diff mbox series

[v4,03/19] powerpc: Mark variable `l` as unused, remove `path`

Message ID 20180405202648.2836-1-malat@debian.org (mailing list archive)
State Superseded
Headers show
Series None | expand

Commit Message

Mathieu Malaterre April 5, 2018, 8:26 p.m. UTC 
Add gcc attribute unused for `l` variable, replace `path` variable directly
with prom_scratch. Fix warnings treated as errors with W=1:

  arch/powerpc/kernel/prom_init.c:607:6: error: variable ‘l’ set but not used [-Werror=unused-but-set-variable]
  arch/powerpc/kernel/prom_init.c:1388:8: error: variable ‘path’ set but not used [-Werror=unused-but-set-variable]

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
---
v4: redo v3 since path variable can be avoided
v3: really move path within ifdef DEBUG_PROM
v2: move path within ifdef DEBUG_PROM

 arch/powerpc/kernel/prom_init.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Comments

Christophe Leroy April 6, 2018, 3:33 p.m. UTC | #1 
Mathieu Malaterre <malat@debian.org> a écrit :

> Add gcc attribute unused for `l` variable, replace `path` variable directly
> with prom_scratch. Fix warnings treated as errors with W=1:
>
>   arch/powerpc/kernel/prom_init.c:607:6: error: variable ‘l’ set but  
> not used [-Werror=unused-but-set-variable]
>   arch/powerpc/kernel/prom_init.c:1388:8: error: variable ‘path’ set  
> but not used [-Werror=unused-but-set-variable]
>
> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Mathieu Malaterre <malat@debian.org>
> ---
> v4: redo v3 since path variable can be avoided
> v3: really move path within ifdef DEBUG_PROM
> v2: move path within ifdef DEBUG_PROM
>
>  arch/powerpc/kernel/prom_init.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/prom_init.c  
> b/arch/powerpc/kernel/prom_init.c
> index f8a9a50ff9b5..4b223a9470be 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -604,7 +604,7 @@ static void __init early_cmdline_parse(void)
>  	const char *opt;
>
>  	char *p;
> -	int l = 0;
> +	int l __maybe_unused = 0;

Instead of hiding the problem with __maybe_unused, I think we could  
replace the
#ifdef CONFIG_CMDLINE
by a
if (IS_ENABLED(CONFIG_CMDLINE_BOOL))

This is recommanded by Linux codying style

Christophe

>
>  	prom_cmd_line[0] = 0;
>  	p = prom_cmd_line;
> @@ -1386,7 +1386,7 @@ static void __init reserve_mem(u64 base, u64 size)
>  static void __init prom_init_mem(void)
>  {
>  	phandle node;
> -	char *path, type[64];
> +	char type[64];
>  	unsigned int plen;
>  	cell_t *p, *endp;
>  	__be32 val;
> @@ -1407,7 +1407,6 @@ static void __init prom_init_mem(void)
>  	prom_debug("root_size_cells: %x\n", rsc);
>
>  	prom_debug("scanning memory:\n");
> -	path = prom_scratch;
>
>  	for (node = 0; prom_next_node(&node); ) {
>  		type[0] = 0;
> @@ -1432,9 +1431,9 @@ static void __init prom_init_mem(void)
>  		endp = p + (plen / sizeof(cell_t));
>
>  #ifdef DEBUG_PROM
> -		memset(path, 0, PROM_SCRATCH_SIZE);
> -		call_prom("package-to-path", 3, 1, node, path, PROM_SCRATCH_SIZE-1);
> -		prom_debug("  node %s :\n", path);
> +		memset(prom_scratch, 0, PROM_SCRATCH_SIZE);
> +		call_prom("package-to-path", 3, 1, node, prom_scratch,  
> PROM_SCRATCH_SIZE - 1);
> +		prom_debug("  node %s :\n", prom_scratch);
>  #endif /* DEBUG_PROM */
>
>  		while ((endp - p) >= (rac + rsc)) {
> --
> 2.11.0
Mathieu Malaterre April 6, 2018, 6:32 p.m. UTC | #2 
On Fri, Apr 6, 2018 at 5:33 PM, LEROY Christophe
<christophe.leroy@c-s.fr> wrote:
> Mathieu Malaterre <malat@debian.org> a écrit :
>
>> Add gcc attribute unused for `l` variable, replace `path` variable
>> directly
>> with prom_scratch. Fix warnings treated as errors with W=1:
>>
>>   arch/powerpc/kernel/prom_init.c:607:6: error: variable ‘l’ set but not
>> used [-Werror=unused-but-set-variable]
>>   arch/powerpc/kernel/prom_init.c:1388:8: error: variable ‘path’ set but
>> not used [-Werror=unused-but-set-variable]
>>
>> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
>> Signed-off-by: Mathieu Malaterre <malat@debian.org>
>> ---
>> v4: redo v3 since path variable can be avoided
>> v3: really move path within ifdef DEBUG_PROM
>> v2: move path within ifdef DEBUG_PROM
>>
>>  arch/powerpc/kernel/prom_init.c | 11 +++++------
>>  1 file changed, 5 insertions(+), 6 deletions(-)
>>
>> diff --git a/arch/powerpc/kernel/prom_init.c
>> b/arch/powerpc/kernel/prom_init.c
>> index f8a9a50ff9b5..4b223a9470be 100644
>> --- a/arch/powerpc/kernel/prom_init.c
>> +++ b/arch/powerpc/kernel/prom_init.c
>> @@ -604,7 +604,7 @@ static void __init early_cmdline_parse(void)
>>         const char *opt;
>>
>>         char *p;
>> -       int l = 0;
>> +       int l __maybe_unused = 0;
>
>
> Instead of hiding the problem with __maybe_unused, I think we could replace
> the
> #ifdef CONFIG_CMDLINE
> by a
> if (IS_ENABLED(CONFIG_CMDLINE_BOOL))
>
> This is recommanded by Linux codying style

