Add a module dependency check tool.

This calculates dependencies for modules and then tries to link them
against the kernel to see if there are any missing symbols, and might
reveal if you are missing dependencies or spelled something wrong. Due
to the way the current module build system works, this hasn't been
integrated into the Makefile yet.

util/mod_deps.py

@@ -0,0 +1,72 @@
+#!/usr/bin/env python2
+# coding: utf-8
+"""
+Extract dependencies from kernel modules.
+"""
+
+import os
+import sys
+import subprocess
+
+def processModule(path):
+    p = subprocess.Popen(["i686-pc-toaru-nm",path,"-p"], stdout=subprocess.PIPE)
+    symbols, errors = p.communicate()
+    name = [ x[2].replace("module_info_","") for x in [x.strip().split(" ") for x in symbols.split("\n") if len(x.strip().split(" ")) > 2] if x[1] == "D" and x[2].startswith("module_info_") ][0]
+    dependencies = [ x[2].replace("_mod_dependency_","") for x in [x.strip().split(" ") for x in symbols.split("\n") if len(x.strip().split(" ")) > 2] if x[1] == "d" and x[2].startswith("_mod_dependency_") ]
+    return path, name, dependencies
+
+modules = {}
+files = {}
+
+# Read the symbols from the file.
+for module in os.listdir("hdd/mod"):
+    if module.endswith(".ko"):
+        path,name,deps = processModule("hdd/mod/" + module)
+        modules[name] = (path,deps)
+        files[path] = name
+
+# Okay, now let's spit out the dependencies for our module.
+if len(sys.argv) < 2:
+    print >>sys.stderr, "Expected a path to a module (from the root of the build tree), eg. hdd/mod/test.ko"
+    sys.exit(1)
+
+me = sys.argv[-1]
+name = files[me]
+deps = modules[name][1]
+
+def calculate(depends, new):
+    for k in new:
+        if not k in depends:
+            depends.append(k)
+            _, other = modules[k]
+            depends = calculate(depends, other)
+    return depends
+
+depends = calculate([], deps)
+
+satisfied = []
+a = depends[:]
+
+while set(satisfied) != set(depends):
+    b = []
+    for k in a:
+        if all([x in satisfied for x in modules[k][1]]):
+            satisfied.append(k)
+        else:
+            b.append(k)
+    a = b[:]
+
+if len(sys.argv) > 2:
+    for i in sys.argv[1:-1]:
+        if i == '--print-deps':
+            print name, "→", " ".join(["\033[31m{mod}\033[m".format(mod=x) if not x in deps else x for x in satisfied])
+
+        if i == '--print-files':
+            for i in satisfied:
+                print modules[i][0], "(dep-of-dep)" if i not in deps else ""
+
+
+p = subprocess.Popen(["i686-pc-toaru-ld","-T","kernel/link.ld","-o","/dev/null","toaruos-kernel",]+[modules[x][0] for x in satisfied]+[me])
+sys.exit(p.wait())
+
+