static ILGeneratorExtensions()
{
var emit = typeof(ILGenerator).GetMethod(nameof(ILGenerator.EmitCalli),
new[] { typeof(OpCode), typeof(CallingConvention), typeof(Type), typeof(Type) });
var getSigHelper = (GetMethodSigHelper)typeof(SignatureHelper)
.GetMethod(nameof(SignatureHelper.GetMethodSigHelper), new[] { typeof(CallingConvention), typeof(Type) })
?.CreateDelegate(typeof(GetMethodSigHelper));
_emitCalliDelegate = (EmitCalliDelegate)emit?.CreateDelegate(typeof(EmitCalliDelegate)) ??
((il, op, convention, ret, types) =>
{
if (getSigHelper is null)
{
// TODO: Update this with a link to documentation.
throw new PlatformNotSupportedException(
"Unmanaged indirect call emission is not supported on this platform.");
}
var sigHelper = getSigHelper(convention, ret);
foreach (var param in types)
{
sigHelper.AddArgument(param);
}
il.Emit(op, sigHelper);
});
}
private static void GenerateCheckedMethodIl(ILGenerator generator, FieldInfo apiField, string fieldName, Type[] parameters, EmitCalliDelegate emitCalli)
{
for (int i = 0; i < parameters.Length; i++)
{
generator.Emit(OpCodes.Ldarg, i + 1); // Load parameter, +1 from static
}
generator.Emit(OpCodes.Ldarg_0); // Load this
generator.Emit(OpCodes.Ldfld, apiField); // Load address of field
generator.Emit(OpCodes.Ldfld, typeof(NativeQuicApi).GetField(fieldName)); // Load function pointer
emitCalli(generator, OpCodes.Calli, CallingConvention.Cdecl, typeof(int), parameters); // call function pointer
var local = generator.DeclareLocal(typeof(int));
generator.Emit(OpCodes.Stloc_0);
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldc_I4_0);
var label = generator.DefineLabel();
if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
// generate check for failures = < 0
generator.Emit(OpCodes.Bge, label);
}
else
{
// generate check for failures = > 0
generator.Emit(OpCodes.Ble, label);
}
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Call, typeof(Helpers).GetMethod(nameof(Helpers.CheckException)));
generator.MarkLabel(label);
generator.Emit(OpCodes.Ret);
}
private static void GenerateMethodIl(ILGenerator generator, FieldInfo apiField, string fieldName, Type[] parameters, Type returnType, EmitCalliDelegate emitCalli)
{
for (int i = 0; i < parameters.Length; i++)
{
generator.Emit(OpCodes.Ldarg, i + 1); // Load parameter, +1 from static
}
generator.Emit(OpCodes.Ldarg_0); // Load this
generator.Emit(OpCodes.Ldfld, apiField); // Load address of field
generator.Emit(OpCodes.Ldfld, typeof(NativeQuicApi).GetField(fieldName)); // Load function pointer
emitCalli(generator, OpCodes.Calli, CallingConvention.Cdecl, returnType, parameters); // call function pointer
generator.Emit(OpCodes.Ret);
}
