/usr/share/pyshared/pychecker2/VariableChecks.py is in pychecker 0.8.19-12.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 | from pychecker2.Check import Check
from pychecker2.Options import Opt, BoolOpt
from pychecker2.Warning import Warning
from pychecker2.util import *
from pychecker2 import symbols
from compiler import ast, walk
def _is_method(scope):
return scope.__class__ is symbols.FunctionScope and \
scope.parent.__class__ is symbols.ClassScope
def _is_self(scope, name):
return _is_method(scope) and name in scope.node.argnames[:1]
def is_arg_and_defaulted_to_same_name(name, scope):
if isinstance(scope, symbols.FunctionScope):
if name in scope.node.argnames and scope.node.defaults:
# compute default args
args = scope.node.argnames[:]
# knock off kwargs
if scope.node.kwargs:
args = args[:-1]
# knock off varags
if scope.node.varargs:
args = args[:-1]
# take the last args as the defaults
args = args[-len(scope.node.defaults):]
try:
# get the corresponding default arg value
default = scope.node.defaults[args.index(name)]
# must be a Name node of the same name
if isinstance(default, ast.Name) and \
default.name == name:
return 1
except ValueError:
pass
return None
class ShadowCheck(Check):
"""Use symbol information to check that no scope defines a name
already known to a parent scope"""
defineNone = Warning('Report any redefinition of None',
'Do not redefine None')
shadowBuiltins = Warning('Report names that shadow builtins',
'Identifier (%s) shadows builtin', 0)
shadowIdentifier = Warning('Report names already defined in outer scopes',
'Identifier (%s) shadows definition in scope %s')
def check(self, file, unused_checker):
# warn if any name defined in a scope is defined in a parent scope
# or even the builtins
for node, scope in file.not_class_scopes():
for name in scope.defs:
if name == 'None':
file.warning(scope.defs[name], self.defineNone)
continue
if name in scope.globals:
continue
if is_arg_and_defaulted_to_same_name(name, scope):
continue
if _is_self(scope, name):
continue
if __builtins__.has_key(name):
file.warning(scope.defs[name], self.shadowBuiltins, name)
for p in parents(scope):
if p.defs.has_key(name) and \
not isinstance(p, symbols.ClassScope):
file.warning(scope.defs[name], \
self.shadowIdentifier, name, `p`)
def _str_value(s):
if type(s) == type(''):
return eval(s)
return s
def _empty_function(stmts):
if not stmts:
return 1
stmt = stmts[0]
# functions which only raise exceptions
if isinstance(stmt, ast.Raise):
return 1
# functions which do nothing
if len(stmts) == 1 and isinstance(stmt, ast.Pass):
return 1
# functions which just return a constant
if len(stmts) == 1 and \
isinstance(stmt, ast.Return) and isinstance(stmt.value, ast.Const):
return 1
# functions which only assert falsehood
if isinstance(stmt, ast.Assert):
if (isinstance(stmt.test, ast.Const) and not stmt.test.value) or \
(isinstance(stmt.test, ast.Name) and stmt.test.name == 'None'):
return 1
return 0
class UnusedCheck(Check):
"""Use symbol information to check that no scope defines a name
not used in this or any child scope"""
unused = Warning('Report names not used', 'Identifier (%s) not used')
def __init__(self):
self.reportUnusedSelf = None
self.unusedPrefixes = None
def get_options(self, options):
desc = 'Ignore unused identifiers that start with these values'
default = ['unused', 'empty', 'dummy',
'__pychecker__', '__all__', '__version__', 'ignored']
options.add(Opt(self, 'unusedPrefixes', desc, default))
desc = 'Ignore unused method "self" parameter'
options.add(BoolOpt(self, 'reportUnusedSelf', desc))
def check(self, file, unused_checker):
self.unusedPrefixes = _str_value(self.unusedPrefixes)
def used(name, parent_scope):
if parent_scope.uses.has_key(name):
return 1
for c in parent_scope.get_children():
if used(name, c):
return 1
return 0
for nodes, scope in file.not_class_scopes():
if isinstance(nodes, ast.Function):
if _empty_function(nodes.code.nodes):
continue
# ensure that every defined variable is used in some scope
for var in scope.defs:
# ignore '_'... just because
if var == '_':
continue
# check for method self
if not self.reportUnusedSelf and _is_self(scope, var):
continue
# ignore names in the root scope which are not imported:
# class defs, function defs, variables, etc, unless
# they start with '_'
if scope == file.root_scope:
if not scope.imports.has_key(var):
if not var.startswith('_'):
continue
for prefix in self.unusedPrefixes:
if var.startswith(prefix):
break
else:
if not used(var, scope) and not scope.globals.has_key(var):
file.warning(scope.defs[var], self.unused, var)
def _importedName(scope, name):
if scope.imports.has_key(name):
return 1
if scope.parent:
return _importedName(scope.parent, name)
return None
class UnknownCheck(Check):
"""Use symbol information to check that no scope uses a name
not defined in a parent scope"""
unknown = Warning('Report names that are not defined',
'Unknown identifier: %s')
