* Strange GDB behavior
@ 2004-07-26 11:34 True Sylvia
2004-07-26 11:48 ` Monika Chaddha
2004-07-26 13:15 ` Daniel Jacobowitz
0 siblings, 2 replies; 6+ messages in thread
From: True Sylvia @ 2004-07-26 11:34 UTC (permalink / raw)
To: gdb
Hi,
Am using the following flavor of GDB
Current directory is /tftproot/code/
GDB is free software and you are welcome to distribute copies of it
under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.16 (sparc-sun-solaris2.5.1 --target mips64orion-elf),
Copyright 1996 Free Software Foundation, Inc...
(gdb)
I have attached GDB to my executable and the following happens when i stop
on one of the breakpoints that i have set
(gdb) info br
Num Type Disp Enb Address What
1 breakpoint keep y 0x8087c728 in egp_peer_close at egp_init.c:5265
(gdb)
(gdb) c
Continuing.
[New thread 22682896]
[Switching to thread 22682896]
Breakpoint 1, egp_peer_close (bnp=0x82a461c8, event=2) at egp_init.c:5265
(gdb) p *bnp
$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0, egp_conf = {
action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0, as_count
= 0,
---Type <return> to continue, or q <return> to quit---q
Quit
(gdb)
(gdb) p *bnp->as_count
There is no member named as_count.
(gdb)
(gdb) p *bnp->egp_options
There is no member named egp_options.
*Why* is this happening? I have members as_count and egp_options in my bnp
structure. Why isnt GDB showing me thses?
Regards,
Sylvia T.
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Strange GDB behavior
2004-07-26 11:34 Strange GDB behavior True Sylvia
@ 2004-07-26 11:48 ` Monika Chaddha
2004-07-26 13:15 ` Daniel Jacobowitz
1 sibling, 0 replies; 6+ messages in thread
From: Monika Chaddha @ 2004-07-26 11:48 UTC (permalink / raw)
To: 'True Sylvia'; +Cc: gdb
Hi Sylvia,
Compile yours source code with option -O0 and than try again.... As this
can be a problem due to optimization...
Are you getting the same problem with the other structures also?
Regards
Monika
>-----Original Message-----
>From: True Sylvia [mailto:truesylvia@yahoo.co.uk]
>Sent: Monday, July 26, 2004 2:24 PM
>To: gdb@sources.redhat.com
>Subject: Strange GDB behavior
>
>Hi,
>
>Am using the following flavor of GDB
>
>Current directory is /tftproot/code/
>GDB is free software and you are welcome to distribute copies of it
> under certain conditions; type "show copying" to see the conditions.
>There is absolutely no warranty for GDB; type "show warranty" for
details.
>GDB 4.16 (sparc-sun-solaris2.5.1 --target mips64orion-elf),
>Copyright 1996 Free Software Foundation, Inc...
>(gdb)
>
>I have attached GDB to my executable and the following happens when i
stop
>on one of the breakpoints that i have set
>
>(gdb) info br
>Num Type Disp Enb Address What
>1 breakpoint keep y 0x8087c728 in egp_peer_close at
egp_init.c:5265
>(gdb)
>(gdb) c
>Continuing.
>[New thread 22682896]
>[Switching to thread 22682896]
>
>Breakpoint 1, egp_peer_close (bnp=0x82a461c8, event=2) at
egp_init.c:5265
>(gdb) p *bnp
>$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
> egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0, egp_conf
= {
> action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0,
>as_count
>= 0,
> ---Type <return> to continue, or q <return> to quit---q
>Quit
>(gdb)
>
>(gdb) p *bnp->as_count
>There is no member named as_count.
>(gdb)
>(gdb) p *bnp->egp_options
>There is no member named egp_options.
>
>*Why* is this happening? I have members as_count and egp_options in my
bnp
>structure. Why isnt GDB showing me thses?
>
>Regards,
>Sylvia T.
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Strange GDB behavior
2004-07-26 11:34 Strange GDB behavior True Sylvia
2004-07-26 11:48 ` Monika Chaddha
@ 2004-07-26 13:15 ` Daniel Jacobowitz
1 sibling, 0 replies; 6+ messages in thread
From: Daniel Jacobowitz @ 2004-07-26 13:15 UTC (permalink / raw)
To: True Sylvia; +Cc: gdb
On Mon, Jul 26, 2004 at 02:24:05PM +0530, True Sylvia wrote:
> Hi,
>
> Am using the following flavor of GDB
>
> Current directory is /tftproot/code/
> GDB is free software and you are welcome to distribute copies of it
> under certain conditions; type "show copying" to see the conditions.
