public override AstNode Visit(FunctionDefinition node)
{
// Process attributes.
ProcessAttributes(node);
// Ignore pure declarations.
if(node.GetChildren() == null)
return node;
// Update the scope.
PushScope(node.GetScope());
// Visit the children.
VisitList(node.GetChildren());
// Restore the scope.
PopScope();
return node;
}
private Function CreateGenerator_MoveNext(FunctionDefinition node)
{
// Get the generator class.
Class genClass = node.GeneratorClass;
// Create the function type.
FunctionType functionType =
FunctionType.Create(ChelaType.GetBoolType(),
new IChelaType[]{ReferenceType.Create(node.GeneratorClassInstance)}, false);
// Create the method.
Method method = new Method("MoveNext", MemberFlags.Public, genClass);
method.SetFunctionType(functionType);
method.DefinitionNode = node;
genClass.AddFunction("MoveNext", method);
// Swap the exception contexts.
method.SwapExceptionContexts(currentFunction);
// Store the old function.
Function oldFunction = currentFunction;
currentFunction = method;
// Create the jump table block.
BasicBlock jmpBlock = CreateBasicBlock();
jmpBlock.SetName("jmp");
// Generate the main code.
BasicBlock topBlock = CreateBasicBlock();
topBlock.SetName("top");
builder.SetBlock(topBlock);
// Prepare returning.
LexicalScope topScope = (LexicalScope) node.GetScope();
PrepareReturning(node, currentFunction, topScope);
// Create the function body.
VisitList(node.GetChildren());
// Finish returning.
FinishReturn(node, currentFunction);
// Create the state jump table.
builder.SetBlock(jmpBlock);
// Load the current state.
builder.CreateLoadArg(0);
builder.CreateLoadField(node.GeneratorState);
// Build the jump table.
int numstates = node.Yields.Count*2+3;
int[] stateConstants = new int[numstates];
BasicBlock[] stateEntries = new BasicBlock[numstates];
// The default case is return.
stateConstants[0] = -1;
stateEntries[0] = currentFunction.ReturnBlock;
// The first state is the top block.
stateConstants[1] = 0;
stateEntries[1] = topBlock;
// The second state is the return block.
stateConstants[2] = 1;
stateEntries[2] = currentFunction.ReturnBlock;
// The next states are the yield merges followed by yield disposes.
for(int i = 0; i < node.Yields.Count; ++i)
{
ReturnStatement yieldStmnt = node.Yields[i];
// Emit the merge state.
int stateId = i*2+2;
int entryIndex = stateId+1;
stateConstants[entryIndex] = stateId;
stateEntries[entryIndex] = yieldStmnt.MergeBlock;
// Emit the dispose state.
stateConstants[entryIndex+1] = stateId+1;
stateEntries[entryIndex+1] = yieldStmnt.DisposeBlock;
}
builder.CreateSwitch(stateConstants, stateEntries);
// Restore the old function.
currentFunction = oldFunction;
return method;
}
private void DefineGeneratorBody(FunctionDefinition node)
{
// Get entry function.
Function entryFunction = node.GetFunction();
// Rebase his locals.
entryFunction.RebaseLocals();
// Create the generator class.
Scope spaceScope = entryFunction.GetParentScope();
Class generatorClass =
new Class(GenSym(), MemberFlags.Internal, spaceScope);
node.GeneratorClass = generatorClass;
// Use the same generic prototype as the entry point function.
generatorClass.SetGenericPrototype(entryFunction.GetGenericPrototype());
// Add the generator class to the same scope as the function.
if(spaceScope.IsClass() || spaceScope.IsStructure())
{
Structure parentClass = (Structure)spaceScope;
parentClass.AddType(generatorClass);
}
else if(spaceScope.IsNamespace())
{
Namespace parentSpace = (Namespace)spaceScope;
parentSpace.AddMember(generatorClass);
}
else
{
Error(node, "Cannot create generator class in {0}", spaceScope.GetFullName());
}
// Add the enumerable interface.
Structure enumerableIface = null;
if(node.IsEnumerable)
{
enumerableIface = currentModule.GetEnumerableIface();
if(node.IsGenericIterator)
{
enumerableIface = currentModule.GetEnumerableGIface();
GenericInstance gargs = new GenericInstance(enumerableIface.GetGenericPrototype(),
new IChelaType[]{node.YieldType});
enumerableIface = (Structure)enumerableIface.InstanceGeneric(gargs, currentModule);
}
generatorClass.AddInterface(enumerableIface);
}
// Add the enumerator interface.
Structure enumeratorIface = currentModule.GetEnumeratorIface();
if(node.IsGenericIterator)
{
enumeratorIface = currentModule.GetEnumeratorGIface();
GenericInstance gargs = new GenericInstance(enumeratorIface.GetGenericPrototype(),
new IChelaType[]{node.YieldType});
enumeratorIface = (Structure)enumeratorIface.InstanceGeneric(gargs, currentModule);
}
generatorClass.AddInterface(enumeratorIface);
// Create the yielded field.
FieldVariable yieldedValue = new FieldVariable("yielded", MemberFlags.Private, node.YieldType, generatorClass);
generatorClass.AddField(yieldedValue);
node.YieldedValue = yieldedValue;
// Create the generator state variable.
FieldVariable generatorState = new FieldVariable("state", MemberFlags.Private, ChelaType.GetIntType(), generatorClass);
generatorClass.AddField(generatorState);
node.GeneratorState = generatorState;
// Encapsulate the locals in fields.
foreach(LocalVariable local in entryFunction.GetLocals())
{
if(!local.IsPseudoLocal)
continue;
// Variables containing arguments must be public.
