using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Text;
namespace Godot.SourceGenerators
{
[Generator]
public class ScriptSignalsGenerator : ISourceGenerator
{
public void Initialize(GeneratorInitializationContext context)
{
}
public void Execute(GeneratorExecutionContext context)
{
if (context.IsGodotSourceGeneratorDisabled("ScriptSignals"))
return;
INamedTypeSymbol[] godotClasses = context
.Compilation.SyntaxTrees
.SelectMany(tree =>
tree.GetRoot().DescendantNodes()
.OfType<ClassDeclarationSyntax>()
.SelectGodotScriptClasses(context.Compilation)
// Report and skip non-partial classes
.Where(x =>
{
if (x.cds.IsPartial())
{
if (x.cds.IsNested() && !x.cds.AreAllOuterTypesPartial(out _))
{
return false;
}
return true;
}
return false;
})
.Select(x => x.symbol)
)
.Distinct<INamedTypeSymbol>(SymbolEqualityComparer.Default)
.ToArray();
if (godotClasses.Length > 0)
{
var typeCache = new MarshalUtils.TypeCache(context.Compilation);
foreach (var godotClass in godotClasses)
{
VisitGodotScriptClass(context, typeCache, godotClass);
}
}
}
internal static string SignalDelegateSuffix = "EventHandler";
private static void VisitGodotScriptClass(
GeneratorExecutionContext context,
MarshalUtils.TypeCache typeCache,
INamedTypeSymbol symbol
)
{
INamespaceSymbol namespaceSymbol = symbol.ContainingNamespace;
string classNs = namespaceSymbol != null && !namespaceSymbol.IsGlobalNamespace ?
namespaceSymbol.FullQualifiedNameOmitGlobal() :
string.Empty;
bool hasNamespace = classNs.Length != 0;
bool isInnerClass = symbol.ContainingType != null;
string uniqueHint = symbol.FullQualifiedNameOmitGlobal().SanitizeQualifiedNameForUniqueHint()
+ "_ScriptSignals.generated";
var source = new StringBuilder();
source.Append("using Godot;\n");
source.Append("using Godot.NativeInterop;\n");
source.Append("\n");
if (hasNamespace)
{
source.Append("namespace ");
source.Append(classNs);
source.Append(" {\n\n");
}
if (isInnerClass)
{
var containingType = symbol.ContainingType;
AppendPartialContainingTypeDeclarations(containingType);
void AppendPartialContainingTypeDeclarations(INamedTypeSymbol? containingType)
{
if (containingType == null)
return;
AppendPartialContainingTypeDeclarations(containingType.ContainingType);
source.Append("partial ");
source.Append(containingType.GetDeclarationKeyword());
source.Append(" ");
source.Append(containingType.NameWithTypeParameters());
source.Append("\n{\n");
}
}
source.Append("partial class ");
source.Append(symbol.NameWithTypeParameters());
source.Append("\n{\n");
var members = symbol.GetMembers();
var signalDelegateSymbols = members
.Where(s => s.Kind == SymbolKind.NamedType)
.Cast<INamedTypeSymbol>()
.Where(namedTypeSymbol => namedTypeSymbol.TypeKind == TypeKind.Delegate)
.Where(s => s.GetAttributes()
.Any(a => a.AttributeClass?.IsGodotSignalAttribute() ?? false));
List<GodotSignalDelegateData> godotSignalDelegates = new();
foreach (var signalDelegateSymbol in signalDelegateSymbols)
{
if (!signalDelegateSymbol.Name.EndsWith(SignalDelegateSuffix))
{
context.ReportDiagnostic(Diagnostic.Create(
Common.SignalDelegateMissingSuffixRule,
signalDelegateSymbol.Locations.FirstLocationWithSourceTreeOrDefault(),
signalDelegateSymbol.ToDisplayString()
));
continue;
}
string signalName = signalDelegateSymbol.Name;
signalName = signalName.Substring(0, signalName.Length - SignalDelegateSuffix.Length);
var invokeMethodData = signalDelegateSymbol
