C#: Static marshaling for bindings and source generators

Previously, we added source generators for invoking/accessing methods,
properties and fields in scripts. This freed us from the overhead of
reflection. However, the generated code still used our dynamic
marshaling functions, which do runtime type checking and box value
types.

This commit changes the bindings and source generators to include
'static' marshaling. Based on the types known at compile time, now
we generate the appropriate marshaling call for each type.

1 files changed, 299 insertions, 6 deletions

diff --git a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/MarshalUtils.cs b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/MarshalUtils.cs
index 5a4badd66e..9dff404ede 100644
--- a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/MarshalUtils.cs
+++ b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/MarshalUtils.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Linq;
+using System.Text;
 using Microsoft.CodeAnalysis;
 
 namespace Godot.SourceGenerators
@@ -11,7 +12,11 @@ namespace Godot.SourceGenerators
             public INamedTypeSymbol GodotObjectType { get; }
             public INamedTypeSymbol GodotGenericDictionary { get; }
             public INamedTypeSymbol GodotGenericArray { get; }
+
+            // ReSharper disable once InconsistentNaming
             public INamedTypeSymbol IDictionary { get; }
+
+            // ReSharper disable once InconsistentNaming
             public INamedTypeSymbol ICollection { get; }
             public INamedTypeSymbol GenericIDictionary { get; }
             public INamedTypeSymbol SystemGenericDictionary { get; }
@@ -74,14 +79,15 @@ namespace Godot.SourceGenerators
                 MarshalType.ByteArray => VariantType.PackedByteArray,
                 MarshalType.Int32Array => VariantType.PackedInt32Array,
                 MarshalType.Int64Array => VariantType.PackedInt64Array,
-                MarshalType.SingleArray => VariantType.PackedFloat32Array,
-                MarshalType.DoubleArray => VariantType.PackedFloat64Array,
+                MarshalType.Float32Array => VariantType.PackedFloat32Array,
+                MarshalType.Float64Array => VariantType.PackedFloat64Array,
                 MarshalType.StringArray => VariantType.PackedStringArray,
                 MarshalType.Vector2Array => VariantType.PackedVector2Array,
                 MarshalType.Vector3Array => VariantType.PackedVector3Array,
                 MarshalType.ColorArray => VariantType.PackedColorArray,
                 MarshalType.GodotObjectOrDerivedArray => VariantType.Array,
                 MarshalType.SystemObjectArray => VariantType.Array,
+                MarshalType.SystemArrayOfSupportedType => VariantType.Array,
                 MarshalType.GodotGenericDictionary => VariantType.Dictionary,
                 MarshalType.GodotGenericArray => VariantType.Array,
                 MarshalType.SystemGenericDictionary => VariantType.Dictionary,
@@ -187,9 +193,9 @@ namespace Godot.SourceGenerators
                             case SpecialType.System_Int64:
                                 return MarshalType.Int64Array;
                             case SpecialType.System_Single:
-                                return MarshalType.SingleArray;
+                                return MarshalType.Float32Array;
                             case SpecialType.System_Double:
-                                return MarshalType.DoubleArray;
+                                return MarshalType.Float64Array;
                             case SpecialType.System_String:
                                 return MarshalType.StringArray;
                             case SpecialType.System_Object:
@@ -209,12 +215,12 @@ namespace Godot.SourceGenerators
                                 case { Name: "Vector3" }:
                                     return MarshalType.Vector3Array;
                                 case { Name: "Color" }:
-                                return MarshalType.ColorArray;
+                                    return MarshalType.ColorArray;
                             }
                         }
 
                         if (ConvertManagedTypeToMarshalType(elementType, typeCache) != null)
-                            return MarshalType.GodotArray;
+                            return MarshalType.SystemArrayOfSupportedType;
 
                         return null;
                     }
@@ -316,5 +322,292 @@ namespace Godot.SourceGenerators
 
             return null;
         }
+
