public override AstNode Visit(FixedVariableDecl node)
{
// Begin the node.
builder.BeginNode(node);
// Get the fixed local.
LocalVariable local = node.GetVariable();
// Get the value expression.
Expression valueExpr = node.GetValueExpression();
valueExpr.Accept(this);
// Get the associated types.
IChelaType type = node.GetNodeType();
IChelaType coercionType = node.GetCoercionType();
IChelaType valueType = valueExpr.GetNodeType();
// Perform coercion.
if(valueType != coercionType )
Cast(node, valueExpr.GetNodeValue(), valueType, coercionType);
// Pin references, cast pointers.
if(coercionType.IsPointer())
{
// Cast the pointer.
if(coercionType != type)
Cast(node, null, coercionType, type);
// Store the pointer in a local.
builder.CreateStoreLocal(local);
}
else
{
// References.
valueType = DeReferenceType(coercionType);
// Give a null value for null references.
builder.CreateDup1();
// Create the blocks for the comparison
BasicBlock notNullBlock = CreateBasicBlock();
notNullBlock.SetName("notNull");
BasicBlock nullBlock = CreateBasicBlock();
nullBlock.SetName("null");
BasicBlock nullMerge = CreateBasicBlock();
nullMerge.SetName("nullMerge");
// Compare to null.
builder.CreateLoadNull();
builder.CreateCmpEQ();
builder.CreateBr(nullBlock, notNullBlock);
// Set the null block content.
builder.SetBlock(nullBlock);
builder.CreatePop();
builder.CreateLoadNull();
builder.CreateStoreLocal(local);
builder.CreateJmp(nullMerge);
// Set the not null content.
builder.SetBlock(notNullBlock);
// Use the first element of the array.
if(valueType.IsArray())
{
ArrayType array = (ArrayType)valueType;
for(int i = 0; i < array.GetDimensions(); ++i)
builder.CreateLoadUInt8(0);
builder.CreateLoadArraySlotAddr(array);
// Cast the result.
IChelaType slotType = PointerType.Create(array.GetValueType());
if(slotType != type)
Cast(node, null, slotType, type);
}
else
Error(node, "unsupported fixed object of type {0}.", valueType.GetName());
// Store the value.
builder.CreateStoreLocal(local);
// Merge the results.
builder.CreateJmp(nullMerge);
builder.SetBlock(nullMerge);
}
// End.
return builder.EndNode();
}
public override AstNode Visit(FixedVariableDecl node)
{
// Get the variable type.
IChelaType type = node.GetNodeType();
// Create the variable.
LocalVariable fixedVar = new LocalVariable(node.GetName(), (LexicalScope)currentScope, type);
node.SetVariable(fixedVar);
// Visit the value expression.
Expression valueExpr = node.GetValueExpression();
valueExpr.Accept(this);
// Get the value type.
IChelaType valueType = valueExpr.GetNodeType();
// The value must be a reference or a pointer.
if(!valueType.IsReference() && !valueType.IsPointer())
Error(valueExpr, "the value expression must be a reference or a pointer.");
if(valueType.IsPointer())
{
if(Coerce(node, type, valueType, valueExpr.GetNodeValue()) != type)
Error(valueExpr, "cannot convert {0} into {1}.", valueType.GetName(), type.GetName());
// Coerce the value.
node.SetCoercionType(type);
}
else
{
// Remove references.
IChelaType refType = DeReferenceType(valueType);
if(refType.IsReference())
refType = DeReferenceType(refType);
// Only support arrays
if(refType.IsArray())
{
ArrayType array = (ArrayType)refType;
IChelaType pointerType = PointerType.Create(array.GetValueType());
if(Coerce(node, type, pointerType, null) != type)
Error(valueExpr, "cannot convert {0} into {1}.", pointerType.GetName(), type.GetName());
}
// Set the new coercion type.
node.SetCoercionType(ReferenceType.Create(refType));
}
return node;
}