Re: [XEN PATCH 12/13] xen: address violations of MISRA C:2012 Directive 4.10

[Simone Ballarin <simone.ballarin@bugseng.com>]

On 29/08/23 00:51, Stefano Stabellini wrote:
> On Mon, 28 Aug 2023, Simone Ballarin wrote:
>> Move or amended inclusion guards to address violations of
>> MISRA C:2012 Directive 4.10 ("Precautions shall be taken in order
>> to prevent the contents of a header file being included more than
>> once").
>>
>> Inclusion guards must appear at the beginning of the headers
>> (comments are permitted anywhere) and the #if directive cannot
>> be used for other checks.
>>
>> Mechanical change.
>>
>> Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
>> ---
>>   xen/include/xen/err.h       | 4 +++-
>>   xen/include/xen/pci_ids.h   | 5 +++++
>>   xen/include/xen/softirq.h   | 4 +++-
>>   xen/include/xen/unaligned.h | 7 ++++---
>>   xen/include/xen/vmap.h      | 4 +++-
>>   5 files changed, 18 insertions(+), 6 deletions(-)
>>
>> diff --git a/xen/include/xen/err.h b/xen/include/xen/err.h
>> index 2f29b57d28..a6323d82d7 100644
>> --- a/xen/include/xen/err.h
>> +++ b/xen/include/xen/err.h
>> @@ -1,5 +1,6 @@
>> -#if !defined(__XEN_ERR_H__) && !defined(__ASSEMBLY__)
>> +#if !defined(__XEN_ERR_H__)
>>   #define __XEN_ERR_H__
>> +#if !defined(__ASSEMBLY__)
> 
> The original pattern was also guarding the header file sufficiently,
> protecting it from double-inclusion. In fact, it is posing stricter
> restrictions than usual (not laxer). This change is unnecessary?

The MISRA directive asks to use one of the two following forms:

<start-of-file>
#if !defined ( identifier )
#define identifier
/* Contents of file */
#endif
<end-of-file>

<start-of-file>
#ifndef identifier
#define identifier
/* Contents of file */
#endif
<end-of-file>

I do not see any reason for deviating, but if you ask that, I can do it.

> 
> 
>>   #include <xen/compiler.h>
>>   #include <xen/errno.h>
>> @@ -54,4 +55,5 @@ static inline int __must_check PTR_RET(const void *ptr)
>>   	return IS_ERR(ptr) ? PTR_ERR(ptr) : 0;
>>   }
>>   
>> +#endif /* __ASSEMBLY__ */
>>   #endif /* __XEN_ERR_H__ */
>> diff --git a/xen/include/xen/pci_ids.h b/xen/include/xen/pci_ids.h
>> index e798477a7e..1a739d4c92 100644
>> --- a/xen/include/xen/pci_ids.h
>> +++ b/xen/include/xen/pci_ids.h
>> @@ -1,3 +1,6 @@
>> +#ifndef __XEN_PCI_IDS_H__
>> +#define __XEN_PCI_IDS_H__
>> +
>>   #define PCI_VENDOR_ID_AMD                0x1022
>>   
>>   #define PCI_VENDOR_ID_NVIDIA             0x10de
>> @@ -11,3 +14,5 @@
>>   #define PCI_VENDOR_ID_BROADCOM           0x14e4
>>   
>>   #define PCI_VENDOR_ID_INTEL              0x8086
>> +
>> +#endif /* __XEN_PCI_IDS_H__ */
>> diff --git a/xen/include/xen/softirq.h b/xen/include/xen/softirq.h
>> index 33d6f2ecd2..092ec733b7 100644
>> --- a/xen/include/xen/softirq.h
>> +++ b/xen/include/xen/softirq.h
>> @@ -1,5 +1,6 @@
>> -#if !defined(__XEN_SOFTIRQ_H__) && !defined(__ASSEMBLY__)
>> +#if !defined(__XEN_SOFTIRQ_H__)
>>   #define __XEN_SOFTIRQ_H__
>> +#if !defined(__ASSEMBLY__)
> 
> same here
> 
> 
>>   /* Low-latency softirqs come first in the following list. */
>>   enum {
>> @@ -40,4 +41,5 @@ void cpu_raise_softirq_batch_finish(void);
>>    */
>>   void process_pending_softirqs(void);
>>   
>> +#endif /* __ASSEMBLY__ */
>>   #endif /* __XEN_SOFTIRQ_H__ */
>> diff --git a/xen/include/xen/unaligned.h b/xen/include/xen/unaligned.h
>> index 0a2b16d05d..45f03b3f1b 100644
>> --- a/xen/include/xen/unaligned.h
>> +++ b/xen/include/xen/unaligned.h
>> @@ -3,13 +3,14 @@
>>    * without faulting, and at least reasonably efficiently.  Other architectures
>>    * will need to have a custom asm/unaligned.h.
>>    */
>> -#ifndef __ASM_UNALIGNED_H__
>> -#error "xen/unaligned.h should not be included directly - include asm/unaligned.h instead"
>> -#endif
>>   
>>   #ifndef __XEN_UNALIGNED_H__
>>   #define __XEN_UNALIGNED_H__
>>   
>> +#ifndef __ASM_UNALIGNED_H__
>> +#error "xen/unaligned.h should not be included directly - include asm/unaligned.h instead"
>> +#endif
>> +
>>   #ifdef __XEN__
>>   #include <xen/types.h>
>>   #include <asm/byteorder.h>
>> diff --git a/xen/include/xen/vmap.h b/xen/include/xen/vmap.h
>> index b0f7632e89..7a61dea54a 100644
>> --- a/xen/include/xen/vmap.h
>> +++ b/xen/include/xen/vmap.h
>> @@ -1,5 +1,6 @@
>> -#if !defined(__XEN_VMAP_H__) && defined(VMAP_VIRT_START)
>> +#if !defined(__XEN_VMAP_H__)
>>   #define __XEN_VMAP_H__
>> +#if defined(VMAP_VIRT_START)
> 
> same here
> 
> 
>>   #include <xen/mm-frame.h>
>>   #include <xen/page-size.h>
>> @@ -38,4 +39,5 @@ static inline void vm_init(void)
>>       vm_init_type(VMAP_DEFAULT, (void *)VMAP_VIRT_START, arch_vmap_virt_end());
>>   }
>>   
>> +#endif /* VMAP_VIRT_START */
>>   #endif /* __XEN_VMAP_H__ */
>> -- 
>> 2.34.1
>>
> 

-- 
Simone Ballarin, M.Sc.

Field Application Engineer, BUGSENG (https://bugseng.com)