This document describes how to use the sparse source code checking tool
to check the source code of the open source XFS commands and utilites
("xfsprogs").

First you need to install sparse, either from your distribution or from
source as provided at http://www.kernel.org/pub/software/devel/sparse/.

Then, run make with "make C=1" to run sparse on all the C files that get
recompiled, or use "make C=2" to run sparse on the files whether they need to
be recompiled or not.  The latter is a fast way to check the whole tree if you
have already built it.

See the top-level Makefile for a list of which sparse flags are enabled.

If you'd rather run sparse more manually, just set the compiler to cgcc,
which is a wrapper that calls both sparse and gcc using:

	CC=cgcc ./configure

Now that default warnings from sparse are a little bit verbose checking
for various not that important things and also complaining about the
glibc system headers.  It does however not check for bitwise annotation
which are very important for xfsprogs to verify the endianess handling
of the on-disk structures is correct.  To get a more reasonable set
of warnings build xfsprogs using:

	LCFLAGS="-Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl" make

You are of course free to experiment with the warnings flags documented
in the sparse manpage to check xfsprogs for other issues.