CC Mode Manual
7.4.2 Adding Styles
If none of the built-in styles is appropriate, you'll probably want to
add a new style definition. Styles are kept in the
c-style-alist variable, but you should never modify this variable
directly. Instead, CC Mode provides the function
c-add-style that you can use to easily add new styles or change
existing styles. This function takes two arguments, a stylename
string, and an association list description of style
customizations. If stylename is not already in
c-style-alist, the new style is added, otherwise the style is
changed to the new description.
This function also takes an optional third argument, which if
nil, automatically applies the new style to the current
The sample `.emacs' file provides a concrete example of how a new
style can be added and automatically set. See section D. Sample .emacs file.