+        private static StringBuilder Append(this StringBuilder source, string a, string b, string c)
+            => source.Append(a).Append(b).Append(c);
+
+        private static StringBuilder Append(this StringBuilder source, string a, string b,
+            string c, string d)
+            => source.Append(a).Append(b).Append(c).Append(d);
+
+        private static StringBuilder Append(this StringBuilder source, string a, string b,
+            string c, string d, string e)
+            => source.Append(a).Append(b).Append(c).Append(d).Append(e);
+
+        private static StringBuilder Append(this StringBuilder source, string a, string b,
+            string c, string d, string e, string f)
+            => source.Append(a).Append(b).Append(c).Append(d).Append(e).Append(f);
+
+        private static StringBuilder Append(this StringBuilder source, string a, string b,
+            string c, string d, string e, string f, string g)
+            => source.Append(a).Append(b).Append(c).Append(d).Append(e).Append(f).Append(g);
+
+        private static StringBuilder Append(this StringBuilder source, string a, string b,
+            string c, string d, string e, string f, string g, string h)
+            => source.Append(a).Append(b).Append(c).Append(d).Append(e).Append(f).Append(g).Append(h);
+
+        private const string Marshaling = "global::Godot.NativeInterop.Marshaling";
+        private const string VariantUtils = "global::Godot.NativeInterop.VariantUtils";
+
+        public static StringBuilder AppendVariantToManagedExpr(this StringBuilder source,
+            string inputExpr, ITypeSymbol typeSymbol, MarshalType marshalType)
+        {
+            return marshalType switch
+            {
+                MarshalType.Boolean =>
+                    source.Append(VariantUtils, ".ConvertToBool(", inputExpr, ")"),
+                MarshalType.Char =>
+                    source.Append("(char)", VariantUtils, ".ConvertToUInt16(", inputExpr, ")"),
+                MarshalType.SByte =>
+                    source.Append(VariantUtils, ".ConvertToInt8(", inputExpr, ")"),
+                MarshalType.Int16 =>
+                    source.Append(VariantUtils, ".ConvertToInt16(", inputExpr, ")"),
+                MarshalType.Int32 =>
+                    source.Append(VariantUtils, ".ConvertToInt32(", inputExpr, ")"),
+                MarshalType.Int64 =>
+                    source.Append(VariantUtils, ".ConvertToInt64(", inputExpr, ")"),
+                MarshalType.Byte =>
+                    source.Append(VariantUtils, ".ConvertToUInt8(", inputExpr, ")"),
+                MarshalType.UInt16 =>
+                    source.Append(VariantUtils, ".ConvertToUInt16(", inputExpr, ")"),
+                MarshalType.UInt32 =>
+                    source.Append(VariantUtils, ".ConvertToUInt32(", inputExpr, ")"),
+                MarshalType.UInt64 =>
+                    source.Append(VariantUtils, ".ConvertToUInt64(", inputExpr, ")"),
+                MarshalType.Single =>
+                    source.Append(VariantUtils, ".ConvertToFloat32(", inputExpr, ")"),
+                MarshalType.Double =>
+                    source.Append(VariantUtils, ".ConvertToFloat64(", inputExpr, ")"),
+                MarshalType.String =>
+                    source.Append(VariantUtils, ".ConvertToStringObject(", inputExpr, ")"),
+                MarshalType.Vector2 =>
+                    source.Append(VariantUtils, ".ConvertToVector2(", inputExpr, ")"),
+                MarshalType.Vector2i =>
+                    source.Append(VariantUtils, ".ConvertToVector2i(", inputExpr, ")"),
+                MarshalType.Rect2 =>
+                    source.Append(VariantUtils, ".ConvertToRect2(", inputExpr, ")"),
+                MarshalType.Rect2i =>
+                    source.Append(VariantUtils, ".ConvertToRect2i(", inputExpr, ")"),
+                MarshalType.Transform2D =>
+                    source.Append(VariantUtils, ".ConvertToTransform2D(", inputExpr, ")"),
+                MarshalType.Vector3 =>
+                    source.Append(VariantUtils, ".ConvertToVector3(", inputExpr, ")"),
+                MarshalType.Vector3i =>
+                    source.Append(VariantUtils, ".ConvertToVector3i(", inputExpr, ")"),
+                MarshalType.Basis =>
+                    source.Append(VariantUtils, ".ConvertToBasis(", inputExpr, ")"),
+                MarshalType.Quaternion =>
+                    source.Append(VariantUtils, ".ConvertToQuaternion(", inputExpr, ")"),
+                MarshalType.Transform3D =>
+                    source.Append(VariantUtils, ".ConvertToTransform3D(", inputExpr, ")"),
