tools/lint/libpref/__init__.py

   1 # -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
   2 # vim: set filetype=python:
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 import re
   8 import sys
   9
  10 import yaml
  11 from mozlint import result
  12 from mozlint.pathutils import expand_exclusions
  13
  14 # This simple linter checks for duplicates from
  15 # modules/libpref/init/StaticPrefList.yaml against modules/libpref/init/all.js
  16
  17 # If for any reason a pref needs to appear in both files, add it to this set.
  18 IGNORE_PREFS = {
  19     "devtools.console.stdout.chrome",  # Uses the 'sticky' attribute.
  20     "devtools.console.stdout.content",  # Uses the 'sticky' attribute.
  21     "fission.autostart",  # Uses the 'locked' attribute.
  22     "browser.dom.window.dump.enabled",  # Uses the 'sticky' attribute.
  23     "apz.fling_curve_function_y2",  # This pref is a part of a series.
  24     "dom.postMessage.sharedArrayBuffer.bypassCOOP_COEP.insecure.enabled",  # NOQA: E501; Uses the 'locked' attribute.
  25     "extensions.backgroundServiceWorkerEnabled.enabled",  # NOQA: E501; Uses the 'locked' attribute.
  26 }
  27 PATTERN = re.compile(r"\s*pref\(\s*\"(?P<pref>.+)\"\s*,\s*(?P<val>.+)\)\s*;.*")
  28
  29
  30 def get_names(pref_list_filename):
  31     pref_names = {}
  32     # We want to transform patterns like 'foo: @VAR@' into valid yaml. This
  33     # pattern does not happen in 'name', so it's fine to ignore these.
  34     # We also want to evaluate all branches of #ifdefs for pref names, so we
  35     # ignore anything else preprocessor related.
  36     file = open(pref_list_filename, encoding="utf-8").read().replace("@", "")
  37     try:
  38         pref_list = yaml.safe_load(file)
  39     except (IOError, ValueError) as e:
  40         print("{}: error:\n  {}".format(pref_list_filename, e), file=sys.stderr)
  41         sys.exit(1)
  42
  43     for pref in pref_list:
  44         if pref["name"] not in IGNORE_PREFS:
  45             pref_names[pref["name"]] = pref["value"]
  46
  47     return pref_names
  48
  49
  50 # Check the names of prefs against each other, and if the pref is a duplicate
  51 # that has not previously been noted, add that name to the list of errors.
  52 def check_against(path, pref_names):
  53     errors = []
  54     prefs = read_prefs(path)
  55     for pref in prefs:
  56         if pref["name"] in pref_names:
  57             errors.extend(check_value_for_pref(pref, pref_names[pref["name"]], path))
  58     return errors
  59
  60
  61 def check_value_for_pref(some_pref, some_value, path):
  62     errors = []
  63     if some_pref["value"] == some_value:
  64         errors.append(
  65             {
  66                 "path": path,
  67                 "message": some_pref["raw"],
  68                 "lineno": some_pref["line"],
  69                 "hint": "Remove the duplicate pref or add it to IGNORE_PREFS.",
  70                 "level": "error",
  71             }
  72         )
  73     return errors
  74
  75
  76 # The entries in the *.js pref files are regular enough to use simple pattern
  77 # matching to load in prefs.
  78 def read_prefs(path):
  79     prefs = []
  80     with open(path, encoding="utf-8") as source:
  81         for lineno, line in enumerate(source, start=1):
  82             match = PATTERN.match(line)
  83             if match:
  84                 prefs.append(
  85                     {
  86                         "name": match.group("pref"),
  87                         "value": evaluate_pref(match.group("val")),
  88                         "line": lineno,
  89                         "raw": line,
  90                     }
  91                 )
  92     return prefs
  93
  94
  95 def evaluate_pref(value):
  96     bools = {"true": True, "false": False}
  97     if value in bools:
  98         return bools[value]
  99     elif value.isdigit():
 100         return int(value)
 101     return value
 102
 103
 104 def checkdupes(paths, config, **kwargs):
 105     results = []
 106     errors = []
 107     pref_names = get_names(config["support-files"][0])
 108     files = list(expand_exclusions(paths, config, kwargs["root"]))
 109     for file in files:
 110         errors.extend(check_against(file, pref_names))
 111     for error in errors:
 112         results.append(result.from_config(config, **error))
 113     return results