Code Styling Tips

Here are some miscellaneous tips for good code styling:

Proper Linux Kernel Coding Style
See the kernel coding style guide in any kernel source tree at: Documentation/CodingStyle (Online here)

Greg Kroah-Hartman wrote some additional tips in his article: Proper Linux Kernel Coding Style

Michael S. Tsirkin made a kernel guide to space (a boring list of rules) which got polished on a worth reading thread in LKML in 2005.

use of #ifdefs
Rob Landley writes:

Read: http://doc.cat-v.org/henry_spencer/ifdef_considered_harmful.pdf

Personally, I tend to have symbols #defined to a constant 0 or 1 depending on whether or not a function is enabled, and then just use if(SYMBOL) as a guard and let the compiler's dead code eliminator take it out for me at compile time (because if(0) {blah;} shouldn't put any code in the resulting .o file with any optimizer worth its salt. Borland C for DOS managed simple dead code elimination 20 years ago...)