[Xapian-devel] PHP Latest

[Olly Betts]

On Thu, Apr 20, 2006 at 08:53:09AM +0100, Sam Liddicott wrote:
> The generated .cc had this in:
> 
> #define SWIG_PHP_Error(code,msg) ErrorCode() = code; ErrorMsg() = msg; 
> SWIG_fail;
> 
> which looks dangerous if SWIG_PHP_ERROR is part of an if/else block.
> 
> Surely it should be in { } or even the:
> do { } while (0)
> trick
> 
> I don't know if that is ever used, it just stood out as looking highly 
> dodgy.

Well spotted.

It is used in xapian_wrap.cc, but only explicitly in { } by itself so it's not
causing any problems for us currently.

But it would make more sense to make it safe to use anywhere, otherwise
it's a bug waiting to happen when someone perfectly reasonably uses it
in another context (perhaps even in a user typemap if it's permitted
there).

Actually, looking where it can be used by SWIG this has already happened - the
input typemap for "void *" uses it like this:

    %typemap(in) void *
    {
	if(SWIG_ConvertPtr(*$input, (void **) &$1, 0, 0) < 0) {
	  /* Allow NULL from php for void* */
	  if ((*$input)->type==IS_NULL) $1=0;
	  else
            SWIG_PHP_Error(E_ERROR, "Type error in argument $argnum of $symname. Expected $&1_descriptor");
	}
    }

So that will always SWIG_fail, but without setting the error code in the case
where it should have worked.  A couple of "throws" typemaps might also be
problematic, but it depends where they actually get inserted.

I'll send a patch to the SWIG people.

Cheers,
    Olly