Add Cyclomatic complexity GCC plugin

Add a very simple plugin to demonstrate the GCC plugin infrastructure. This GCC
plugin computes the cyclomatic complexity of each function.

The complexity M of a function's control flow graph is defined as:
M = E - N + 2P
where
E = the number of edges
N = the number of nodes
P = the number of connected components (exit nodes).

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michal Marek <mmarek@suse.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 1b93632198fa..04ca45262ad1 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -372,6 +372,18 @@ menuconfig GCC_PLUGINS
 
           See Documentation/gcc-plugins.txt for details.
 
+config GCC_PLUGIN_CYC_COMPLEXITY
+        bool "Compute the cyclomatic complexity of a function"
+        depends on GCC_PLUGINS
+        help
+          The complexity M of a function's control flow graph is defined as:
+           M = E - N + 2P
+          where
+
+          E = the number of edges
+          N = the number of nodes
+          P = the number of connected components (exit nodes).
+
 config HAVE_CC_STACKPROTECTOR
         bool
         help