Re: [PATCH 7/11] Add BFIN_MAX_REGISTER_SIZE

[Andreas Schwab <schwab@suse.de>]

On Apr 05 2017, Alan Hayward <Alan.Hayward@arm.com> wrote:

>> On 5 Apr 2017, at 11:28, Yao Qi <qiyaoltc@gmail.com> wrote:
>> 
>> Alan Hayward <Alan.Hayward@arm.com> writes:
>> 
>>> diff --git a/gdb/bfin-tdep.c b/gdb/bfin-tdep.c
>>> index 3df1ba387a323dc6827b1189432f8877d1833184..9b45633cab15b8e0adb0d51a2fa650dc2bc6339b 100644
>>> --- a/gdb/bfin-tdep.c
>>> +++ b/gdb/bfin-tdep.c
>>> @@ -689,7 +689,7 @@ static enum register_status
>>> bfin_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
>>> 			   int regnum, gdb_byte *buffer)
>>> {
>>> -  gdb_byte *buf = (gdb_byte *) alloca (MAX_REGISTER_SIZE);
>>> +  gdb_byte *buf = (gdb_byte *) alloca (BFIN_MAX_REGISTER_SIZE);
>> 
>> Why don't you do "gdb_byte buf[4];"?  It is only for CC register which
>> is 32-bit.
>> 
>
> Is it not clearer code to add and use a macro rather than a magic number ?
>
> It’s also not obvious anywhere that the astat register is 32bits. I had to go
> digging inside regformats/reg-bfin.dat before I found it out.
>
> Given that BFIN_MAX_REGISTER_SIZE is also 4, it compiles to the same size anyway.

Since BFIN_MAX_REGISTER_SIZE is a constant you don't need alloca either
way.

Andreas.

-- 
Andreas Schwab, SUSE Labs, schwab@suse.de
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