Re: error, setjmp and exceptions

[Mark Hamburg <mhamburg@...>]

Throwing the Lua state is a little interesting as a choice but I guess it
doesn't cause any problems.

Please make it possible to separately define L_THROW and L_TRY as well
though I suspect that in order to do exception translation I will probably
still end up overriding luaD_throw and luaD_rawrunprotected.

Thanks.
Mark

on 12/18/03 11:57 AM, Roberto Ierusalimschy at roberto@inf.puc-rio.br wrote:

>> The vector's destructor never gets called and its memory is leaked.
> 
> If you compile Lua as C++ code, it is not difficult to change it
> to use real exceptions instead of setjmp/longjmp. Lua 5.1 will have
> a compilation flag for that. I hope the next lines give the
> general idea:
> 
>>  #ifndef LUA_USEEXCEPTIONS
>> 
>>  #define L_THROW(c)      longjmp((c)->b, 1)
>>  #define L_TRY(c,a)      if (setjmp((c)->b) == 0) { a }
>> 
>>  #else
>> 
>>  #define L_THROW(c)      throw(c)
>>  #define L_TRY(c,a)      try { a } catch(...) \
>>                                  { if ((c)->status == 0) (c)->status = -1; }
>> 
>>  #endif
> 
> This is not a perfect solution (other C++ exceptions are also catched
> by Lua protected calls), but it seems to work ok.
> 
> -- Roberto
>