The ucw documentation system is based on the ASCIIDOC documentation formatter. It supports all it’s markup, but it was extended slightly.

Markup extensions

Cross referencing

ASCIIDOC supports creating anchors with \[[anchor-name]] and links to them with \<<anchor,caption>>. The extension supports links to anchor in other files (\\<<filename:anchor,caption>>) or to other files (\\<<filename:,caption>>). The filename is without any suffix like .txt or .html, it is added to the link automatically. The caption is optional, if you omit it, some reasonable one will be guessed from the anchor name.

The links support linking to function descriptions (the anchors for them are generated automatically by header extraction). Just write \<<function(),caption>> or \\<<filename:function(),caption>>.

Symbol formatting

If you talk about function parameter, prefix its name with @. It will be typeset in monospace italic font to mark it visually, like this: parameter.

If a word is suffixed by parenthesis without a space (eg. word()), it is considered to be a function name and is typeset in monospace font.

You can prefix a function name by @, which makes it a link to that function (\@function() is equivalent to \<<function()>>).

If you write NULL anywhere, it is recognized and typeset in monospace.

Header extraction

Line starting with two exclamation marks, followed by a filename, is a command to process source file. Special comments and commented declarations are extracted and included in the place of the command.

The command looks like this:


Stand-alone comments

C comments with tripled asterisks are extracted, the left side asterisk decoration is removed and the rest is put trough verbatim.

Single-line version looks like

/*** This will be put into documentation. ***/

If you need more than one line, use the same type of comment.

 * This is part of documentation too.
 * But the asterisks on the left side aren't.

Definition comments

You can write comments documenting specific definition. Definition comment has the asterisks doubled. The multi-line version must be directly above the definition, the single-line on the same line right of the definition or on a line before.

void function(int parameter);  /** This is a function. **/


/** This is a function. **/
void function(int parameter);


 * This is a complicated function.
 * It takes multiple lines to describe how useful it is.
void function(int parameter);

Each such commented definition is taken and formatted, with the description attached. It also generates an anchor for the symbol name. The anchors look like symboltype_symbolname. The symbol types are these:

  • fun for functions

  • def for preprocessor macro

  • var for variable

  • struct for structure

  • enum for enumeration

  • type for a type definition

There is a support for building a page with list of all symbols with links to them. Look into ucw/doc/Makefile to see how to request that.

Support for macro generics

Some of the headers contain macro generics. Since the preprocessor macros look somewhat weird, the documentation extractor needs some help to understand them.

Extraction of generics

When extracting info from some header, the extractor needs to know, which prefix macros are used in the source file, to distinguish them from function calls. To inform it about them, append a comma separated list of such macros to the extraction command, like this:


Then this will be correctly identified as a structure:

struct PREFIX_MACRO_ONE(struct_name) {

Since the anchors for them are generated in a complicated manner and typing them in plain-text would convert them back to the original, with real parenthesis, there is a special pattern to create the symbolname part of the anchor. It looks like:


So link to the above structure would look like:

<<struct__GENERIC_LINK_|PREFIX_MACRO_ONE|struct_name|,link text>>

However, this is implemented only in the included header files (if it is needed, it will be implemented in the top-level documentation files too).