21139: Improves consistency of nulls handling for various opcodes (#210)

src/Amalgam/evaluablenode/EvaluableNode.h

@@ -402,7 +402,7 @@ class EvaluableNode
 	static inline size_t GetDeepSize(EvaluableNode *n)
 	{
 		if(n == nullptr)
-			return 0;
+			return 1;
 
 		if(!n->GetNeedCycleCheck())
 		{

src/Amalgam/interpreter/Interpreter.cpp

@@ -620,7 +620,7 @@ EvaluableNodeReference Interpreter::InterpretNodeIntoUniqueStringIDValueEvaluabl
 
 double Interpreter::InterpretNodeIntoNumberValue(EvaluableNode *n)
 {
-	if(n == nullptr)
+	if(EvaluableNode::IsNull(n))
 		return std::numeric_limits<double>::quiet_NaN();
 
 	auto type = n->GetType();
@@ -659,7 +659,7 @@ EvaluableNodeReference Interpreter::InterpretNodeIntoUniqueNumberValueEvaluableN
 bool Interpreter::InterpretNodeIntoBoolValue(EvaluableNode *n, bool value_if_null)
 {
 	//shortcut if the node has what is being asked
-	if(n == nullptr)
+	if(EvaluableNode::IsNull(n))
 		return value_if_null;
 
 	auto result = InterpretNodeForImmediateUse(n, true);

src/Amalgam/interpreter/InterpreterOpcodesBase.cpp

@@ -432,7 +432,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_CONCLUDE_and_RETURN(Evalua
 	auto &ocn = en->GetOrderedChildNodes();
 
 	//if no parameter, then return itself for performance
-	if(ocn.size() == 0 || ocn[0] == nullptr)
+	if(ocn.size() == 0)
 		return EvaluableNodeReference(en, false);
 
 	//if idempotent, can just return a copy without any metadata
@@ -458,7 +458,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_CALL(EvaluableNode *en, bo
 		return EvaluableNodeReference::Null();
 
 	auto function = InterpretNodeForImmediateUse(ocn[0]);
-	if(function == nullptr)
+	if(EvaluableNode::IsNull(function))
 		return EvaluableNodeReference::Null();
 
 	auto node_stack = CreateInterpreterNodeStackStateSaver(function);
@@ -497,7 +497,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_CALL_SANDBOXED(EvaluableNo
 		return EvaluableNodeReference::Null();
 
 	auto function = InterpretNodeForImmediateUse(ocn[0]);
-	if(function == nullptr)
+	if(EvaluableNode::IsNull(function))
 		return EvaluableNodeReference::Null();
 
 	auto node_stack = CreateInterpreterNodeStackStateSaver(function);
@@ -1066,7 +1066,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_RETRIEVE(EvaluableNode *en
 #endif
 
 	//get the value(s)
-	if(to_lookup == nullptr || IsEvaluableNodeTypeImmediate(to_lookup->GetType()))
+	if(EvaluableNode::IsNull(to_lookup) || IsEvaluableNodeTypeImmediate(to_lookup->GetType()))
 	{
 		StringInternPool::StringID symbol_name_sid = EvaluableNode::ToStringIDIfExists(to_lookup);
 		EvaluableNode* symbol_value = GetCallStackSymbol(symbol_name_sid);
@@ -1415,7 +1415,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_ARGS(EvaluableNode *en, bo
 EvaluableNodeReference GenerateRandomValueBasedOnRandParam(EvaluableNodeReference param, Interpreter *interpreter,
 	RandomStream &random_stream, bool &can_free_param, bool immediate_result)
 {
-	if(param == nullptr)
+	if(EvaluableNode::IsNull(param))
 		return interpreter->AllocReturn(random_stream.RandFull(), immediate_result);
 
 	auto &ocn = param->GetOrderedChildNodes();
@@ -1548,7 +1548,9 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_RAND(EvaluableNode *en, bo
 	}
 
 	if(can_free_param)
+	{
 		evaluableNodeManager->FreeNodeTreeIfPossible(param);
+	}
 	else
 	{
 		//if used the parameters, a parameter might be used more than once
@@ -1714,14 +1716,14 @@ size_t GetRandomWeightedValueIndex(std::vector<EvaluableNode *> &probability_nod
 // if any part of param is preserved in the return value, then can_free_param will be set to false, otherwise it will be left alone
 EvaluableNodeReference GenerateWeightedRandomValueBasedOnRandParam(EvaluableNodeReference param, EvaluableNodeManager *enm, RandomStream &random_stream, bool &can_free_param)
 {
-	if(param == nullptr)
+	if(EvaluableNode::IsNull(param))
 		return EvaluableNodeReference::Null();
 
