/// <summary>
/// Makes a new static field slot. Type is ignored. If we ever change ignoring type then we
/// need to make BuiltinWrapper generic and update StaticFieldBuiltinSlot to get the correct
/// type.
/// </summary>
public override Slot MakeSlot(Name name, Type type)
{
StaticFieldSlot fs;
object builtin;
if (!fields.TryGetValue(name, out fs))
{
if (!TypeCache.Builtin.TryGetSlot(DefaultContext.Default, SymbolTable.StringToId(name.GetString()), out builtin))
{
// name does not collide w/ a built-in name, define a real field.
FieldBuilder fb = typeGen.myType.DefineField(name.GetString(), typeof(object), FieldAttributes.Public | FieldAttributes.Static);
fs = new StaticFieldSlot(fb);
}
else
{
// name collides w/ a built-in name. Our field becomes strongly typed to
// BuiltinWrapper. We then return a
// StaticFieldBuiltinSlot which checks the value to see if it's a built-in or
// not.
FieldBuilder fb = typeGen.myType.DefineField(name.GetString(), typeof(BuiltinWrapper), FieldAttributes.Public | FieldAttributes.Static);
fs = new StaticFieldBuiltinSlot(fb);
}
fields[name] = fs;
}
return(fs);
}
//
// This generates a method like the following:
//
// TryGetExtraValue(int name, object out value) {
// if (name1 == name) {
// value = type.name1Slot;
// return true;
// }
// if (name2 == name) {
// value = type.name2Slot;
// return true;
// }
// ...
// return false
// }
private void MakeGetMethod()
{
CodeGen cg = tg.DefineMethodOverride(typeof(CustomFieldIdDict).GetMethod("TryGetExtraValue"));
foreach (KeyValuePair <Name, Slot> entry in names.Slots)
{
cg.EmitSymbolIdInt(entry.Key.GetString());
cg.EmitArgAddr(0);
cg.EmitFieldGet(typeof(SymbolId), "Id");
Label next = cg.DefineLabel();
cg.Emit(OpCodes.Bne_Un, next);
cg.EmitArgGet(1);
// ugly special casing builtins this way, but they're special...
// Builtins can be in one of two states:
// Not defined, but available internally to the module
// Defined, and exposed externally from the module.
// In both cases we have static fields for these, and we're in the custom dict.
//
// Therefore we keep track of which state they're in w/ a wrapper object,
// and here we need to emit the real value, not the value that's availble
// internally to the module.
StaticFieldBuiltinSlot builtin = entry.Value as StaticFieldBuiltinSlot;
if (builtin == null)
{
entry.Value.EmitGet(cg);
}
else
{
builtin.EmitGetRaw(cg);
}
cg.Emit(OpCodes.Stind_Ref);
cg.EmitInt(1);
cg.EmitReturn();
cg.MarkLabel(next);
}
cg.EmitInt(0);
cg.EmitReturn();
cg.Finish();
}
