cxref(1)cxref(1)NAMEcxref - C Cross Referencing & Documenting tool.
SYNOPSIScxref filename [ ... filename] [-Odirname] [-Nbasename] [-Rbasename]
[-all-comments] [-no-comments] [-verbatim-comments] [-block-comments]
[-xref[-all][-file][-func][-var][-type]] [-warn[-all][-comment][-xref]]
[-index[-all][-file][-func][-var][-type]] [-raw] [-latex] [-html[-src]]
[-rtf] [-sgml] [-Idirname] [-Ddefine] [-Udefine] [-CPP cpp_program]
[-- cpp_args ... cpp_args]
cxref filename [ ... filename] -delete [-Odirname] [-Nbasename]
[-Rbasename]
DESCRIPTION
A program that can automatically generate documentation and cross ref‐
erences for a C program.
The input is any C program with appropriate comments and the output is
LaTeX, HTML, RTF or SGML files.
OPTIONS
filename
The name of the file to document, any number of files may be
documented at a time.
-delete
The files named are to be deleted from the output directory and
their entries in the cross reference database and main output
files are to be removed.
-Odirname
The name of a directory to use for the output latex files and
the location of the cross reference files that are created.
-Nbasename
The name to use for the first part of the output and cross ref‐
erence files instead of cxref, the file extensions remain the
same.
-Rdirname
When the source files are in more than one directory, set
dirname to the name of the root directory of the source tree
(use relative path if easier e.g. `-R../..'). This will then
run cxref from that root directory and the `-Odirname' must be
relative to that directory.
-all-comments
In case you think that the existing comments might work, (see
above for description of special comments). [Danger! This
option can produce weird results.]
-no-comments
Ignores all comments, useful if you just want the cross refer‐
ences and not the documentation.
-verbatim-comments
When the comments that you have in the code are formatted in a
predetermined style that you want to preserve on the output,
this option will force them not to be reformatted. [Note, this
is for file and function comments only.]
-block-comments
When the comments in the program are formatted in the `block'
style (with a leading '*' character on every line), this option
will remove that character from the output. [Works for a single
`*', `+', `|' or `:' on each line.]
-xref Produce cross referencing information (see below).
-all All cross references.
-file Cross references for files.
-func Cross references for functions.
-var Cross references for variables.
-type Cross references for types.
-warn Produce warnings, the options must be concatenated together:
-all All warnings.
-comment Warn of missing comments.
-xref Warn of missing cross references.
-index Produce a cross reference index, the options must be concate‐
nated together:
-all All indexes.
-file Index of files.
-func Index of functions.
-var Index of variables.
-type Index of types.
-raw Produce a raw form of output, not really of much use except with
-warn.
-latex Produce a LaTeX file to document each of the source files and
also an extra file that includes each of these files.
-html Produce an HTML 4.01 file to document each of the source files
and a main file to reference each of these files.
-html-src
Produce the HTML output and an HTML version of the source file
with links into it.
-rtf Produce a Rich Text Format (RTF) file to document the source
file.
-sgml Produce an SGML file to document the source file. (Using the
LinuxDoc DTD).
-Idirname
GCC option to specify the path for include files.
-Ddefine
GCC option to define a pre-processor symbol.
-Udefine
GCC option to undefine a pre-processor symbol.
-CPP program
The name of the program to use instead of the compile time
default. The program must be able to perform all of the actions
that `gcc -E -C -dD' does to work. If the program takes argu‐
ments then the whole thing needs to be in quotes so that it is
interpreted as a single argument to cxref.
--arg ... arg
Extra arguments to be passed to the pre-processor can be placed
after the `--' separator.
C Compiler Replacement cxref-cc
To simplify using cxref on existing source code, there is now a shell
script that will call the C compiler and then call cxref to process the
source file. This means that it can be used as a drop in replacement
for CC in Makefiles and the like.
Usage: cxref-cc [usual cc options]
The name of the source file is extracted from the list of options as
well as the `-D*', `-I*', `-U*' flags and when the C compiler exits
succesfully cxref will be called. The name of the C compiler to use is
controlled by the CXREFCC environment variable, or if this is not set
then the CC environment variable, or failing this just gcc.
Using this script requires the use of a `.cxref' configuration file to
contain the options since there is nowhere to put the options on the
command line for the C compiler.
This will only cross-reference and document the C source files since
they are the only ones that are compiled, but it will make sure that
they are cross-referenced with the correct options etc.
Cxref Configuration File
These command line arguments can also be put into a file named `.cxref'
instead of on the command line. When cxref is run the arguments to the
program are interpreted in the following order.
(1) Those on the command line. (2) Those in the `.cxref' file in the
current directory. (3) Those in the `.cxref' file in the source tree
root specified by `-R'.
