internal Slot CreateSlot(CodeGen cg)
{
switch (_kind) {
case VariableKind.Local:
if (_storage == null) {
// Fall back on a runtime lookup if this variable does not have storage associated with it
// (e.g. if the variable belongs to a block in interpreted mode).
return new LocalNamedFrameSlot(cg.ContextSlot, _name);
} else {
return CreateSlotForVariable(cg);
}
case VariableKind.Parameter:
if (_lift) {
if (_storage == null) {
return new LocalNamedFrameSlot(cg.ContextSlot, _name);
} else {
return CreateSlotForVariable(cg);
}
} else {
//Debug.Assert(cg.Allocator.ActiveScope == _block);
return MarkLocal(GetArgumentSlot(cg));
}
case VariableKind.Global:
if (_storage == null) {
return new NamedFrameSlot(cg.ContextSlot, _name);
} else {
// Globals are accessed via context slot
return _storage.CreateSlot(cg.ContextSlot);
}
case VariableKind.Temporary:
return cg.GetNamedLocal(_type, SymbolTable.IdToString(_name));
case VariableKind.GeneratorTemporary:
if (!cg.IsGenerator) {
goto case VariableKind.Temporary;
}
// Allocate in environment if emitting generator.
// This must be done here for now because the environment
// allocation, which is generally done in Allocate(),
// is done in the context of the outer generator codegen,
// which is not marked IsGenerator so the generator temps
// would go onto CLR stack rather than environment.
// TODO: Fix this once we have lifetime analysis in place.
_storage = _block.EnvironmentFactory.MakeEnvironmentReference(_name, _type);
return CreateSlotForVariable(cg);
}
Debug.Assert(false, "Unexpected variable kind: " + _kind.ToString());
return null;
}
/// <summary>
/// Will allocate the storage in the environment and return slot to access
/// the variable in the current scope (so that it can be initialized)
/// </summary>
private Slot AllocInEnv(CodeGen cg)
{
//Debug.Assert(_storage == null);
Debug.Assert(_block.EnvironmentFactory != null, "Allocating in environment without environment factory.\nIs HasEnvironment set?");
_storage = _block.EnvironmentFactory.MakeEnvironmentReference(_name, _type);
return _storage.CreateSlot(cg.Allocator.GetClosureAccessSlot(_block));
}
internal void Allocate(CodeGen cg)
{
Debug.Assert(cg.Allocator.Block == Block);
switch (_kind) {
case VariableKind.Local:
if (_block.IsGlobal) {
// Local on global level, simply allocate the storage
_storage = cg.Allocator.LocalAllocator.AllocateStorage(_name, _type);
if (_defaultValue != null) {
Slot slot = CreateSlotForVariable(cg);
_defaultValue.Emit(cg);
slot.EmitSet(cg);
}
} else {
Slot slot;
// If lifting local into closure, allocate in the environment
if (_lift) {
// allocate space in the environment and set it to Uninitialized
slot = AllocInEnv(cg);
} else {
// Allocate the storage
_storage = cg.Allocator.LocalAllocator.AllocateStorage(_name, _type);
// No access slot for local variables, pass null.
slot = _storage.CreateSlot(_storage.RequireAccessSlot ? cg.Allocator.GetScopeAccessSlot(_block) : null);
MarkLocal(slot);
}
if (_uninitialized || _defaultValue != null) {
// Emit initialization (environments will be initialized all at once)
if (_defaultValue != null) {
_defaultValue.Emit(cg);
slot.EmitSet(cg);
} else if (_type == typeof(object)) {
// Only set variables of type object to "Uninitialized"
//throw new UnInitializedUsageException(this, "Attempted to use uninitialized variable");
slot.EmitSetUninitialized(cg);
}
}
}
break;
case VariableKind.Parameter:
// Lifting parameter into closure, allocate in env and move.
if (_lift) {
Slot slot = AllocInEnv(cg);
Slot src = GetArgumentSlot(cg);
// Copy the value from the parameter (src) into the environment (slot)
slot.EmitSet(cg, src);
} else {
Debug.Assert(cg.Allocator.Block == Block);
// Nothing to do here
}
break;
case VariableKind.Global:
if (_defaultValue is UnboundExpression || cg.Allocator.Parent.Parent.Parent != null)
{
_storage = cg.Allocator.GlobalAllocator.AllocateStorage(_name, _type);
}
else
{
_storage = cg.Allocator.Parent.LocalAllocator.AllocateStorage(_name, _type);
}
Debug.Assert(_storage != null);
break;
case VariableKind.Temporary:
// Nothing to do here
break;
case VariableKind.GeneratorTemporary:
// Do the work in CreateSlot
break;
}
}