Louis M wrote:
> Hello Everyone!
> I have a little problem here. I am making a wrapper for a C library and I
> have a function like this:
> int funcAssign(objectAssign **obj)
> This function assign an object to the pointer in parameter and return 0 when
> no error or something else when error. I create this external eiffel
> function to wrap this function:
> frozen c_funcAssign(optr:POINTER):INTEGER is
> external
> "C inline use <lib.h>"
> alias
> "return (EIF_INTEGER) funcAssign((objectAssign **) &$optr);"
> end
> Then I use the eiffel external fonction:
> make is
> -- Run application.
> local
> opointer:POINTER
> the_result:INTEGER
> do
> the_result:={OBJECT}.c_funcAssign(opointer)
> if the_result/=0 then
> print("Error.%N")
> else
> print(opointer)
> end
> end
>
> Then, when I run the application, I get no error, but the value of the
> opointer point to 0x0 (The NULL pointer). I think that the object didn't
> change at all. But I am sure that the pointer that was send to the C
> function funcAssign was change. Does anybody know how to get this kind of
> function working.
I think that what you pass to 'funcAssign' is the address of `optr'
(the argument of `c_funcAssign', and not the address of `opointer'
(the local variable in `make'). Try that:
~~~~~~~~~~~~~~~~~
frozen c_funcAssign (optr:POINTER): INTEGER is
external
"C inline use <lib.h>"
alias
"return (EIF_INTEGER) funcAssign((objectAssign **) $optr);"
end
make is
-- Run application.
local
opointer: POINTER
the_result: INTEGER
do
the_result := {OBJECT}.c_funcAssign ($opointer)
if the_result /= 0 then
print ("Error.%N")
else
print (opointer)
end
end
~~~~~~~~~~~~~~~~~
--
Eric Bezault
mailto:
ericb@...
http://www.gobosoft.com
