diff options
author | Ignacio Roldán Etcheverry <ignalfonsore@gmail.com> | 2022-10-28 22:59:13 +0200 |
---|---|---|
committer | Ignacio Roldán Etcheverry <ignalfonsore@gmail.com> | 2022-10-30 01:24:15 +0200 |
commit | 282bd37e5c9dbc1bba4fe349fc7868643a54164b (patch) | |
tree | 6e3d5f7499ceb4b0d928764fd9b8da16548911ce /modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators | |
parent | f013315980ca13f4b66df29b5e32d3ecc310cb84 (diff) |
C#: Remove need for reflection to invoking callable delegates
We aim to make the C# API reflection-free, mainly for concerns about
performance, and to be able to target NativeAOT in refletion-free mode,
which reduces the binary size.
One of the main usages of reflection still left was the dynamic
invokation of callable delegates, and for some time I wasn't sure
I would find an alternative solution that I'd be happy with.
The new solution uses trampoline functions to invoke the delegates:
```
static void Trampoline(object delegateObj, NativeVariantPtrArgs args, out godot_variant ret)
{
if (args.Count != 1)
throw new ArgumentException($"Callable expected 1 arguments but received {args.Count}.");
string res = ((Func<int, string>)delegateObj)(
VariantConversionCallbacks.GetToManagedCallback<int>()(args[0])
);
ret = VariantConversionCallbacks.GetToVariantCallback<string>()(res);
}
Callable.CreateWithUnsafeTrampoline((int num) => "Foo" + num, &Trampoline);
```
Of course, this is too much boilerplate for user code. To improve this,
the `Callable.From` methods were added. These are overloads that take
`Action` and `Func` delegates, which covers the most common use cases:
lambdas and method groups:
```
// Lambda
Callable.From((int num) => "Foo" + num);
// Method group
string AppendNum(int num) => "Foo" + num;
Callable.From(AppendNum);
```
Unfortunately, due to limitations in the C# language, implicit
conversions from delegates to `Callable` are not supported.
`Callable.From` does not support custom delegates. These should be
uncommon, but the Godot C# API actually uses them for event signals.
As such, the bindings generator was updated to generate trampoline
functions for event signals. It was also optimized to use `Action`
instead of a custom delegate for parameterless signals, which removes
the need for the trampoline functions for those signals.
The change to reflection-free invokation removes one of the last needs
for `ConvertVariantToManagedObjectOfType`. The only remaining usage is
from calling script constructors with parameters from the engine
(`CreateManagedForGodotObjectScriptInstance`). Once that one is made
reflection-free, `ConvertVariantToManagedObjectOfType` can be removed.
Diffstat (limited to 'modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators')
-rw-r--r-- | modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptMethodsGenerator.cs | 6 | ||||
-rw-r--r-- | modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptSignalsGenerator.cs | 7 |
2 files changed, 7 insertions, 6 deletions
diff --git a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptMethodsGenerator.cs b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptMethodsGenerator.cs index d915eeac0b..d5d80df643 100644 --- a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptMethodsGenerator.cs +++ b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptMethodsGenerator.cs @@ -188,14 +188,14 @@ namespace Godot.SourceGenerators if (godotClassMethods.Length > 0) { source.Append(" protected override bool InvokeGodotClassMethod(in godot_string_name method, "); - source.Append("NativeVariantPtrArgs args, int argCount, out godot_variant ret)\n {\n"); + source.Append("NativeVariantPtrArgs args, out godot_variant ret)\n {\n"); foreach (var method in godotClassMethods) { GenerateMethodInvoker(method, source); } - source.Append(" return base.InvokeGodotClassMethod(method, args, argCount, out ret);\n"); + source.Append(" return base.InvokeGodotClassMethod(method, args, out ret);\n"); source.Append(" }\n"); } @@ -364,7 +364,7 @@ namespace Godot.SourceGenerators source.Append(" if (method == MethodName."); source.Append(methodName); - source.Append(" && argCount == "); + source.Append(" && args.Count == "); source.Append(method.ParamTypes.Length); source.Append(") {\n"); diff --git a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptSignalsGenerator.cs b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptSignalsGenerator.cs index 4e443ce26e..50196b84f0 100644 --- a/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptSignalsGenerator.cs +++ b/modules/mono/editor/Godot.NET.Sdk/Godot.SourceGenerators/ScriptSignalsGenerator.cs @@ -167,6 +167,7 @@ namespace Godot.SourceGenerators Common.ReportSignalDelegateSignatureMustReturnVoid(context, signalDelegateSymbol); } } + continue; } @@ -257,14 +258,14 @@ namespace Godot.SourceGenerators { source.Append( " protected override void RaiseGodotClassSignalCallbacks(in godot_string_name signal, "); - source.Append("NativeVariantPtrArgs args, int argCount)\n {\n"); + source.Append("NativeVariantPtrArgs args)\n {\n"); foreach (var signal in godotSignalDelegates) { GenerateSignalEventInvoker(signal, source); } - source.Append(" base.RaiseGodotClassSignalCallbacks(signal, args, argCount);\n"); + source.Append(" base.RaiseGodotClassSignalCallbacks(signal, args);\n"); source.Append(" }\n"); } @@ -404,7 +405,7 @@ namespace Godot.SourceGenerators source.Append(" if (signal == SignalName."); source.Append(signalName); - source.Append(" && argCount == "); + source.Append(" && args.Count == "); source.Append(invokeMethodData.ParamTypes.Length); source.Append(") {\n"); source.Append(" backing_"); |