private void CheckVariableAssignmentUsedInStartEndExpression(IdentifierNode loopVariable, Node startExpression, Node endExpression, Node loopBody)
{
var stack = new Stack<Node>();
stack.Push(endExpression);
stack.Push(startExpression);
var loopExpressionVariables = new Dictionary<IdentifierNode, IdentifierNode>();
while (stack.Count != 0)
{
var current = stack.Pop();
if (current is IdentifierNode && ((IdentifierNode)current).Name != loopVariable.Name)
{
var id = (IdentifierNode)current;
if (!loopExpressionVariables.ContainsKey(id))
{
loopExpressionVariables.Add(id, id);
}
}
foreach (var child in current.Children)
{
stack.Push(child);
}
}
stack.Push(loopBody);
while (stack.Count != 0)
{
var current = stack.Pop();
if (current is VariableAssignmentNode &&
loopExpressionVariables.ContainsKey(new IdentifierNode(0, 0, ((VariableAssignmentNode)current).Name)))
{
reporter.ReportError(
Error.WARNING,
"Possibly incorrect or confusing assignment to a variable '" +
((VariableAssignmentNode)current).Name + "', used in loop expression,",
current.Line,
current.Column);
var id = loopExpressionVariables[new IdentifierNode(0, 0, ((VariableAssignmentNode)current).Name)];
reporter.ReportError(
Error.NOTE,
"Previous usage here",
id.Line,
id.Column);
reporter.ReportError(
Error.NOTE_GENERIC,
"Loop start and end expressions are evaluated only once before entering the loop",
0,
0);
break;
}
foreach (var child in current.Children)
{
stack.Push(child);
}
}
}
private void ReportUndeclaredVariable(IdentifierNode node)
{
ReportUndeclaredVariable(node, node.Name);
}
private void CheckLoopControlVariableUsageInStartEndExpression(ForNode node, IdentifierNode loopVariable, Node startExpression, Node endExpression)
{
var stack = new Stack<Node>();
stack.Push(endExpression);
stack.Push(startExpression);
while (stack.Count != 0)
{
var current = stack.Pop();
if (current is IdentifierNode && ((IdentifierNode)current).Name == loopVariable.Name)
{
reporter.ReportError(
Error.WARNING,
"Possibly incorrect or confusing usage of loop control variable '" + loopVariable.Name + "' in loop expression",
current.Line,
current.Column);
reporter.ReportError(
Error.NOTE,
"Loop is here",
node.Line,
node.Column);
reporter.ReportError(
Error.NOTE_GENERIC,
"Loop start and end expressions are evaluated only once before entering the loop",
0,
0);
break;
}
foreach (var child in current.Children)
{
stack.Push(child);
}
}
}
private void CheckLoopControlVariableAssignmentInBody(ForNode node, IdentifierNode loopVariable, Node loopBody)
{
var stack = new Stack<Node>();
stack.Push(loopBody);
while (stack.Count != 0)
{
var current = stack.Pop();
if (current is VariableAssignmentNode && ((VariableAssignmentNode)current).Name == loopVariable.Name)
{
reporter.ReportError(
Error.SEMANTIC_ERROR,
"Cannot reassign control variable '" + loopVariable.Name + "'",
current.Line,
current.Column);
reporter.ReportError(
Error.NOTE,
"Loop is here",
node.Line,
node.Column);
break;
}
foreach (var child in current.Children)
{
stack.Push(child);
}
}
}
public void Visit(IdentifierNode node)
{
if (SymbolTable.ContainsKey(node.Name))
{
node.SetType(SymbolTable[node.Name].node.NodeType());
}
else
{
node.SetType(VariableType.ERROR_TYPE);
ReportUndeclaredVariable(node);
}
}
public ReadNode(int line, int column, IdentifierNode identifier)
: base(line, column)
{
Children.Add(identifier);
}
public void Visit(IdentifierNode node)
{
var data = symbolTable[node.Name];
switch (data.node.Type)
{
case VariableType.INTEGER:
Emit(Bytecode.PUSH_INT_VAR);
break;
case VariableType.STRING:
Emit(Bytecode.PUSH_STRING_VAR);
break;
case VariableType.BOOLEAN:
Emit(Bytecode.PUSH_BOOLEAN_VAR);
break;
default:
throw new InternalCompilerError("Invalid variable type");
}
Emit(data.id);
}
