Running M-x gdb hangs emacs

Running M-x gdb hangs emacs

[Zhongwei Yao]

Hi, all,

When run M-x gdb with following command:
  gdb -i=mi -x ~/.gdb/config

and the .gdb/config file are:
==config==
  set non-stop off
  file /my/path/to/exe-file
  target remote 192.168.1.2:5049
  break func_foo
==config==

emacs returns me a buffer *gud-config* with following content:
==*gud-config* buffer==
Current directory is ~/.gdb/
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-linux-gnu
--target=arm-linux-android".
For bug reporting instructions, please see:
<http://source.android.com/source/report-bugs.html>.
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.Cannot access memory at address 0x0
==*gud-config* buffer==

Then emacs will hang there.
However, I can get gdb work by running: gdb -x ~/.gdb/config in bash. It
returns:
==*gdb in bash*==
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-linux-gnu
--target=arm-linux-android".
For bug reporting instructions, please see:
<http://source.android.com/source/report-bugs.html>.
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.
0xf77b6254 in ?? ()
Cannot access memory at address 0x0
Breakpoint 1 at 0xab0cd2e4: file ../../test_foo.c, line 29.
(gdb)
==*gdb in bash*==

How can get gdb also work in emacs? Thanks a lot!
--
Zhongwei

Re: Running M-x gdb hangs emacs

[Eli Zaretskii]

> Date: Thu, 22 Jan 2015 19:52:07 +0800
> From: Zhongwei Yao <ashi08104@gmail.com>
> 
> When run M-x gdb with following command:
>   gdb -i=mi -x ~/.gdb/config
> 
> and the .gdb/config file are:
> ==config==
>   set non-stop off
>   file /my/path/to/exe-file
>   target remote 192.168.1.2:5049
>   break func_foo
> ==config==
> 
> emacs returns me a buffer *gud-config* with following content:
> ==*gud-config* buffer==
> Current directory is ~/.gdb/
> GNU gdb (GDB) 7.6
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html
> >
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "--host=x86_64-linux-gnu
> --target=arm-linux-android".
> For bug reporting instructions, please see:
> <http://source.android.com/source/report-bugs.html>.
> warning: Unable to find dynamic linker breakpoint function.
> GDB will be unable to debug shared library initializers
> and track explicitly loaded dynamic code.Cannot access memory at address 0x0
> ==*gud-config* buffer==
> 
> Then emacs will hang there.

Does the problem go away if you invoke GDB like this:

  M-x gud-gdb RET

?  Also, what version of Emacs is that?

Re: Running M-x gdb hangs emacs

[Zhongwei Yao]

Hi, Eli,
gud-gdb works. And my Emacs version is 24.3.1.

But how can I get the fancy gdb interface back in Emacs with gud-gdb?
Thanks!

--
Zhongwei

On Fri, Jan 23, 2015 at 12:12 AM, Eli Zaretskii <eliz@gnu.org> wrote:

> > Date: Thu, 22 Jan 2015 19:52:07 +0800
> > From: Zhongwei Yao <ashi08104@gmail.com>
> >
> > When run M-x gdb with following command:
> >   gdb -i=mi -x ~/.gdb/config
> >
> > and the .gdb/config file are:
> > ==config==
> >   set non-stop off
> >   file /my/path/to/exe-file
> >   target remote 192.168.1.2:5049
> >   break func_foo
> > ==config==
> >
> > emacs returns me a buffer *gud-config* with following content:
> > ==*gud-config* buffer==
> > Current directory is ~/.gdb/
> > GNU gdb (GDB) 7.6
> > Copyright (C) 2013 Free Software Foundation, Inc.
> > License GPLv3+: GNU GPL version 3 or later <
> http://gnu.org/licenses/gpl.html
> > >
> > This is free software: you are free to change and redistribute it.
> > There is NO WARRANTY, to the extent permitted by law.  Type "show
> copying"
> > and "show warranty" for details.
> > This GDB was configured as "--host=x86_64-linux-gnu
> > --target=arm-linux-android".
> > For bug reporting instructions, please see:
> > <http://source.android.com/source/report-bugs.html>.
> > warning: Unable to find dynamic linker breakpoint function.
> > GDB will be unable to debug shared library initializers
> > and track explicitly loaded dynamic code.Cannot access memory at address
> 0x0
> > ==*gud-config* buffer==
> >
> > Then emacs will hang there.
>
> Does the problem go away if you invoke GDB like this:
>
>   M-x gud-gdb RET
>
> ?  Also, what version of Emacs is that?
>
>

Re: Running M-x gdb hangs emacs

[Eli Zaretskii]

> Date: Fri, 23 Jan 2015 10:45:08 +0800
> From: Zhongwei Yao <ashi08104@gmail.com>
> Cc: help-gnu-emacs@gnu.org
> 
> gud-gdb works. And my Emacs version is 24.3.1.
> 
> But how can I get the fancy gdb interface back in Emacs with gud-gdb? Thanks!

You can't have the fancy UI with gud-gdb.  My suggestion was an
attempt to see if the problem is caused by the use of the GDB/MI
interface.  It sounds like it is.

Does it help to use "M-x gdb" from "emacs -Q"?  If in "emacs -Q" you
see no problems, then look into your customizations or your site init
file for the reasons for the hang.

If that doesn't help, I'd suggest to upgrade to the latest GDB (7.8.2
was just released) and to the latest Emacs 24.4.  The reason is that I
don't see any problems with those latest versions in your usage
scenario.

If upgrading doesn't help, please submit a full bug report with all
the details using "M-x report-emacs-bug".

Re: Running M-x gdb hangs emacs

[Zhongwei Yao]

Emacs -Q still has same problem. But upgrading to Emacs 24.4.1 fixes my
problem (without upgrading gdb). Thanks!

--
Zhongwei

On Fri, Jan 23, 2015 at 6:00 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> > Date: Fri, 23 Jan 2015 10:45:08 +0800
> > From: Zhongwei Yao <ashi08104@gmail.com>
> > Cc: help-gnu-emacs@gnu.org
> >
> > gud-gdb works. And my Emacs version is 24.3.1.
> >
> > But how can I get the fancy gdb interface back in Emacs with gud-gdb?
> Thanks!
>
> You can't have the fancy UI with gud-gdb.  My suggestion was an
> attempt to see if the problem is caused by the use of the GDB/MI
> interface.  It sounds like it is.
>
> Does it help to use "M-x gdb" from "emacs -Q"?  If in "emacs -Q" you
> see no problems, then look into your customizations or your site init
> file for the reasons for the hang.
>
> If that doesn't help, I'd suggest to upgrade to the latest GDB (7.8.2
> was just released) and to the latest Emacs 24.4.  The reason is that I
> don't see any problems with those latest versions in your usage
> scenario.
>
> If upgrading doesn't help, please submit a full bug report with all
> the details using "M-x report-emacs-bug".
>
>