This means that in a multi-directory source tree, each sub-directory
can have a `.cxref' file containing just the line `-R..' or appropri‐
ate. The main directory can have a `.cxref' file containing the
remainder of the options. This removes completely the need to have any
options on the command line apart from the source file names.
The format of the `.cxref' file is any number of lines, each one con‐
taining a single command line argument (equivalent to one of the argv).
The only options that cannot be used are the names of source files
themselves and the `-delete' option. Blank lines are ignored and lines
starting with a '#' are comments.
Program Documentation Comments
The documentation for the program is produced from comments in the code
that are appropriately formatted. The cross referencing comes from the
code itself and requires no extra work.
The special comments are `/**** ****/' (for a file) and `/*++++ ++++*/'
(for a data object) any number of `*' or `+' can be used inside of the
standard `/*' and `*/' comment delimiters in the comments, they are
ignored.
If a comment line starts with whitespace and is followed by `+html+'
then the rest of the line is included only in the HTML output, and is
not processed so it can include HTML markup, `-html-' means that the
rest of the line is included in all except the HTML output. The same
also applies to the other output formats, `+none+' can be used for
lines not to appear in any output. The exception to this is that the
raw output does not do any checking and will output all lines.
In any situation where a comment follows a `,', `;' or `)' separated
only by spaces and tabs, the comment is pushed to before the punctua‐
tion to apply to object there.
The program is implemented using a full ANSI C grammar parser with some
GCC extensions, this means that the style of the code is unimportant,
only the content and comments.
Cross Referencing
The cross referencing is performed for the following items
Files
The files that the current file is included in
(even when included via other files).
#includes
Files included in the current file.
Files included by these files etc.
Variables
The location of the definition of external variables.
The files that have visibility of global variables.
The files / functions that use the variable.
Functions
The file that the function is prototyped in.
The functions that the function calls.
The functions that call the function.
The files and functions that reference the function.
The variables that are used in the function.
Each of these items is cross referenced in the output.
The cross referencing uses files `cxref.variable', `cxref.function',
`cxref.include' and `cxref.typedef' in the output directory. These are
a complete list of the function and variable usage in the program and
could be used to generate a function call hierarchy or variable usage
diagram for example. Two cxref passes of each file is needed, the
first to build up the cross referencing files and the second to use
them.
(The file names are different if the `-N' option is used.)
LaTeX Output
The default LaTeX output is a file for each of the source files with
one extra file `cxref.tex' that includes each of the other files. This
is to allow a makefile to only update the changed files (although the
references may require all of the files to be checked again). When the
cxref.tex file has been written it can be modified by the user, any new
files that are added are added at the end of the source code section,
the rest of the file being unchanged.
The index is written to a file called `cxref.apdx.tex' and cxref.tex is
updated to refer to it.
Also written out are three LaTeX style files `page.sty', `fonts.sty'
and `cxref.sty'. These set up the page to use a smaller margin and
smaller fonts to allow more to appear on a page and also define the new
commands for typesetting the cxref output.
(The file names `cxref.tex' and `cxref.apdx.tex' are different if the
`-N' option is used.)
HTML Output
The default HTML output is a file for each of the source files with one
extra file `cxref.html' that includes each of the other files. This is
to allow a makefile to only update the changed files (although the ref‐
erences may require all of the files to be checked again). When the
cxref.html file has been written it can be modified by the user, any
new files that are added are added at the end before the table of con‐
tents, the rest of the file being unchanged.
The index is written to a file called `cxref.apdx.html' and cxref.html
is updated to refer to it.
(The file names `cxref.html' and `cxref.apdx.html' are different if the
`-N' option is used.)
The HTML output uses the HTML 4.01 standard and all pages validate cor‐
rectly.
RTF Output
Rich Text Format is a fairly low level page description format devised
by Microsoft. It is not a well defined and easy to understand standard
as are the other formats, but it is popular for document exchange.
There is a single output file for each of the source files and an index
file.
SGML Output
Since SGML is a meta-language it is necessary to define the layout ele‐
ments as well as provide the information. The cxref output uses the
LinuxDoc document format and is designed for use with the SGMLtools
programs (http://www.sgmltools.org/).
There is a single output file for each of the source files and an index
file.
SEE ALSO
The files that come with the cxref source code distribution give more
information. The README file gives examples of how to use the comments
in source code. There is a list of frequently asked questions and
their answers for the cxref program in the FAQ file. A list of
improvements planned for future versions of the program are listed in
the file TODO.
More up-to-date information can be found on the cxref homepage
http://www.gedanken.org.uk/software/cxref/.
AUTHOR
The cxref program was written by Andrew M. Bishop in 1995-2004.
The cxref program is copyright Andrew M. Bishop 1995-2004.
The cxref-cpp program is copyright Free Software Foundation, Inc.
The cxref and cxref-cpp programs can be freely distributed according to
the terms of the GNU General Public License (see the file `COPYING').
June 15 2004 cxref(1)