MemberFlags access = MemberFlags.Private;
if(local.ArgumentIndex >= 0)
access = MemberFlags.Public;
// Create the field to hold the state.
FieldVariable localField = new FieldVariable(GenSym(), access, local.GetVariableType(), generatorClass);
generatorClass.AddField(localField);
local.ActualVariable = localField;
}
// Create an instance of the generator class.
Structure generatorClassInstance = generatorClass.GetClassInstance();
if(generatorClass.GetGenericPrototype().GetPlaceHolderCount() != 0)
{
// Create an instance using the same placeholders.
GenericPrototype proto = generatorClass.GetGenericPrototype();
int numargs = proto.GetPlaceHolderCount();
IChelaType[] protoInstance = new IChelaType[numargs];
for(int i = 0; i < numargs; ++i)
protoInstance[i] = proto.GetPlaceHolder(i);
// Instance the generic class.
GenericInstance instance = new GenericInstance(proto, protoInstance);
generatorClassInstance = (Structure)generatorClassInstance.InstanceGeneric(instance, currentModule);
}
node.GeneratorClassInstance = generatorClassInstance;
// Create the trivial constructor.
Function ctor = CreateTrivialConstructor(generatorClass, generatorClassInstance);
if(generatorClass.IsGeneric())
ctor = FindFirstConstructor(generatorClassInstance);
// Create a local to hold the created closure.
LexicalScope topScope = (LexicalScope)node.GetScope();
LocalVariable closureLocal = new LocalVariable("closure", topScope, ReferenceType.Create(generatorClassInstance));
// Create the entry point content.
BasicBlock entryBlock = CreateBasicBlock();
entryBlock.SetName("entry");
builder.SetBlock(entryBlock);
// Create the closure and store it in his local.
builder.CreateNewObject(generatorClassInstance, ctor, 0);
builder.CreateStoreLocal(closureLocal);
// Load the closure.
builder.CreateLoadLocal(closureLocal);
// Store the arguments into the closure.
FunctionPrototype prototype = node.GetPrototype();
AstNode argument = prototype.GetArguments();
byte index = 0;
while(argument != null)
{
FunctionArgument argNode = (FunctionArgument) argument;
// TODO: Forbid ref, out, stream arguments here.
// Store the argument in the closure.
LocalVariable argVar = argNode.GetVariable();
if(argVar != null)
{
// Load the closure
builder.CreateDup1();
// Load the argument.
builder.CreateLoadArg(index);
// Store it into the field.
builder.CreateStoreField((FieldVariable)argVar.ActualVariable);
}
// Process the next argument.
argument = argument.GetNext();
index++;
}
// Encapsulate the argument variables.
foreach(ArgumentVariable argVar in node.ArgumentVariables)
{
if(!argVar.IsPseudoArgument)
continue;
// Create the argument field.
FieldVariable argField = new FieldVariable(GenSym(), MemberFlags.Public, argVar.GetVariableType(), generatorClass);
generatorClass.AddField(argField);
argVar.ActualVariable = argField;
// Store the self field.
if(!currentFunction.IsStatic() && argVar.GetArgumentIndex() == 0)
node.GeneratorSelf = argField;
// Load the closure.
builder.CreateDup1();
// Load the argument.
builder.CreateLoadArg((byte)argVar.GetArgumentIndex());
// Store it into the closure.
builder.CreateStoreField(argField);
}
// Return the generator.
builder.CreateRet();
// Notify the yields about their states.
int stateIndex = 2;
foreach(ReturnStatement yieldStmtn in node.Yields)
{
yieldStmtn.YieldState = stateIndex;
stateIndex += 2;
}
// Implement IEnumerator.
if(node.IsEnumerable)
{
// Create the object GetEnumerator method.
CreateGenerator_GetEnumerator(node, currentModule.GetEnumeratorIface(), false);
// Create the generic GetEnumerator method
if(node.IsGenericIterator)
CreateGenerator_GetEnumerator(node, enumeratorIface, true);
}
// Create the Current property.
CreateGenerator_Current(node, false);
if(node.IsGenericIterator)
CreateGenerator_Current(node, true);
// Create the Reset method.
CreateGenerator_Reset(node);
// Create the MoveNext method.
Function moveNext = CreateGenerator_MoveNext(node);
// Create the Dispose method.
CreateGenerator_Dispose(node, moveNext);
// Fix the inheritance.
generatorClass.FixInheritance();
}
public override AstNode Visit(FunctionDefinition node)
{
// Begin the node.
builder.BeginNode(node);
// Process attributes.
ProcessAttributes(node);
// Get the prototype.
FunctionPrototype prototype = node.GetPrototype();
// Get the function.
Function function = prototype.GetFunction();
// Ignore functions without a body.
if(node.GetChildren() == null)
return builder.EndNode();
// Store the old function.
// TODO: Add closures
Function oldFunction = currentFunction;
currentFunction = function;
// Update the securiry.
if(function.IsUnsafe())
PushUnsafe();
// Get the function lexical scope.
LexicalScope topScope = (LexicalScope)node.GetScope();
// Update the scope.
PushScope(topScope);
// Define the generator or function body
if(node.IsGenerator)
DefineGeneratorBody(node);
else
DefineFunctionBody(node, function, topScope);
// Restore the scope.
PopScope();
// Restore the security.
if(function.IsUnsafe())
PopUnsafe();
// Restore the current function.
currentFunction = oldFunction;
return builder.EndNode();
}