[v1] address some violations of MISRA C Rule 20.7

[XEN PATCH 11/11] x86/public: hvm: address violations of MISRA C Rule 20.7

Posted by Nicola Vetrini 1 year, 10 months ago

MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses". Therefore, some
macro definitions should gain additional parentheses to ensure that all
current and future users will be safe with respect to expansions that
can possibly alter the semantics of the passed-in macro parameter.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
 xen/include/public/arch-x86/xen.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/include/public/arch-x86/xen.h b/xen/include/public/arch-x86/xen.h
index c0f4551247f4..a9a87d9b50de 100644
--- a/xen/include/public/arch-x86/xen.h
+++ b/xen/include/public/arch-x86/xen.h
@@ -36,7 +36,7 @@
 #define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
 #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
 #define XEN_GUEST_HANDLE_PARAM(name)    XEN_GUEST_HANDLE(name)
-#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } while (0)
+#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = (val); } while (0)
 #define set_xen_guest_handle(hnd, val) set_xen_guest_handle_raw(hnd, val)
 
 #if defined(__i386__)
-- 
2.34.1

Re: [XEN PATCH 11/11] x86/public: hvm: address violations of MISRA C Rule 20.7

Posted by Jan Beulich 1 year, 10 months ago

On 22.03.2024 17:02, Nicola Vetrini wrote:
> MISRA C Rule 20.7 states: "Expressions resulting from the expansion
> of macro parameters shall be enclosed in parentheses". Therefore, some
> macro definitions should gain additional parentheses to ensure that all
> current and future users will be safe with respect to expansions that
> can possibly alter the semantics of the passed-in macro parameter.
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>

Btw, I've taken the liberty to drop the (secondary) hvm: prefix from the
subject; I can't ...

> --- a/xen/include/public/arch-x86/xen.h
> +++ b/xen/include/public/arch-x86/xen.h
> @@ -36,7 +36,7 @@
>  #define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
>  #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
>  #define XEN_GUEST_HANDLE_PARAM(name)    XEN_GUEST_HANDLE(name)
> -#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } while (0)
> +#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = (val); } while (0)
>  #define set_xen_guest_handle(hnd, val) set_xen_guest_handle_raw(hnd, val)

... spot anything HVM-specific in this change.

Jan

Re: [XEN PATCH 11/11] x86/public: hvm: address violations of MISRA C Rule 20.7

Posted by Jan Beulich 1 year, 10 months ago

On 22.03.2024 17:02, Nicola Vetrini wrote:
> MISRA C Rule 20.7 states: "Expressions resulting from the expansion
> of macro parameters shall be enclosed in parentheses". Therefore, some
> macro definitions should gain additional parentheses to ensure that all
> current and future users will be safe with respect to expansions that
> can possibly alter the semantics of the passed-in macro parameter.
> 
> No functional change.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>

Acked-by: Jan Beulich <jbeulich@suse.com>

> --- a/xen/include/public/arch-x86/xen.h
> +++ b/xen/include/public/arch-x86/xen.h
> @@ -36,7 +36,7 @@
>  #define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
>  #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
>  #define XEN_GUEST_HANDLE_PARAM(name)    XEN_GUEST_HANDLE(name)
> -#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } while (0)
> +#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = (val); } while (0)
>  #define set_xen_guest_handle(hnd, val) set_xen_guest_handle_raw(hnd, val)
>  
>  #if defined(__i386__)

Would have been nice though to do the same thing for Arm at the same time.
PPC and RISC-V already have "val" parenthesized there.

Jan

Re: [XEN PATCH 11/11] x86/public: hvm: address violations of MISRA C Rule 20.7

Posted by Nicola Vetrini 1 year, 10 months ago

On 2024-03-26 11:15, Jan Beulich wrote:
> On 22.03.2024 17:02, Nicola Vetrini wrote:
>> MISRA C Rule 20.7 states: "Expressions resulting from the expansion
>> of macro parameters shall be enclosed in parentheses". Therefore, some
>> macro definitions should gain additional parentheses to ensure that 
>> all
>> current and future users will be safe with respect to expansions that
>> can possibly alter the semantics of the passed-in macro parameter.
>> 
>> No functional change.
>> 
>> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
> 
> Acked-by: Jan Beulich <jbeulich@suse.com>
> 
>> --- a/xen/include/public/arch-x86/xen.h
>> +++ b/xen/include/public/arch-x86/xen.h
>> @@ -36,7 +36,7 @@
>>  #define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
>>  #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
>>  #define XEN_GUEST_HANDLE_PARAM(name)    XEN_GUEST_HANDLE(name)
>> -#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } 
>> while (0)
>> +#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = (val); } 
>> while (0)
>>  #define set_xen_guest_handle(hnd, val) set_xen_guest_handle_raw(hnd, 
>> val)
>> 
>>  #if defined(__i386__)
> 
> Would have been nice though to do the same thing for Arm at the same 
> time.
> PPC and RISC-V already have "val" parenthesized there.
> 
> Jan

Ok, no problem.

-- 
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)