+                MarshalType.AABB =>
+                    source.Append(VariantUtils, ".ConvertToAABB(", inputExpr, ")"),
+                MarshalType.Color =>
+                    source.Append(VariantUtils, ".ConvertToColor(", inputExpr, ")"),
+                MarshalType.Plane =>
+                    source.Append(VariantUtils, ".ConvertToPlane(", inputExpr, ")"),
+                MarshalType.Callable =>
+                    source.Append(VariantUtils, ".ConvertToCallableManaged(", inputExpr, ")"),
+                MarshalType.SignalInfo =>
+                    source.Append(VariantUtils, ".ConvertToSignalInfo(", inputExpr, ")"),
+                MarshalType.Enum =>
+                    source.Append("(", typeSymbol.FullQualifiedName(),
+                        ")", VariantUtils, ".ConvertToInt32(", inputExpr, ")"),
+                MarshalType.ByteArray =>
+                    source.Append(VariantUtils, ".ConvertAsPackedByteArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.Int32Array =>
+                    source.Append(VariantUtils, ".ConvertAsPackedInt32ArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.Int64Array =>
+                    source.Append(VariantUtils, ".ConvertAsPackedInt64ArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.Float32Array =>
+                    source.Append(VariantUtils, ".ConvertAsPackedFloat32ArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.Float64Array =>
+                    source.Append(VariantUtils, ".ConvertAsPackedFloat64ArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.StringArray =>
+                    source.Append(VariantUtils, ".ConvertAsPackedStringArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.Vector2Array =>
+                    source.Append(VariantUtils, ".ConvertAsPackedVector2ArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.Vector3Array =>
+                    source.Append(VariantUtils, ".ConvertAsPackedVector3ArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.ColorArray =>
+                    source.Append(VariantUtils, ".ConvertAsPackedColorArrayToSystemArray(", inputExpr, ")"),
+                MarshalType.GodotObjectOrDerivedArray =>
+                    source.Append(VariantUtils, ".ConvertToSystemArrayOfGodotObject<",
+                        ((IArrayTypeSymbol)typeSymbol).ElementType.FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.SystemObjectArray =>
+                    source.Append(VariantUtils, ".ConvertToSystemArrayOfVariant(", inputExpr, ")"),
+                MarshalType.SystemArrayOfSupportedType =>
+                    source.Append(VariantUtils, ".ConvertToSystemArrayOfSupportedType<",
+                        ((IArrayTypeSymbol)typeSymbol).ElementType.FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.GodotGenericDictionary =>
+                    source.Append(VariantUtils, ".ConvertToGenericDictionaryObject<",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[0].FullQualifiedName(), ", ",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[1].FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.GodotGenericArray =>
+                    source.Append(VariantUtils, ".ConvertToGenericArrayObject<",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[0].FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.SystemGenericDictionary =>
+                    source.Append(VariantUtils, ".ConvertToSystemGenericDictionary<",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[0].FullQualifiedName(), ", ",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[1].FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.SystemGenericList =>
+                    source.Append(VariantUtils, ".ConvertToSystemGenericList<",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[0].FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.GenericIDictionary =>
+                    source.Append(VariantUtils, ".ConvertToGenericDictionaryObject<",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[0].FullQualifiedName(), ", ",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[1].FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.GenericICollection or MarshalType.GenericIEnumerable =>
+                    source.Append(VariantUtils, ".ConvertToGenericArrayObject<",
+                        ((INamedTypeSymbol)typeSymbol).TypeArguments[0].FullQualifiedName(), ">(", inputExpr, ")"),
+                MarshalType.SystemObject =>
+                    source.Append(Marshaling, ".ConvertVariantToManagedObject(", inputExpr, ")"),
+                MarshalType.GodotObjectOrDerived =>
