[gambit-list] Linking to C++ problems
Dan Hristodorescu
dhristodorescu at borderfree.com
Wed Feb 23 10:35:42 EST 2005
Hi Marc,
I've done more investigation in the DLL problem and I've tried a lot of
things, different compilation switches but I cannot make it work.
I would really appreciate any suggestion you might have.
It goes like this:
Using the g++ (mingw) compiler I compiled both the program and Gambit
runtime.
If I replace the Scheme call with the equivalent C implementation (without
going through the Gambit runtime) in all scenarios (console or graphical
interface) works fine when loading the DLL.
If I call a Scheme method in a small console program it works fine. I assume
that happens because the DLL is loaded at a lower memory address and the
pointers in the scheme method are valid.
If however I use a graphical interface test program, the DLL gets loaded at
a higher memory location and I get "Segmentation fault" inside the scheme
code. It seems that some pointers inside Gambit runtime are invalid but I
don't know why this happens.
This is the error:
Program received signal SIGSEGV, Segmentation fault.
0x6abc123a in pluginEntry () from c:\compile\fox-1.4.2\tests\test.dll
(gdb) bt
#0 0x6abc123a in pluginEntry () from c:\compile\fox-1.4.2\tests\test.dll
#1 0x6abc11b5 in entryPoint at 4 () from c:\compile\fox-1.4.2\tests\test.dll
#2 0x004013fc in main ()
And this is the code I use:
extern void pluginEntry(EXNOTE*);
#define ___VERSION 40062
#include "gambit.h"
#define SCHEME_LIBRARY_LINKER ____20_testscm__
___BEGIN_C_LINKAGE
extern ___mod_or_lnk SCHEME_LIBRARY_LINKER (___global_state_struct*);
___END_C_LINKAGE
CALLBACK void entryPoint(EXNOTE* note1)
{
___setup_params_struct setup_params;
___setup_params_reset (&setup_params);
setup_params.version = ___VERSION;
setup_params.linker = SCHEME_LIBRARY_LINKER;
___setup (&setup_params);
pluginEntry(note1);
___cleanup ();
}
(c-define-type EXNOTE* (pointer "EXNOTE"))
(c-define (pluginEntry x) (EXNOTE*) void "pluginEntry" ""
(write x))
Thank you,
Dan.
-----Original Message-----
From: Marc Feeley [mailto:feeley at IRO.UMontreal.CA]
Sent: Monday, February 21, 2005 5:55 PM
To: dhristodorescu at borderfree.com
Cc: gambit-list at IRO.UMontreal.CA
Subject: Re: [gambit-list] Linking to C++ problems
> Sorry to replay to my own message but I figure out what was the =
> problem.
> It was just the mangling of DLL exported symbols (I was referring a =
> wrong
> name); it works fine now.
Great.
> The only relevant part of the message that remains is the one about the
> extern "C" generation.
I don't understand your point here. You should either compile
the whole Gambit runtime system and your program with a C
compiler, or with a C++ compiler, and then the names will be
mangled appropriately. Are you mixing C and C++ code? (this is
a bad idea in general because of the way exceptions are handled....)
Marc
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.iro.umontreal.ca/pipermail/gambit-list/attachments/20050223/25990e1d/attachment.htm>
More information about the Gambit-list
mailing list