# -*- test-case-name: pyflakes -*-
# (c) 2005-2008 Divmod, Inc.
# See LICENSE file for details
import os.path
from compiler import ast
#lint:disable
try:
import builtins
except ImportError:
import __builtin__ as builtins
#lint:enable
from ninja_ide.core import settings
from ninja_ide.dependencies.pyflakes_mod import messages
PYTHON_BUILTINS = dir(builtins)
class Binding(object):
"""
Represents the binding of a value to a name.
The checker uses this to keep track of which names have been bound and
which names have not. See L{Assignment} for a special type of binding that
is checked with stricter rules.
@ivar used: pair of (L{Scope}, line-number) indicating the scope and
line number that this binding was last used
"""
def __init__(self, name, source):
self.name = name
self.source = source
self.used = False
def __str__(self):
return self.name
def __repr__(self):
return '<%s object %r from line %r at 0x%x>' % (
self.__class__.__name__,
self.name,
self.source.lineno,
id(self))
class UnBinding(Binding):
'''Created by the 'del' operator.'''
class Importation(Binding):
"""
A binding created by an import statement.
@ivar fullName: The complete name given to the import statement,
possibly including multiple dotted components.
@type fullName: C{str}
"""
def __init__(self, name, source):
self.fullName = name
name = name.split('.')[0]
super(Importation, self).__init__(name, source)
class Argument(Binding):
"""
Represents binding a name as an argument.
"""
class Assignment(Binding):
"""
Represents binding a name with an explicit assignment.
The checker will raise warnings for any Assignment that isn't used. Also,
the checker does not consider assignments in tuple/list unpacking to be
Assignments, rather it treats them as simple Bindings.
"""
class FunctionDefinition(Binding):
pass
class ExportBinding(Binding):
"""
A binding created by an C{__all__} assignment. If the names in the list
can be determined statically, they will be treated as names for export and
additional checking applied to them.
The only C{__all__} assignment that can be recognized is one which takes
the value of a literal list containing literal strings. For example::
__all__ = ["foo", "bar"]
Names which are imported and not otherwise used but appear in the value of
C{__all__} will not have an unused import warning reported for them.
"""
def names(self):
"""
Return a list of the names referenced by this binding.
"""
names = []
if isinstance(self.source, ast.List):
for node in self.source.nodes:
if isinstance(node, ast.Const):
names.append(node.value)
return names
class Scope(dict):
importStarred = False # set to True when import * is found
def __repr__(self):
return '<%s at 0x%x %s>' % (self.__class__.__name__, id(self),
dict.__repr__(self))
def __init__(self):
super(Scope, self).__init__()
class ClassScope(Scope):
pass
class FunctionScope(Scope):
"""
I represent a name scope for a function.
@ivar globals: Names declared 'global' in this function.
"""
def __init__(self):
super(FunctionScope, self).__init__()
self.globals = {}
class ModuleScope(Scope):
pass
# Globally defined names which are not attributes of the builtins module.
_MAGIC_GLOBALS = ['__file__', '__builtins__']
class Checker(object):
"""
I check the cleanliness and sanity of Python code.
@ivar _deferredFunctions: Tracking list used by L{deferFunction}. Elements
of the list are two-tuples. The first element is the callable passed
to L{deferFunction}. The second element is a copy of the scope stack
at the time L{deferFunction} was called.
@ivar _deferredAssignments: Similar to C{_deferredFunctions}, but for
callables which are deferred assignment checks.
"""
nodeDepth = 0
traceTree = False
builtIns = set(dir(builtins)) | set(_MAGIC_GLOBALS)
def __init__(self, tree, filename='(none)', builtins=None):
self._deferredFunctions = []
self._deferredAssignments = []
self.dead_scopes = []
self.messages = []
self.filename = filename
if builtins:
self.builtIns = self.builtIns.union(builtins)
self.scopeStack = [ModuleScope()]
self.futuresAllowed = True
self.handleChildren(tree)
self._runDeferred(self._deferredFunctions)
# Set _deferredFunctions to None so that deferFunction will fail
# noisily if called after we've run through the deferred functions.
self._deferredFunctions = None
self._runDeferred(self._deferredAssignments)
# Set _deferredAssignments to None so that deferAssignment will fail
# noisly if called after we've run through the deferred assignments.
self._deferredAssignments = None
del self.scopeStack[1:]
self.popScope()
self.check_dead_scopes()
def deferFunction(self, callable):
'''
Schedule a function handler to be called just before completion.
