Add a new section to the CodingStyle file, encouraging people not to re-invent available kernel macros such as ARRAY_SIZE(), FIELD_SIZEOF(), min() and max(), among others.
Signed-off-by: Robert P. J. Day <[EMAIL PROTECTED]> --- NOTE: at the moment, there is not a single invocation of the FIELD_SIZEOF() macro anywhere in the entire source tree, so if someone had a hankering to rename it to something more catchy, now would be a good time and i can always resubmit the patch i sent in yesterday. diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index 0ad6dcb..a736333 100644 --- a/Documentation/CodingStyle +++ b/Documentation/CodingStyle @@ -682,6 +682,24 @@ result. Typical examples would be functions that return pointers; they use NULL or the ERR_PTR mechanism to report failure. + Chapter 17: Don't re-invent the kernel macros + +The header file include/linux/kernel.h contains a number of macros that +you should use, rather than explicitly coding some variant of them yourself. +For example, if you need to calculate the length of an array, take advantage +of the macro + + #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) + +Similarly, if you need to calculate the size of some structure member, use + + #define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f)) + +There are also min() and max() macros that do strict type checking if you +need them. Feel free to peruse that header file to see what else is already +defined that you shouldn't reproduce in your code. + + Appendix I: References - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/