Neat. I was not aware of this trick. Does not work in this case though:

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 7925f64fefde..19634739b279 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -604,17 +604,16 @@ static void __init early_cmdline_parse(void)
        const char *opt;

        char *p;
-       int l __maybe_unused = 0;
+       int l = 0;

        prom_cmd_line[0] = 0;
        p = prom_cmd_line;
        if ((long)prom.chosen > 0)
                l = prom_getprop(prom.chosen, "bootargs", p,
COMMAND_LINE_SIZE-1);
-#ifdef CONFIG_CMDLINE
-       if (l <= 0 || p[0] == '\0') /* dbl check */
-               strlcpy(prom_cmd_line,
-                       CONFIG_CMDLINE, sizeof(prom_cmd_line));
-#endif /* CONFIG_CMDLINE */
+       if (IS_ENABLED(CONFIG_CMDLINE_BOOL))
+               if (l <= 0 || p[0] == '\0') /* dbl check */
+                       strlcpy(prom_cmd_line,
+                               CONFIG_CMDLINE, sizeof(prom_cmd_line));
        prom_printf("command line: %s\n", prom_cmd_line);

 #ifdef CONFIG_PPC64


leads to:

  CC      arch/powerpc/kernel/prom_init.o
../arch/powerpc/kernel/prom_init.c: In function ‘early_cmdline_parse’:
../arch/powerpc/kernel/prom_init.c:616:5: error: ‘CONFIG_CMDLINE’
undeclared (first use in this function)
     CONFIG_CMDLINE, sizeof(prom_cmd_line));
     ^~~~~~~~~~~~~~
../arch/powerpc/kernel/prom_init.c:616:5: note: each undeclared
identifier is reported only once for each function it appears in
../scripts/Makefile.build:312: recipe for target
'arch/powerpc/kernel/prom_init.o' failed
make[6]: *** [arch/powerpc/kernel/prom_init.o] Error 1


