[Swig-devel] Re: Storage class for variables?

[Surendra S. <efu...@ne...>]

Hello,

William S Fulton <ws...@fu...> writes:
> Surendra Singhi wrote:
>> William S Fulton <ws...@fu...> wrote:
>>
>>>Surendra Singhi wrote:
>>>> Hello,  Is there any reason why SWIG parser doesn't associates a
>>>> storage class with
>>>>the variable, when parsing this code
>>>>
>>>>extern "C" {
>>>>  int x;
>>>>}
>>>>
>>>>The storage class is associated if the code is written as
>>>>extern int x;
>>>>
>>>>
>>>The storage class should not be extern as
>>>
>>>extern "C" {
>>>  int x;
>>>}
>>>
>>>is not the same as
>>>
>>>extern int x;
>>>
>>>In fact it is much the same as
>>>
>>>int x;
>>>
>>> it, just has C name mangling. If you look at the parse tree, you'll
>>> see the extern "C" is there. Is there something you want to do with
>>> this information?
>>>
>> Thanks for the help. extern "C" {
>>   int x;
>> }
>> When a variable is declared as above, it is exported in the dll
>> file. So, while generating scripting code, I want to find out
>> whether a variable is just a plain global variable or is it some
>> variable which is exported (in which case there needs to be SWIG
>> generated code in the scripting language file to access it)? How can
>> I know this?
>>
>
> I don't believe the storage class is of concern to you. Consider what
> happens when a user parses a header file with the examples you have
> given. Access to the variable is possible whether it is a global or
> exported in a dll. 

OK.

>What the storage is won't make any difference to
> the wrappers being generated, as the variable is simply read or
> written to. Why do you want to differentiate between these two?
>

In lisp programs, the interpreter first loads the foreign library DLL/.so, and
then it can only access the variables which are exported by the DLL/.so. So, when
SWIG language module parses the header files, it should be able to find out
which are the variables which this header file wants to export in the dll/.so, and
then accordingly generate lisp code for accessing those variables. 

This is what I want to achieve, and for functions I am able to do so using the
storage class. I was wondering how to achieve the same for variables.

Thanks.
-- 
Surendra Singhi
http://ssinghi.kreeti.com, http://www.kreeti.com
Read my blog at: http://cuttingtheredtape.blogspot.com/
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