> There is absolutely no warranty for GDB; type "show warranty" for details.
> GDB 4.16 (sparc-sun-solaris2.5.1 --target mips64orion-elf),
> Copyright 1996 Free Software Foundation, Inc...
> (gdb)
You may wish to try a version of GDB newer than 1996; we're not likely
to be able to give you meaningful help with version 4.16.
--
Daniel Jacobowitz
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Strange GDB behavior
2004-07-26 11:58 Arun Vishwanathan
@ 2004-07-26 13:00 ` Monika Chaddha
0 siblings, 0 replies; 6+ messages in thread
From: Monika Chaddha @ 2004-07-26 13:00 UTC (permalink / raw)
To: 'Arun Vishwanathan', 'True Sylvia'; +Cc: gdb
> Hence I think this statement is incorrect
>> (gdb) p *bnp->as_count
Yes I m agree with u that this is incorrect but in this case also it
should give error like
if as_count=0
"Cannot access memory at address 0x0"
and it should not give like " There is no member named egp_options."
Regards
Monika
>
>It should be
>
>(gdb) p bnp->as_count
>
>
>-----Original Message-----
>From: gdb-owner@sources.redhat.com
[mailto:gdb-owner@sources.redhat.com] On
>Behalf Of Arun Vishwanathan
>Sent: Monday, July 26, 2004 5:18 PM
>To: Monika Chaddha; True Sylvia
>Cc: gdb@sources.redhat.com
>Subject: RE: Strange GDB behavior
>
>>From your following command it is evident that "bnp" is a pointer to a
>structure.
>
>>(gdb) p *bnp
>>$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
>> egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0,
egp_conf
>= {
>> action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0,
>>as_count
>>= 0,
>> ---Type <return> to continue, or q <return> to quit---q
>>Quit
>
>
> Hence I think this statement is incorrect
>> (gdb) p *bnp->as_count
>
>It should be
>
>(gdb) p bnp->as_count
>
>
>
>Regards,
>Arun
>
>-----Original Message-----
>From: gdb-owner@sources.redhat.com
[mailto:gdb-owner@sources.redhat.com]
>On Behalf Of Monika Chaddha
>Sent: Monday, July 26, 2004 4:51 PM
>To: 'True Sylvia'
>Cc: gdb@sources.redhat.com
>Subject: RE: Strange GDB behavior
>
>Hi Sylvia,
>
>Compile yours source code with option -O0 and than try again.... As
this
>can be a problem due to optimization...
>Are you getting the same problem with the other structures also?
>
>Regards
>Monika
>
>>-----Original Message-----
>>From: True Sylvia [mailto:truesylvia@yahoo.co.uk]
>>Sent: Monday, July 26, 2004 2:24 PM
>>To: gdb@sources.redhat.com
>>Subject: Strange GDB behavior
>>
>>Hi,
>>
>>Am using the following flavor of GDB
>>
>>Current directory is /tftproot/code/
>>GDB is free software and you are welcome to distribute copies of it
>> under certain conditions; type "show copying" to see the conditions.
>>There is absolutely no warranty for GDB; type "show warranty" for
>details.
>>GDB 4.16 (sparc-sun-solaris2.5.1 --target mips64orion-elf),
>>Copyright 1996 Free Software Foundation, Inc...
>>(gdb)
>>
>>I have attached GDB to my executable and the following happens when i
>stop
>>on one of the breakpoints that i have set
>>
>>(gdb) info br
>>Num Type Disp Enb Address What
>>1 breakpoint keep y 0x8087c728 in egp_peer_close at
>egp_init.c:5265
>>(gdb)
>>(gdb) c
>>Continuing.
>>[New thread 22682896]
>>[Switching to thread 22682896]
>>
>>Breakpoint 1, egp_peer_close (bnp=0x82a461c8, event=2) at
>egp_init.c:5265
>>(gdb) p *bnp
>>$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
>> egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0,
egp_conf
>= {
>> action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0,
>>as_count
>>= 0,
>> ---Type <return> to continue, or q <return> to quit---q
>>Quit
>>(gdb)
>>
>>(gdb) p *bnp->as_count
>>There is no member named as_count.
>>(gdb)
>>(gdb) p *bnp->egp_options
>>There is no member named egp_options.
>>
>>*Why* is this happening? I have members as_count and egp_options in my
>bnp
>>structure. Why isnt GDB showing me thses?
>>
>>Regards,
>>Sylvia T.
>>
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Strange GDB behavior
@ 2004-07-26 12:09 Atul Talesara
0 siblings, 0 replies; 6+ messages in thread
From: Atul Talesara @ 2004-07-26 12:09 UTC (permalink / raw)
To: gdb
From your following command it is evident that "bnp" is a pointer to a
>structure.
