Re: [PATCH v1] misra: add deviation for rules 21.1 and 21.2

[Jan Beulich <jbeulich@xxxxxxxx>]

On 18.07.2025 11:17, Dmytro Prokopchuk1 wrote:
> On 7/18/25 08:31, Jan Beulich wrote:
>> On 17.07.2025 22:47, Dmytro Prokopchuk1 wrote:
>>> I tried to play with Rule 21.1 deviations.
>>>
>>> After applying the following configurations:
>>>
>>> -config=MC3A2.R21.1,macros+={safe, "^offsetof$ || ^(is|to)[a-z]+$ ||
>>> name(NULL) || name(bool) || name(true) || name(false)"}
>>> -config=MC3A2.R21.1,macros+={safe,
>>> "loc(file(^xen/include/xen/inttypes\\.h$))"}
>>> -config=MC3A2.R21.1,macros+={safe, "loc(file(^xen/include/xen/types\\.h$))"}
>>> -config=MC3A2.R21.1,macros+={safe, "^str[a-z]+$ || ^(v)?sprintf$ ||
>>> ^va_[a-z]+$"}
>>
>> Can you spell these out in words? I can only vaguely interpret these Eclair
>> patterns, sorry.
> Yes, sure.
> 
> That means to deviate the following macros:
> - offsetof
> - begin with either ‘is’ or ‘to’ followed by a lowercase letters 
> (islower, isdigit, tolower, toupper, etc.)
> - NULL
> - bool
> - true
> - false
> - all PRI/SCN macros for printing/scanning format specifiers from header 
> file xen/include/xen/inttypes.h
> - all macros from header file xen/include/xen/types.h (limits: 
> UINT8_MAX, INT_MAX, LONG_MIN, etc.)
> - begin with 'str' followed by a lowercase letters (string functions)
> - sprintf/vsprintf
> - begin with 'va_' followed by a lowercase letters (va_copy, va_start, 
> va_end, va_arg)

That's all stuff the library defines, when there is an (external) library.
I Xen we have (or should I say "we are") the library. Why are we not
permitted to define what a library is expected to define? How would one
go about dealing with an actual library implementation, when it is not
allowed to define anything a library is expected to define?

Jan