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 it. > > 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 > > Link: https://lore.kernel.org/r/264fa39d-aed6-4a54-a085-107997078f8d@xxxxxxxxxxxx/ > Link: https://lore.kernel.org/r/f511170fe61d7e7214a3a062661cf4103980dad6.camel@xxxxxxxxxxx/ > Signed-off-by: Max Kellermann <max.kellermann@xxxxxxxxx> > --- > V1 -> V2: removed "volatile" on gregkh's request. > V2 -> V3: moved patch changelog below the "---" line > --- > 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:: I notice that clang-format reflows that example to: const void *a; void *const b; void **const c; void *const *const d; int strcmp(const char *a, const char *b); ...but someone more clang-format savvy than me would need to propose the changes to the kernel's .clang-format template to match the style suggestion.
