linux_dsm_epyc7002/scripts/gcc-plugins/cyc_complexity_plugin.c
Emese Revfy 0dae776c6b 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>
2016-06-07 22:57:10 +02:00

74 lines
1.9 KiB
C

/*
* Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com>
* Licensed under the GPL v2, or (at your option) v3
*
* Homepage:
* https://github.com/ephox-gcc-plugins/cyclomatic_complexity
*
* http://en.wikipedia.org/wiki/Cyclomatic_complexity
* The complexity M is then defined as:
* M = E - N + 2P
* where
*
* E = the number of edges of the graph
* N = the number of nodes of the graph
* P = the number of connected components (exit nodes).
*
* Usage (4.5 - 5):
* $ make clean; make run
*/
#include "gcc-common.h"
int plugin_is_GPL_compatible;
static struct plugin_info cyc_complexity_plugin_info = {
.version = "20160225",
.help = "Cyclomatic Complexity\n",
};
static unsigned int cyc_complexity_execute(void)
{
int complexity;
expanded_location xloc;
/* M = E - N + 2P */
complexity = n_edges_for_fn(cfun) - n_basic_blocks_for_fn(cfun) + 2;
xloc = expand_location(DECL_SOURCE_LOCATION(current_function_decl));
fprintf(stderr, "Cyclomatic Complexity %d %s:%s\n", complexity,
xloc.file, DECL_NAME_POINTER(current_function_decl));
return 0;
}
#define PASS_NAME cyc_complexity
#define NO_GATE
#define TODO_FLAGS_FINISH TODO_dump_func
#include "gcc-generate-gimple-pass.h"
int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
{
const char * const plugin_name = plugin_info->base_name;
struct register_pass_info cyc_complexity_pass_info;
cyc_complexity_pass_info.pass = make_cyc_complexity_pass();
cyc_complexity_pass_info.reference_pass_name = "ssa";
cyc_complexity_pass_info.ref_pass_instance_number = 1;
cyc_complexity_pass_info.pos_op = PASS_POS_INSERT_AFTER;
if (!plugin_default_version_check(version, &gcc_version)) {
error(G_("incompatible gcc/plugin versions"));
return 1;
}
register_callback(plugin_name, PLUGIN_INFO, NULL,
&cyc_complexity_plugin_info);
register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL,
&cyc_complexity_pass_info);
return 0;
}