From 6de16eba62b3b4d01b2b232ea7724d5450a19e30 Mon Sep 17 00:00:00 2001 From: Jonathan Corbet Date: Tue, 23 Dec 2014 08:38:24 -0700 Subject: Docs: Remove "tips and tricks" from SubmittingPatches This section was just a weird collection of stuff that is better found elsewhere. The "coding style" section somewhat duplicated the previous coding style section; the useful information there has been collected into a single place. Signed-off-by: Jonathan Corbet --- Documentation/SubmittingPatches | 117 ++++++++-------------------------------- 1 file changed, 21 insertions(+), 96 deletions(-) (limited to 'Documentation/SubmittingPatches') diff --git a/Documentation/SubmittingPatches b/Documentation/SubmittingPatches index 1fa1caa198eb..8f416a2b409f 100644 --- a/Documentation/SubmittingPatches +++ b/Documentation/SubmittingPatches @@ -193,17 +193,33 @@ then only post say 15 or so at a time and wait for review and integration. -4) Style check your changes. +4) Style-check your changes. +---------------------------- Check your patch for basic style violations, details of which can be found in Documentation/CodingStyle. Failure to do so simply wastes the reviewers time and will get your patch rejected, probably without even being read. -At a minimum you should check your patches with the patch style -checker prior to submission (scripts/checkpatch.pl). You should -be able to justify all violations that remain in your patch. +One significant exception is when moving code from one file to +another -- in this case you should not modify the moved code at all in +the same patch which moves it. This clearly delineates the act of +moving the code and your changes. This greatly aids review of the +actual differences and allows tools to better track the history of +the code itself. + +Check your patches with the patch style checker prior to submission +(scripts/checkpatch.pl). Note, though, that the style checker should be +viewed as a guide, not as a replacement for human judgment. If your code +looks better with a violation then its probably best left alone. +The checker reports at three levels: + - ERROR: things that are very likely to be wrong + - WARNING: things requiring careful review + - CHECK: things requiring thought + +You should be able to justify all violations that remain in your +patch. 5) Select e-mail destination. @@ -684,100 +700,9 @@ new/deleted or renamed files. With rename detection, the statistics are rather different [...] because git will notice that a fair number of the changes are renames. ------------------------------------ -SECTION 2 - HINTS, TIPS, AND TRICKS ------------------------------------ - -This section lists many of the common "rules" associated with code -submitted to the kernel. There are always exceptions... but you must -have a really good reason for doing so. You could probably call this -section Linus Computer Science 101. - - - -1) Read Documentation/CodingStyle - -Nuff said. If your code deviates too much from this, it is likely -to be rejected without further review, and without comment. - -One significant exception is when moving code from one file to -another -- in this case you should not modify the moved code at all in -the same patch which moves it. This clearly delineates the act of -moving the code and your changes. This greatly aids review of the -actual differences and allows tools to better track the history of -the code itself. - -Check your patches with the patch style checker prior to submission -(scripts/checkpatch.pl). The style checker should be viewed as -a guide not as the final word. If your code looks better with -a violation then its probably best left alone. - -The checker reports at three levels: - - ERROR: things that are very likely to be wrong - - WARNING: things requiring careful review - - CHECK: things requiring thought - -You should be able to justify all violations that remain in your -patch. - - - -2) #ifdefs are ugly - -Code cluttered with ifdefs is difficult to read and maintain. Don't do -it. Instead, put your ifdefs in a header, and conditionally define -'static inline' functions, or macros, which are used in the code. -Let the compiler optimize away the "no-op" case. - -Simple example, of poor code: - - dev = alloc_etherdev (sizeof(struct funky_private)); - if (!dev) - return -ENODEV; - #ifdef CONFIG_NET_FUNKINESS - init_funky_net(dev); - #endif - -Cleaned-up example: - -(in header) - #ifndef CONFIG_NET_FUNKINESS - static inline void init_funky_net (struct net_device *d) {} - #endif - -(in the code itself) - dev = alloc_etherdev (sizeof(struct funky_private)); - if (!dev) - return -ENODEV; - init_funky_net(dev); - - - -3) 'static inline' is better than a macro - -Static inline functions are greatly preferred over macros. -They provide type safety, have no length limitations, no formatting -limitations, and under gcc they are as cheap as macros. - -Macros should only be used for cases where a static inline is clearly -suboptimal [there are a few, isolated cases of this in fast paths], -or where it is impossible to use a static inline function [such as -string-izing]. - -'static inline' is preferred over 'static __inline__', 'extern inline', -and 'extern __inline__'. - - - -4) Don't over-design. - -Don't try to anticipate nebulous future cases which may or may not -be useful: "Make it as simple as you can, and no simpler." - - ---------------------- -SECTION 3 - REFERENCES +SECTION 2 - REFERENCES ---------------------- Andrew Morton, "The perfect patch" (tpp). -- cgit v1.2.3-58-ga151