> Christophe
>
>
>>
>>         prom_cmd_line[0] = 0;
>>         p = prom_cmd_line;
>> @@ -1386,7 +1386,7 @@ static void __init reserve_mem(u64 base, u64 size)
>>  static void __init prom_init_mem(void)
>>  {
>>         phandle node;
>> -       char *path, type[64];
>> +       char type[64];
>>         unsigned int plen;
>>         cell_t *p, *endp;
>>         __be32 val;
>> @@ -1407,7 +1407,6 @@ static void __init prom_init_mem(void)
>>         prom_debug("root_size_cells: %x\n", rsc);
>>
>>         prom_debug("scanning memory:\n");
>> -       path = prom_scratch;
>>
>>         for (node = 0; prom_next_node(&node); ) {
>>                 type[0] = 0;
>> @@ -1432,9 +1431,9 @@ static void __init prom_init_mem(void)
>>                 endp = p + (plen / sizeof(cell_t));
>>
>>  #ifdef DEBUG_PROM
>> -               memset(path, 0, PROM_SCRATCH_SIZE);
>> -               call_prom("package-to-path", 3, 1, node, path,
>> PROM_SCRATCH_SIZE-1);
>> -               prom_debug("  node %s :\n", path);
>> +               memset(prom_scratch, 0, PROM_SCRATCH_SIZE);
>> +               call_prom("package-to-path", 3, 1, node, prom_scratch,
>> PROM_SCRATCH_SIZE - 1);
>> +               prom_debug("  node %s :\n", prom_scratch);
>>  #endif /* DEBUG_PROM */
>>
>>                 while ((endp - p) >= (rac + rsc)) {
>> --
>> 2.11.0
>
>
>
Christophe Leroy April 24, 2018, 7:20 p.m. UTC | #3 
Le 06/04/2018 à 20:32, Mathieu Malaterre a écrit :
> On Fri, Apr 6, 2018 at 5:33 PM, LEROY Christophe
> <christophe.leroy@c-s.fr> wrote:
>> Mathieu Malaterre <malat@debian.org> a écrit :
>>
>>> Add gcc attribute unused for `l` variable, replace `path` variable
>>> directly
>>> with prom_scratch. Fix warnings treated as errors with W=1:
>>>
>>>    arch/powerpc/kernel/prom_init.c:607:6: error: variable ‘l’ set but not
>>> used [-Werror=unused-but-set-variable]
>>>    arch/powerpc/kernel/prom_init.c:1388:8: error: variable ‘path’ set but
>>> not used [-Werror=unused-but-set-variable]
>>>
>>> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
>>> Signed-off-by: Mathieu Malaterre <malat@debian.org>
>>> ---
>>> v4: redo v3 since path variable can be avoided
>>> v3: really move path within ifdef DEBUG_PROM
>>> v2: move path within ifdef DEBUG_PROM
>>>
>>>   arch/powerpc/kernel/prom_init.c | 11 +++++------
>>>   1 file changed, 5 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/arch/powerpc/kernel/prom_init.c
>>> b/arch/powerpc/kernel/prom_init.c
>>> index f8a9a50ff9b5..4b223a9470be 100644
>>> --- a/arch/powerpc/kernel/prom_init.c
>>> +++ b/arch/powerpc/kernel/prom_init.c
>>> @@ -604,7 +604,7 @@ static void __init early_cmdline_parse(void)
>>>          const char *opt;
>>>
>>>          char *p;
>>> -       int l = 0;
>>> +       int l __maybe_unused = 0;
>>
>>
>> Instead of hiding the problem with __maybe_unused, I think we could replace
>> the
>> #ifdef CONFIG_CMDLINE
>> by a
>> if (IS_ENABLED(CONFIG_CMDLINE_BOOL))
>>
>> This is recommanded by Linux codying style
> 
> Neat. I was not aware of this trick. Does not work in this case though:
> 
> diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
> index 7925f64fefde..19634739b279 100644
> --- a/arch/powerpc/kernel/prom_init.c
> +++ b/arch/powerpc/kernel/prom_init.c
> @@ -604,17 +604,16 @@ static void __init early_cmdline_parse(void)
>          const char *opt;
> 
>          char *p;
> -       int l __maybe_unused = 0;
> +       int l = 0;
> 
>          prom_cmd_line[0] = 0;
>          p = prom_cmd_line;
>          if ((long)prom.chosen > 0)
>                  l = prom_getprop(prom.chosen, "bootargs", p,
> COMMAND_LINE_SIZE-1);
> -#ifdef CONFIG_CMDLINE
> -       if (l <= 0 || p[0] == '\0') /* dbl check */
> -               strlcpy(prom_cmd_line,
> -                       CONFIG_CMDLINE, sizeof(prom_cmd_line));
> -#endif /* CONFIG_CMDLINE */
> +       if (IS_ENABLED(CONFIG_CMDLINE_BOOL))
> +               if (l <= 0 || p[0] == '\0') /* dbl check */
> +                       strlcpy(prom_cmd_line,
> +                               CONFIG_CMDLINE, sizeof(prom_cmd_line));
>          prom_printf("command line: %s\n", prom_cmd_line);
> 
>   #ifdef CONFIG_PPC64
> 
> 
> leads to:
> 
>    CC      arch/powerpc/kernel/prom_init.o
> ../arch/powerpc/kernel/prom_init.c: In function ‘early_cmdline_parse’:
> ../arch/powerpc/kernel/prom_init.c:616:5: error: ‘CONFIG_CMDLINE’
> undeclared (first use in this function)
>       CONFIG_CMDLINE, sizeof(prom_cmd_line));
>       ^~~~~~~~~~~~~~
> ../arch/powerpc/kernel/prom_init.c:616:5: note: each undeclared
> identifier is reported only once for each function it appears in
> ../scripts/Makefile.build:312: recipe for target
> 'arch/powerpc/kernel/prom_init.o' failed
> make[6]: *** [arch/powerpc/kernel/prom_init.o] Error 1