 	auto &ocn = param->GetOrderedChildNodes();
 	//need to have a value and probability list
 	if(ocn.size() >= 2)
 	{
-		if(ocn[0] == nullptr || ocn[1] == nullptr)
+		if(EvaluableNode::IsNull(ocn[0]) || EvaluableNode::IsNull(ocn[1]))
 			return EvaluableNodeReference::Null();
 
 		can_free_param = false;
@@ -1798,7 +1800,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_WEIGHTED_RAND(EvaluableNod
 		{
 			EvaluableNodeReference retval(evaluableNodeManager->AllocNode(ENT_LIST), true);
 
-			if(param_ocn.size() < 2 || param_ocn[0] == nullptr || param_ocn[1] == nullptr)
+			if(param_ocn.size() < 2 || EvaluableNode::IsNull(param_ocn[0]) || EvaluableNode::IsNull(param_ocn[1]))
 				return retval;
 
 			//clamp to the maximum number that can possibly be generated
@@ -1864,7 +1866,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_WEIGHTED_RAND(EvaluableNod
 	//if generating many values with weighted probabilites, use fast method
 	if(param_ocn.size() > 0 && (number_to_generate > 10 || (number_to_generate > 3 && param_ocn.size() > 200)))
 	{
-		if(param_ocn.size() < 2 || param_ocn[0] == nullptr || param_ocn[1] == nullptr)
+		if(param_ocn.size() < 2 || EvaluableNode::IsNull(param_ocn[0]) || EvaluableNode::IsNull(param_ocn[1]))
 		{
 			evaluableNodeManager->FreeNodeIfPossible(param);
 			return retval;
@@ -1918,7 +1920,9 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_WEIGHTED_RAND(EvaluableNod
 	}
 
 	if(can_free_param)
+	{
 		evaluableNodeManager->FreeNodeTreeIfPossible(param);
+	}
 	else
 	{
 		//if used the parameters, a parameter might be used more than once

src/Amalgam/interpreter/InterpreterOpcodesDataTypes.cpp

@@ -983,8 +983,8 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_ZIP_LABELS(EvaluableNode *
 	auto source = InterpretNode(ocn[1]);
 
 	//if no label list, or no source or source is immediate, then just return the source
-	if(label_list == nullptr || !label_list->IsOrderedArray()
-			|| source == nullptr || !source->IsOrderedArray())
+	if(EvaluableNode::IsNull(label_list) || !label_list->IsOrderedArray()
+			|| EvaluableNode::IsNull(source) || !source->IsOrderedArray())
 		return source;
 
 	node_stack.PopEvaluableNode();

src/Amalgam/interpreter/InterpreterOpcodesTransformations.cpp

@@ -27,7 +27,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_REWRITE(EvaluableNode *en,
 		return EvaluableNodeReference::Null();
 
 	auto function = InterpretNodeForImmediateUse(ocn[0]);
-	if(function == nullptr)
+	if(EvaluableNode::IsNull(function))
 		return EvaluableNodeReference::Null();
 	auto node_stack = CreateInterpreterNodeStackStateSaver(function);
 
@@ -1645,7 +1645,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_ZIP(EvaluableNode *en, boo
 		}
 
 		//if no function, then just put value into the appropriate slot for the index
-		if(function == nullptr)
+		if(EvaluableNode::IsNull(function))
 		{
 			result->SetMappedChildNodeWithReferenceHandoff(index_sid, value, true);
 		}
@@ -1674,7 +1674,7 @@ EvaluableNodeReference Interpreter::InterpretNode_ENT_ZIP(EvaluableNode *en, boo
 	//the index list has been converted to strings, so therefore can be freed
 	evaluableNodeManager->FreeNodeTreeIfPossible(index_list);
 
-	if(function != nullptr)
+	if(!EvaluableNode::IsNull(function))
 	{
 		//the values have likely been copied, so only the top node can be freed as long as it doesn't point back to itself
 		if(!value_list.GetNeedCycleCheck())