }
+
+    [Fact, Trait("Category", "Symbols"),
+     Trait("Target Language", "C#")]
+    public void StringTestWithParams()
+    {
+        var symbol = new FunctionPointerTypeReference
+            (new ExternalTypeReference(null, new IdentifierSymbol("Ret")), new TypeReference[]
+            {
+                new ExternalTypeReference(null, new IdentifierSymbol("Param1")),
+                new ExternalTypeReference(null, new IdentifierSymbol("Param2")),
+            }.ToImmutableArray());
+
+        var transformed = Transform(symbol);
+
+        Assert.Equal("delegate* unmanaged<Param1, Param2, Ret>", transformed.ToFullString());
+    }
+}

tests/Silk.NET.SilkTouch.IntegrationTests/TestHelper.cs

@@ -55,6 +55,7 @@ public static string GetCSharpOutputFromCpp(string cpp)
         var processors = new SymbolVisitor[]
         {
             ActivatorUtilities.CreateInstance<PointerTypeResolver>(serviceProvider, typeStore),
+            ActivatorUtilities.CreateInstance<FunctionPointerTypeResolver>(serviceProvider, typeStore),
             ActivatorUtilities.CreateInstance<PrimitiveTypeResolver>(serviceProvider, typeStore),
 
             typeScopeSymbolVisitor,

tests/Silk.NET.SilkTouch.Symbols.Tests/SymbolVisitorTests/FunctionPointerTypeReferenceTests.cs

@@ -0,0 +1,36 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Immutable;
+using Moq;
+using Moq.Protected;
+using Xunit;
+
+namespace Silk.NET.SilkTouch.Symbols.Tests.SymbolVisitorTests;
+
+public class FunctionPointerTypeReferenceTests
+{
+    [Fact, Trait("Category", "Symbols")]
+    public void VisitedAsSelf()
+    {
+        var symbol = new FunctionPointerTypeReference(new InternalTypeReference(TypeId.CreateNew()), ImmutableArray<TypeReference>.Empty);
+        var visitor = new Mock<MockSymbolVisitor> { CallBase = true };
+        visitor.Object.Visit(symbol);
+
+        visitor.Protected()
+            .Verify<FunctionPointerTypeReference>
+                ("VisitFunctionPointerTypeReference", Times.Once(), ItExpr.IsAny<FunctionPointerTypeReference>());
+    }
+
+    [Fact, Trait("Category", "Symbols")]
+    public void VisitedAsRef()
+    {
+        var symbol = new FunctionPointerTypeReference(new InternalTypeReference(TypeId.CreateNew()), ImmutableArray<TypeReference>.Empty);
+        var visitor = new Mock<MockSymbolVisitor> { CallBase = true };
+        visitor.Object.Visit(symbol);
+
+        visitor.Protected()
+            .Verify<TypeReference>
+                ("VisitTypeReference", Times.Once(), ItExpr.Is<TypeReference>(x => ReferenceEquals(x, symbol)));
+    }
+}