Setting Prog pointer back in the prog

Setting Prog pointer back in the prog

[Jean-Eric Cuendet]

Hi,
With MsDev debugger, you can set the program pointer back in the code
(Set Next Statement).
Is it also possible with GDB?
If yes, how? Why doesn't Eclipse/Insight/DDD/... don't provide that?
If no, why? Will it be implemented in a next version? Or is it a MsDev
bug? :-)

Thanks
-jec

-- 
Jean-Eric Cuendet
Linkvest SA
Av des Baumettes 9, 1020 Renens Switzerland
Tel +41 21 632 9043  Fax +41 21 632 9090
E-mail: jean-eric.cuendet@linkvest.com
http://www.linkvest.com
--------------------------------------------------------

Re: Setting Prog pointer back in the prog

[Daniel Jacobowitz]

On Wed, Nov 20, 2002 at 12:07:30PM +0100, Jean-Eric Cuendet wrote:
> Hi,
> With MsDev debugger, you can set the program pointer back in the code
> (Set Next Statement).
> Is it also possible with GDB?
> If yes, how? Why doesn't Eclipse/Insight/DDD/... don't provide that?
> If no, why? Will it be implemented in a next version? Or is it a MsDev
> bug? :-)

Try: "set $pc = <address>".  You have to use PC values, not line
numbers.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

Re: Setting Prog pointer back in the prog

[Andrew Cagney]

> On Wed, Nov 20, 2002 at 12:07:30PM +0100, Jean-Eric Cuendet wrote:
> 
>> Hi,
>> With MsDev debugger, you can set the program pointer back in the code
>> (Set Next Statement).
>> Is it also possible with GDB?
>> If yes, how? Why doesn't Eclipse/Insight/DDD/... don't provide that?
>> If no, why? Will it be implemented in a next version? Or is it a MsDev
>> bug? :-)
> 
> 
> Try: "set $pc = <address>".  You have to use PC values, not line
> numbers.

FYI,

(gdb) help jump
Continue program being debugged at specified line or address.
Give as argument either LINENUM or *ADDR, where ADDR is an expression
for an address to start at.

Andrew

Re: Setting Prog pointer back in the prog

[Daniel Jacobowitz]

On Wed, Nov 20, 2002 at 12:21:35PM -0500, Andrew Cagney wrote:
> >On Wed, Nov 20, 2002 at 12:07:30PM +0100, Jean-Eric Cuendet wrote:
> >
> >>Hi,
> >>With MsDev debugger, you can set the program pointer back in the code
> >>(Set Next Statement).
> >>Is it also possible with GDB?
> >>If yes, how? Why doesn't Eclipse/Insight/DDD/... don't provide that?
> >>If no, why? Will it be implemented in a next version? Or is it a MsDev
> >>bug? :-)
> >
> >
> >Try: "set $pc = <address>".  You have to use PC values, not line
> >numbers.
> 
> FYI,
> 
> (gdb) help jump
> Continue program being debugged at specified line or address.
> Give as argument either LINENUM or *ADDR, where ADDR is an expression
> for an address to start at.

Learn something new every day.... thanks Andrew!

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer

Re: Setting Prog pointer back in the prog

[Andrew Cagney]

> On Wed, Nov 20, 2002 at 12:21:35PM -0500, Andrew Cagney wrote:
> 
>> >On Wed, Nov 20, 2002 at 12:07:30PM +0100, Jean-Eric Cuendet wrote:
>> >
> 
>> >>Hi,
>> >>With MsDev debugger, you can set the program pointer back in the code
>> >>(Set Next Statement).
>> >>Is it also possible with GDB?
>> >>If yes, how? Why doesn't Eclipse/Insight/DDD/... don't provide that?
>> >>If no, why? Will it be implemented in a next version? Or is it a MsDev
>> >>bug? :-)
> 
>> >
>> >
>> >Try: "set $pc = <address>".  You have to use PC values, not line
>> >numbers.
> 
>> 
>> FYI,
>> 
>> (gdb) help jump
>> Continue program being debugged at specified line or address.
>> Give as argument either LINENUM or *ADDR, where ADDR is an expression
>> for an address to start at.
> 
> 
> Learn something new every day.... thanks Andrew!

(Ha!  You've not spent enough time reading the testsuite gdb.log output. 
  Learn all sorts of things.)

BTW, on some architectures a simple:

set $pc = ...

May not do what you want.  SPARC would need both $pc and $npc set - jump 
does this.  Wonder if this is documented ...
http://sources.redhat.com/gdb/current/onlinedocs/gdb_15.html#IDX545
Almost, bug report.

Andrew