* [RFA] regcache pseudo-reg tweak
@ 2002-02-05 18:33 Michael Snyder
2002-02-05 19:11 ` Andrew Cagney
0 siblings, 1 reply; 3+ messages in thread
From: Michael Snyder @ 2002-02-05 18:33 UTC (permalink / raw)
To: cagney, gdb-patches
Andrew,
I think you left out an "else" when you made this change in december.
We must not call target_[fetch/store]_register with a pseudo-register,
or they will choke. By definition, a pseudo-register is one that
cannot be fetched from the target.
Remote_fetch_register, for instance, aborts on this.
Michael
2002-02-05 Michael Snyder <msnyder@redhat.com>
* regcache.c (fetch_register): Don't call target_fetch_register
for a pseudo_register.
(store_register): Don't call target_store_register for a
pseudo_register.
Index: regcache.c
===================================================================
RCS file: /cvs/src/src/gdb/regcache.c,v
retrieving revision 1.31
diff -c -3 -p -r1.31 regcache.c
*** regcache.c 2002/01/29 20:24:27 1.31
--- regcache.c 2002/02/06 02:30:46
*************** fetch_register (int regnum)
*** 125,131 ****
if (FETCH_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
FETCH_PSEUDO_REGISTER (regnum);
! target_fetch_registers (regnum);
}
/* Write register REGNUM cached value to the target. */
--- 125,132 ----
if (FETCH_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
FETCH_PSEUDO_REGISTER (regnum);
! else if (real_register (regnum))
! target_fetch_registers (regnum);
}
/* Write register REGNUM cached value to the target. */
*************** store_register (int regnum)
*** 140,146 ****
if (STORE_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
STORE_PSEUDO_REGISTER (regnum);
! target_store_registers (regnum);
}
/* Low level examining and depositing of registers.
--- 141,148 ----
if (STORE_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
STORE_PSEUDO_REGISTER (regnum);
! else if (real_register (regnum))
! target_store_registers (regnum);
}
/* Low level examining and depositing of registers.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RFA] regcache pseudo-reg tweak
2002-02-05 18:33 [RFA] regcache pseudo-reg tweak Michael Snyder
@ 2002-02-05 19:11 ` Andrew Cagney
2002-02-05 19:17 ` Michael Snyder
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Cagney @ 2002-02-05 19:11 UTC (permalink / raw)
To: Michael Snyder; +Cc: cagney, gdb-patches
> I think you left out an "else" when you made this change in december.
> We must not call target_[fetch/store]_register with a pseudo-register,
> or they will choke. By definition, a pseudo-register is one that
> cannot be fetched from the target.
Oops, kind of.
> Index: regcache.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/regcache.c,v
> retrieving revision 1.31
> diff -c -3 -p -r1.31 regcache.c
> *** regcache.c 2002/01/29 20:24:27 1.31
> --- regcache.c 2002/02/06 02:30:46
> *************** fetch_register (int regnum)
> *** 125,131 ****
> if (FETCH_PSEUDO_REGISTER_P ()
> && pseudo_register (regnum))
> FETCH_PSEUDO_REGISTER (regnum);
> ! target_fetch_registers (regnum);
> }
>
> /* Write register REGNUM cached value to the target. */
> --- 125,132 ----
> if (FETCH_PSEUDO_REGISTER_P ()
> && pseudo_register (regnum))
> FETCH_PSEUDO_REGISTER (regnum);
> ! else if (real_register (regnum))
> ! target_fetch_registers (regnum);
> }
>
> /* Write register REGNUM cached value to the target. */
There should be an else but not else if (real_register ()) ....
A target can handle registers two ways - using pseudo-registers or using
register_{read,write}(). If a target uses the latter then it will
likely end up fetching registers in the pseudo-register range from the
target.
A simple example of this might be a modified x86 where not only the user
registers but also the system registers (MSRs?) are accessable. The
MSR's wouldn't be returned via the G packet but instead fetched
individually. Unfortunatly, NUM_REGS determines which registers are
included in a G packet (and many other obscure things).
