Fw: objc: SIGSEGV (in gdb only) during module loading

[Michael Scheibler]

To: "Michael Scheibler" <michael.scheibler@onevision.de>
Sent: Friday, May 11, 2001 8:20 PM
> On Mon, 7 May 2001 08:42:13 +0200, "Michael Scheibler"
<michael.scheibler@onevision.de> wrote:
>
> >
> > From: "Ovidiu Predescu" <ovidiu@cup.hp.com>
> > Sent: Friday, May 04, 2001 5:30 PM
> >
> > > On Fri, 4 May 2001 10:02:42 +0200, "Michael Scheibler"
> > <michael.scheibler@onevision.de> wrote:
> > >
> > > >
> > > > I am currently working with cygwin (on Win2K), my sources are
compiled
> > > > with gcc -mno-cygwin (thats mingw). I wanted to test our huge
project
> > with
> > > > objc and gnustep-base linked as a shared DLL. When I run it from my
> > > > console everything seems to be okay, but when I try to debug it
using
> > > > cygwin's gdb 5.0, I get a SIGSEGV fault even before main() is
invoked.
> > > >
> > > > Program received signal SIGSEGV, Segmentation fault.
> > > > 0x67bc867d in sarray_free ()
> > > >
> > > > When I use objc_d, I can see, that the error occurs when the
Objective-C
> > > > runtime loads and registers all the classes and their methods of our
> > project
> > > > (loading of gnustep-base classes has been successful). By changing
the
> > > > compilation order of my source files it happens while loading a
> > different
> > > > module.
> > > >
> > > > The error always occurs in sarray_free()
> > > >
> > > >   429 #else /* OBJC_SPARSE2 */
> > > > - 430     struct sbucket* bkt = array->buckets[counter];
> > > > - 431     if ((bkt != array->empty_bucket) &&
> > > >   432  (bkt->version.version == array->version.version))
> > > >
> > > >        // btk->version.version => Access violation
> > > >
> > > >   433       {
> > > > - 434  sarray_free_garbage(bkt);
> > > > - 435  nbuckets -= 1;
> > > > - 436       }
> > > >   437 #endif
> > > >
> > > >
> > > > Is there a bug in libobjc?
> > >
> > > More likely there is a memory allocation bug happening somewhere else
> > > in your application, which just happens to be manifest itself within
> > > the ObjC runtime. I suggest you check the application you wrote for
> > > invalid object management.
> > >
> > > Ovidiu
> > >
> >
> > 1. My application doesn't even start up.
> > 2. It only happens using gdb.
> >
> > The next problem is that it doesn't happen always. It's more likely to
> > happen on Win2K than on WinNT 4.0.
> > I also have strange debugging problems while the application runs. I can
> > hardly use gdb at all. To use printfs instead of comfortable gdb can be
very
> > annoying...
>
> Oh, I didn't realize you're on Windows. There might be a problem with
> the way libobjc is built on this platform. I'm not familiar with
> Windows systems, but what I suggest you is to post your question on
> the GNUstep mailing list. Helge Hess <helge.hess@skyrix.com> has a lot
> of experience with this, you may also contact him.
>
> Ovidiu
>