[PATCH] powerpc/mm/radix: add missing braces for single statement block

[PATCH] powerpc/mm/radix: add missing braces for single statement block

[Mathieu Malaterre]

In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
disable_radix") an `if` statement was added for a possible empty body
(prom_debug).

Fix the following warning, treated as error with W=1:

  arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]

Signed-off-by: Mathieu Malaterre <malat@debian.org>
---
 arch/powerpc/kernel/prom_init.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 5ae153b97d0a..f0e802495530 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -652,8 +652,9 @@ static void __init early_cmdline_parse(void)
 		} else
 			prom_radix_disable = true;
 	}
-	if (prom_radix_disable)
+	if (prom_radix_disable) {
 		prom_debug("Radix disabled from cmdline\n");
+	}
 }
 
 #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
-- 
2.11.0

Re: [PATCH] powerpc/mm/radix: add missing braces for single statement block

[Randy Dunlap]

On 04/08/2018 12:44 PM, Mathieu Malaterre wrote:
> In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
> disable_radix") an `if` statement was added for a possible empty body
> (prom_debug).
> 
> Fix the following warning, treated as error with W=1:
> 
>   arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
> 
> Signed-off-by: Mathieu Malaterre <malat@debian.org>
> ---
>  arch/powerpc/kernel/prom_init.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
> index 5ae153b97d0a..f0e802495530 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -652,8 +652,9 @@ static void __init early_cmdline_parse(void)
>  		} else
>  			prom_radix_disable = true;
>  	}
> -	if (prom_radix_disable)
> +	if (prom_radix_disable) {
>  		prom_debug("Radix disabled from cmdline\n");

Looks like the macro for #prom_debug() should be fixed instead.

> +	}
>  }
>  
>  #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
> 


-- 
~Randy

Re: [PATCH] powerpc/mm/radix: add missing braces for single statement block

[Mathieu Malaterre]

On Sun, Apr 8, 2018 at 10:34 PM, Randy Dunlap <rdunlap@infradead.org> wrote:
> On 04/08/2018 12:44 PM, Mathieu Malaterre wrote:
>> In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
>> disable_radix") an `if` statement was added for a possible empty body
>> (prom_debug).
>>
>> Fix the following warning, treated as error with W=1:
>>
>>   arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
>>
>> Signed-off-by: Mathieu Malaterre <malat@debian.org>
>> ---
>>  arch/powerpc/kernel/prom_init.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
>> index 5ae153b97d0a..f0e802495530 100644
>> --- a/arch/powerpc/kernel/prom_init.c
>> +++ b/arch/powerpc/kernel/prom_init.c
>> @@ -652,8 +652,9 @@ static void __init early_cmdline_parse(void)
>>               } else
>>                       prom_radix_disable = true;
>>       }
>> -     if (prom_radix_disable)
>> +     if (prom_radix_disable) {
>>               prom_debug("Radix disabled from cmdline\n");
>
> Looks like the macro for #prom_debug() should be fixed instead.

Well if I try instead:

@@ -101,9 +101,9 @@ int of_workarounds;
 } while (0)

 #ifdef DEBUG_PROM
-#define prom_debug(x...) prom_printf(x)
+#define prom_debug(x...) do { prom_printf(x); } while (0)
 #else
-#define prom_debug(x...)
+#define prom_debug(x...) do { } while (0)
 #endif


the checkpatch script returns:

WARNING: Single statement macros should not use a do {} while (0) loop
#33: FILE: arch/powerpc/kernel/prom_init.c:104:
+#define prom_debug(x...) do { prom_printf(x); } while (0)


So I suspect we cannot do much better than my original patch unfortunately.

>> +     }
>>  }
>>
>>  #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
>>
>
>
> --
> ~Randy

Re: [PATCH] powerpc/mm/radix: add missing braces for single statement block

[Mathieu Malaterre]

