#!/usr/bin/env python
# Copyright (C) 2014 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the 'License');
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an 'AS IS' BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Enforces common Android public API design patterns. It ignores lint messages from
a previous API level, if provided.
Usage: apilint.py current.txt
Usage: apilint.py current.txt previous.txt
You can also splice in blame details like this:
$ git blame api/current.txt -t -e > /tmp/currentblame.txt
$ apilint.py /tmp/currentblame.txt previous.txt --no-color
"""
import re, sys, collections, traceback
BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(8)
def format(fg=None, bg=None, bright=False, bold=False, dim=False, reset=False):
# manually derived from http://en.wikipedia.org/wiki/ANSI_escape_code#Codes
if "--no-color" in sys.argv: return ""
codes = []
if reset: codes.append("0")
else:
if not fg is None: codes.append("3%d" % (fg))
if not bg is None:
if not bright: codes.append("4%d" % (bg))
else: codes.append("10%d" % (bg))
if bold: codes.append("1")
elif dim: codes.append("2")
else: codes.append("22")
return "\033[%sm" % (";".join(codes))
class Field():
def __init__(self, clazz, raw, blame):
self.clazz = clazz
self.raw = raw.strip(" {;")
self.blame = blame
raw = raw.split()
self.split = list(raw)
for r in ["field", "volatile", "transient", "public", "protected", "static", "final", "deprecated"]:
while r in raw: raw.remove(r)
self.typ = raw[0]
self.name = raw[1].strip(";")
if len(raw) >= 4 and raw[2] == "=":
self.value = raw[3].strip(';"')
else:
self.value = None
self.ident = self.raw.replace(" deprecated ", " ")
def __repr__(self):
return self.raw
class Method():
def __init__(self, clazz, raw, blame):
self.clazz = clazz
self.raw = raw.strip(" {;")
self.blame = blame
# drop generics for now
raw = re.sub("<.+?>", "", raw)
raw = re.split("[\s(),;]+", raw)
for r in ["", ";"]:
while r in raw: raw.remove(r)
self.split = list(raw)
for r in ["method", "public", "protected", "static", "final", "deprecated", "abstract"]:
while r in raw: raw.remove(r)
self.typ = raw[0]
self.name = raw[1]
self.args = []
for r in raw[2:]:
if r == "throws": break
self.args.append(r)
# identity for compat purposes
ident = self.raw
ident = ident.replace(" deprecated ", " ")
ident = ident.replace(" synchronized ", " ")
ident = re.sub("<.+?>", "", ident)
if " throws " in ident:
ident = ident[:ident.index(" throws ")]
self.ident = ident
def __repr__(self):
return self.raw
class Class():
def __init__(self, pkg, raw, blame):
self.pkg = pkg
self.raw = raw.strip(" {;")
self.blame = blame
self.ctors = []
self.fields = []
self.methods = []
raw = raw.split()
self.split = list(raw)
if "class" in raw:
self.fullname = raw[raw.index("class")+1]
elif "interface" in raw:
self.fullname = raw[raw.index("interface")+1]
else:
raise ValueError("Funky class type %s" % (self.raw))
if "extends" in raw:
self.extends = raw[raw.index("extends")+1]
else:
self.extends = None
self.fullname = self.pkg.name + "." + self.fullname
self.name = self.fullname[self.fullname.rindex(".")+1:]
def __repr__(self):
return self.raw
class Package():
def __init__(self, raw, blame):
self.raw = raw.strip(" {;")
self.blame = blame
raw = raw.split()
self.name = raw[raw.index("package")+1]
def __repr__(self):
return self.raw
def parse_api(fn):
api = {}
pkg = None
clazz = None
blame = None
re_blame = re.compile("^([a-z0-9]{7,}) \(<([^>]+)>.+?\) (.+?)$")
with open(fn) as f:
for raw in f.readlines():
raw = raw.rstrip()
match = re_blame.match(raw)
if match is not None:
blame = match.groups()[0:2]
raw = match.groups()[2]
else:
blame = None
if raw.startswith("package"):
pkg = Package(raw, blame)
elif raw.startswith(" ") and raw.endswith("{"):
clazz = Class(pkg, raw, blame)
api[clazz.fullname] = clazz
elif raw.startswith(" ctor"):
clazz.ctors.append(Method(clazz, raw, blame))
elif raw.startswith(" method"):
clazz.methods.append(Method(clazz, raw, blame))
elif raw.startswith(" field"):
clazz.fields.append(Field(clazz, raw, blame))
return api
failures = {}
def _fail(clazz, detail, msg):
"""Records an API failure to be processed later."""