Andrew
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RFA] regcache pseudo-reg tweak
2002-02-05 19:11 ` Andrew Cagney
@ 2002-02-05 19:17 ` Michael Snyder
0 siblings, 0 replies; 3+ messages in thread
From: Michael Snyder @ 2002-02-05 19:17 UTC (permalink / raw)
To: Andrew Cagney; +Cc: cagney, gdb-patches
[-- Attachment #1: Type: text/plain, Size: 1932 bytes --]
Andrew Cagney wrote:
>
> > I think you left out an "else" when you made this change in december.
> > We must not call target_[fetch/store]_register with a pseudo-register,
> > or they will choke. By definition, a pseudo-register is one that
> > cannot be fetched from the target.
>
> Oops, kind of.
>
> > Index: regcache.c
> > ===================================================================
> > RCS file: /cvs/src/src/gdb/regcache.c,v
> > retrieving revision 1.31
> > diff -c -3 -p -r1.31 regcache.c
> > *** regcache.c 2002/01/29 20:24:27 1.31
> > --- regcache.c 2002/02/06 02:30:46
> > *************** fetch_register (int regnum)
> > *** 125,131 ****
> > if (FETCH_PSEUDO_REGISTER_P ()
> > && pseudo_register (regnum))
> > FETCH_PSEUDO_REGISTER (regnum);
> > ! target_fetch_registers (regnum);
> > }
> >
> > /* Write register REGNUM cached value to the target. */
> > --- 125,132 ----
> > if (FETCH_PSEUDO_REGISTER_P ()
> > && pseudo_register (regnum))
> > FETCH_PSEUDO_REGISTER (regnum);
> > ! else if (real_register (regnum))
> > ! target_fetch_registers (regnum);
> > }
> >
> > /* Write register REGNUM cached value to the target. */
>
> There should be an else but not else if (real_register ()) ....
>
> A target can handle registers two ways - using pseudo-registers or using
> register_{read,write}(). If a target uses the latter then it will
> likely end up fetching registers in the pseudo-register range from the
> target.
>
> A simple example of this might be a modified x86 where not only the user
> registers but also the system registers (MSRs?) are accessable. The
> MSR's wouldn't be returned via the G packet but instead fetched
> individually. Unfortunatly, NUM_REGS determines which registers are
> included in a G packet (and many other obscure things).
Good. Replaced with a simple "else" and checked in as attached below.
[-- Attachment #2: pseudo.patch --]
[-- Type: text/plain, Size: 1526 bytes --]
2002-02-05 Michael Snyder <msnyder@redhat.com>
* regcache.c (fetch_register): Call target_fetch_register
only if we don't call FETCH_PSEUDO_REGISTER.
(store_register): Call target_store_register only if we
don't call STORE_PSEUDO_REGISTER.
Index: regcache.c
===================================================================
RCS file: /cvs/src/src/gdb/regcache.c,v
retrieving revision 1.31
diff -c -3 -p -r1.31 regcache.c
*** regcache.c 2002/01/29 20:24:27 1.31
--- regcache.c 2002/02/06 02:30:46
*************** fetch_register (int regnum)
*** 125,131 ****
if (FETCH_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
FETCH_PSEUDO_REGISTER (regnum);
! target_fetch_registers (regnum);
}
/* Write register REGNUM cached value to the target. */
--- 125,132 ----
if (FETCH_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
FETCH_PSEUDO_REGISTER (regnum);
! else
! target_fetch_registers (regnum);
}
/* Write register REGNUM cached value to the target. */
*************** store_register (int regnum)
*** 140,146 ****
if (STORE_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
STORE_PSEUDO_REGISTER (regnum);
! target_store_registers (regnum);
}
/* Low level examining and depositing of registers.
--- 141,148 ----
if (STORE_PSEUDO_REGISTER_P ()
&& pseudo_register (regnum))
STORE_PSEUDO_REGISTER (regnum);
! else
! target_store_registers (regnum);
}
/* Low level examining and depositing of registers.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2002-02-05 18:33 [RFA] regcache pseudo-reg tweak Michael Snyder
2002-02-05 19:11 ` Andrew Cagney
2002-02-05 19:17 ` Michael Snyder
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