Re: [RFC PATCH 1/5] [WIP]misra: add entries to the excluded list

[Luca Fancellu <Luca.Fancellu@xxxxxxx>]

> On 31 Jul 2023, at 16:20, Jan Beulich <jbeulich@xxxxxxxx> wrote:
> 
> On 31.07.2023 17:11, Luca Fancellu wrote:
>>>> +        {
>>>> +            "rel_path": "arch/x86/include/asm/bug.h",
>>>> +            "comment": "Includes mostly assembly macro"
>>>> +        },
>>> 
>>> Mind me asking why assembly macros wouldn't want maintaining in proper
>>> style?
>> 
>> From what I know (experts on CF correct me if I am wrong) clang-format is 
>> meant to format only some languages
>> (C/C++/...) and assembly is not one of them, so what is happening is that 
>> most of the time clang-format breaks
>> it, in fact we are formatting only .c and .h, but since we have some headers 
>> with assembly macros, I’ve seen some issues
>> that ranges from really ugly formatting to build break.
>> 
>> One thing we could do, is to export the headers that contain only assembly 
>> stuffs in dedicate headers (<header>_asm.h ?)
>> so that we could easily use a name regex to exclude "*_asm.h” from 
>> clang-format? And also these headers could #error if
>> included when __ASSEMBLY__ is not defined?
> 
> In principle this may be a route to go (naming aside), but first of all
> I wonder what "assembler macros" are to you: We use both C macros and
> true assembler macros in assembly code. The former I would hope formatting
> tools don't have an issue with.

Yes, C macros are clearly not an issue, true assembler macros are, like the 
example below:

    .macro BUG_FRAME type, line, file_str, second_frame, msg

    .if \type >= BUGFRAME_NR
        .error "Invalid BUGFRAME index"
    .endif

    .L\@ud: ud2a

    .pushsection .rodata.str1, "aMS", @progbits, 1
         .L\@s1: .asciz "\file_str"
    .popsection

    .pushsection .bug_frames.\type, "a", @progbits
        .p2align 2
        .L\@bf:
        .long (.L\@ud - .L\@bf) + \
               ((\line >> BUG_LINE_LO_WIDTH) << BUG_DISP_WIDTH)
        .long (.L\@s1 - .L\@bf) + \
               ((\line & ((1 << BUG_LINE_LO_WIDTH) - 1)) << BUG_DISP_WIDTH)

        .if \second_frame
            .pushsection .rodata.str1, "aMS", @progbits, 1
                .L\@s2: .asciz "\msg"
            .popsection
            .long 0, (.L\@s2 - .L\@bf)
        .endif
    .popsection
    .endm

I don’t think CF has knowledge of the token .macro/.endm/.if/[...] and so it 
formats them
in weird ways

> 
> Jan