global failures
sig = "%s-%s-%s" % (clazz.fullname, repr(detail), msg)
sig = sig.replace(" deprecated ", " ")
res = msg
blame = clazz.blame
if detail is not None:
res += "\n in " + repr(detail)
blame = detail.blame
res += "\n in " + repr(clazz)
res += "\n in " + repr(clazz.pkg)
if blame is not None:
res += "\n last modified by %s in %s" % (blame[1], blame[0])
failures[sig] = res
def warn(clazz, detail, msg):
_fail(clazz, detail, "%sWarning:%s %s" % (format(fg=YELLOW, bg=BLACK, bold=True), format(reset=True), msg))
def error(clazz, detail, msg):
_fail(clazz, detail, "%sError:%s %s" % (format(fg=RED, bg=BLACK, bold=True), format(reset=True), msg))
def verify_constants(clazz):
"""All static final constants must be FOO_NAME style."""
if re.match("android\.R\.[a-z]+", clazz.fullname): return
for f in clazz.fields:
if "static" in f.split and "final" in f.split:
if re.match("[A-Z0-9_]+", f.name) is None:
error(clazz, f, "Constant field names should be FOO_NAME")
def verify_enums(clazz):
"""Enums are bad, mmkay?"""
if "extends java.lang.Enum" in clazz.raw:
error(clazz, None, "Enums are not allowed")
def verify_class_names(clazz):
"""Try catching malformed class names like myMtp or MTPUser."""
if clazz.fullname.startswith("android.opengl"): return
if clazz.fullname.startswith("android.renderscript"): return
if re.match("android\.R\.[a-z]+", clazz.fullname): return
if re.search("[A-Z]{2,}", clazz.name) is not None:
warn(clazz, None, "Class name style should be Mtp not MTP")
if re.match("[^A-Z]", clazz.name):
error(clazz, None, "Class must start with uppercase char")
def verify_method_names(clazz):
"""Try catching malformed method names, like Foo() or getMTU()."""
if clazz.fullname.startswith("android.opengl"): return
if clazz.fullname.startswith("android.renderscript"): return
if clazz.fullname == "android.system.OsConstants": return
for m in clazz.methods:
if re.search("[A-Z]{2,}", m.name) is not None:
warn(clazz, m, "Method name style should be getMtu() instead of getMTU()")
if re.match("[^a-z]", m.name):
error(clazz, m, "Method name must start with lowercase char")
def verify_callbacks(clazz):
"""Verify Callback classes.
All callback classes must be abstract.
All methods must follow onFoo() naming style."""
if clazz.fullname == "android.speech.tts.SynthesisCallback": return
if clazz.name.endswith("Callbacks"):
error(clazz, None, "Class name must not be plural")
if clazz.name.endswith("Observer"):
warn(clazz, None, "Class should be named FooCallback")
if clazz.name.endswith("Callback"):
if "interface" in clazz.split:
error(clazz, None, "Callback must be abstract class to enable extension in future API levels")
for m in clazz.methods:
if not re.match("on[A-Z][a-z]*", m.name):
error(clazz, m, "Callback method names must be onFoo() style")
def verify_listeners(clazz):
"""Verify Listener classes.
All Listener classes must be interface.
All methods must follow onFoo() naming style.
