Skip to main content

Commenting And Documentation

Geoffrey Hunter Author

General Tips

  • Always use \\ style comments where possible. This allows you to use /* style comments for commenting out large blocks of code when debugging. If you want to comment a block of code which has /* comments inside it, you will run into problems! (unfortunately, */ style comments don't nest in c).
  • However, sometimes you still need to comment out blocks of code which have /* comments already inside them (maybe your using someone elses code?). To do this, you can use the preprocessor trick #if 0 (see code below).
// This is a single lined comment, and the preferred way of doing things

/* This is
a multilined
And should be used sparingly as these don't nest */

// The following example shows how you can comment out code blocks
// containing "/*" comments using the pre-processor and "#if 0"
#if 0
void test1()
/* Annoying multi-line
comment in a block
of code you want to comment */
#endif // #if 0

C Supports URL's, Wait What?

Did you know that:

is valid syntax in C? Wait, what? O.K., I was lying, C doesn't support URLs, but the syntax is still valid! What it actually represents is a label (http:), followed by a single-line comment (//

Commenting Styles

Some people put function descriptions after the function name and parameters, and before the opening curly brace (for example, some windows driver files). I find this method weird and hard to read.


Routine Description:

Installable driver initialization entry point.
This entry point is called directly by the I/O system.


DriverObject - pointer to the driver object

RegistryPath - pointer to a unicode string representing the path,
to driver-specific key in the registry.

Return Value:

STATUS_SUCCESS if successful,

NTSTATUS status;

rest of function code...


Doxygen is a powerful documentation generator that can be used with the C language. For more information and code examples with Doxygen, go to the Doxygen page.