scripts/gcc-plugins/cyc_complexity_plugin.c

   1 /*
   2  * Copyright 2011-2016 by Emese Revfy <re.emese@gmail.com>
   3  * Licensed under the GPL v2, or (at your option) v3
   4  *
   5  * Homepage:
   6  * https://github.com/ephox-gcc-plugins/cyclomatic_complexity
   7  *
   8  * https://en.wikipedia.org/wiki/Cyclomatic_complexity
   9  * The complexity M is then defined as:
  10  * M = E - N + 2P
  11  * where
  12  *
  13  *  E = the number of edges of the graph
  14  *  N = the number of nodes of the graph
  15  *  P = the number of connected components (exit nodes).
  16  *
  17  * Usage (4.5 - 5):
  18  * $ make clean; make run
  19  */
  20
  21 #include "gcc-common.h"
  22
  23 __visible int plugin_is_GPL_compatible;
  24
  25 static struct plugin_info cyc_complexity_plugin_info = {
  26         .version        = "20160225",
  27         .help           = "Cyclomatic Complexity\n",
  28 };
  29
  30 static unsigned int cyc_complexity_execute(void)
  31 {
  32         int complexity;
  33         expanded_location xloc;
  34
  35         /* M = E - N + 2P */
  36         complexity = n_edges_for_fn(cfun) - n_basic_blocks_for_fn(cfun) + 2;
  37
  38         xloc = expand_location(DECL_SOURCE_LOCATION(current_function_decl));
  39         fprintf(stderr, "Cyclomatic Complexity %d %s:%s\n", complexity,
  40                 xloc.file, DECL_NAME_POINTER(current_function_decl));
  41
  42         return 0;
  43 }
  44
  45 #define PASS_NAME cyc_complexity
  46
  47 #define NO_GATE
  48 #define TODO_FLAGS_FINISH TODO_dump_func
  49
  50 #include "gcc-generate-gimple-pass.h"
  51
  52 __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
  53 {
  54         const char * const plugin_name = plugin_info->base_name;
  55
  56         PASS_INFO(cyc_complexity, "ssa", 1, PASS_POS_INSERT_AFTER);
  57
  58         if (!plugin_default_version_check(version, &gcc_version)) {
  59                 error(G_("incompatible gcc/plugin versions"));
  60                 return 1;
  61         }
  62
  63         register_callback(plugin_name, PLUGIN_INFO, NULL,
  64                                 &cyc_complexity_plugin_info);
  65         register_callback(plugin_name, PLUGIN_PASS_MANAGER_SETUP, NULL,
  66                                 &cyc_complexity_pass_info);
  67
  68         return 0;
  69 }