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docs: sphinxify sparse.txt and move to dev-tools

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Fold the sparse document into the development tools set; no changes to the
text itself beyond formatting.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Jonathan Corbet 2016-08-07 15:09:14 -06:00
parent 4b9033a334
commit d228af5bcb
2 changed files with 25 additions and 15 deletions
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39
Documentation/sparse.txt → Documentation/dev-tools/sparse.rst
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@ -1,11 +1,20 @@
Copyright 2004 Linus Torvalds
Copyright 2004 Pavel Machek <pavel@ucw.cz>
Copyright 2006 Bob Copeland <me@bobcopeland.com>
.. Copyright 2004 Linus Torvalds
.. Copyright 2004 Pavel Machek <pavel@ucw.cz>
.. Copyright 2006 Bob Copeland <me@bobcopeland.com>
Sparse
======
Sparse is a semantic checker for C programs; it can be used to find a
number of potential problems with kernel code. See
https://lwn.net/Articles/689907/ for an overview of sparse; this document
contains some kernel-specific sparse information.
Using sparse for typechecking
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-----------------------------
"__bitwise" is a type attribute, so you have to do something like this:
"__bitwise" is a type attribute, so you have to do something like this::
typedef int __bitwise pm_request_t;
@ -20,13 +29,13 @@ but in this case we really _do_ want to force the conversion). And because
the enum values are all the same type, now "enum pm_request" will be that
type too.
And with gcc, all the __bitwise/__force stuff goes away, and it all ends
up looking just like integers to gcc.
And with gcc, all the "__bitwise"/"__force stuff" goes away, and it all
ends up looking just like integers to gcc.
Quite frankly, you don't need the enum there. The above all really just
boils down to one special "int __bitwise" type.
So the simpler way is to just do
So the simpler way is to just do::
typedef int __bitwise pm_request_t;
@ -50,7 +59,7 @@ __bitwise - noisy stuff; in particular, __le*/__be* are that. We really
don't want to drown in noise unless we'd explicitly asked for it.
Using sparse for lock checking
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
------------------------------
The following macros are undefined for gcc and defined during a sparse
run to use the "context" tracking feature of sparse, applied to
@ -69,22 +78,22 @@ annotation is needed. The tree annotations above are for cases where
sparse would otherwise report a context imbalance.
Getting sparse
~~~~~~~~~~~~~~
--------------
You can get latest released versions from the Sparse homepage at
https://sparse.wiki.kernel.org/index.php/Main_Page
Alternatively, you can get snapshots of the latest development version
of sparse using git to clone..
of sparse using git to clone::
git://git.kernel.org/pub/scm/devel/sparse/sparse.git
DaveJ has hourly generated tarballs of the git tree available at..
DaveJ has hourly generated tarballs of the git tree available at::
http://www.codemonkey.org.uk/projects/git-snapshots/sparse/
Once you have it, just do
Once you have it, just do::
make
make install
@ -92,7 +101,7 @@ Once you have it, just do
as a regular user, and it will install sparse in your ~/bin directory.
Using sparse
~~~~~~~~~~~~
------------
Do a kernel 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
@ -101,7 +110,7 @@ have already built it.
The optional make variable CF can be used to pass arguments to sparse. The
build system passes -Wbitwise to sparse automatically. To perform endianness
checks, you may define __CHECK_ENDIAN__:
checks, you may define __CHECK_ENDIAN__::
make C=2 CF="-D__CHECK_ENDIAN__"

1
Documentation/dev-tools/tools.rst
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@ -15,3 +15,4 @@ whole; patches welcome!
:maxdepth: 2
coccinelle
sparse