+                    source.Append("(", typeSymbol.FullQualifiedName(),
+                        ")", VariantUtils, ".ConvertToGodotObject(", inputExpr, ")"),
+                MarshalType.StringName =>
+                    source.Append(VariantUtils, ".ConvertToStringNameObject(", inputExpr, ")"),
+                MarshalType.NodePath =>
+                    source.Append(VariantUtils, ".ConvertToNodePathObject(", inputExpr, ")"),
+                MarshalType.RID =>
+                    source.Append(VariantUtils, ".ConvertToRID(", inputExpr, ")"),
+                MarshalType.GodotDictionary =>
+                    source.Append(VariantUtils, ".ConvertToDictionaryObject(", inputExpr, ")"),
+                MarshalType.GodotArray =>
+                    source.Append(VariantUtils, ".ConvertToArrayObject(", inputExpr, ")"),
+                MarshalType.IDictionary =>
+                    source.Append(VariantUtils, ".ConvertToDictionaryObject(", inputExpr, ")"),
+                MarshalType.ICollection or MarshalType.IEnumerable =>
+                    source.Append(VariantUtils, ".ConvertToArrayObject(", inputExpr, ")"),
+                _ => throw new ArgumentOutOfRangeException(nameof(marshalType), marshalType,
+                    "Received unexpected marshal type")
+            };
+        }
+
+        public static StringBuilder AppendManagedToVariantExpr(
+            this StringBuilder source, string inputExpr, MarshalType marshalType)
+        {
+            return marshalType switch
+            {
+                MarshalType.Boolean =>
+                    source.Append(VariantUtils, ".CreateFromBool(", inputExpr, ")"),
+                MarshalType.Char =>
+                    source.Append(VariantUtils, ".CreateFromInt((ushort)", inputExpr, ")"),
+                MarshalType.SByte =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.Int16 =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.Int32 =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.Int64 =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.Byte =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.UInt16 =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.UInt32 =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.UInt64 =>
+                    source.Append(VariantUtils, ".CreateFromInt(", inputExpr, ")"),
+                MarshalType.Single =>
+                    source.Append(VariantUtils, ".CreateFromFloat(", inputExpr, ")"),
+                MarshalType.Double =>
+                    source.Append(VariantUtils, ".CreateFromFloat(", inputExpr, ")"),
+                MarshalType.String =>
+                    source.Append(VariantUtils, ".CreateFromString(", inputExpr, ")"),
+                MarshalType.Vector2 =>
+                    source.Append(VariantUtils, ".CreateFromVector2(", inputExpr, ")"),
+                MarshalType.Vector2i =>
+                    source.Append(VariantUtils, ".CreateFromVector2i(", inputExpr, ")"),
+                MarshalType.Rect2 =>
+                    source.Append(VariantUtils, ".CreateFromRect2(", inputExpr, ")"),
+                MarshalType.Rect2i =>
+                    source.Append(VariantUtils, ".CreateFromRect2i(", inputExpr, ")"),
+                MarshalType.Transform2D =>
+                    source.Append(VariantUtils, ".CreateFromTransform2D(", inputExpr, ")"),
+                MarshalType.Vector3 =>
+                    source.Append(VariantUtils, ".CreateFromVector3(", inputExpr, ")"),
+                MarshalType.Vector3i =>
+                    source.Append(VariantUtils, ".CreateFromVector3i(", inputExpr, ")"),
+                MarshalType.Basis =>
+                    source.Append(VariantUtils, ".CreateFromBasis(", inputExpr, ")"),
+                MarshalType.Quaternion =>
+                    source.Append(VariantUtils, ".CreateFromQuaternion(", inputExpr, ")"),
+                MarshalType.Transform3D =>
+                    source.Append(VariantUtils, ".CreateFromTransform3D(", inputExpr, ")"),
+                MarshalType.AABB =>
+                    source.Append(VariantUtils, ".CreateFromAABB(", inputExpr, ")"),
+                MarshalType.Color =>
+                    source.Append(VariantUtils, ".CreateFromColor(", inputExpr, ")"),
+                MarshalType.Plane =>
+                    source.Append(VariantUtils, ".CreateFromPlane(", inputExpr, ")"),
+                MarshalType.Callable =>
+                    source.Append(VariantUtils, ".CreateFromCallable(", inputExpr, ")"),
+                MarshalType.SignalInfo =>
