On Thu, Jun 30, 2011 at 10:37 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Thu, Jun 30, 2011 at 9:08 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Thu, Jun 30, 2011 at 8:03 AM, Jason Merrill <jason@redhat.com> wrote:
>>> On 06/30/2011 10:42 AM, H.J. Lu wrote:
>>>>
>>>> Register may be saved/restored either by address or value. My patch
>>>> doesn't change the reg field.  The other way will be
>>>>
>>>> #ifdef USE_UNWIND_WORD
>>>>     _Unwind_Word reg[DWARF_FRAME_REGISTERS+1];
>>>> #else
>>>>      void *reg[DWARF_FRAME_REGISTERS+1];
>>>> #endif
>>>>
>>>> We need it so that we are binary compatible with the existing
>>>> unwind context.  Once we do that we need many
>>>>
>>>> #ifdef USE_UNWIND_WORD
>>>> #endif
>>>>
>>>> whenever the reg field is accessed since the reg field is changed.
>>>
>>> But your patch already changes all but one place where reg is accessed.  And
>>> we can avoid lots of ifdefs by abstraction with macros/inlines so there's
>>> one interface.
>>
>> I can do that.
>>
>>> Also, why change SIGNAL_FRAME_BIT?
>>>
>>
>> The current one is
>>
>>  /* Signal frame context.  */
>> #define SIGNAL_FRAME_BIT ((~(_Unwind_Word) 0 >> 1) + 1)
>>
>> It is defined such a strange way to be binary backward compatible.
>> Since there is no such a problem with if REG_VALUE_IN_UNWIND_CONTEXT
>> is defined, I simply define it as
>>
>>  /* Signal frame context.  */
>> #define SIGNAL_FRAME_BIT ((_Unwind_Word) 1 >> 0)
>>
>
> Here is the updated patch.  OK for trunk if there are no regressions?
>
> Thanks.
>
> --
> H.J.
> ---
> gcc/
>
> 2011-06-30  H.J. Lu  <hongjiu.lu@intel.com>
>
>        * config.gcc (libgcc_tm_file): Add i386/value-unwind.h for
>        Linux/x86.
>
>        * system.h (REG_VALUE_IN_UNWIND_CONTEXT): Poisoned.
>
>        * unwind-dw2.c (_Unwind_Context_Reg_Val): New.
>        (_Unwind_Get_Unwind_Word): Likewise.
>        (_Unwind_Get_Unwind_Context_Reg_Val): Likewise.
>        (_Unwind_Context): Use _Unwind_Context_Reg_Val on the reg field.
>        (SIGNAL_FRAME_BIT): Define if REG_VALUE_IN_UNWIND_CONTEXT is
>        defined.
>        (_Unwind_IsExtendedContext): Likewise.
>        (EXTENDED_CONTEXT_BIT): Don't define if REG_VALUE_IN_UNWIND_CONTEXT
>        is defined.
>        (_Unwind_GetGR): Updated.
>        (_Unwind_SetGR): Likewise.
>        (_Unwind_GetGRPtr): Likewise.
>        (_Unwind_SetGRPtr): Likewise.
>        (_Unwind_SetGRValue): Likewise.
>        (_Unwind_GRByValue): Likewise.
>        (__frame_state_for): Likewise.
>        (uw_install_context_1): Likewise.
>
>        * doc/tm.texi.in: Document REG_VALUE_IN_UNWIND_CONTEXT.
>        * doc/tm.texi: Regenerated.
>
> libgcc/
>
> 2011-06-30  H.J. Lu  <hongjiu.lu@intel.com>
>
>        * config/i386/value-unwind.h: New.
>

config.gcc has some extra changes for x32 and missed doc changes.
This one fixed them.  Sorry for that.

-- 
H.J.