godot/modules/mono/mono_gd/gd_mono_cache.h
Ignacio Roldán Etcheverry 282bd37e5c 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.
2022-10-30 01:24:15 +02:00

151 lines
9.8 KiB
C++

/*************************************************************************/
/* gd_mono_cache.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef GD_MONO_CACHE_H
#define GD_MONO_CACHE_H
#include <stdint.h>
#include "../csharp_script.h"
#include "../interop_types.h"
#include "../mono_gc_handle.h"
#include "core/object/object.h"
#include "core/string/string_name.h"
#include "core/string/ustring.h"
#include "core/variant/callable.h"
#include "core/variant/dictionary.h"
#include "core/variant/variant.h"
class CSharpScript;
namespace GDMonoCache {
#ifndef GD_CLR_STDCALL
#ifdef WIN32
#define GD_CLR_STDCALL __stdcall
#else
#define GD_CLR_STDCALL
#endif
#endif
struct godotsharp_property_info {
godot_string_name name; // Not owned
godot_string hint_string;
Variant::Type type;
PropertyHint hint;
PropertyUsageFlags usage;
bool exported;
};
struct godotsharp_property_def_val_pair {
godot_string_name name; // Not owned
godot_variant value;
};
struct ManagedCallbacks {
using Callback_ScriptManagerBridge_GetPropertyInfoList_Add = void(GD_CLR_STDCALL *)(CSharpScript *p_script, const String *, void *p_props, int32_t p_count);
using Callback_ScriptManagerBridge_GetPropertyDefaultValues_Add = void(GD_CLR_STDCALL *)(CSharpScript *p_script, void *p_def_vals, int32_t p_count);
using FuncSignalAwaiter_SignalCallback = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Variant **, int32_t, bool *);
using FuncDelegateUtils_InvokeWithVariantArgs = void(GD_CLR_STDCALL *)(GCHandleIntPtr, void *, const Variant **, int32_t, const Variant *);
using FuncDelegateUtils_DelegateEquals = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, GCHandleIntPtr);
using FuncDelegateUtils_TrySerializeDelegateWithGCHandle = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const Array *);
using FuncDelegateUtils_TryDeserializeDelegateWithGCHandle = bool(GD_CLR_STDCALL *)(const Array *, GCHandleIntPtr *);
using FuncScriptManagerBridge_FrameCallback = void(GD_CLR_STDCALL *)();
using FuncScriptManagerBridge_CreateManagedForGodotObjectBinding = GCHandleIntPtr(GD_CLR_STDCALL *)(const StringName *, Object *);
using FuncScriptManagerBridge_CreateManagedForGodotObjectScriptInstance = bool(GD_CLR_STDCALL *)(const CSharpScript *, Object *, const Variant **, int32_t);
using FuncScriptManagerBridge_GetScriptNativeName = void(GD_CLR_STDCALL *)(const CSharpScript *, StringName *);
using FuncScriptManagerBridge_SetGodotObjectPtr = void(GD_CLR_STDCALL *)(GCHandleIntPtr, Object *);
using FuncScriptManagerBridge_RaiseEventSignal = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const StringName *, const Variant **, int32_t, bool *);
using FuncScriptManagerBridge_ScriptIsOrInherits = bool(GD_CLR_STDCALL *)(const CSharpScript *, const CSharpScript *);
using FuncScriptManagerBridge_AddScriptBridge = bool(GD_CLR_STDCALL *)(const CSharpScript *, const String *);
using FuncScriptManagerBridge_GetOrCreateScriptBridgeForPath = void(GD_CLR_STDCALL *)(const String *, Ref<CSharpScript> *);
using FuncScriptManagerBridge_RemoveScriptBridge = void(GD_CLR_STDCALL *)(const CSharpScript *);
using FuncScriptManagerBridge_TryReloadRegisteredScriptWithClass = bool(GD_CLR_STDCALL *)(const CSharpScript *);
using FuncScriptManagerBridge_UpdateScriptClassInfo = void(GD_CLR_STDCALL *)(const CSharpScript *, bool *, Array *, Dictionary *, Dictionary *, Ref<CSharpScript> *);
using FuncScriptManagerBridge_SwapGCHandleForType = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, GCHandleIntPtr *, bool);
using FuncScriptManagerBridge_GetPropertyInfoList = void(GD_CLR_STDCALL *)(CSharpScript *, Callback_ScriptManagerBridge_GetPropertyInfoList_Add);
using FuncScriptManagerBridge_GetPropertyDefaultValues = void(GD_CLR_STDCALL *)(CSharpScript *, Callback_ScriptManagerBridge_GetPropertyDefaultValues_Add);
using FuncCSharpInstanceBridge_Call = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const StringName *, const Variant **, int32_t, Callable::CallError *, Variant *);
