GDB Interrupts on Cygwin
When running a Windows application from GDB, GDB gives control to the application at a certain point. It would be nice to, at an arbitrary time, suspend the application and give control back to GDB. I know that I can set breakpoints, but sometimes I don't know exactly when I want to break until after I'm running the application. Ctrl-C supposedly sends the SIGINT signal to GDB, breaking the running application and restoring control to GDB. However, this does not appear to work, at least not on Cygwin. I've tried /bin/kill -f -s SIGINT pid. Sending SIGINT, or in fact any other signal, simply terminates the Windows application. I even wrote a simple program to suspend the Windows application at my command using the Win32 API function SuspendThread. While the program does indeed suspend, GDB remains locked. Perhaps there is some way to, using the Windows API, simulate a SIGINT signal, or another signal to break the program (perhaps SIGSEGV would be easiest). Perhaps GDB could be modified in some way--it could map Windows messages to UNIX signals. Or maybe it could look for keystrokes using Windows hooks rather than its current method (I'm not even entirely sure what its current method is). If anyone thinks any of these methods would be feasible, I would be happy to contribute code. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
RE: GDB Interrupts on Cygwin
On 17 March 2006 08:55, Doug Bohl wrote: When running a Windows application from GDB, Ctrl-C supposedly sends the SIGINT signal to GDB, breaking the running application and restoring control to GDB. However, this does not appear to work, at least not on Cygwin. I've tried /bin/kill -f -s SIGINT pid. Sending SIGINT, or in fact any other signal, simply terminates the Windows application. It's not entirely surprising that windows applications aren't aware of cygwin signal handling! Have you tried running it with a mingw (i.e. windows native) version of gdb? cheers, DaveK -- Can't think of a witty .sigline today -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: GDB Interrupts on Cygwin
On Fri, Mar 17, 2006 at 03:55:08AM -0500, Doug Bohl wrote: When running a Windows application from GDB, GDB gives control to the application at a certain point. It would be nice to, at an arbitrary time, suspend the application and give control back to GDB. I know that I can set breakpoints, but sometimes I don't know exactly when I want to break until after I'm running the application. Ctrl-C supposedly sends the SIGINT signal to GDB, breaking the running application and restoring control to GDB. However, this does not appear to work, at least not on Cygwin. Even though this may seem strange, try this. Before starting GDB, type 'tty' at the console. Then, after you start GDB, run the command 'tty outputofttycommandfromconsole'. I think this will enable the ^c. It's a bug in GDB that hopefully I'll get to look at one day. Bob Rossi -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: GDB Interrupts on Cygwin
On Fri, Mar 17, 2006 at 06:56:55AM -0500, Bob Rossi wrote: On Fri, Mar 17, 2006 at 03:55:08AM -0500, Doug Bohl wrote: When running a Windows application from GDB, GDB gives control to the application at a certain point. It would be nice to, at an arbitrary time, suspend the application and give control back to GDB. I know that I can set breakpoints, but sometimes I don't know exactly when I want to break until after I'm running the application. Ctrl-C supposedly sends the SIGINT signal to GDB, breaking the running application and restoring control to GDB. However, this does not appear to work, at least not on Cygwin. Even though this may seem strange, try this. Before starting GDB, type 'tty' at the console. Then, after you start GDB, run the command 'tty outputofttycommandfromconsole'. I think this will enable the ^c. This is a no-voodoo zone. CTRL-C works fine in gdb. I use it ALL of the time. Maybe the OP has CYGWIN=tty set or is trying to run from rxvt. If so, don't do that. Run gdb from a windows console and it should work fine. cgf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: GDB Interrupts on Cygwin
On Fri, Mar 17, 2006 at 10:15:13AM -0500, Christopher Faylor wrote: On Fri, Mar 17, 2006 at 06:56:55AM -0500, Bob Rossi wrote: On Fri, Mar 17, 2006 at 03:55:08AM -0500, Doug Bohl wrote: When running a Windows application from GDB, GDB gives control to the application at a certain point. It would be nice to, at an arbitrary time, suspend the application and give control back to GDB. I know that I can set breakpoints, but sometimes I don't know exactly when I want to break until after I'm running the application. Ctrl-C supposedly sends the SIGINT signal to GDB, breaking the running application and restoring control to GDB. However, this does not appear to work, at least not on Cygwin. Even though this may seem strange, try this. Before starting GDB, type 'tty' at the console. Then, after you start GDB, run the command 'tty outputofttycommandfromconsole'. I think this will enable the ^c. This is a no-voodoo zone. CTRL-C works fine in gdb. I use it ALL of the time. Maybe the OP has CYGWIN=tty set or is trying to run from rxvt. If so, don't do that. Run gdb from a windows console and it should work fine. O, right. Sorry. The bug I was talking about only appears when you fork/exec GDB from within a program. Bob Rossi -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: GDB Interrupts on Cygwin
Yes, I'm running it from a Windows console. I had CYGWIN=tty, but I've now removed it, and Ctrl-C still isn't working. I tried the MinGW version of GDB. Still no Ctrl-C. I tried Bob's tty 'voodoo'. Still no Ctrl-C. I'm using GDB 6.3.50_2004-12-28-cvs (cygwin-special), I have also compiled GDB 6.4 but it crashes immediately upon trying to debug a program (I'm not interested in solving this problem for now). For anyone who has gotten Ctrl-C to work on Cygwin: what version of GDB are you using? On 3/17/06, Christopher Faylor [EMAIL PROTECTED] wrote: On Fri, Mar 17, 2006 at 06:56:55AM -0500, Bob Rossi wrote: On Fri, Mar 17, 2006 at 03:55:08AM -0500, Doug Bohl wrote: When running a Windows application from GDB, GDB gives control to the application at a certain point. It would be nice to, at an arbitrary time, suspend the application and give control back to GDB. I know that I can set breakpoints, but sometimes I don't know exactly when I want to break until after I'm running the application. Ctrl-C supposedly sends the SIGINT signal to GDB, breaking the running application and restoring control to GDB. However, this does not appear to work, at least not on Cygwin. Even though this may seem strange, try this. Before starting GDB, type 'tty' at the console. Then, after you start GDB, run the command 'tty outputofttycommandfromconsole'. I think this will enable the ^c. This is a no-voodoo zone. CTRL-C works fine in gdb. I use it ALL of the time. Maybe the OP has CYGWIN=tty set or is trying to run from rxvt. If so, don't do that. Run gdb from a windows console and it should work fine. cgf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/ -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: GDB Interrupts on Cygwin
On Fri, Mar 17, 2006 at 02:11:54PM -0500, Doug Bohl wrote: Yes, I'm running it from a Windows console. I had CYGWIN=tty, but I've now removed it, and Ctrl-C still isn't working. What does I've removed it mean? You can't just unset it in a bash shell. You have to remove it before any cygwin program runs. cgf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: GDB Interrupts on Cygwin
I know. I removed it using the Environment Variables option in My Computer, logged off, and logged back on, went into Cygwin, and checked the $CYGWIN variable. tty was no longer there. On 3/17/06, Christopher Faylor [EMAIL PROTECTED] wrote: On Fri, Mar 17, 2006 at 02:11:54PM -0500, Doug Bohl wrote: Yes, I'm running it from a Windows console. I had CYGWIN=tty, but I've now removed it, and Ctrl-C still isn't working. What does I've removed it mean? You can't just unset it in a bash shell. You have to remove it before any cygwin program runs. cgf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/ -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
