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author | Robert P. J. Day <rpjday@mindspring.com> | 2006-12-22 10:09:11 +0100 |
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committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-22 17:55:49 +0100 |
commit | 58637ec90b7ceed5909e726ac90118852f79d2b1 (patch) | |
tree | f5478b2f088d31b609ed07bb10fb641bad7cd10e | |
parent | [PATCH] Make JFFS depend on CONFIG_BROKEN (diff) | |
download | linux-58637ec90b7ceed5909e726ac90118852f79d2b1.tar.xz linux-58637ec90b7ceed5909e726ac90118852f79d2b1.zip |
[PATCH] Add a new section to CodingStyle, promoting include/linux/kernel.h
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 <rpjday@mindspring.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r-- | Documentation/CodingStyle | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index 0ad6dcb5d45f..9069189e78ef 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 |