Re: [patch, arm] Consistent display of registers in corefile

[Yao Qi <yao@codesourcery.com>]

On 12/10/2010 10:43 PM, Mark Kettenis wrote:
>> Date: Fri, 10 Dec 2010 21:37:30 +0800
>> From: Yao Qi <yao@codesourcery.com>
>>
>> GDB trunk has a test failure on ARM,
>>
>>    FAIL: gdb.base/gcore.exp: corefile restored general registers
>>
>> In short, this failure is caused by output of 'info registers' before
>> coredump doesn't match output of 'info registers' when corefole is
>> loaded again, there are mainly two differences, [1] and [2].
>>
>> Output before coredump,
>> r0             0x12008  73736^M
>> r1             0xbea1f0c0       -1096683328^M
>> [...]
>> sp             0xbea1f0a4       0xbea1f0a4^M
>> lr             0x849b   33947^M
>> pc             0x83fc   0x83fc <terminal_func+4>^M
>> cpsr           0x20000030       536870960^M
>>
>> Output when corefile is loaded,
>> r0             0x12008  73736^M
>> r1             0xbea1f0c0       3198283968^M  // <---- [1]
>> [...]
>> sp             0xbea1f0a4       0xbea1f0a4^M
>> lr             0x849b   33947^M
>> pc             0x83fc   0x83fc <terminal_func+4>^M
>> fps            0x727a622f       1920623151^M  // <---- [2]
>> cpsr           0x20000030       536870960^M
>>
>> The difference [1] is caused by different register types, uint32 vs.
>> int32.  In tdesc, the type of general register is "int", while in
>> arm_register_type, it is regarded as builtin_uint32.  This can be fixed
>> when register type is handled in a consistent way (in reg_type.patch).
> 
> I would suspect that the proper thing to do would be to align the
> tdesc with the code instead of the other way around.  The arm-core.xml
> file seems to underspecify things by omitting the type=xxx clause on
> many registers.  Whoever wrote arm_register_type() at least had to
> make a conscious decision about the signedness of the type used for
> the general purpose registers.

I prefer unsigned for general purpose registers.  Any objections?  If we
agree on this, I'll add type="uint32" to r0-r12 in arm-core.xml.

-- 
Yao (齐尧)