Re: [PATCH] docs: Introduce deprecated APIs list

From: Randy Dunlap
Date: Wed Oct 17 2018 - 13:09:04 EST


On 10/17/18 3:00 AM, Jani Nikula wrote:
> On Tue, 16 Oct 2018, Randy Dunlap <rdunlap@xxxxxxxxxxxxx> 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@xxxxxxxxxxxx>
>>> ---
>>> 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.
>
> BR,
> Jani.
>
>>
>>> * @p: Pointer to the structure.
>>> * @member: Name of the array member.
>>> * @n: Number of elements in the array.
>>
>>
>> thanks.


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';
}



--
~Randy