qSymbol when using symbol-file

qSymbol when using symbol-file

[catalin.udma]

Hi,

In the gdb/gdbserver scenario, gdb is not sending qSymbol packet when using "symbol-file", without "file" or "exec-file".
The steps are:
  start gdb (with no arguments)
  (gdb) symbol-file <file>
  (gdb) target remote <ip>:<port>
  ->  qSymbol packet is not sent.

If the "file" command  is used instead of "symbol-file", the qSymbol packet is sent to gdbserver.

The question makes more sense in the following context: Using Eclipse and DSF -GDB Hardware Debugging . Here, Eclipse is not using "file", but only "symbol-file" ( as explained why here: [1] ).  This  makes qSymbol notification not working. 

My questions/comments:
- In the above scenario, does make sense to enable qSymbol notification even when the exec-file is not specified? Here is not required to specify the  exec file. Or even in the gdb/gdbserver scenario where the application/executable is started by gdbserver on target.

- For the particular case when some symbol files are added after "target remote", gdb is sending qSymbol, even without having the exec file specified.  The above proposal would be in sync with this.

- What would be your other thoughts to fix the qSymbol for the gdb + Eclipse with DSF GDB Hardware Debugging scenario ?

Regards,
Catalin

[1] https://bugs.eclipse.org/bugs/show_bug.cgi?id=310304

RE: qSymbol when using symbol-file

[catalin.udma]

Hi,
Just a reminder for the email below. Have any of you had the time to look into it ?

Regard,
Catalin


> -----Original Message-----
> From: gdb-owner@sourceware.org [mailto:gdb-owner@sourceware.org] On
> Behalf Of catalin.udma@freescale.com
> Sent: Tuesday, June 03, 2014 11:59 AM
> To: gdb@sourceware.org
> Cc: Sendroiu Adrian-B46904
> Subject: qSymbol when using symbol-file
> 
> Hi,
> 
> In the gdb/gdbserver scenario, gdb is not sending qSymbol packet when
> using "symbol-file", without "file" or "exec-file".
> The steps are:
>   start gdb (with no arguments)
>   (gdb) symbol-file <file>
>   (gdb) target remote <ip>:<port>
>   ->  qSymbol packet is not sent.
> 
> If the "file" command  is used instead of "symbol-file", the qSymbol
> packet is sent to gdbserver.
> 
> The question makes more sense in the following context: Using Eclipse and
> DSF -GDB Hardware Debugging . Here, Eclipse is not using "file", but only
> "symbol-file" ( as explained why here: [1] ).  This  makes qSymbol
> notification not working.
> 
> My questions/comments:
> - In the above scenario, does make sense to enable qSymbol notification
> even when the exec-file is not specified? Here is not required to specify
> the  exec file. Or even in the gdb/gdbserver scenario where the
> application/executable is started by gdbserver on target.
> 
> - For the particular case when some symbol files are added after "target
> remote", gdb is sending qSymbol, even without having the exec file
> specified.  The above proposal would be in sync with this.
> 
> - What would be your other thoughts to fix the qSymbol for the gdb +
> Eclipse with DSF GDB Hardware Debugging scenario ?
> 
> Regards,
> Catalin
> 
> [1] https://bugs.eclipse.org/bugs/show_bug.cgi?id=310304

Re: qSymbol when using symbol-file

[Yao Qi]

On 06/03/2014 04:58 PM, catalin.udma@freescale.com wrote:
> In the gdb/gdbserver scenario, gdb is not sending qSymbol packet when using "symbol-file", without "file" or "exec-file".
> The steps are:
>   start gdb (with no arguments)
>   (gdb) symbol-file <file>
>   (gdb) target remote <ip>:<port>
>   ->  qSymbol packet is not sent.

I can reproduce it on GDB 7.7, but can't reproduce it on GDB HEAD
(20140617) and 7.8 pre-release (gdb-7.7.90).

1. Start gdbserver
   $ ./gdbserver/gdbserver :1234 ./testsuite/gdb.base/wchar
2. Start gdb
   $ ./gdb
   (gdb) symbol-file ./testsuite/gdb.base/wchar
   Reading symbols from ./testsuite/gdb.base/wchar...done.
   (gdb) set debug remote 1
   (gdb) target remote :1234
   ....
   0x42d0c050 in ?? ()
Sending packet: $qSymbol::#5b...Packet received:
qSymbol:6764625f6167656e745f6764625f74705f686561705f627566666572
Packet qSymbol (symbol-lookup) is supported
Sending packet:
$qSymbol::6764625f6167656e745f6764625f74705f686561705f627566666572#1e...Packet
received: qSymbol:6e70746c5f76657273696f6e
Sending packet: $qSymbol::6e70746c5f76657273696f6e#4d...Packet received: OK

qSymbol is sent.  You can use gdb 7.8 which will be released soon.

-- 
Yao (齐尧)

Re: qSymbol when using symbol-file

[Tim Sander]

Hi

Thanks for your replies!

Am Mittwoch, 18. Juni 2014, 10:25:19 schrieb Yao Qi:
> On 06/03/2014 04:58 PM, catalin.udma@freescale.com wrote:
> > In the gdb/gdbserver scenario, gdb is not sending qSymbol packet when
> > using "symbol-file", without "file" or "exec-file".> 
> > The steps are:
> >   start gdb (with no arguments)
> >   (gdb) symbol-file <file>
> >   (gdb) target remote <ip>:<port>
> >   ->  qSymbol packet is not sent.
> 
> I can reproduce it on GDB 7.7, but can't reproduce it on GDB HEAD
> (20140617) and 7.8 pre-release (gdb-7.7.90).
> 
> 1. Start gdbserver
>    $ ./gdbserver/gdbserver :1234 ./testsuite/gdb.base/wchar
> 2. Start gdb
>    $ ./gdb
>    (gdb) symbol-file ./testsuite/gdb.base/wchar
>    Reading symbols from ./testsuite/gdb.base/wchar...done.
>    (gdb) set debug remote 1
>    (gdb) target remote :1234
>    ....
>    0x42d0c050 in ?? ()
> Sending packet: $qSymbol::#5b...Packet received:
> qSymbol:6764625f6167656e745f6764625f74705f686561705f627566666572
> Packet qSymbol (symbol-lookup) is supported
> Sending packet:
> $qSymbol::6764625f6167656e745f6764625f74705f686561705f627566666572#1e...Pack
> et received: qSymbol:6e70746c5f76657273696f6e
> Sending packet: $qSymbol::6e70746c5f76657273696f6e#4d...Packet received: OK
> 
> qSymbol is sent.  You can use gdb 7.8 which will be released soon.
Thanks for the information. I searched the internet but couldn't find some 
documentation besides the release notes and a high level description in the 
online manual?

Its currently not clear to me how that feature is to be used, especially for 
the bare hw layer?

Best regards
Tim

Re: qSymbol when using symbol-file

[Yao Qi]

On 06/18/2014 09:43 PM, Tim Sander wrote:
> Thanks for the information. I searched the internet but couldn't find some 
> documentation besides the release notes and a high level description in the 
> online manual?

What do you need from the documentation and manual?

> 
> Its currently not clear to me how that feature is to be used, especially for 
> the bare hw layer?

If "that feature" is qSymbol, it is documented here
<https://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html>

-- 
Yao (齐尧)