kernel: add python script to generate init dependency graph

gen_dep_graph.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+# Generates a graph of the Kernel's init dependencies
+
+import os
+import subprocess
+from matplotlib import pyplot as plt
+import networkx as nx
+from networkx.drawing.nx_agraph import graphviz_layout
+
+path = os.path.abspath(__file__)
+kernel_source = os.path.dirname(path) + '/kernel-src'
+
+routine_dependencies = {}
+
+lines = subprocess.Popen(['grep', '-R', 'INIT_ROUTINE_DEFINE(', kernel_source], stdout=subprocess.PIPE).stdout.readlines()
+
+for line in lines:
+    if b"#define" in line:
+        continue
+
+    line = line.strip()
+
+    junk, line = line.split(b'(')
+
+    line = line.replace(b';', b'').replace(b')', b'')
+
+    if line.count(b',') > 2:
+        name, flags, function, dependencies = line.split(b',', 3)
+    else:
+        # no dependencies
+        name, flags, function = line.split(b',', 2)
+        dependencies = b''
+
+    name = name.strip().decode('utf-8')
+    routine_dependencies[name] = []
+
+    dependencies = dependencies.split(b',')
+
+    for dep in dependencies:
+        dep = dep.strip().decode('utf-8')
+        if dep == '':
+            continue
+
+        routine_dependencies[name].insert(0, dep)
+
+for routine in routine_dependencies:
+    print("routine '", routine, "' has dependencies: ", end='', sep='')
+    dependencies = routine_dependencies[routine]
+    print(dependencies)
+
+# plot
+
+graph = nx.DiGraph()
+
+graph.add_nodes_from(routine_dependencies.keys())
+
+edges = []
+for routine in routine_dependencies:
+    for dep in routine_dependencies[routine]:
+        edges.insert(0, (dep, routine))
+
+graph.add_edges_from(edges)
+
+plt.figure(figsize=(20, 16))
+
+pos = graphviz_layout(graph, prog='dot')
+nx.draw(graph, pos, with_labels=True, node_size=3000)
+plt.title("Kernel init dependencies")
+plt.savefig('graph_kernel_deps.png')
+
+print("File saved in graph_kernel_deps.png")