Re: [PATCH 3/3] xen/MISRA: Remove nonstandard inline keywords

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 22 Nov 2023, Andrew Cooper wrote:
> The differences between inline, __inline and __inline__ keywords are a
> vestigial remnant of older C standards, and in Xen we use inline almost
> exclusively.
> 
> Replace __inline and __inline__ with regular inline, and remove their
> exceptions from the MISRA configuration.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
>
> diff --git a/docs/misra/C-language-toolchain.rst 
> b/docs/misra/C-language-toolchain.rst
> index 2866cb191b1a..b7c2000992ac 100644
> --- a/docs/misra/C-language-toolchain.rst
> +++ b/docs/misra/C-language-toolchain.rst
> @@ -84,7 +84,7 @@ The table columns are as follows:
>            see Sections "6.48 Alternate Keywords" and "6.47 How to Use Inline 
> Assembly Language in C Code" of GCC_MANUAL.
>         __volatile__:
>            see Sections "6.48 Alternate Keywords" and "6.47.2.1 Volatile" of 
> GCC_MANUAL.
> -       __const__, __inline__, __inline:
> +       __const__:
>            see Section "6.48 Alternate Keywords" of GCC_MANUAL.
>         typeof, __typeof__:
>            see Section "6.7 Referring to a Type with typeof" of GCC_MANUAL.

Asking the Bugseng guys as well, do we need to add to
C-language-toolchain.rst:
inline __attribute__((__always_inline__))
inline __attribute__((__gnu_inline__))

Given that the problem was also present before this patch:

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> diff --git a/xen/include/xen/compiler.h b/xen/include/xen/compiler.h
> index 04b8bc18df0e..16d554f2a593 100644
> --- a/xen/include/xen/compiler.h
> +++ b/xen/include/xen/compiler.h
> @@ -20,9 +20,8 @@
>  #define likely(x)     __builtin_expect(!!(x),1)
>  #define unlikely(x)   __builtin_expect(!!(x),0)
>  
> -#define inline        __inline__
> -#define always_inline __inline__ __attribute__ ((__always_inline__))
> -#define gnu_inline    __inline__ __attribute__ ((__gnu_inline__))
> +#define always_inline inline __attribute__((__always_inline__))
> +#define gnu_inline    inline __attribute__((__gnu_inline__))
>  #define noinline      __attribute__((__noinline__))
>  
>  #define noreturn      __attribute__((__noreturn__))

This is where they are used.


> @@ -83,7 +82,7 @@
>   * inline functions not expanded inline get placed in .init.text.
>   */
>  #include <xen/init.h>
> -#define __inline__ __inline__ __init
> +#define inline inline __init
>  #endif
>  
>  #define __attribute_pure__  __attribute__((__pure__))
> -- 
> 2.30.2
> 
>