Re: [PATCH] docs: Introduce deprecated APIs list

[Randy Dunlap <rdunlap@infradead.org>]

On 10/17/18 3:37 PM, Kees Cook wrote:
> On Wed, Oct 17, 2018 at 10:08 AM, Randy Dunlap <rdunlap@infradead.org> wrote:
>> On 10/17/18 3:00 AM, Jani Nikula wrote:
>>> On Tue, 16 Oct 2018, Randy Dunlap <rdunlap@infradead.org> wrote:
>>>> On 10/16/18 7:17 PM, Kees Cook wrote:
>>>>> As discussed in the "API replacement/deprecation" thread[1], this
>>>>> makes an effort to document what things shouldn't get (re)added to the
>>>>> kernel, by introducing Documentation/process/deprecated.rst. It also
>>>>> adds the overflow kerndoc to ReST output, and tweaks the struct_size()
>>>>> documentation to parse correctly.
>>>>>
>>>>> [1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2018-September/005282.html
>>>>>
>>>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>>>> ---
>>>>>  Documentation/driver-api/basics.rst  |  3 +
>>>>>  Documentation/process/deprecated.rst | 99 ++++++++++++++++++++++++++++
>>>>>  Documentation/process/index.rst      |  1 +
>>>>>  include/linux/overflow.h             |  2 +-
>>>>>  4 files changed, 104 insertions(+), 1 deletion(-)
>>>>>  create mode 100644 Documentation/process/deprecated.rst
>>>>
>>>>
>>>>> diff --git a/include/linux/overflow.h b/include/linux/overflow.h
>>>>> index 40b48e2133cb..2f224f43dd06 100644
>>>>> --- a/include/linux/overflow.h
>>>>> +++ b/include/linux/overflow.h
>>>>> @@ -291,7 +291,7 @@ static inline __must_check size_t __ab_c_size(size_t n, size_t size, size_t c)
>>>>>  }
>>>>>
>>>>>  /**
>>>>> - * struct_size() - Calculate size of structure with trailing array.
>>>>> + * function struct_size() - Calculate size of structure with trailing array.
>>>>
>>>> That syntax is not explained nor documented in Documentation/doc-guide/kernel-doc.rst.
>>>>
>>>> Is the root problem that the function name begins with "struct"?
>>>> Please explain in the patch description.
>>>
>>> Indeed, shouldn't be needed.
> 
> I actually thought the problem was with it not knowing how to deal
> with struct_size() being a macro instead of a real function.
> 
>> Well, this is just a guess (no testing), but in scripts/kernel-doc (at line
>> 1907 in 4.19-rc8), we can see:
>>
>>         if ($identifier =~ m/^struct/) {
>>             $decl_type = 'struct';
>>         } elsif ($identifier =~ m/^union/) {
>>             $decl_type = 'union';
>>         } elsif ($identifier =~ m/^enum/) {
>>             $decl_type = 'enum';
>>         } elsif ($identifier =~ m/^typedef/) {
>>             $decl_type = 'typedef';
>>         } else {
>>             $decl_type = 'function';
>>         }
>>
>> I wouldn't be surprised if a function named "struct_size" looks like a
>> type struct.  Maybe it needs to be more strict, with either a space or
>> word boundary at the end of each type string.  E.g.:
>>
>>         if ($identifier =~ m/^struct\b/) {
>>             $decl_type = 'struct';
>>         } elsif ($identifier =~ m/^union\b/) {
>>             $decl_type = 'union';
>>         } elsif ($identifier =~ m/^enum\b/) {
>>             $decl_type = 'enum';
>>         } elsif ($identifier =~ m/^typedef\b/) {
>>             $decl_type = 'typedef';
>>         } else {
>>             $decl_type = 'function';
>>         }
> 
> But I see it's actually the prefix! :P
> 
> Using the above code fixes it for me. Can you send this fix with my
> Tested-by, and I'll spin a v2 of my "deprecated.rst" patch without the
> overflow.h change?

OK, but I'll have to first test for unexpected consequences of it.
(i.e., run full docs build with and without the patch)

-- 
~Randy