[PATCH v2] Documentation/process/coding-style.rst: space around const

[PATCH v2] Documentation/process/coding-style.rst: space around const

[Max Kellermann]

There are currently no rules on the placement of "const", but a recent
code submission revealed that there is clearly a preference for spaces
around them.

checkpatch.pl has no check at all for this; though it does sometimes
complain, but only because it erroneously thinks that the "*" (on
local variables) is an unary dereference operator, not a pointer type.

Current coding style for const pointers-to-pointers:

 "*const*": 2 occurrences
 "* const*": 3
 "*const *": 182
 "* const *": 681

Just const pointers:

 "*const": 2833 occurrences
 "* const": 16615

Changed in v2: removed "volatile" on gregkh's request.

Link: https://lore.kernel.org/r/264fa39d-aed6-4a54-a085-107997078f8d@roeck-us.net/
Link: https://lore.kernel.org/r/f511170fe61d7e7214a3a062661cf4103980dad6.camel@perches.com/
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
---
 Documentation/process/coding-style.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst
index 6db37a46d305..71d62d81e506 100644
--- a/Documentation/process/coding-style.rst
+++ b/Documentation/process/coding-style.rst
@@ -271,6 +271,17 @@ adjacent to the type name.  Examples:
 	unsigned long long memparse(char *ptr, char **retptr);
 	char *match_strdup(substring_t *s);
 
+Use space around the ``const`` keyword (except when adjacent to
+parentheses).  Example:
+
+.. code-block:: c
+
+	const void *a;
+	void * const b;
+	void ** const c;
+	void * const * const d;
+	int strcmp(const char *a, const char *b);
+
 Use one space around (on each side of) most binary and ternary operators,
 such as any of these::
 
-- 
2.39.2

Re: [PATCH v2] Documentation/process/coding-style.rst: space around const

[Greg KH]

On Tue, Oct 10, 2023 at 02:29:35PM +0200, Max Kellermann wrote:
> There are currently no rules on the placement of "const", but a recent
> code submission revealed that there is clearly a preference for spaces
> around them.
> 
> checkpatch.pl has no check at all for this; though it does sometimes
> complain, but only because it erroneously thinks that the "*" (on
> local variables) is an unary dereference operator, not a pointer type.
> 
> Current coding style for const pointers-to-pointers:
> 
>  "*const*": 2 occurrences
>  "* const*": 3
>  "*const *": 182
>  "* const *": 681
> 
> Just const pointers:
> 
>  "*const": 2833 occurrences
>  "* const": 16615
> 
> Changed in v2: removed "volatile" on gregkh's request.
> 
> Link: https://lore.kernel.org/r/264fa39d-aed6-4a54-a085-107997078f8d@roeck-us.net/
> Link: https://lore.kernel.org/r/f511170fe61d7e7214a3a062661cf4103980dad6.camel@perches.com/
> Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
> ---
>  Documentation/process/coding-style.rst | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst
> index 6db37a46d305..71d62d81e506 100644
> --- a/Documentation/process/coding-style.rst
> +++ b/Documentation/process/coding-style.rst
> @@ -271,6 +271,17 @@ adjacent to the type name.  Examples:
>  	unsigned long long memparse(char *ptr, char **retptr);
>  	char *match_strdup(substring_t *s);
>  
> +Use space around the ``const`` keyword (except when adjacent to
> +parentheses).  Example:
> +
> +.. code-block:: c
> +
> +	const void *a;
> +	void * const b;
> +	void ** const c;
> +	void * const * const d;
> +	int strcmp(const char *a, const char *b);
> +
>  Use one space around (on each side of) most binary and ternary operators,
>  such as any of these::
>  
> -- 
> 2.39.2
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/process/submitting-patches.rst for what
  needs to be done here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot