What are limitations of Event arguments?

Question

Are there any limitation on the amount of arguments that can be send in an event?

I have a function in which I want to trigger event that has 12 arguments of which 6 arguments are arrays. I get Stack too deep, try using less variables. Without the event the function works normally.

I am guessing event arguments have some limitations or count towards max arguments in a solidity function but I cannot find any documentation around it.

Can anyone clarify this?

Answer 1

To answer my own question:

If you look at the ContractCompiler.cpp where FunctionDefinition is declared, you see there is a limit of 17 elements on the stack ;

if (stackLayout.size() > 17)           
  BOOST_THROW_EXCEPTION(   
        CompilerError() <<     
    errinfo_sourceLocation(_function.location()) <<     
    errinfo_comment("Stack too deep, try removing local variables.")     
);  

Events are defined as functions, as can be seen in ExpressionCompiler.cpp.

Simply put Events are treated as functions so they have a limit of 17 arguments. Array counts as 2 so in my example where I have 6 arrays + 6 normal arguments this equals 18 and I'm breaking the stack by 1.