Re: C++, %glr-parser and non-POD semantic values

[Hans Aberg]

On 29 May 2007, at 11:49, Frans Englich wrote:

> I'm switching a parser to be GLR in order to simplify the lexer.  
> It's all in
> C++, the parser & tokenizer must be exceptions safe(hence, Bison  
> destructors
> cannot be used to free values, as far as I know), and it must be  
> reentrant.
>
> My current parser does not use the C++ skeleton despite being  
> compiled as C++
> code, which from my understanding is bad practice(correct?).

I don't know about the GLR parser, but the ordinary C parser stack  
does not invoke the copy constructors correctly when it reallocates:  
it just copies over the memory data.

> My semantic
> value is a class with non-POD members; I don't use %union.

So either use a semantic type which does not use non-trivial copy  
constructors, or a stack that does not re-allocate (using say  
std::vector or std::deque), or a C++ stack.

  Hans Aberg