Re: [PATCH 1/7] xz: add fall-through comments to a switch statement

[Julien Grall <julien@xen.org>]

On 25/11/2021 16:49, Julien Grall wrote:
> On 19/11/2021 10:21, Jan Beulich wrote:
>> From: Lasse Collin <lasse.collin@tukaani.org>
>>
>> It's good style. I was also told that GCC 7 is more strict and might
>> give a warning when such comments are missing.
>>
>> Suggested-by: Andrei Borzenkov <arvidjaar@gmail.com>
>> Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>

Actually, any reason why there are some signed-off-by missing?

>> [Linux commit: 5a244f48ecbbd03a11eb84819c5c599db81823ee]
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> Acked-by: Julien Grall <jgrall@amazon.com>
> 
> Cheers,
> 
>> ---
>> Linux has meanwhile further moved to using the "fallthrough" pseudo-
>> keyword, but us doing so requires the tool stack to first make this
>> available for use in at least stubdom builds.
>>
>> --- a/xen/common/xz/dec_stream.c
>> +++ b/xen/common/xz/dec_stream.c
>> @@ -583,6 +583,8 @@ static enum xz_ret __init dec_main(struc
>>               if (ret != XZ_OK)
>>                   return ret;
>> +        /* Fall through */
>> +
>>           case SEQ_BLOCK_START:
>>               /* We need one byte of input to continue. */
>>               if (b->in_pos == b->in_size)
>> @@ -606,6 +608,8 @@ static enum xz_ret __init dec_main(struc
>>               s->temp.pos = 0;
>>               s->sequence = SEQ_BLOCK_HEADER;
>> +        /* Fall through */
>> +
>>           case SEQ_BLOCK_HEADER:
>>               if (!fill_temp(s, b))
>>                   return XZ_OK;
>> @@ -616,6 +620,8 @@ static enum xz_ret __init dec_main(struc
>>               s->sequence = SEQ_BLOCK_UNCOMPRESS;
>> +        /* Fall through */
>> +
>>           case SEQ_BLOCK_UNCOMPRESS:
>>               ret = dec_block(s, b);
>>               if (ret != XZ_STREAM_END)
>> @@ -623,6 +629,8 @@ static enum xz_ret __init dec_main(struc
>>               s->sequence = SEQ_BLOCK_PADDING;
>> +        /* Fall through */
>> +
>>           case SEQ_BLOCK_PADDING:
>>               /*
>>                * Size of Compressed Data + Block Padding
>> @@ -643,6 +651,8 @@ static enum xz_ret __init dec_main(struc
>>               s->sequence = SEQ_BLOCK_CHECK;
>> +        /* Fall through */
>> +
>>           case SEQ_BLOCK_CHECK:
>>               if (s->check_type == XZ_CHECK_CRC32) {
>>                   ret = crc32_validate(s, b);
>> @@ -665,6 +675,8 @@ static enum xz_ret __init dec_main(struc
>>               s->sequence = SEQ_INDEX_PADDING;
>> +        /* Fall through */
>> +
>>           case SEQ_INDEX_PADDING:
>>               while ((s->index.size + (b->in_pos - s->in_start))
>>                       & 3) {
>> @@ -687,6 +699,8 @@ static enum xz_ret __init dec_main(struc
>>               s->sequence = SEQ_INDEX_CRC32;
>> +        /* Fall through */
>> +
>>           case SEQ_INDEX_CRC32:
>>               ret = crc32_validate(s, b);
>>               if (ret != XZ_STREAM_END)
>> @@ -695,6 +709,8 @@ static enum xz_ret __init dec_main(struc
>>               s->temp.size = STREAM_HEADER_SIZE;
>>               s->sequence = SEQ_STREAM_FOOTER;
>> +        /* Fall through */
>> +
>>           case SEQ_STREAM_FOOTER:
>>               if (!fill_temp(s, b))
>>                   return XZ_OK;
>>
> 

-- 
Julien Grall