private void PrepareReturning(AstNode where, Function function, LexicalScope scope)
{
// Get the definition node and check for generator.
FunctionDefinition defNode = function.DefinitionNode;
bool isGenerator = false;
if(defNode != null)
isGenerator = defNode.IsGenerator;
// Use standard return.
if(function.GetExceptionContext() == null && !isGenerator)
return;
// Create the return block.
BasicBlock returnBlock = new BasicBlock(function);
returnBlock.SetName("retBlock");
function.ReturnBlock = returnBlock;
// Create the return value local.
FunctionType functionType = function.GetFunctionType();
IChelaType retType = functionType.GetReturnType();
if(retType != ChelaType.GetVoidType() && !isGenerator)
function.ReturnValueVar = new LocalVariable(GenSym() + "_retval", scope, retType);
// Create the is returning flag.
function.ReturningVar = new LocalVariable(GenSym() + "_isret", scope, ChelaType.GetBoolType(), isGenerator);
function.ReturningVar.Type = LocalType.Return;
// Create the field for generators.
if(isGenerator)
{
FieldVariable returningField = new FieldVariable("returning", MemberFlags.Private,
ChelaType.GetBoolType(), defNode.GeneratorClass);
defNode.GeneratorClass.AddField(returningField);
function.ReturningVar.ActualVariable = returningField;
}
// Initializer the returning flag to false.
builder.CreateLoadBool(false);
PerformAssignment(where, function.ReturningVar);
}
private void CreateGenerator_GetEnumerator(FunctionDefinition node, Structure enumeratorType, bool generic)
{
// Get the generator class.
Class genClass = node.GeneratorClass;
// Use the GetEnumerator name for the most specific version.
string name = "GetEnumerator";
Function contract = null;
if(!generic && node.IsGenericIterator)
{
name = GenSym();
contract = FindFirstConstract(currentModule.GetEnumerableIface(), "GetEnumerator");
}
// Create the function type.
FunctionType functionType =
FunctionType.Create(ReferenceType.Create(enumeratorType),
new IChelaType[]{ReferenceType.Create(node.GeneratorClassInstance)}, false);
// Create the method.
Method method = new Method(name, MemberFlags.Public, genClass);
method.SetFunctionType(functionType);
genClass.AddFunction(name, method);
// Set the explicit contract.
if(contract != null)
method.SetExplicitContract(contract);
// Create the method block.
BasicBlock block = new BasicBlock(method);
block.SetName("top");
// Return this.
builder.SetBlock(block);
builder.CreateLoadArg(0);
builder.CreateRet();
}
private Method CreateTrivialConstructor(Structure building, Structure buildingInstance)
{
// Create the constructor function type.
FunctionType type = FunctionType.Create(ChelaType.GetVoidType(),
new IChelaType[]{ReferenceType.Create(buildingInstance)}, false);
// Create the constructor.
Method ctor = new Method(".ctor", MemberFlags.Public | MemberFlags.Constructor, building);
ctor.SetFunctionType(type);
building.AddFunction(".ctor", ctor);
// Create the constructor block.
BasicBlock top = new BasicBlock(ctor);
top.SetName("top");
top.Append(new Instruction(OpCode.RetVoid, null));
return ctor;
}
private void CreateGenerator_Current(FunctionDefinition node, bool generic)
{
// Get the generator class.
Class genClass = node.GeneratorClass;
// Use the get_Current name for the most specific version.
string name = "get_Current";
Function contract = null;
if(!generic && node.IsGenericIterator)
{
name = GenSym();
contract = FindFirstConstract(currentModule.GetEnumeratorIface(), "get_Current");
}
// Select the current type.
IChelaType currentType = node.YieldType;
if(!generic)
currentType = ReferenceType.Create(currentModule.GetObjectClass());
// Create the function type.
FunctionType functionType =
FunctionType.Create(currentType,
new IChelaType[]{ReferenceType.Create(node.GeneratorClassInstance)}, false);
// Create the method.
Method method = new Method(name, MemberFlags.Public, genClass);
method.SetFunctionType(functionType);
genClass.AddFunction(name, method);
// Set the explicit contract.
if(contract != null)
method.SetExplicitContract(contract);
// Create the method block.
BasicBlock block = new BasicBlock(method);
block.SetName("top");
// Create the return and error blocks.
BasicBlock retBlock = new BasicBlock(method);
retBlock.SetName("ret");
BasicBlock errorBlock = new BasicBlock(method);
errorBlock.SetName("error");
// Make sure reset was called before the first Current.
builder.SetBlock(block);
builder.CreateLoadArg(0);
builder.CreateLoadField(node.GeneratorState);
builder.CreateLoadInt32(0);
builder.CreateCmpEQ();
builder.CreateBr(errorBlock, retBlock);
// Raise an error if reset wasn't called.
builder.SetBlock(errorBlock);
Class excpt = (Class)ExtractClass(node, currentModule.GetLangMember("InvalidOperationException"));
builder.CreateLoadString("IEnumerator.MoveNext must be called before than IEnumerator.Current.");
builder.CreateNewObject(excpt, GetExceptionCtor(node, excpt), 1);
builder.CreateThrow();
// Load the yielded value.
builder.SetBlock(retBlock);
builder.CreateLoadArg(0);
builder.CreateLoadField(node.YieldedValue);
// Cast the yielded value.
Cast(node, null, node.YieldType, currentType);
// Return.
builder.CreateRet();
}