crcpp
A CRC preprocessor: inserts CRC-32 checksums into C or C++ code.

1. Status

I've tried this on Windows and Mac platforms.  It may even compile on others.

2. Download and Source Repository

The source and executables are available on my github.com page:
http://github.com/zach/crcpp

Here is a direct link to a .zip archive of the current release:
http://github.com/zach/crcpp/zipball/master

3. Installing from source

A Win32 executable as well as a directly-compilable .c version is available at the repository.

On other platforms, you'll need to install from source, using Ragel:

http://www.cs.queensu.ca/~thurston/ragel/

And you'll need zlib if you don't have it already available:

http://zlib.net/

Use Ragel to compile crcpp.rl into crcpp.c:

    ragel crcpp.rl

Then compile the resulting .c file with the zlib library, for instance like so:

    gcc -o crcpp crcpp.c -lz

3. License

The files in this project are licensed under an MIT-style license as explained in
the LICENSE file.

4. Rationale

I know that it isn't so hard to do this in Perl or a similar language.  As an example
of a very flexible cpp replacement in Perl, the filepp project is worth looking at.

But Ragel compiled to C produces a very fast executable.  For a tool designed to run
on every file in a very large project before it is compiled, that is essential.

Finally, this preprocessor has the very-appreciated functionality that it will leave
a file alone (not write or touch it at all) if no updates need to be made.  Not only
does that account for the overwhelming majority of cases in which it's used (and so
spare the disk access that would otherwise occur), it also keeps your source control
and dates correct on the source files it's used on.

4. Limitations

String concatenation (a string broken up into multiple strings separated by newline)
do not work.  However, escaped newlines should.

Errors are hardly reported on.

If you put anything besides a hex number in the place of the CRC value, it will not be
updated or flagged for an error.

5. Possibilities for Modification

This source can easily be adapted to do other tasks, like different hash algorithms,
checking with an external list to detect hash collisions, or more elaborate things
such as flexible name-to-asset mapping or lookups into an asset database.

6. Contact

Please email me at [email protected] if you have any questions or suggestions.

-- Zach Baker.