Re: [cdt-debug-dev] Problem suspending Cygwin-based GDB from Ecli pse/CD

[Stefan Bylund <steby@xxxxxxx>]

Thanks Doug!

I tried the latest CDT 3.1.2 build (20071122) and suspension of 
Cygwin-based (cygwin1.dll 1.5.20-1 or later) GDBs now work! However, if 
you are using cygwin1.dll 1.5.19-4 or earlier it no longer works... But 
I guess you can't have it all and it's not a problem for us. Thank you 
again for your fast response.

Regards,
Stefan


Doug Schaefer wrote:

> Yes, CDT 3.1.2 will have trouble suspending newer cygwin-based gdb's. There
> are more recent CDT 3.1.x builds where this has been fixed (by grabing the
> spawner and starter from CDT 4.0 and bringing it back). Cygwin changed the
> mechanism by which suspends work sometime last year.
>
> The 3.1.2 builds are on the nightly build site.
>
>  http://download.eclipse.org/tools/cdt/builds/3.1.2
>
> Cheers,
> Doug Schaefer, QNX Software Systems
> Eclipse CDT Project Lead, http://cdtdoug.blogspot.com
>
>
>  
>
> > -----Original Message-----
> > From: cdt-debug-dev-bounces@xxxxxxxxxxx [mailto:cdt-debug-dev-
> > bounces@xxxxxxxxxxx] On Behalf Of Stefan Bylund
> > Sent: Monday, December 03, 2007 10:23 AM
> > To: cdt-debug-dev@xxxxxxxxxxx
> > Subject: [cdt-debug-dev] Problem suspending Cygwin-based GDB from
> > Eclipse/CDT (and some findings)
> >
> > Hi,
> >
> > I'm cross-posting this from the cygwin mailing list since I believe it
> > can be of interest to other Eclipse/CDT developers and users.
> >
> >
> > Message from cygwin mailing list:
> > ---------------------------------
> >
> > Hi,
> >
> > We have a source code debug solution based on Eclipse / CDT / GDB / GCC
> > / Cygwin DLL. We are using Eclipse 3.2.2 / CDT 3.1.2 / GDB 6.3 / GCC
> > 3.4.4 / Cygwin DLL 1.5.19-4 (cygwin1.dll).
> >
> > Until now, we have only supported Windows XP but recently we were forced
> > to upgrade to a newer version of the cygwin1.dll (1.5.24-2) since we had
> > to support Windows Vista, and Cygwin-based GCCs didn't work correctly
> > with cygwin1.dll 1.5.19-4 on Windows Vista due to heap errors in
> > cygwin1.dll. However, GDB works fine with cygwin1.dll 1.5.19-4 on
> > Windows Vista.
> >
> > Unfortunately, I just discovered that suspending GDB from Eclipse/CDT no
> > longer works. So I tried all versions of the cygwin1.dll from 1.5.19-4
> > to the forthcoming 1.5.25-3 and found that starting from version
> > 1.5.20-1, the signal handling in cygwin1.dll seems to have changed in
> > such a way that suspending GDB from Eclipse/CDT no longer works. Note
> > that versions before 1.5.19-4 of the cygwin1.dll also works correct with
> > respect to suspending GDB from Eclipse/CDT.
> >
> > By searching the cygwin mailing list, it seems that it is a general
> > problem when trying to programatically send a SIGINT from one process to
> > another process.
> >
> > I looked at the cygwin change list from 1.5.19-4 to 1.5.20-1
> > (http://cygwin.com/ml/cygwin-announce/2006-07/msg00000.html) and noticed
> > the following signal-related changes:
> >
> > * cgf: When sending signals, assume that any code which is not directly
> > associated with a DLL or an executable is user code.
> >
> > * cgf: Pass cygwin signals to gdb. Fix the dreaded SIGSEGV found in some
> > pthread functions.
> >
> > * corinna: Implement sigignore and sigset.
> >
> > * cgf: Make SA_RESTART sigaction flag work more like linux.
> >
> > It seems that one or more of the changes listed above (or some other
> > change(s) described in
> > http://cygwin.com/ml/cygwin-announce/2006-07/msg00000.html) is the cause
> > of this problem. It is a bit ironic that one of the changes mentions
> > passing cygwin signals to gdb since it is exactly this functionality
> > that is now broken but, from our experience, worked in 1.5.19-4.
> >
> > I'm cross posting this mail to the CDT mailing list as well, since there
> > may be other Eclipse/CDT users interested in this issue.
> >
> > Is there anything I can do to help in finding out why versions starting
> > from 1.5.20-1 of the cygwin1.dll no longer supports programatically
> > sending a SIGINT from one process to another? If nothing else, I can at
> > least help out with testing.
> >
> >
> > Best Regards,
> > Stefan Bylund
> >
> >
> > --
> > ---------------------------------
> > Stefan Bylund
> > Senior Software Engineer
> > Enea
> > Skalholtsgatan 9,
> > Box 1033, SE-164 21 Kista, Sweden
> > Direct: +46 8 50 71 43 25
> > Mobile: +46 709 71 43 25
> > stefan.bylund@xxxxxxxx
> > www.enea.com
> > ---------------------------------
> > Enea - Embedded for Leaders
> > ---------------------------------
> >
> > _______________________________________________
> > cdt-debug-dev mailing list
> > cdt-debug-dev@xxxxxxxxxxx
> > https://dev.eclipse.org/mailman/listinfo/cdt-debug-dev
> >    
> _______________________________________________
> cdt-debug-dev mailing list
> cdt-debug-dev@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/cdt-debug-dev
>  


--
---------------------------------
Stefan Bylund
Senior Software Engineer
Enea
Skalholtsgatan 9,
Box 1033, SE-164 21 Kista, Sweden
Direct: +46 8 50 71 43 25
Mobile: +46 709 71 43 25
stefan.bylund@xxxxxxxx
www.enea.com
---------------------------------
Enea - Embedded for Leaders
---------------------------------