riscv-openocd/doc/manual/style.txt

/** @page styleguide OpenOCD Coding C Style Guide

The following rules describe a formatting, naming, and other conventions
that should be followed when writing or changing the OpenOCD C code.
Many of the general rules should apply to OpenOCD's Jim/TCL code as well.

The goals of this guide are:
- to produce code that appears clean, consistent, and readable,
- to allow developers to create patches that conform to a standard,
- to eliminate these issues as points of future contention.
consistent.

Some of these rules may be ignored in the spirit of these stated goals;
however, such exceptions should be fairly rare.

@section styleformat Formatting Rules

- remove any trailing white space at the end of lines.
- use TAB characters for indentation; do NOT use spaces.
- displayed TAB width is 4 characters.
- use Unix line endings ('\\n'); do NOT use DOS endings ('\\r\\n')
- limit adjacent empty lines to at most two (2).
- remove any trailing empty lines at the end of source files
- do not "comment out" code from the tree; instead, one should either:
  -# remove it entirely (Subversion can retrieve the old version), or
  -# use an @c #if/#endif block.

Finally, try to avoid lines of code that are longer than than 72-80 columns:

- long lines frequently indicate other style problems:
  - insufficient use of static functions, macros, or temporary variables
  - poor flow-control structure; "inverted" logical tests
- a few lines may be wider than this limit (typically format strings), but:
  - all C compilers will concatenate series of string constants.
  - all long string constants should be split across multiple lines.

@section stylenames Naming Rules

- most identifiers must use lower-case letters (and digits) only.
  - macros must use upper-case letters (and digits) only.
  - OpenOCD identifiers should NEVER use @c MixedCaps.
- structure names must end with the '_s' suffix.
- typedef names must end with the '_t' suffix.
- use underline characters between consecutive words in identifiers
  (e.g. @c more_than_one_word).

@section stylec99 C99 Rules

- inline functions
- @c // comments -- in new code, prefer these for single-line comments
- trailing comma allowed in enum declarations
- designated initializers (@{ .field = value @})
- variables declarations may be mixed with code
- new block scopes for selection and iteration statements

@section stylefunc Functions

- static inline functions should be prefered over macros:
@code
/** do NOT define macro-like functions like this... */
#define CUBE(x) ((x) * (x) * (x))
/** instead, define the same expression using a C99 inline function */
static inline int cube(int x) { return x * x * x; }
@endcode
- Functions should be declared static unless required by other modules
  - define static functions before first usage to avoid forward declarations.
- Functions should have no space between its name and its parameter list:
@code
int f(int x1, int x2)
{
	...
	int y = f(x1, x2 - x1);
	...
}
@endcode

@section styledoxygen Doxygen Rules

- use @c /// to for one-line documentation
- for multiple lines, use a "block" style with one space
@verbatim
/**
 * @brief Short description.
 * Full description here.
 * @param foo Describe foo.
 */
@endverbatim
- if the total line length will be less than 72 columns, then
  - The @c /**< form can be used on the same line.
  - This style should be used sparingly; the best use is for fields:
    - @code int field /**< field description */ @endcode

 */