.DelegateInvokeMethod?.HasGodotCompatibleSignature(typeCache);
if (invokeMethodData == null)
{
if (signalDelegateSymbol.DelegateInvokeMethod is IMethodSymbol methodSymbol)
{
foreach (var parameter in methodSymbol.Parameters)
{
if (parameter.RefKind != RefKind.None)
{
context.ReportDiagnostic(Diagnostic.Create(
Common.SignalParameterTypeNotSupportedRule,
parameter.Locations.FirstLocationWithSourceTreeOrDefault(),
parameter.ToDisplayString()
));
continue;
}
var marshalType = MarshalUtils.ConvertManagedTypeToMarshalType(parameter.Type, typeCache);
if (marshalType == null)
{
context.ReportDiagnostic(Diagnostic.Create(
Common.SignalParameterTypeNotSupportedRule,
parameter.Locations.FirstLocationWithSourceTreeOrDefault(),
parameter.ToDisplayString()
));
}
}
if (!methodSymbol.ReturnsVoid)
{
context.ReportDiagnostic(Diagnostic.Create(
Common.SignalDelegateSignatureMustReturnVoidRule,
signalDelegateSymbol.Locations.FirstLocationWithSourceTreeOrDefault(),
signalDelegateSymbol.ToDisplayString()
));
}
}
continue;
}
godotSignalDelegates.Add(new(signalName, signalDelegateSymbol, invokeMethodData.Value));
}
source.Append("#pragma warning disable CS0109 // Disable warning about redundant 'new' keyword\n");
source.Append(" /// <summary>\n")
.Append(" /// Cached StringNames for the signals contained in this class, for fast lookup.\n")
.Append(" /// </summary>\n");
source.Append(
$" public new class SignalName : {symbol.BaseType!.FullQualifiedNameIncludeGlobal()}.SignalName {{\n");
// Generate cached StringNames for methods and properties, for fast lookup
foreach (var signalDelegate in godotSignalDelegates)
{
string signalName = signalDelegate.Name;
source.Append(" /// <summary>\n")
.Append(" /// Cached name for the '")
.Append(signalName)
.Append("' signal.\n")
.Append(" /// </summary>\n");
source.Append(" public new static readonly global::Godot.StringName @");
source.Append(signalName);
source.Append(" = \"");
source.Append(signalName);
source.Append("\";\n");
}
source.Append(" }\n"); // class GodotInternal
// Generate GetGodotSignalList
if (godotSignalDelegates.Count > 0)
{
const string ListType = "global::System.Collections.Generic.List<global::Godot.Bridge.MethodInfo>";
source.Append(" /// <summary>\n")
.Append(" /// Get the signal information for all the signals declared in this class.\n")
.Append(" /// This method is used by Godot to register the available signals in the editor.\n")
.Append(" /// Do not call this method.\n")
.Append(" /// </summary>\n");
source.Append(" [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]\n");
source.Append(" internal new static ")
.Append(ListType)
.Append(" GetGodotSignalList()\n {\n");
source.Append(" var signals = new ")
.Append(ListType)
.Append("(")
.Append(godotSignalDelegates.Count)
.Append(");\n");
foreach (var signalDelegateData in godotSignalDelegates)
{
var methodInfo = DetermineMethodInfo(signalDelegateData);
AppendMethodInfo(source, methodInfo);
}
source.Append(" return signals;\n");
source.Append(" }\n");
}
source.Append("#pragma warning restore CS0109\n");
// Generate signal event
foreach (var signalDelegate in godotSignalDelegates)
{
string signalName = signalDelegate.Name;
// TODO: Hide backing event from code-completion and debugger
// The reason we have a backing field is to hide the invoke method from the event,
// as it doesn't emit the signal, only the event delegates. This can confuse users.
