/// <summary>
/// Expects a reference to an array of the given element type and an index on the stack.
///
/// Pops both, and pushes the address of the element at the given index.
/// </summary>
public Emit <DelegateType> LoadElementAddress(Type elementType)
{
if (!AllowsUnverifiableCIL)
{
FailUnverifiable("LoadElementAddress");
}
var arrayType = elementType.MakeArrayType();
// needs to be markable so we can keep track of what makes use of this value
var pushToStack = TypeOnStack.Get(elementType.MakeByRefType());
// Shove this away, later on we'll figure out if we can insert a readonly here
ReadonlyPatches.Add(SigilTuple.Create(IL.Index, pushToStack));
var transitions =
new[]
{
new StackTransition(new [] { TypeOnStack.Get <NativeIntType>(), TypeOnStack.Get(arrayType) }, new [] { pushToStack }),
new StackTransition(new [] { TypeOnStack.Get <int>(), TypeOnStack.Get(arrayType) }, new [] { pushToStack })
};
UpdateState(OpCodes.Ldelema, elementType, Wrap(transitions, "LoadElementAddress"));
return(this);
}
private void InjectReadOnly()
{
while (ReadonlyPatches.Count > 0)
{
var elem = ReadonlyPatches[0];
ReadonlyPatches.RemoveAt(0);
var at = elem.Item1;
var value = elem.Item2;
var asObjToLdfd = value.CountMarks(OpCodes.Ldfld, 0);
var asObjToLdfda = value.CountMarks(OpCodes.Ldflda, 0);
var asObjToStfd = value.CountMarks(OpCodes.Stfld, 0);
var asObjToCall = value.CountMarks(OpCodes.Call, 0);
var asPtrToLdobj = value.CountMarks(OpCodes.Ldobj, 0);
var asPtrToLdind =
value.CountMarks(OpCodes.Ldind_I, 0) +
value.CountMarks(OpCodes.Ldind_I1, 0) +
value.CountMarks(OpCodes.Ldind_I2, 0) +
value.CountMarks(OpCodes.Ldind_I4, 0) +
value.CountMarks(OpCodes.Ldind_I8, 0) +
value.CountMarks(OpCodes.Ldind_R4, 0) +
value.CountMarks(OpCodes.Ldind_R8, 0) +
value.CountMarks(OpCodes.Ldind_Ref, 0) +
value.CountMarks(OpCodes.Ldind_U1, 0) +
value.CountMarks(OpCodes.Ldind_U2, 0) +
value.CountMarks(OpCodes.Ldind_U4, 0);
var asSourceToCpobj = value.CountMarks(OpCodes.Cpobj, 0);
var totalAllowedUses =
asObjToLdfd +
asObjToLdfda +
asObjToStfd +
asPtrToLdobj +
asPtrToLdind +
asSourceToCpobj +
asObjToCall;
var totalActualUses = value.CountMarks();
if (totalActualUses == totalAllowedUses)
{
InsertInstruction(at, OpCodes.Readonly);
}
}
}