If only a single method, it must match class name:
interface OnFooListener { void onFoo() }"""
if clazz.name.endswith("Listener"):
if " abstract class " in clazz.raw:
error(clazz, None, "Listener should be an interface, otherwise renamed Callback")
for m in clazz.methods:
if not re.match("on[A-Z][a-z]*", m.name):
error(clazz, m, "Listener method names must be onFoo() style")
if len(clazz.methods) == 1 and clazz.name.startswith("On"):
m = clazz.methods[0]
if (m.name + "Listener").lower() != clazz.name.lower():
error(clazz, m, "Single listener method name should match class name")
def verify_actions(clazz):
"""Verify intent actions.
All action names must be named ACTION_FOO.
All action values must be scoped by package and match name:
package android.foo {
String ACTION_BAR = "android.foo.action.BAR";
}"""
for f in clazz.fields:
if f.value is None: continue
if f.name.startswith("EXTRA_"): continue
if f.name == "SERVICE_INTERFACE" or f.name == "PROVIDER_INTERFACE": continue
if "static" in f.split and "final" in f.split and f.typ == "java.lang.String":
if "_ACTION" in f.name or "ACTION_" in f.name or ".action." in f.value.lower():
if not f.name.startswith("ACTION_"):
error(clazz, f, "Intent action constant name must be ACTION_FOO")
else:
if clazz.fullname == "android.content.Intent":
prefix = "android.intent.action"
elif clazz.fullname == "android.provider.Settings":
prefix = "android.settings"
elif clazz.fullname == "android.app.admin.DevicePolicyManager" or clazz.fullname == "android.app.admin.DeviceAdminReceiver":
prefix = "android.app.action"
else:
prefix = clazz.pkg.name + ".action"
expected = prefix + "." + f.name[7:]
if f.value != expected:
error(clazz, f, "Inconsistent action value; expected %s" % (expected))
def verify_extras(clazz):
"""Verify intent extras.
All extra names must be named EXTRA_FOO.
All extra values must be scoped by package and match name:
package android.foo {
String EXTRA_BAR = "android.foo.extra.BAR";
}"""
if clazz.fullname == "android.app.Notification": return
if clazz.fullname == "android.appwidget.AppWidgetManager": return
for f in clazz.fields:
if f.value is None: continue
if f.name.startswith("ACTION_"): continue
if "static" in f.split and "final" in f.split and f.typ == "java.lang.String":
if "_EXTRA" in f.name or "EXTRA_" in f.name or ".extra" in f.value.lower():
if not f.name.startswith("EXTRA_"):
error(clazz, f, "Intent extra must be EXTRA_FOO")
else:
if clazz.pkg.name == "android.content" and clazz.name == "Intent":
prefix = "android.intent.extra"
elif clazz.pkg.name == "android.app.admin":
prefix = "android.app.extra"
else:
prefix = clazz.pkg.name + ".extra"
expected = prefix + "." + f.name[6:]
if f.value != expected:
error(clazz, f, "Inconsistent extra value; expected %s" % (expected))
def verify_equals(clazz):
"""Verify that equals() and hashCode() must be overridden together."""
methods = [ m.name for m in clazz.methods ]
eq = "equals" in methods
hc = "hashCode" in methods
if eq != hc:
error(clazz, None, "Must override both equals and hashCode; missing one")
def verify_parcelable(clazz):
"""Verify that Parcelable objects aren't hiding required bits."""
if "implements android.os.Parcelable" in clazz.raw:
creator = [ i for i in clazz.fields if i.name == "CREATOR" ]
write = [ i for i in clazz.methods if i.name == "writeToParcel" ]
describe = [ i for i in clazz.methods if i.name == "describeContents" ]
if len(creator) == 0 or len(write) == 0 or len(describe) == 0:
error(clazz, None, "Parcelable requires CREATOR, writeToParcel, and describeContents; missing one")
def verify_protected(clazz):
"""Verify that no protected methods are allowed."""
for m in clazz.methods:
if "protected" in m.split:
error(clazz, m, "No protected methods; must be public")
for f in clazz.fields:
if "protected" in f.split:
error(clazz, f, "No protected fields; must be public")
def verify_fields(clazz):
"""Verify that all exposed fields are final.
Exposed fields must follow myName style.
Catch internal mFoo objects being exposed."""