>
>>(gdb) p *bnp
>>$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
>> egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0,
egp_conf
>= {
>> action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0,
>>as_count
>>= 0,
>> ---Type <return> to continue, or q <return> to quit---q
>>Quit
>
>
> Hence I think this statement is incorrect
>> (gdb) p *bnp->as_count
*bnp->as_count is equivalent to *(bnp->as_count).
This will take the value of as_count and try to
dereference it, and you should typically get an error
something like "Cannot access memory at address 0x..."
and not "There is no member named ..." Nonetheless
*bnp->as_count won't give you desired value.
>
>It should be
>
>(gdb) p bnp->as_count
Or equivalently:
p (*bnp).as_count
Regards,
Atul P Talesara
----------------------------------------------------------
Be not afraid of life. Believe that life is worth living,
and your belief will help create the fact."
- Henry James
----------------------------------------------------------
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: Strange GDB behavior
@ 2004-07-26 11:58 Arun Vishwanathan
2004-07-26 13:00 ` Monika Chaddha
0 siblings, 1 reply; 6+ messages in thread
From: Arun Vishwanathan @ 2004-07-26 11:58 UTC (permalink / raw)
To: Monika Chaddha, True Sylvia; +Cc: gdb
From your following command it is evident that "bnp" is a pointer to a
structure.
>(gdb) p *bnp
>$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
> egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0, egp_conf
= {
> action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0,
>as_count
>= 0,
> ---Type <return> to continue, or q <return> to quit---q
>Quit
Hence I think this statement is incorrect
> (gdb) p *bnp->as_count
It should be
(gdb) p bnp->as_count
Regards,
Arun
-----Original Message-----
From: gdb-owner@sources.redhat.com [mailto:gdb-owner@sources.redhat.com]
On Behalf Of Monika Chaddha
Sent: Monday, July 26, 2004 4:51 PM
To: 'True Sylvia'
Cc: gdb@sources.redhat.com
Subject: RE: Strange GDB behavior
Hi Sylvia,
Compile yours source code with option -O0 and than try again.... As this
can be a problem due to optimization...
Are you getting the same problem with the other structures also?
Regards
Monika
>-----Original Message-----
>From: True Sylvia [mailto:truesylvia@yahoo.co.uk]
>Sent: Monday, July 26, 2004 2:24 PM
>To: gdb@sources.redhat.com
>Subject: Strange GDB behavior
>
>Hi,
>
>Am using the following flavor of GDB
>
>Current directory is /tftproot/code/
>GDB is free software and you are welcome to distribute copies of it
> under certain conditions; type "show copying" to see the conditions.
>There is absolutely no warranty for GDB; type "show warranty" for
details.
>GDB 4.16 (sparc-sun-solaris2.5.1 --target mips64orion-elf),
>Copyright 1996 Free Software Foundation, Inc...
>(gdb)
>
>I have attached GDB to my executable and the following happens when i
stop
>on one of the breakpoints that i have set
>
>(gdb) info br
>Num Type Disp Enb Address What
>1 breakpoint keep y 0x8087c728 in egp_peer_close at
egp_init.c:5265
>(gdb)
>(gdb) c
>Continuing.
>[New thread 22682896]
>[Switching to thread 22682896]
>
>Breakpoint 1, egp_peer_close (bnp=0x82a461c8, event=2) at
egp_init.c:5265
>(gdb) p *bnp
>$1 = {egp_next = 0x0, egp_sort_next = 0x0, egp_group = 0x82a45ef0,
> egp_flags = 138412032, egp_hisrcvdcaps = 0, egp_hiscaps = 0, egp_conf
= {
> action = 0 '\000'}, egpc_peer_as = 0, egpc_description = 0x0,
>as_count
>= 0,
> ---Type <return> to continue, or q <return> to quit---q
>Quit
>(gdb)
>
>(gdb) p *bnp->as_count
>There is no member named as_count.
>(gdb)
>(gdb) p *bnp->egp_options
>There is no member named egp_options.
>
>*Why* is this happening? I have members as_count and egp_options in my
bnp
>structure. Why isnt GDB showing me thses?
>
>Regards,
>Sylvia T.
>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2004-07-26 11:34 Strange GDB behavior True Sylvia
2004-07-26 11:48 ` Monika Chaddha
2004-07-26 13:15 ` Daniel Jacobowitz
2004-07-26 11:58 Arun Vishwanathan
2004-07-26 13:00 ` Monika Chaddha
2004-07-26 12:09 Atul Talesara
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