And what about something like :


+       if (l <= 0 || p[0] == '\0') { /* dbl check */
  #ifdef CONFIG_CMDLINE
-       if (l <= 0 || p[0] == '\0') /* dbl check */
                 strlcpy(prom_cmd_line,
                         CONFIG_CMDLINE, sizeof(prom_cmd_line));
  #endif /* CONFIG_CMDLINE */
+}
          prom_printf("command line: %s\n", prom_cmd_line);

Christophe


> 
> 
>> Christophe
>>
>>
>>>
>>>          prom_cmd_line[0] = 0;
>>>          p = prom_cmd_line;
>>> @@ -1386,7 +1386,7 @@ static void __init reserve_mem(u64 base, u64 size)
>>>   static void __init prom_init_mem(void)
>>>   {
>>>          phandle node;
>>> -       char *path, type[64];
>>> +       char type[64];
>>>          unsigned int plen;
>>>          cell_t *p, *endp;
>>>          __be32 val;
>>> @@ -1407,7 +1407,6 @@ static void __init prom_init_mem(void)
>>>          prom_debug("root_size_cells: %x\n", rsc);
>>>
>>>          prom_debug("scanning memory:\n");
>>> -       path = prom_scratch;
>>>
>>>          for (node = 0; prom_next_node(&node); ) {
>>>                  type[0] = 0;
>>> @@ -1432,9 +1431,9 @@ static void __init prom_init_mem(void)
>>>                  endp = p + (plen / sizeof(cell_t));
>>>
>>>   #ifdef DEBUG_PROM
>>> -               memset(path, 0, PROM_SCRATCH_SIZE);
>>> -               call_prom("package-to-path", 3, 1, node, path,
>>> PROM_SCRATCH_SIZE-1);
>>> -               prom_debug("  node %s :\n", path);
>>> +               memset(prom_scratch, 0, PROM_SCRATCH_SIZE);
>>> +               call_prom("package-to-path", 3, 1, node, prom_scratch,
>>> PROM_SCRATCH_SIZE - 1);
>>> +               prom_debug("  node %s :\n", prom_scratch);
>>>   #endif /* DEBUG_PROM */
>>>
>>>                  while ((endp - p) >= (rac + rsc)) {
>>> --
>>> 2.11.0
>>
>>
>>

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diff mbox series

Patch

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index f8a9a50ff9b5..4b223a9470be 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -604,7 +604,7 @@  static void __init early_cmdline_parse(void)
 	const char *opt;
 
 	char *p;
-	int l = 0;
+	int l __maybe_unused = 0;
 
 	prom_cmd_line[0] = 0;
 	p = prom_cmd_line;
@@ -1386,7 +1386,7 @@  static void __init reserve_mem(u64 base, u64 size)
 static void __init prom_init_mem(void)
 {
 	phandle node;
-	char *path, type[64];
+	char type[64];
 	unsigned int plen;
 	cell_t *p, *endp;
 	__be32 val;
@@ -1407,7 +1407,6 @@  static void __init prom_init_mem(void)
 	prom_debug("root_size_cells: %x\n", rsc);
 
 	prom_debug("scanning memory:\n");
-	path = prom_scratch;
 
 	for (node = 0; prom_next_node(&node); ) {
 		type[0] = 0;
@@ -1432,9 +1431,9 @@  static void __init prom_init_mem(void)
 		endp = p + (plen / sizeof(cell_t));
 
 #ifdef DEBUG_PROM
-		memset(path, 0, PROM_SCRATCH_SIZE);
-		call_prom("package-to-path", 3, 1, node, path, PROM_SCRATCH_SIZE-1);
-		prom_debug("  node %s :\n", path);
+		memset(prom_scratch, 0, PROM_SCRATCH_SIZE);
+		call_prom("package-to-path", 3, 1, node, prom_scratch, PROM_SCRATCH_SIZE - 1);
+		prom_debug("  node %s :\n", prom_scratch);
 #endif /* DEBUG_PROM */
 
 		while ((endp - p) >= (rac + rsc)) {