// Maybe we should directly connect the delegates, as we do with native signals?
source.Append(" private ")
.Append(signalDelegate.DelegateSymbol.FullQualifiedNameIncludeGlobal())
.Append(" backing_")
.Append(signalName)
.Append(";\n");
source.Append(
$" /// <inheritdoc cref=\"{signalDelegate.DelegateSymbol.FullQualifiedNameIncludeGlobal()}\"/>\n");
source.Append($" {signalDelegate.DelegateSymbol.GetAccessibilityKeyword()} event ")
.Append(signalDelegate.DelegateSymbol.FullQualifiedNameIncludeGlobal())
.Append(" @")
.Append(signalName)
.Append(" {\n")
.Append(" add => backing_")
.Append(signalName)
.Append(" += value;\n")
.Append(" remove => backing_")
.Append(signalName)
.Append(" -= value;\n")
.Append("}\n");
// Generate On{EventName} method to raise the event
var invokeMethodSymbol = signalDelegate.InvokeMethodData.Method;
int paramCount = invokeMethodSymbol.Parameters.Length;
string raiseMethodModifiers = signalDelegate.DelegateSymbol.ContainingType.IsSealed ?
"private" :
"protected";
source.Append($" {raiseMethodModifiers} void On{signalName}(");
for (int i = 0; i < paramCount; i++)
{
var paramSymbol = invokeMethodSymbol.Parameters[i];
source.Append($"{paramSymbol.Type.FullQualifiedNameIncludeGlobal()} {paramSymbol.Name}");
if (i < paramCount - 1)
{
source.Append(", ");
}
}
source.Append(")\n");
source.Append(" {\n");
source.Append($" EmitSignal(SignalName.{signalName}");
foreach (var paramSymbol in invokeMethodSymbol.Parameters)
{
// Enums must be converted to the underlying type before they can be implicitly converted to Variant
if (paramSymbol.Type.TypeKind == TypeKind.Enum)
{
var underlyingType = ((INamedTypeSymbol)paramSymbol.Type).EnumUnderlyingType;
source.Append($", ({underlyingType.FullQualifiedNameIncludeGlobal()}){paramSymbol.Name}");
continue;
}
source.Append($", {paramSymbol.Name}");
}
source.Append(");\n");
source.Append(" }\n");
}
// Generate RaiseGodotClassSignalCallbacks
if (godotSignalDelegates.Count > 0)
{
source.Append(" /// <inheritdoc/>\n");
source.Append(" [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]\n");
source.Append(
" protected override void RaiseGodotClassSignalCallbacks(in godot_string_name signal, ");
source.Append("NativeVariantPtrArgs args)\n {\n");
foreach (var signal in godotSignalDelegates)
{
GenerateSignalEventInvoker(signal, source);
}
source.Append(" base.RaiseGodotClassSignalCallbacks(signal, args);\n");
source.Append(" }\n");
}
// Generate HasGodotClassSignal
if (godotSignalDelegates.Count > 0)
{
source.Append(" /// <inheritdoc/>\n");
source.Append(" [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]\n");
source.Append(
" protected override bool HasGodotClassSignal(in godot_string_name signal)\n {\n");
foreach (var signal in godotSignalDelegates)
{
GenerateHasSignalEntry(signal.Name, source);
}
source.Append(" return base.HasGodotClassSignal(signal);\n");
source.Append(" }\n");
}
source.Append("}\n"); // partial class
if (isInnerClass)
{
var containingType = symbol.ContainingType;
while (containingType != null)
{
source.Append("}\n"); // outer class
containingType = containingType.ContainingType;
}
}
if (hasNamespace)
{
source.Append("\n}\n");
}
context.AddSource(uniqueHint, SourceText.From(source.ToString(), Encoding.UTF8));
}
private static void AppendMethodInfo(StringBuilder source, MethodInfo methodInfo)
{
source.Append(" signals.Add(new(name: SignalName.@")
.Append(methodInfo.Name)
.Append(", returnVal: ");
AppendPropertyInfo(source, methodInfo.ReturnVal);
source.Append(", flags: (global::Godot.MethodFlags)")
.Append((int)methodInfo.Flags)
.Append(", arguments: ");
if (methodInfo.Arguments is { Count: > 0 })
{
source.Append("new() { ");
