/// <summary>
/// Fill in the GC-relevant stack frame locations.
/// </summary>
private void FakeGcScanRoots(MethodDesc method, ArgIterator argit, CORCOMPILE_GCREFMAP_TOKENS[] frame)
{
// Encode generic instantiation arg
if (argit.HasParamType)
{
if (method.RequiresInstMethodDescArg())
{
frame[argit.GetParamTypeArgOffset()] = CORCOMPILE_GCREFMAP_TOKENS.GCREFMAP_METHOD_PARAM;
}
else if (method.RequiresInstMethodTableArg())
{
frame[argit.GetParamTypeArgOffset()] = CORCOMPILE_GCREFMAP_TOKENS.GCREFMAP_TYPE_PARAM;
}
}
// If the function has a this pointer, add it to the mask
if (argit.HasThis)
{
bool isUnboxingStub = false; // TODO: is this correct?
bool interior = method.OwningType.IsValueType && !isUnboxingStub;
frame[_transitionBlock.ThisOffset] = (interior ? CORCOMPILE_GCREFMAP_TOKENS.GCREFMAP_INTERIOR : CORCOMPILE_GCREFMAP_TOKENS.GCREFMAP_REF);
}
if (argit.IsVarArg)
{
frame[argit.GetVASigCookieOffset()] = CORCOMPILE_GCREFMAP_TOKENS.GCREFMAP_VASIG_COOKIE;
// We are done for varargs - the remaining arguments are reported via vasig cookie
return;
}
// Also if the method has a return buffer, then it is the first argument, and could be an interior ref,
// so always promote it.
if (argit.HasRetBuffArg())
{
frame[_transitionBlock.GetRetBuffArgOffset(argit.HasThis)] = CORCOMPILE_GCREFMAP_TOKENS.GCREFMAP_INTERIOR;
}
//
// Now iterate the arguments
//
// Cycle through the arguments, and call GcScanRoots for each
int argIndex = 0;
int argOffset;
while ((argOffset = argit.GetNextOffset()) != TransitionBlock.InvalidOffset)
{
ArgLocDesc? argLocDescForStructInRegs = argit.GetArgLoc(argOffset);
ArgDestination argDest = new ArgDestination(_transitionBlock, argOffset, argLocDescForStructInRegs);
GcScanRoots(method.Signature[argIndex], in argDest, delta: 0, frame);
argIndex++;
}
}