protected override ExpressionSyntax Generate(CsCallable callable, PlatformDetectionType platform)
{
var interopSig = callable.InteropSignatures[platform];
var interopReturnType = interopSig.ReturnTypeSyntax;
var arguments = IterateNativeArguments(callable is CsMethod, interopSig).ToArray();
var vtblAccess = callable switch
{
CsMethod method => ElementAccessExpression(
ThisExpression(),
BracketedArgumentList(
SingletonSeparatedList(
Argument(
method.CustomVtbl
? MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
ThisExpression(),
IdentifierName($"{callable.Name}__vtbl_index")
)
: method.VTableOffsetExpression(platform)
)
)
)
),
_ => null
};
ExpressionSyntax FnPtrCall()
{
var fnptrParameters = arguments
.Select(x => x.Type)
.Append(interopReturnType)
.Select(FunctionPointerParameter);
return(GeneratorHelpers.CastExpression(
FunctionPointerType(
FunctionPointerCallingConvention(
Token(SyntaxKind.UnmanagedKeyword),
FunctionPointerUnmanagedCallingConventionList(
SingletonSeparatedList(
FunctionPointerUnmanagedCallingConvention(
Identifier(callable.CppCallingConvention.ToCallConvShortName())
)
)
)
),
FunctionPointerParameterList(SeparatedList(fnptrParameters))
),
vtblAccess
));
}
var what = callable switch
{
CsFunction => IdentifierName(
callable.CppElementName + GeneratorHelpers.GetPlatformSpecificSuffix(platform)
),
CsMethod => GeneratorHelpers.WrapInParentheses(FnPtrCall()),
_ => throw new ArgumentOutOfRangeException()
};
ExpressionSyntax call = InvocationExpression(
what,
ArgumentList(SeparatedList(arguments.Select(x => x.Argument)))
);
if (interopSig.ForcedReturnBufferSig || !callable.HasReturnType)
{
return(call);
}
var generatesMarshalVariable = GetMarshaller(callable.ReturnValue).GeneratesMarshalVariable(callable.ReturnValue);
var publicTypeSyntax = ReverseCallablePrologCodeGenerator.GetPublicType(callable.ReturnValue);
if (callable.HasReturnTypeValue && !generatesMarshalVariable && !publicTypeSyntax.IsEquivalentTo(interopSig.ReturnTypeSyntax))
{
call = CastExpression(publicTypeSyntax, call);
}
return(AssignmentExpression(
SyntaxKind.SimpleAssignmentExpression,
generatesMarshalVariable
? MarshallerBase.GetMarshalStorageLocation(callable.ReturnValue)
: IdentifierName(callable.ReturnValue.Name),
call
));
}