builtins = {}
builtins.update(__builtins__)
builtins['__builtins__'] = __builtins__
builtins['WindowsError'] = getattr(__builtins__, 'WindowsError', None)
def check(self, file, unused_checker):
# if a name used is not found in the defined variables, complain
for scope in file.scopes.values():
unknown = dict_minus(scope.uses, scope.defs)
unknown = dict_minus(unknown, self.builtins)
for var in unknown:
for p in parents(scope):
if p.defs.has_key(var):
break
else:
if not _importedName(scope, var):
file.warning(scope.uses[var], self.unknown, var)
def _first_arg_defaulted(function_node):
count = len(function_node.argnames)
if function_node.varargs:
count -= 1
if function_node.kwargs:
count -= 1
if count > 0 and len(function_node.defaults) == count:
return 1
return None
class SelfCheck(Check):
'Check for simple self parameter'
selfName = Warning('Report any methods whose first argument is not self',
'First argument to method %s (%s) is not in %s')
selfDefault = Warning('Report a self parameter with a default value',
'First argument to method %s (%s) has a default value')
functionSelf = Warning('Report functions (not methods) with '
'arguments named "self"',
'Argument to function (%s) is "%s"')
missingSelf = Warning('Report methods without "self"',
'Method %s is missing self parameter')
def get_options(self, options):
desc = 'Name of self parameter'
default = ["self", "this", "s"]
options.add(Opt(self, 'selfNames', desc, default))
desc = 'Suspicious self parameters'
self.selfSuspicious = ["self"]
options.add(Opt(self, 'selfSuspicious', desc, self.selfSuspicious))
def check(self, file, unused_checker):
self.selfNames = _str_value(self.selfNames)
self.selfSuspicious = _str_value(self.selfSuspicious)
for node, scope in file.function_scopes():
args = node.argnames
name = getattr(scope.node, 'name', 'lambda')
if _is_method(scope):
if not args:
file.warning(scope.node, self.missingSelf, name)
else:
if args[0] not in self.selfNames:
file.warning(scope.node, self.selfName,
name, args[0], `self.selfNames`)
if _first_arg_defaulted(scope.node):
file.warning(scope.node, self.selfDefault,
name, args[0])
else:
for arg in args:
if arg in self.selfSuspicious:
file.warning(scope.defs[arg], self.functionSelf,
name, arg)
class UnpackCheck(Check):
'Mark all unpacked variables as used'
def __init__(self):
self.unpackedUsed = None
def get_options(self, options):
desc = 'Do not treat variables used in tuple assignment as used'
options.add(BoolOpt(self, 'unpackedUsed', desc, 1))
def check(self, file, unused_checker):
if not self.unpackedUsed:
return
class Visitor:
def visitAssTuple(self, node):
for c in node.getChildNodes():
for n in parents(c):
try:
file.scopes[n].uses[c.name] = node
break
except (KeyError, AttributeError):
pass
visitAssList = visitAssTuple
# local args unpacked on the `def' line are used, too
for scope_node, scope in file.function_scopes():
for arg in type_filter(scope_node.argnames, tuple):
for unpacked in ast.flatten(arg):
scope.uses[unpacked] = scope.uses.get(unpacked, scope_node)
if file.root_scope:
walk(file.root_scope.node, Visitor())
def intersect2(a, b):
return [i for i in a if i in b]
def intersect(items):
result = items[0]
for item in items[1:]:
result = intersect2(result, item)
return result
class UsedBeforeSetCheck(Check):
usedBeforeDefined = \
Warning('Report variables that may be used before they are defined',
'The local %s may be used before defined')
def check(self, file, unused_checker):
class Visitor(BaseVisitor):
def __init__(self, defines = None, uses = None):
# list of vars defined
self.defines = []
# name->node vars used before defined
self.uses = {}
if defines is not None:
self.defines = defines[:]
if uses is not None:
self.uses = uses.copy()
def visitFunction(self, n):
self.defines.append(n.name)
visitClass = visitFunction
visitAssName = visitFunction
def visitGlobal(self, node):
for name in node.names:
self.defines.append(name)
def visitListComp(self, n):
# visit qualifiers before expression
children = ast.flatten_nodes(n.quals) + [n.expr]
for c in children:
self.visit(c)
def visitName(self, n):
if n.name not in self.defines:
self.uses[n.name] = self.uses.get(n.name, n)
def visitIf(self, n):
if not n.else_:
return
visits = []
for test, code in n.tests:
visits.append(walk(code, Visitor(self.defines, self.uses)))
visits.append(walk(n.else_, Visitor(self.defines, self.uses)))
# compute the intersection of defines
self.defines = intersect([v.defines for v in visits])
# compute the union of uses, perserving first occurances
union = {}
visits.reverse()
for v in visits:
union.update(v.uses)
union.update(self.uses)
self.uses = union
for node, scope in file.function_scopes():
predefined = ast.flatten(scope.params) + scope.imports.keys()
visitor = walk(node.code, Visitor(predefined))
usedBefore = dict_intersect(visitor.uses, scope.defs)
for name, use_node in usedBefore.items():
file.warning(use_node, self.usedBeforeDefined, name)
|