IGNORE_BARE_FIELDS = [
"android.app.ActivityManager.RecentTaskInfo",
"android.app.Notification",
"android.content.pm.ActivityInfo",
"android.content.pm.ApplicationInfo",
"android.content.pm.FeatureGroupInfo",
"android.content.pm.InstrumentationInfo",
"android.content.pm.PackageInfo",
"android.content.pm.PackageItemInfo",
"android.os.Message",
"android.system.StructPollfd",
]
for f in clazz.fields:
if not "final" in f.split:
if clazz.fullname in IGNORE_BARE_FIELDS:
pass
elif clazz.fullname.endswith("LayoutParams"):
pass
elif clazz.fullname.startswith("android.util.Mutable"):
pass
else:
error(clazz, f, "Bare fields must be marked final; consider adding accessors")
if not "static" in f.split:
if not re.match("[a-z]([a-zA-Z]+)?", f.name):
error(clazz, f, "Non-static fields must be named with myField style")
if re.match("[ms][A-Z]", f.name):
error(clazz, f, "Don't expose your internal objects")
if re.match("[A-Z_]+", f.name):
if "static" not in f.split or "final" not in f.split:
error(clazz, f, "Constants must be marked static final")
def verify_register(clazz):
"""Verify parity of registration methods.
Callback objects use register/unregister methods.
Listener objects use add/remove methods."""
methods = [ m.name for m in clazz.methods ]
for m in clazz.methods:
if "Callback" in m.raw:
if m.name.startswith("register"):
other = "unregister" + m.name[8:]
if other not in methods:
error(clazz, m, "Missing unregister method")
if m.name.startswith("unregister"):
other = "register" + m.name[10:]
if other not in methods:
error(clazz, m, "Missing register method")
if m.name.startswith("add") or m.name.startswith("remove"):
error(clazz, m, "Callback methods should be named register/unregister")
if "Listener" in m.raw:
if m.name.startswith("add"):
other = "remove" + m.name[3:]
if other not in methods:
error(clazz, m, "Missing remove method")
if m.name.startswith("remove") and not m.name.startswith("removeAll"):
other = "add" + m.name[6:]
if other not in methods:
error(clazz, m, "Missing add method")
if m.name.startswith("register") or m.name.startswith("unregister"):
error(clazz, m, "Listener methods should be named add/remove")
def verify_sync(clazz):
"""Verify synchronized methods aren't exposed."""
for m in clazz.methods:
if "synchronized" in m.split:
error(clazz, m, "Internal lock exposed")
def verify_intent_builder(clazz):
"""Verify that Intent builders are createFooIntent() style."""
if clazz.name == "Intent": return
for m in clazz.methods:
if m.typ == "android.content.Intent":
if m.name.startswith("create") and m.name.endswith("Intent"):
pass
else:
error(clazz, m, "Methods creating an Intent should be named createFooIntent()")
def verify_helper_classes(clazz):
"""Verify that helper classes are named consistently with what they extend.
All developer extendable methods should be named onFoo()."""
test_methods = False
if "extends android.app.Service" in clazz.raw:
test_methods = True
if not clazz.name.endswith("Service"):
error(clazz, None, "Inconsistent class name; should be FooService")
found = False
for f in clazz.fields:
if f.name == "SERVICE_INTERFACE":
found = True
if f.value != clazz.fullname:
error(clazz, f, "Inconsistent interface constant; expected %s" % (clazz.fullname))
if not found:
warn(clazz, None, "Missing SERVICE_INTERFACE constant")
if "abstract" in clazz.split and not clazz.fullname.startswith("android.service."):
warn(clazz, None, "Services extended by developers should be under android.service")
if "extends android.content.ContentProvider" in clazz.raw:
test_methods = True
if not clazz.name.endswith("Provider"):
error(clazz, None, "Inconsistent class name; should be FooProvider")
found = False
for f in clazz.fields:
if f.name == "PROVIDER_INTERFACE":
found = True
if f.value != clazz.fullname:
error(clazz, f, "Inconsistent interface name; expected %s" % (clazz.fullname))
if not found:
warn(clazz, None, "Missing PROVIDER_INTERFACE constant")
if "abstract" in clazz.split and not clazz.fullname.startswith("android.provider."):
warn(clazz, None, "Providers extended by developers should be under android.provider")
if "extends android.content.BroadcastReceiver" in clazz.raw:
test_methods = True
if not clazz.name.endswith("Receiver"):
error(clazz, None, "Inconsistent class name; should be FooReceiver")
if "extends android.app.Activity" in clazz.raw:
test_methods = True
if not clazz.name.endswith("Activity"):
error(clazz, None, "Inconsistent class name; should be FooActivity")
if test_methods:
for m in clazz.methods:
if "final" in m.split: continue
if not re.match("on[A-Z]", m.name):
if "abstract" in m.split:
error(clazz, m, "Methods implemented by developers must be named onFoo()")
else:
warn(clazz, m, "If implemented by developer, should be named onFoo(); otherwise consider marking final")
def verify_builder(clazz):
"""Verify builder classes.
