1 files changed, 115 insertions, 0 deletions
diff --git a/scripts/maint/checkIncludes.py b/scripts/maint/checkIncludes.py
new file mode 100755
index 0000000000..46a3f39638
--- /dev/null
+++ b/scripts/maint/checkIncludes.py
@@ -0,0 +1,115 @@
+#!/usr/bin/python3
+# Copyright 2018 The Tor Project, Inc.  See LICENSE file for licensing info.
+
+"""This script looks through all the directories for files matching *.c or
+   *.h, and checks their #include directives to make sure that only "permitted"
+   headers are included.
+
+   Any #include directives with angle brackets (like #include <stdio.h>) are
+   ignored -- only directives with quotes (like #include "foo.h") are
+   considered.
+
+   To decide what includes are permitted, this script looks at a .may_include
+   file in each directory.  This file contains empty lines, #-prefixed
+   comments, filenames (like "lib/foo/bar.h") and file globs (like lib/*/*.h)
+   for files that are permitted.
+"""
+
+
+from __future__ import print_function
+
+import fnmatch
+import os
+import re
+import sys
+
+# Global: Have there been any errors?
+trouble = False
+
+if sys.version_info[0] <= 2:
+    def open_file(fname):
+        return open(fname, 'r')
+else:
+    def open_file(fname):
+        return open(fname, 'r', encoding='utf-8')
+
+def err(msg):
+    """ Declare that an error has happened, and remember that there has
+        been an error. """
+    global trouble
+    trouble = True
+    print(msg, file=sys.stderr)
+
+def fname_is_c(fname):
+    """ Return true iff 'fname' is the name of a file that we should
+        search for possibly disallowed #include directives. """
+    return fname.endswith(".h") or fname.endswith(".c")
+
+INCLUDE_PATTERN = re.compile(r'\s*#\s*include\s+"([^"]*)"')
+RULES_FNAME = ".may_include"
+
+class Rules(object):
+    """ A 'Rules' object is the parsed version of a .may_include file. """
+    def __init__(self, dirpath):
+        self.dirpath = dirpath
+        self.patterns = []
+        self.usedPatterns = set()
+
+    def addPattern(self, pattern):
+        self.patterns.append(pattern)
+
+    def includeOk(self, path):
+        for pattern in self.patterns:
+            if fnmatch.fnmatchcase(path, pattern):
+                self.usedPatterns.add(pattern)
+                return True
+        return False
+
+    def applyToLines(self, lines, context=""):
+        lineno = 0
+        for line in lines:
+            lineno += 1
+            m = INCLUDE_PATTERN.match(line)
+            if m:
+                include = m.group(1)
+                if not self.includeOk(include):
+                    err("Forbidden include of {} on line {}{}".format(
+                        include, lineno, context))
+
+    def applyToFile(self, fname):
+        with open_file(fname) as f:
+            #print(fname)
+            self.applyToLines(iter(f), " of {}".format(fname))
+
+    def noteUnusedRules(self):
+        for p in self.patterns:
+            if p not in self.usedPatterns:
+                print("Pattern {} in {} was never used.".format(p, self.dirpath))
+
+def load_include_rules(fname):
+    """ Read a rules file from 'fname', and return it as a Rules object. """
+    result = Rules(os.path.split(fname)[0])
+    with open_file(fname) as f:
+        for line in f:
+            line = line.strip()
+            if line.startswith("#") or not line:
+                continue
+            result.addPattern(line)
+    return result
+
+list_unused = False
+
+for dirpath, dirnames, fnames in os.walk("src"):
+    if ".may_include" in fnames:
+        rules = load_include_rules(os.path.join(dirpath, RULES_FNAME))
+        for fname in fnames:
+            if fname_is_c(fname):
+                rules.applyToFile(os.path.join(dirpath,fname))
+        if list_unused:
+            rules.noteUnusedRules()
+
+if trouble:
+    err(
+"""To change which includes are allowed in a C file, edit the {}
+files in its enclosing directory.""".format(RULES_FNAME))
+    sys.exit(1)