71 lines
2.4 KiB
ReStructuredText
71 lines
2.4 KiB
ReStructuredText
.. _variable_documentation:
|
|
|
|
Variable Documentation
|
|
######################
|
|
|
|
Variables are the smallest element that requires documentation. As such
|
|
only a brief description is required detailing the purpose of the
|
|
variable. Only significant variables have to be documented. A
|
|
significant variable is a variable that adds functionality to a
|
|
component. Review the `Variable Documentation Examples`_ to understand
|
|
what constitutes a significant variable.
|
|
|
|
Variable Comment Template
|
|
*************************
|
|
|
|
.. code-block:: c
|
|
|
|
/** Brief description of singificant_variable's purpose. */
|
|
int significant_variable;
|
|
|
|
Variable Documentation Examples
|
|
*******************************
|
|
|
|
Example 1
|
|
=========
|
|
|
|
This example shows a function that has been fully documented following
|
|
the best practices.
|
|
|
|
.. literalinclude:: phil_fiber_commented.c
|
|
:language: c
|
|
:lines: 110-168
|
|
:emphasize-lines: 15, 18, 21-23, 25, 31
|
|
:linenos:
|
|
|
|
Lines 15 and 18 show the documentation for two variables. Notice the
|
|
blank line 17. That line is necessary not only to increase the clarity
|
|
of the code but also to avoid Doxygen not determining properly where
|
|
the comment belongs.
|
|
|
|
Lines 21-23 show another acceptable way to document two variables with a
|
|
similar function. Notice that only one of the variables is documented,
|
|
the first one. The argument can be made that **kmutex_t f2** is no
|
|
longer a significant variable because it does not add any functionality
|
|
that has not been described for **kmutex_t f1**.
|
|
|
|
Lines 25 and 31 show us a different situation. Although both variables
|
|
are of the same type and very similar, they have different purposes.
|
|
Therefore both have to be documented and the difference between them
|
|
must be noted.
|
|
|
|
Example 2
|
|
=========
|
|
Variables outside of functions have to be documented as well.
|
|
|
|
.. literalinclude:: hello_commented.c
|
|
:language: c
|
|
:lines: 133-140
|
|
:emphasize-lines: 1, 4, 7
|
|
:linenos:
|
|
|
|
As you can see the syntax of the comment does not change. Always start
|
|
the comment with :literal:`/**` and end it with :literal:`*/`. Remember
|
|
to begin with a capital letter and end with a period, even if the
|
|
comment is only a sentence fragment.
|
|
|
|
Notice that the variable comments also apply for more complex types like
|
|
structs. The comments on lines 4 and 7 apply only to the specific
|
|
variable and not to the whole struct. Complex types must be documented
|
|
wherever they are defined. See :ref:`Structure Documentation` and
|
|
:ref:`Type Definition Documentation` for further details. |