1 Smatch
   2 
   3 1.  Building Smatch
   4 2.  Using Smatch
   5 3.  Smatch vs Sparse
   6 
   7 
   8 Section 1:  Building Smatch
   9 ---------------------------
  10 
  11 Smatch requires sqlite3.  It requires the binaries and the C, Perl and
  12 Python libraries for sqlite3.
  13 
  14 apt-get install sqlite3 libsqlite3-dev libdbd-sqlite3-perl
  15 
  16 Smatch is easy to build.  Just type `make`.  There isn't an install process
  17 right now so just run it from the build directory.
  18 
  19 
  20 Section 2:  Using Smatch
  21 ------------------------
  22 
  23 Smatch can be used with a cross function database. It's not mandatory to
  24 build the database but it's a useful thing to do.  Building the database
  25 for the kernel takes 2-3 hours on my computer.  For the kernel you build
  26 the database with:
  27 
  28         cd ~/path/to/kernel_dir
  29         ~/path/to/smatch_dir/smatch_scripts/build_kernel_data.sh
  30 
  31 For projects other than the kernel you run Smatch with the options
  32 "--call-tree --info --param-mapper --spammy" and finish building the
  33 database by running the script:
  34 
  35         ~/progs/smatch/devel/smatch_data/db/create_db.sh
  36 
  37 Each time you rebuild the cross function database it becomes more accurate. I
  38 normally rebuild the database every morning.
  39 
  40 If you are running Smatch over the whole kernel you can use the following
  41 command:
  42 
  43         ~/progs/smatch/devel/smatch_scripts/test_kernel.sh
  44 
  45 The test_kernel.sh script will create a .c.smatch file for every file it tests
  46 and a combined smatch_warns.txt file with all the warnings.
  47 
  48 If you are running Smatch just over one kernel file:
  49 
  50         ~/progs/smatch/devel/smatch_scripts/kchecker drivers/whatever/file.c
  51 
  52 You can also build a directory like this:
  53 
  54         ~/progs/smatch/devel/smatch_scripts/kchecker drivers/whatever/
  55 
  56 The kchecker script prints its warnings to stdout.
  57 
  58 The above scripts will ensure that any ARCH or CROSS_COMPILE environment
  59 variables are passed to kernel build system - thus allowing for the use of
  60 Smatch with kernels that are normally built with cross-compilers.
  61 
  62 If you are building something else (which is not the Linux kernel) then use
  63 something like:
  64 
  65         make CHECK="~/progs/smatch/devel/smatch --full-path" \
  66                 CC=~/progs/smatch/devel/smatch/cgcc | tee smatch_warns.txt
  67 
  68 The makefile has to let people set the CC with an environment variable for that
  69 to work, of course.
  70 
  71 
  72 Section 3:  Smatch vs Sparse
  73 ----------------------------
  74 
  75 Smatch uses Sparse as a C parser.  I have made a few hacks to Sparse so I
  76 have to distribute the two together.  Sparse is released under the MIT license
  77 and Smatch is GPLv2+.  If you make changes to Sparse please send those to the
  78 Sparse mailing list linux-sparse@vger.kernel.org and I will pick them up from
  79 there.  Partly I do that for licensing reasons because I don't want to pull GPL
  80 changes into the Sparse code I re-distribute.
  81