public override int VisitBlock([NotNull] CBluntParser.BlockContext context)
{
#if DEBUG
Console.WriteLine("VisitBlock");
#endif
AddText("{\n");
for (int count = 0; count < context.ChildCount; ++count)
{
Visit(context.GetChild(count));
}
AddText("}\n");
return(0);
}
/// <summary>
/// Visit a parse tree produced by <see cref="CBluntParser.block"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitBlock([NotNull] CBluntParser.BlockContext context)
{
return(VisitChildren(context));
}
public override int VisitBlock([NotNull] CBluntParser.BlockContext context)
{
#if DEBUG
Console.WriteLine("VisitBlock");
#endif
if (context.Parent.RuleIndex != CBluntParser.RULE_function)
{
SymbolTable.MethodScopeLinkedList.AddLast(new Dictionary <string, VariableProperties>());
}
// In the initial scope of the method, check whether there exists at least one return. Error if there exists multiple
int returnCount = 0;
for (int i = 0; i < context.statement().Count(); ++i)
{
// Skip non-function returns
if (context.statement(i).functionreturn() == null)
{
Visit(context.statement(i));
continue;
}
// Cannot break here as there MAY exist multiple returns
++returnCount;
// Check for void: it cannot return anything
if (context.statement(i).functionreturn().expression() != null && SymbolTable.CurrentMethodType == "void")
{
SyntaxError(context, "Void methods cannot return values");
return(1);
}
// Check for non-void: it MUST return something
if (context.statement(i).functionreturn().expression() == null && SymbolTable.CurrentMethodType != "void")
{
SyntaxError(context, "Method " + SymbolTable.CurrentMethodType + " with type " + SymbolTable.CurrentMethodType + " must return a value");
return(1);
}
// If there exists multiple returns, there is a problem. This accounts for both void and other types
if (returnCount > 1)
{
SyntaxError(context, "Method " + SymbolTable.CurrentMethodType + " with type " + SymbolTable.CurrentMethodType + " cannot return multiple times in its method scope");
return(1);
}
// Initial checks done, now expression has to be visited to determine the return type according to method type
// void can of course be skipped
if (SymbolTable.CurrentMethodType == "void")
{
continue;
}
// Add to the expression store
SymbolTable.ExpressionStoreLinkedList.AddLast(new ExpressionStore());
// Get the type returned
Visit(context.statement(i).functionreturn().expression());
var returnType = SymbolTable.ExpressionStoreLinkedList.Last.Value.Type;
if (SymbolTable.CurrentMethodType != returnType)
{
SyntaxError(context, "A type " + returnType + " is returned, a type " + SymbolTable.CurrentMethodType + " was expected to be returned instead");
return(1);
}
SymbolTable.ExpressionStoreLinkedList.RemoveLast();
}
// If there exists no return and it is NOT a method of type void, output an error
if (returnCount == 0 && SymbolTable.CurrentMethodType != "void" && SymbolTable.MethodScopeLinkedList.Count == 1)
{
SyntaxError(context, "Method " + SymbolTable.CurrentMethodType + " with type " + SymbolTable.CurrentMethodType + " does not return a type " + SymbolTable.CurrentMethodType);
return(1);
}
if (context.Parent.RuleIndex != CBluntParser.RULE_function)
{
SymbolTable.MethodScopeLinkedList.RemoveLast();
}
return(0);
}
public override int VisitBlock([NotNull] CBluntParser.BlockContext context)
{
return(base.VisitBlock(context));
}
