Re: [Qemu-devel] [PATCH] checkpatch.pl: disable arch-specific test for linux-user

[Riku Voipio <riku.voipio@linaro.org>]

On 27 September 2016 at 00:08, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 26 September 2016 at 12:58,  <riku.voipio@linaro.org> wrote:
>> From: Riku Voipio <riku.voipio@linaro.org>
>>
>> Linux-user and bsd-user code needs lots of arch-specific ifdefs,
>> so disable the warning.
>>
>> Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
>> ---
>>  scripts/checkpatch.pl | 5 +++--
>>  1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
>> index dde3f5f..98a007f 100755
>> --- a/scripts/checkpatch.pl
>> +++ b/scripts/checkpatch.pl
>> @@ -2405,8 +2405,9 @@ sub process {
>>                 }
>>  # check of hardware specific defines
>>  # we have e.g. CONFIG_LINUX and CONFIG_WIN32 for common cases
>> -# where they might be necessary.
>> -               if ($line =~ m@^.\s*\#\s*if.*\b__@) {
>> +# where they might be necessary. Skip test on linux-user and bsd-user
>> +# where arch defines are needed
>> +               if (!($realfile =~ /^(linux|bsd)-user/) &&  $line =~ m@^.\s*\#\s*if.*\b__@) {
>>                         ERROR("architecture specific defines should be avoided\n" .  $herecurr);
>>                 }
>
> Do you have some examples of the false positives you want
> to suppress here? For new code I would hope that we can
> handle host-arch-specifics by having new files (or just
> new #defines etc) in linux-user/host/$ARCH/ rather than
> inline #ifdeffery in the main files.

One example from your patch:

https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg05650.html

And another from Laurent:

https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg06486.html

Every new syscall will comes with "#ifdef TARGET_NR_foo and
defined(__NR_foo)", while host/target combos catch up. Now, most
TARGET_NR_foo's are needed only for unicore32, but the __NR_foo
defines will be needed for a very long time.

Riku