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