+                    source.Append(VariantUtils, ".CreateFromSignalInfo(", inputExpr, ")"),
+                MarshalType.Enum =>
+                    source.Append(VariantUtils, ".CreateFromInt((int)", inputExpr, ")"),
+                MarshalType.ByteArray =>
+                    source.Append(VariantUtils, ".CreateFromPackedByteArray(", inputExpr, ")"),
+                MarshalType.Int32Array =>
+                    source.Append(VariantUtils, ".CreateFromPackedInt32Array(", inputExpr, ")"),
+                MarshalType.Int64Array =>
+                    source.Append(VariantUtils, ".CreateFromPackedInt64Array(", inputExpr, ")"),
+                MarshalType.Float32Array =>
+                    source.Append(VariantUtils, ".CreateFromPackedFloat32Array(", inputExpr, ")"),
+                MarshalType.Float64Array =>
+                    source.Append(VariantUtils, ".CreateFromPackedFloat64Array(", inputExpr, ")"),
+                MarshalType.StringArray =>
+                    source.Append(VariantUtils, ".CreateFromPackedStringArray(", inputExpr, ")"),
+                MarshalType.Vector2Array =>
+                    source.Append(VariantUtils, ".CreateFromPackedVector2Array(", inputExpr, ")"),
+                MarshalType.Vector3Array =>
+                    source.Append(VariantUtils, ".CreateFromPackedVector3Array(", inputExpr, ")"),
+                MarshalType.ColorArray =>
+                    source.Append(VariantUtils, ".CreateFromPackedColorArray(", inputExpr, ")"),
+                MarshalType.GodotObjectOrDerivedArray =>
+                    source.Append(VariantUtils, ".CreateFromSystemArrayOfGodotObject(", inputExpr, ")"),
+                MarshalType.SystemObjectArray =>
+                    source.Append(VariantUtils, ".CreateFromSystemArrayOfVariant(", inputExpr, ")"),
+                MarshalType.SystemArrayOfSupportedType =>
+                    source.Append(VariantUtils, ".CreateFromSystemArrayOfSupportedType(", inputExpr, ")"),
+                MarshalType.GodotGenericDictionary =>
+                    source.Append(VariantUtils, ".CreateFromDictionary(", inputExpr, ")"),
+                MarshalType.GodotGenericArray =>
+                    source.Append(VariantUtils, ".CreateFromArray(", inputExpr, ")"),
+                MarshalType.SystemGenericDictionary =>
+                    source.Append(VariantUtils, ".CreateFromSystemDictionary(", inputExpr, ")"),
+                MarshalType.SystemGenericList =>
+                    source.Append(VariantUtils, ".CreateFromSystemICollection(", inputExpr, ")"),
+                MarshalType.GenericIDictionary =>
+                    source.Append(VariantUtils, ".CreateFromSystemGenericIDictionary(", inputExpr, ")"),
+                MarshalType.GenericICollection =>
+                    source.Append(VariantUtils, ".CreateFromSystemGenericICollection(", inputExpr, ")"),
+                MarshalType.GenericIEnumerable =>
+                    source.Append(VariantUtils, ".CreateFromSystemGenericIEnumerable(", inputExpr, ")"),
+                MarshalType.SystemObject =>
+                    source.Append(Marshaling, ".ConvertManagedObjectToVariant(", inputExpr, ")"),
+                MarshalType.GodotObjectOrDerived =>
+                    source.Append(VariantUtils, ".CreateFromGodotObject(", inputExpr, ")"),
+                MarshalType.StringName =>
+                    source.Append(VariantUtils, ".CreateFromStringName(", inputExpr, ")"),
+                MarshalType.NodePath =>
+                    source.Append(VariantUtils, ".CreateFromNodePath(", inputExpr, ")"),
+                MarshalType.RID =>
+                    source.Append(VariantUtils, ".CreateFromRID(", inputExpr, ")"),
+                MarshalType.GodotDictionary =>
+                    source.Append(VariantUtils, ".CreateFromDictionary(", inputExpr, ")"),
+                MarshalType.GodotArray =>
+                    source.Append(VariantUtils, ".CreateFromArray(", inputExpr, ")"),
+                MarshalType.IDictionary =>
+                    source.Append(VariantUtils, ".CreateFromSystemIDictionary(", inputExpr, ")"),
+                MarshalType.ICollection =>
+                    source.Append(VariantUtils, ".CreateFromSystemICollection(", inputExpr, ")"),
+                MarshalType.IEnumerable =>
+                    source.Append(VariantUtils, ".CreateFromSystemIEnumerable(", inputExpr, ")"),
+                _ => throw new ArgumentOutOfRangeException(nameof(marshalType), marshalType,
+                    "Received unexpected marshal type")
+            };
+        }
     }
 }