How to documenting global dependencies for functions? - c

Question

I've got some C code from a 3rd party vendor (for an embedded platform) that uses global variables (for speed & space optimizations). I'm documenting the code, converting to Doxygen format.
How do I put a note in the function documentation that the function requires on global variables and functions?
Doxygen has special commands for annotating parameters and return values as describe here: Doxygen Special Commands. I did not see any commands for global variables.
Example C code:
extern unsigned char data_buffer[]; //!< Global variable.
/*! Returns the next available data byte.
* \return Next data byte.
*/
unsigned char Get_Byte(void)
{
static unsigned int index = 0;
return data_buffer[index++]; //!< Uses global variable.
}
In the above code, I would like to add Doxygen comments that the function depends on the global variable data_buffer.

Answer 1

You can just add a note to that effect and use the \link directive to direct the reader to the description of the global variable.

Answer 2

Doxygen could do with an #global command to complement #param. Until that day arrives you could approximate it with aliases.
In your Doxygen configuration file add the following aliases:
ALIASES += global_START="<dl class=\"params\"><dt>Globals</dt><dd><table class=\"params\">"
ALIASES += global_{2}="<tr><td class=\"paramname\">\1</td><td>: \2</td></tr>"
ALIASES += global_END="</table></dd></dl>"
Example of usage:
int fxnMAIN_Main(void)
{
/**
* #brief Bla Bla Bla.
*
* #global_START
* #global_{bExampleOne, Description Here}
* #global_{bExampleTwo, Second Description Here}
* #global_END
*
* #retval int : Bla Bla Bla.
*/
// Code Here
}