Will GDB extract the entire Variable history in further releases, based on Reverse Debugging?

Will GDB extract the entire Variable history in further releases, based on Reverse Debugging?

[Xing, Charlie]

Hi GDB Team:
I've used the "Reverse Debugging" feature of GDB 7.4 and I'm curious if you guys would provide any advanced features based on it, E.g., Extracting the entire Variable History.
This is especially useful when use GDB as a backend of an IDE (Eclipse CDT 8).

Considering the entire history has been recorded by GDB during the execution (Step/Resume), it sounds reasonable for GDB to extract the history so that a front-end, like CDT 8, will be able to deliver then end user with many brilliant features. Travelling in the Variables History? That will be great to detect the root cause of a program! There won't be any headache in debugging a loop!
Is there a plan to do such things?

Will there be any other advanced features based on the Reverse Debugging? Thanks!

Regards
Charlie

Re: Will GDB extract the entire Variable history in further releases, based on Reverse Debugging?

[Pedro Alves]

On 05/28/2012 02:38 AM, Xing, Charlie wrote:

> Extracting the entire Variable History.

(...)

> Travelling in the Variables History?
(...)


I have to say I didn't really understand what exactly do you mean
by those "Variable History" or "Travelling in the Variables History".  Could
you elaborate?

-- 
Pedro Alves

Re: Will GDB extract the entire Variable history in further releases, based on Reverse Debugging?

[Jan Kratochvil]

On Mon, 28 May 2012 03:38:07 +0200, Xing, Charlie wrote:
> I've used the "Reverse Debugging" feature of GDB 7.4 and I'm curious if you
> guys would provide any advanced features based on it, E.g., Extracting the
> entire Variable History.

Also not sure what you mean like Pedro but I use IMO something like such
feature:

(gdb) l
1	/* 1 */ int var;
2	/* 2 */ int main (void) {
3	/* 3 */   int i; for (i=0;i<100;i++)
4	/* 4 */     var=i/10;
5	/* 5 */  return 0; }
(gdb) start
(gdb) record 
(gdb) adv 5
main () at history.c:5
5	/* 5 */  return 0; }
(gdb) watch var
Hardware watchpoint 2: var
(gdb) reverse-continue 
Continuing.
Hardware watchpoint 2: var

Old value = 9
New value = 8
0x00000000004004c3 in main () at history.c:4
4	/* 4 */     var=i/10;
(gdb) p i
$1 = 90
(gdb) reverse-continue 
Continuing.
Hardware watchpoint 2: var

Old value = 8
New value = 7
0x00000000004004c3 in main () at history.c:4
4	/* 4 */     var=i/10;
(gdb) p i
$2 = 80


Regards,
Jan

RE: Will GDB extract the entire Variable history in further releases, based on Reverse Debugging?

[Xing, Charlie]

It comes from a discussion with the CDT team: http://dev.eclipse.org/mhonarc/lists/cdt-dev/msg24459.html

I wondered if CDT may provide some features based on the existing Reverse Debugging functionality, they are interested in those features but need GNU GDB to provide more functionality. Therefore I turned to you guys.

I hope the link would make things clearer.

Xing Yun

-----Original Message-----
From: Pedro Alves [mailto:palves@redhat.com] 
Sent: 2012年5月28日 23:14
To: Xing, Charlie
Cc: gdb@sourceware.org
Subject: Re: Will GDB extract the entire Variable history in further releases, based on Reverse Debugging?

On 05/28/2012 02:38 AM, Xing, Charlie wrote:

> Extracting the entire Variable History.

(...)

> Travelling in the Variables History?
(...)


I have to say I didn't really understand what exactly do you mean by those "Variable History" or "Travelling in the Variables History".  Could you elaborate?

--
Pedro Alves