using FuncCSharpInstanceBridge_Set = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const StringName *, const Variant *);
using FuncCSharpInstanceBridge_Get = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const StringName *, Variant *);
using FuncCSharpInstanceBridge_CallDispose = void(GD_CLR_STDCALL *)(GCHandleIntPtr, bool);
using FuncCSharpInstanceBridge_CallToString = void(GD_CLR_STDCALL *)(GCHandleIntPtr, String *, bool *);
using FuncCSharpInstanceBridge_HasMethodUnknownParams = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const StringName *);
using FuncCSharpInstanceBridge_SerializeState = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Dictionary *, const Dictionary *);
using FuncCSharpInstanceBridge_DeserializeState = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Dictionary *, const Dictionary *);
using FuncGCHandleBridge_FreeGCHandle = void(GD_CLR_STDCALL *)(GCHandleIntPtr);
using FuncDebuggingUtils_GetCurrentStackInfo = void(GD_CLR_STDCALL *)(Vector<ScriptLanguage::StackInfo> *);
using FuncDisposablesTracker_OnGodotShuttingDown = void(GD_CLR_STDCALL *)();
using FuncGD_OnCoreApiAssemblyLoaded = void(GD_CLR_STDCALL *)(bool);
FuncSignalAwaiter_SignalCallback SignalAwaiter_SignalCallback;
FuncDelegateUtils_InvokeWithVariantArgs DelegateUtils_InvokeWithVariantArgs;
FuncDelegateUtils_DelegateEquals DelegateUtils_DelegateEquals;
FuncDelegateUtils_TrySerializeDelegateWithGCHandle DelegateUtils_TrySerializeDelegateWithGCHandle;
FuncDelegateUtils_TryDeserializeDelegateWithGCHandle DelegateUtils_TryDeserializeDelegateWithGCHandle;
FuncScriptManagerBridge_FrameCallback ScriptManagerBridge_FrameCallback;
FuncScriptManagerBridge_CreateManagedForGodotObjectBinding ScriptManagerBridge_CreateManagedForGodotObjectBinding;
FuncScriptManagerBridge_CreateManagedForGodotObjectScriptInstance ScriptManagerBridge_CreateManagedForGodotObjectScriptInstance;
FuncScriptManagerBridge_GetScriptNativeName ScriptManagerBridge_GetScriptNativeName;
FuncScriptManagerBridge_SetGodotObjectPtr ScriptManagerBridge_SetGodotObjectPtr;
FuncScriptManagerBridge_RaiseEventSignal ScriptManagerBridge_RaiseEventSignal;
FuncScriptManagerBridge_ScriptIsOrInherits ScriptManagerBridge_ScriptIsOrInherits;
FuncScriptManagerBridge_AddScriptBridge ScriptManagerBridge_AddScriptBridge;
FuncScriptManagerBridge_GetOrCreateScriptBridgeForPath ScriptManagerBridge_GetOrCreateScriptBridgeForPath;
FuncScriptManagerBridge_RemoveScriptBridge ScriptManagerBridge_RemoveScriptBridge;
FuncScriptManagerBridge_TryReloadRegisteredScriptWithClass ScriptManagerBridge_TryReloadRegisteredScriptWithClass;
FuncScriptManagerBridge_UpdateScriptClassInfo ScriptManagerBridge_UpdateScriptClassInfo;
FuncScriptManagerBridge_SwapGCHandleForType ScriptManagerBridge_SwapGCHandleForType;
FuncScriptManagerBridge_GetPropertyInfoList ScriptManagerBridge_GetPropertyInfoList;
FuncScriptManagerBridge_GetPropertyDefaultValues ScriptManagerBridge_GetPropertyDefaultValues;
FuncCSharpInstanceBridge_Call CSharpInstanceBridge_Call;
FuncCSharpInstanceBridge_Set CSharpInstanceBridge_Set;
FuncCSharpInstanceBridge_Get CSharpInstanceBridge_Get;
FuncCSharpInstanceBridge_CallDispose CSharpInstanceBridge_CallDispose;
FuncCSharpInstanceBridge_CallToString CSharpInstanceBridge_CallToString;
FuncCSharpInstanceBridge_HasMethodUnknownParams CSharpInstanceBridge_HasMethodUnknownParams;
FuncCSharpInstanceBridge_SerializeState CSharpInstanceBridge_SerializeState;
FuncCSharpInstanceBridge_DeserializeState CSharpInstanceBridge_DeserializeState;
FuncGCHandleBridge_FreeGCHandle GCHandleBridge_FreeGCHandle;
FuncDebuggingUtils_GetCurrentStackInfo DebuggingUtils_GetCurrentStackInfo;
FuncDisposablesTracker_OnGodotShuttingDown DisposablesTracker_OnGodotShuttingDown;
FuncGD_OnCoreApiAssemblyLoaded GD_OnCoreApiAssemblyLoaded;
};
extern ManagedCallbacks managed_callbacks;
extern bool godot_api_cache_updated;
void update_godot_api_cache(const ManagedCallbacks &p_managed_callbacks);
} // namespace GDMonoCache
#endif // GD_MONO_CACHE_H