On Mon, Apr 23, 2018 at 9:31 PM, Mathieu Malaterre <malat@debian.org> wrote:
> On Sun, Apr 8, 2018 at 10:34 PM, Randy Dunlap <rdunlap@infradead.org> wrote:
>> On 04/08/2018 12:44 PM, Mathieu Malaterre wrote:
>>> In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
>>> disable_radix") an `if` statement was added for a possible empty body
>>> (prom_debug).
>>>
>>> Fix the following warning, treated as error with W=1:
>>>
>>>   arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
>>>
>>> Signed-off-by: Mathieu Malaterre <malat@debian.org>
>>> ---
>>>  arch/powerpc/kernel/prom_init.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
>>> index 5ae153b97d0a..f0e802495530 100644
>>> --- a/arch/powerpc/kernel/prom_init.c
>>> +++ b/arch/powerpc/kernel/prom_init.c
>>> @@ -652,8 +652,9 @@ static void __init early_cmdline_parse(void)
>>>               } else
>>>                       prom_radix_disable = true;
>>>       }
>>> -     if (prom_radix_disable)
>>> +     if (prom_radix_disable) {
>>>               prom_debug("Radix disabled from cmdline\n");
>>
>> Looks like the macro for #prom_debug() should be fixed instead.
>
> Well if I try instead:
>
> @@ -101,9 +101,9 @@ int of_workarounds;
>  } while (0)
>
>  #ifdef DEBUG_PROM
> -#define prom_debug(x...) prom_printf(x)
> +#define prom_debug(x...) do { prom_printf(x); } while (0)
>  #else
> -#define prom_debug(x...)
> +#define prom_debug(x...) do { } while (0)
>  #endif
>
>
> the checkpatch script returns:
>
> WARNING: Single statement macros should not use a do {} while (0) loop
> #33: FILE: arch/powerpc/kernel/prom_init.c:104:
> +#define prom_debug(x...) do { prom_printf(x); } while (0)
>
>
> So I suspect we cannot do much better than my original patch unfortunately.

Right, it seems I cannot read the correct line number for a warning.
An updated patch is coming.

>>> +     }
>>>  }
>>>
>>>  #if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_POWERNV)
>>>
>>
>>
>> --
>> ~Randy

[PATCH v2] powerpc/mm/radix: use do/while(0) trick for single statement block

[Mathieu Malaterre]

In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
disable_radix") an `if` statement was added for a possible empty body
(prom_debug).

Fix the following warning, treated as error with W=1:

  arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
---
v2: update macro directly

 arch/powerpc/kernel/prom_init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 5ae153b97d0a..7edf3aa5bc6d 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -103,7 +103,7 @@ int of_workarounds;
 #ifdef DEBUG_PROM
 #define prom_debug(x...)	prom_printf(x)
 #else
-#define prom_debug(x...)
+#define prom_debug(x...)	do { } while (0)
 #endif
 
 
-- 
2.11.0

Re: [PATCH v2] powerpc/mm/radix: use do/while(0) trick for single statement block

[Randy Dunlap]

On 04/23/18 12:36, Mathieu Malaterre wrote:
> In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
> disable_radix") an `if` statement was added for a possible empty body
> (prom_debug).
> 
> Fix the following warning, treated as error with W=1:
> 
>   arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
> 
> Suggested-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Mathieu Malaterre <malat@debian.org>

Acked-by: Randy Dunlap <rdunlap@infradead.org>

Thanks.

> ---
> v2: update macro directly
> 
>  arch/powerpc/kernel/prom_init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
> index 5ae153b97d0a..7edf3aa5bc6d 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -103,7 +103,7 @@ int of_workarounds;
>  #ifdef DEBUG_PROM
>  #define prom_debug(x...)	prom_printf(x)
>  #else
> -#define prom_debug(x...)
> +#define prom_debug(x...)	do { } while (0)
>  #endif
>  
>  
> 


-- 
~Randy

Re: [v2] powerpc/mm/radix: use do/while(0) trick for single statement block

[Michael Ellerman]

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On Mon, 2018-04-23 at 19:36:38 UTC, Mathieu Malaterre wrote:
> In commit 7a22d6321c3d ("powerpc/mm/radix: Update command line parsing for
> disable_radix") an `if` statement was added for a possible empty body
> (prom_debug).
> 
> Fix the following warning, treated as error with W=1:
> 
>   arch/powerpc/kernel/prom_init.c:656:46: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body]
> 
> Suggested-by: Randy Dunlap <rdunlap@infradead.org>
> Signed-off-by: Mathieu Malaterre <malat@debian.org>
> Acked-by: Randy Dunlap <rdunlap@infradead.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/85aa4b98419d74dd5cc914e0893498

cheers