Methods should return the builder to enable chaining."""
if " extends " in clazz.raw: return
if not clazz.name.endswith("Builder"): return
if clazz.name != "Builder":
warn(clazz, None, "Builder should be defined as inner class")
has_build = False
for m in clazz.methods:
if m.name == "build":
has_build = True
continue
if m.name.startswith("get"): continue
if m.name.startswith("clear"): continue
if m.name.startswith("with"):
error(clazz, m, "Builder methods names must follow setFoo() style")
if m.name.startswith("set"):
if not m.typ.endswith(clazz.fullname):
warn(clazz, m, "Methods should return the builder")
if not has_build:
warn(clazz, None, "Missing build() method")
def verify_aidl(clazz):
"""Catch people exposing raw AIDL."""
if "extends android.os.Binder" in clazz.raw or "implements android.os.IInterface" in clazz.raw:
error(clazz, None, "Exposing raw AIDL interface")
def verify_internal(clazz):
"""Catch people exposing internal classes."""
if clazz.pkg.name.startswith("com.android"):
error(clazz, None, "Exposing internal class")
def verify_layering(clazz):
"""Catch package layering violations.
For example, something in android.os depending on android.app."""
ranking = [
["android.service","android.accessibilityservice","android.inputmethodservice","android.printservice","android.appwidget","android.webkit","android.preference","android.gesture","android.print"],
"android.app",
"android.widget",
"android.view",
"android.animation",
"android.provider",
["android.content","android.graphics.drawable"],
"android.database",
"android.graphics",
"android.text",
"android.os",
"android.util"
]
def rank(p):
for i in range(len(ranking)):
if isinstance(ranking[i], list):
for j in ranking[i]:
if p.startswith(j): return i
else:
if p.startswith(ranking[i]): return i
cr = rank(clazz.pkg.name)
if cr is None: return
for f in clazz.fields:
ir = rank(f.typ)
if ir and ir < cr:
warn(clazz, f, "Field type violates package layering")
for m in clazz.methods:
ir = rank(m.typ)
if ir and ir < cr:
warn(clazz, m, "Method return type violates package layering")
for arg in m.args:
ir = rank(arg)
if ir and ir < cr:
warn(clazz, m, "Method argument type violates package layering")
def verify_boolean(clazz, api):
"""Catches people returning boolean from getFoo() style methods.
Ignores when matching setFoo() is present."""
methods = [ m.name for m in clazz.methods ]
builder = clazz.fullname + ".Builder"
builder_methods = []
if builder in api:
builder_methods = [ m.name for m in api[builder].methods ]
for m in clazz.methods:
if m.typ == "boolean" and m.name.startswith("get") and m.name != "get" and len(m.args) == 0:
setter = "set" + m.name[3:]
if setter in methods:
pass
elif builder is not None and setter in builder_methods:
pass
else:
warn(clazz, m, "Methods returning boolean should be named isFoo, hasFoo, areFoo")
def verify_collections(clazz):
"""Verifies that collection types are interfaces."""
