C#: Replace most conversions between Variant and System.Object

This commit replaces most usages of `ConvertManagedObjectToVariant` and
`ConvertVariantToManagedObjectOfType`, by using the `Godot.Variant`
struct instead of `System.Object`.

The most notable change is to the `GetGodotPropertyDefaultValues` method
that's generated for scripts. The dictionary it returns now stores
`Godot.Variant` values.

Remaining usages are:

- The `DelegateUtils` class, for the serialization of closure display
  classes during assembly reloading by the editor. These display classes
  are compiler generated classes to store values captured by a closure.
  Since it's generated by the compiler, the only way we have to access
  the fields is through reflection. This leads to using `System.Object`.
- Converting parameters when invoking constructors from the engine.
  This will be replaced with source generators in the future.
- Legacy support for old `GetGodotPropertyDefaultValues` return values.
  We need to keep supporting the old version of this generated method
  for some time. Otherwise, if loading a project built with the previous
  version, it could lead to the loss of exported property values.
  Ideally, we should remove this legacy support before a stable release.

2 files changed, 9 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 4fdd40f638..6b48f9135b 100644
--- a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/MarshalUtils.cs
+++ b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/MarshalUtils.cs
@@ -368,7 +368,7 @@ namespace Godot.SourceGenerators
                     source.Append(VariantUtils, ".ConvertToSignalInfo(", inputExpr, ")"),
                 MarshalType.Enum =>
                     source.Append("(", typeSymbol.FullQualifiedNameIncludeGlobal(),
-                        ")", VariantUtils, ".ConvertToInt32(", inputExpr, ")"),
+                        ")", VariantUtils, ".ConvertToInt64(", inputExpr, ")"),
                 MarshalType.ByteArray =>
                     source.Append(VariantUtils, ".ConvertAsPackedByteArrayToSystemArray(", inputExpr, ")"),
                 MarshalType.Int32Array =>
@@ -491,7 +491,7 @@ namespace Godot.SourceGenerators
                 MarshalType.SignalInfo =>
                     source.Append(VariantUtils, ".CreateFromSignalInfo(", inputExpr, ")"),
                 MarshalType.Enum =>
-                    source.Append(VariantUtils, ".CreateFromInt((int)", inputExpr, ")"),
+                    source.Append(VariantUtils, ".CreateFromInt((long)", inputExpr, ")"),
                 MarshalType.ByteArray =>
                     source.Append(VariantUtils, ".CreateFromPackedByteArray(", inputExpr, ")"),
                 MarshalType.Int32Array =>
diff --git a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptPropertyDefValGenerator.cs b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptPropertyDefValGenerator.cs
index 63339b3487..501717bf5c 100644
--- a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptPropertyDefValGenerator.cs
+++ b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptPropertyDefValGenerator.cs
@@ -174,7 +174,8 @@ namespace Godot.SourceGenerators
                     }
                     else
                     {
-                        var propertyGet = propertyDeclarationSyntax.AccessorList?.Accessors.Where(a => a.Keyword.IsKind(SyntaxKind.GetKeyword)).FirstOrDefault();
+                        var propertyGet = propertyDeclarationSyntax.AccessorList?.Accessors
+                            .Where(a => a.Keyword.IsKind(SyntaxKind.GetKeyword)).FirstOrDefault();
                         if (propertyGet != null)
                         {
                             if (propertyGet.ExpressionBody != null)
@@ -200,7 +201,8 @@ namespace Godot.SourceGenerators
                             {
                                 var returns = propertyGet.DescendantNodes().OfType<ReturnStatementSyntax>();
                                 if (returns.Count() == 1)
-                                {// Generate only single return
+                                {
+                                    // Generate only single return
                                     var returnStatementSyntax = returns.Single();
                                     if (returnStatementSyntax.Expression is IdentifierNameSyntax identifierNameSyntax)
                                     {
@@ -277,7 +279,8 @@ namespace Godot.SourceGenerators
             {
                 source.Append("#pragma warning disable CS0109 // Disable warning about redundant 'new' keyword\n");
 
-                string dictionaryType = "System.Collections.Generic.Dictionary<Godot.StringName, object>";
+                string dictionaryType =
+                    "global::System.Collections.Generic.Dictionary<global::Godot.StringName, global::Godot.Variant>";
 
                 source.Append("#if TOOLS\n");
                 source.Append("    internal new static ");
@@ -304,7 +307,7 @@ namespace Godot.SourceGenerators
                     source.Append("        values.Add(PropertyName.");
                     source.Append(exportedMember.Name);
                     source.Append(", ");
-                    source.Append(defaultValueLocalName);
+                    source.AppendManagedToVariantExpr(defaultValueLocalName, exportedMember.Type);
                     source.Append(");\n");
                 }