Date: Tue, 19 Aug 1997 08:52:40 From: Hermann Schinagl <schinagl@avl.co.at> To: hackers@freebsd.org Subject: Re: Please Help Me Understand dlopen()] Message-ID: <19970819085282.NTM1204@umes01.avl.co.at>
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>I think the fix should assume that the application most likely wants
>to look up a normal C symbol. So it should do something like this:
>
> /*
> * First try: look for a normal C symbol like (in assembly
> * language) "_foo".
> */
> if (sym starts with "_") /* Assume caller already added "_" */
> trysym = sym;
> else /* Add "_" for caller */
> trysym = concat("_", sym); /* Not C, but you get the idea */
>
> if (lookup(trysym))
> return success;
>
> /*
> * Second try: look for a strange C symbol like (in assembly
> * language) "__foo", or an assembly language symbol "foo" with no
> * underscore at all.
> */
> if (sym starts with "_") /* Assume C symbol really starts with "_" */
> trysym = concat("_", sym);
> else /* Assume caller wants assembly symbol */
> trysym = sym;
>
> if (lookup(trysym))
> return success;
>
> /*
> * Give up.
> */
> return failure;
You forgot that the symbols, which are exported by the lib are
totally different, if you rename a .c file to .cpp and compile
it again. ==> C++ exported symbols
Well, it is easy to add '_' before the symbol, but the function-arguments
of a C++ exported function are append encoded to the symbolname.
eg.: '__func027_dfiv'
So writing a wrapper is not that straight forward as mentioned
above. You should also think of the C++ exporting mechanism.
Ciao Hermann
Regards,
Hermann Schinagl
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Dipl.-Ing. Hermann Schinagl AVL List GmbH
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Power and ignorance is a disgusting cocktail.
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