foreach (var param in methodInfo.Arguments)
{
AppendPropertyInfo(source, param);
// C# allows colon after the last element
source.Append(", ");
}
source.Append(" }");
}
else
{
source.Append("null");
}
source.Append(", defaultArguments: null));\n");
}
private static void AppendPropertyInfo(StringBuilder source, PropertyInfo propertyInfo)
{
source.Append("new(type: (global::Godot.Variant.Type)")
.Append((int)propertyInfo.Type)
.Append(", name: \"")
.Append(propertyInfo.Name)
.Append("\", hint: (global::Godot.PropertyHint)")
.Append((int)propertyInfo.Hint)
.Append(", hintString: \"")
.Append(propertyInfo.HintString)
.Append("\", usage: (global::Godot.PropertyUsageFlags)")
.Append((int)propertyInfo.Usage)
.Append(", exported: ")
.Append(propertyInfo.Exported ? "true" : "false");
if (propertyInfo.ClassName != null)
{
source.Append(", className: new global::Godot.StringName(\"")
.Append(propertyInfo.ClassName)
.Append("\")");
}
source.Append(")");
}
private static MethodInfo DetermineMethodInfo(GodotSignalDelegateData signalDelegateData)
{
var invokeMethodData = signalDelegateData.InvokeMethodData;
PropertyInfo returnVal;
if (invokeMethodData.RetType != null)
{
returnVal = DeterminePropertyInfo(invokeMethodData.RetType.Value.MarshalType,
invokeMethodData.RetType.Value.TypeSymbol,
name: string.Empty);
}
else
{
returnVal = new PropertyInfo(VariantType.Nil, string.Empty, PropertyHint.None,
hintString: null, PropertyUsageFlags.Default, exported: false);
}
int paramCount = invokeMethodData.ParamTypes.Length;
List<PropertyInfo>? arguments;
if (paramCount > 0)
{
arguments = new(capacity: paramCount);
for (int i = 0; i < paramCount; i++)
{
arguments.Add(DeterminePropertyInfo(invokeMethodData.ParamTypes[i],
invokeMethodData.Method.Parameters[i].Type,
name: invokeMethodData.Method.Parameters[i].Name));
}
}
else
{
arguments = null;
}
return new MethodInfo(signalDelegateData.Name, returnVal, MethodFlags.Default, arguments,
defaultArguments: null);
}
private static PropertyInfo DeterminePropertyInfo(MarshalType marshalType, ITypeSymbol typeSymbol, string name)
{
var memberVariantType = MarshalUtils.ConvertMarshalTypeToVariantType(marshalType)!.Value;
var propUsage = PropertyUsageFlags.Default;
if (memberVariantType == VariantType.Nil)
propUsage |= PropertyUsageFlags.NilIsVariant;
string? className = null;
if (memberVariantType == VariantType.Object && typeSymbol is INamedTypeSymbol namedTypeSymbol)
{
className = namedTypeSymbol.GetGodotScriptNativeClassName();
}
return new PropertyInfo(memberVariantType, name,
PropertyHint.None, string.Empty, propUsage, className, exported: false);
}
private static void GenerateHasSignalEntry(
string signalName,
StringBuilder source
)
{
source.Append(" ");
source.Append("if (signal == SignalName.@");
source.Append(signalName);
source.Append(") {\n return true;\n }\n");
}
private static void GenerateSignalEventInvoker(
GodotSignalDelegateData signal,
StringBuilder source
)
{
string signalName = signal.Name;
var invokeMethodData = signal.InvokeMethodData;
source.Append(" if (signal == SignalName.@");
source.Append(signalName);
source.Append(" && args.Count == ");
source.Append(invokeMethodData.ParamTypes.Length);
source.Append(") {\n");
source.Append(" backing_");
source.Append(signalName);
source.Append("?.Invoke(");
for (int i = 0; i < invokeMethodData.ParamTypes.Length; i++)
{
if (i != 0)
source.Append(", ");
source.AppendNativeVariantToManagedExpr(string.Concat("args[", i.ToString(), "]"),
invokeMethodData.ParamTypeSymbols[i], invokeMethodData.ParamTypes[i]);
}
source.Append(");\n");
source.Append(" return;\n");
source.Append(" }\n");
}
}
}
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