protected override Expression VisitDynamic(DynamicExpression node)
{
Type siteType = typeof(CallSite <>).MakeGenericType(node.DelegateType);
// Rewite call site as constant
var siteExpr = VisitConstant(Expression.Constant(DynamicSiteHelpers.MakeSite(node.Binder, siteType)));
// Rewrite all of the arguments
var args = Visit(node.Arguments);
var siteVar = Expression.Variable(siteExpr.Type, "$site");
// ($site = siteExpr).Target.Invoke($site, *args)
return(Expression.Block(
new [] { siteVar },
Expression.Call(
Expression.Field(
Expression.Assign(siteVar, siteExpr),
siteType.GetField("Target")
),
node.DelegateType.GetMethod("Invoke"),
ArrayUtils.Insert(siteVar, args)
)
));
}
/// <summary>
/// Generates stub to receive the CLR call and then call the dynamic language code.
/// </summary>
private object[] EmitClrCallStub(ILGen cg)
{
List <ReturnFixer> fixers = new List <ReturnFixer>(0);
ArgumentInfo[] args = new ArgumentInfo[_parameters.Length];
for (int i = 0; i < args.Length; i++)
{
args[i] = Expression.PositionalArg(i);
}
ConvertBinder convert = _context.CreateConvertBinder(_returnType, true);
InvokeBinder action = _context.CreateInvokeBinder(args);
// Create strongly typed return type from the site.
// This will, among other things, generate tighter code.
Type[] siteTypes = MakeSiteSignature();
Type siteType = DynamicSiteHelpers.MakeCallSiteType(siteTypes);
CallSite callSite = DynamicSiteHelpers.MakeSite(action, siteType);
Type convertSiteType = null;
CallSite convertSite = null;
if (_returnType != typeof(void))
{
convertSiteType = DynamicSiteHelpers.MakeCallSiteType(typeof(object), _returnType);
convertSite = DynamicSiteHelpers.MakeSite(convert, convertSiteType);
}
// build up constants array
object[] constants = new object[] { TargetPlaceHolder, callSite, convertSite };
const int TargetIndex = 0, CallSiteIndex = 1, ConvertSiteIndex = 2;
LocalBuilder convertSiteLocal = null;
FieldInfo convertTarget = null;
if (_returnType != typeof(void))
{
// load up the conversesion logic on the stack
convertSiteLocal = cg.DeclareLocal(convertSiteType);
EmitConstantGet(cg, ConvertSiteIndex, convertSiteType);
cg.Emit(OpCodes.Dup);
cg.Emit(OpCodes.Stloc, convertSiteLocal);
convertTarget = convertSiteType.GetField("Target");
cg.EmitFieldGet(convertTarget);
cg.Emit(OpCodes.Ldloc, convertSiteLocal);
}
// load up the invoke logic on the stack
LocalBuilder site = cg.DeclareLocal(siteType);
EmitConstantGet(cg, CallSiteIndex, siteType);
cg.Emit(OpCodes.Dup);
cg.Emit(OpCodes.Stloc, site);
FieldInfo target = siteType.GetField("Target");
cg.EmitFieldGet(target);
cg.Emit(OpCodes.Ldloc, site);
EmitConstantGet(cg, TargetIndex, typeof(object));
for (int i = 0; i < _parameters.Length; i++)
{
if (_parameters[i].ParameterType.IsByRef)
{
ReturnFixer rf = ReturnFixer.EmitArgument(cg, i + 1, _parameters[i].ParameterType);
if (rf != null)
{
fixers.Add(rf);
}
}
else
{
cg.EmitLoadArg(i + 1);
}
}
// emit the invoke for the call
cg.EmitCall(target.FieldType, "Invoke");
// emit the invoke for the convert
if (_returnType == typeof(void))
{
cg.Emit(OpCodes.Pop);
}
else
{
cg.EmitCall(convertTarget.FieldType, "Invoke");
}
// fixup any references
foreach (ReturnFixer rf in fixers)
{
rf.FixReturn(cg);
}
cg.Emit(OpCodes.Ret);
return(constants);
}