if clazz.fullname == "android.os.Bundle": return
bad = ["java.util.Vector", "java.util.LinkedList", "java.util.ArrayList", "java.util.Stack",
"java.util.HashMap", "java.util.HashSet", "android.util.ArraySet", "android.util.ArrayMap"]
for m in clazz.methods:
if m.typ in bad:
error(clazz, m, "Return type is concrete collection; should be interface")
for arg in m.args:
if arg in bad:
error(clazz, m, "Argument is concrete collection; should be interface")
def verify_flags(clazz):
"""Verifies that flags are non-overlapping."""
known = collections.defaultdict(int)
for f in clazz.fields:
if "FLAG_" in f.name:
try:
val = int(f.value)
except:
continue
scope = f.name[0:f.name.index("FLAG_")]
if val & known[scope]:
warn(clazz, f, "Found overlapping flag constant value")
known[scope] |= val
def verify_style(api):
"""Find all style issues in the given API level."""
global failures
failures = {}
for key in sorted(api.keys()):
clazz = api[key]
if clazz.pkg.name.startswith("java"): continue
if clazz.pkg.name.startswith("junit"): continue
if clazz.pkg.name.startswith("org.apache"): continue
if clazz.pkg.name.startswith("org.xml"): continue
if clazz.pkg.name.startswith("org.json"): continue
if clazz.pkg.name.startswith("org.w3c"): continue
verify_constants(clazz)
verify_enums(clazz)
verify_class_names(clazz)
verify_method_names(clazz)
verify_callbacks(clazz)
verify_listeners(clazz)
verify_actions(clazz)
verify_extras(clazz)
verify_equals(clazz)
verify_parcelable(clazz)
verify_protected(clazz)
verify_fields(clazz)
verify_register(clazz)
verify_sync(clazz)
verify_intent_builder(clazz)
verify_helper_classes(clazz)
verify_builder(clazz)
verify_aidl(clazz)
verify_internal(clazz)
verify_layering(clazz)
verify_boolean(clazz, api)
verify_collections(clazz)
verify_flags(clazz)
return failures
def verify_compat(cur, prev):
"""Find any incompatible API changes between two levels."""
global failures
def class_exists(api, test):
return test.fullname in api
def ctor_exists(api, clazz, test):
for m in clazz.ctors:
if m.ident == test.ident: return True
return False
def all_methods(api, clazz):
methods = list(clazz.methods)
if clazz.extends is not None:
methods.extend(all_methods(api, api[clazz.extends]))
return methods
def method_exists(api, clazz, test):
methods = all_methods(api, clazz)
for m in methods:
if m.ident == test.ident: return True
return False
def field_exists(api, clazz, test):
for f in clazz.fields:
if f.ident == test.ident: return True
return False
failures = {}
for key in sorted(prev.keys()):
prev_clazz = prev[key]
if not class_exists(cur, prev_clazz):
error(prev_clazz, None, "Class removed or incompatible change")
continue
cur_clazz = cur[key]
for test in prev_clazz.ctors:
if not ctor_exists(cur, cur_clazz, test):
error(prev_clazz, prev_ctor, "Constructor removed or incompatible change")
methods = all_methods(prev, prev_clazz)
for test in methods:
if not method_exists(cur, cur_clazz, test):
error(prev_clazz, test, "Method removed or incompatible change")
for test in prev_clazz.fields:
if not field_exists(cur, cur_clazz, test):
error(prev_clazz, test, "Field removed or incompatible change")
return failures
cur = parse_api(sys.argv[1])
cur_fail = verify_style(cur)
if len(sys.argv) > 2:
prev = parse_api(sys.argv[2])
prev_fail = verify_style(prev)
# ignore errors from previous API level
for p in prev_fail:
if p in cur_fail:
del cur_fail[p]
# look for compatibility issues
compat_fail = verify_compat(cur, prev)
print "%s API compatibility issues %s\n" % ((format(fg=WHITE, bg=BLUE, bold=True), format(reset=True)))
for f in sorted(compat_fail):
print compat_fail[f]
print
print "%s API style issues %s\n" % ((format(fg=WHITE, bg=BLUE, bold=True), format(reset=True)))
for f in sorted(cur_fail):
print cur_fail[f]
print