This is used for handling function bodies, which must be deferred
because code later in the file might modify the global scope. When
`callable` is called, the scope at the time this is called will be
restored, however it will contain any new bindings added to it.
'''
self._deferredFunctions.append((callable, self.scopeStack[:]))
def deferAssignment(self, callable):
"""
Schedule an assignment handler to be called just after deferred
function handlers.
"""
self._deferredAssignments.append((callable, self.scopeStack[:]))
def _runDeferred(self, deferred):
"""
Run the callables in C{deferred} using their associated scope stack.
"""
for handler, scope in deferred:
self.scopeStack = scope
handler()
def scope(self):
return self.scopeStack[-1]
scope = property(scope)
def popScope(self):
self.dead_scopes.append(self.scopeStack.pop())
def check_dead_scopes(self):
"""
Look at scopes which have been fully examined and report names in them
which were imported but unused.
"""
for scope in self.dead_scopes:
export = isinstance(scope.get('__all__'), ExportBinding)
if export:
alls = scope['__all__'].names()
if os.path.split(self.filename)[1] != '__init__.py':
# Look for possible mistakes in the export list
undefined = set(alls) - set(scope)
for name in undefined:
self.report(
messages.UndefinedExport,
scope['__all__'].source.lineno,
name)
else:
alls = []
# Look for imported names that aren't used.
for importation in scope.itervalues():
if isinstance(importation, Importation):
if not importation.used and importation.name not in alls:
self.report(
messages.UnusedImport,
importation.source.lineno,
importation.name)
def pushFunctionScope(self):
self.scopeStack.append(FunctionScope())
def pushClassScope(self):
self.scopeStack.append(ClassScope())
def report(self, messageClass, *args, **kwargs):
self.messages.append(messageClass(self.filename, *args, **kwargs))
def handleChildren(self, tree):
for node in tree.getChildNodes():
self.handleNode(node, tree)
def handleNode(self, node, parent):
node.parent = parent
if self.traceTree:
print(' ' * self.nodeDepth + node.__class__.__name__)
self.nodeDepth += 1
nodeType = node.__class__.__name__.upper()
if nodeType not in ('STMT', 'FROM'):
self.futuresAllowed = False
try:
handler = getattr(self, nodeType)
handler(node)
finally:
self.nodeDepth -= 1
if self.traceTree:
print(' ' * self.nodeDepth + 'end ' + node.__class__.__name__)
def ignore(self, node):
pass
STMT = SET = PRINT = PRINTNL = TUPLE = LIST = ASSTUPLE = ASSATTR = \
ASSLIST = GETATTR = SLICE = SLICEOBJ = IF = CALLFUNC = DISCARD = \
RETURN = ADD = MOD = SUB = NOT = UNARYSUB = INVERT = ASSERT = COMPARE = \
SUBSCRIPT = AND = OR = TRYEXCEPT = RAISE = YIELD = DICT = LEFTSHIFT = \
RIGHTSHIFT = KEYWORD = TRYFINALLY = WHILE = EXEC = MUL = DIV = POWER = \
FLOORDIV = BITAND = BITOR = BITXOR = LISTCOMPFOR = LISTCOMPIF = \
AUGASSIGN = BACKQUOTE = UNARYADD = GENEXPR = GENEXPRFOR = GENEXPRIF = \
IFEXP = handleChildren
CONST = PASS = CONTINUE = BREAK = ELLIPSIS = ignore
def addBinding(self, lineno, value, reportRedef=True):
'''Called when a binding is altered.
- `lineno` is the line of the statement responsible for the change
- `value` is the optional new value, a Binding instance, associated
with the binding; if None, the binding is deleted if it exists.
- if `reportRedef` is True (default), rebinding while unused will be
reported.
'''
if (isinstance(self.scope.get(value.name), FunctionDefinition)
and isinstance(value, FunctionDefinition)):
self.report(messages.RedefinedFunction,
lineno, value.name, self.scope[value.name].source.lineno)
if not isinstance(self.scope, ClassScope):
for scope in self.scopeStack[::-1]:
existing = scope.get(value.name)
if (isinstance(existing, Importation)
and not existing.used
and (not isinstance(value, Importation) or
value.fullName == existing.fullName)
and reportRedef):
self.report(messages.RedefinedWhileUnused,
lineno, value.name, scope[value.name].source.lineno)
if isinstance(value, UnBinding):
try:
del self.scope[value.name]
except KeyError:
self.report(messages.UndefinedName, lineno, value.name)
else:
self.scope[value.name] = value
if settings.CHECK_FOR_DOCSTRINGS and \
((value.__class__ is FunctionDefinition) or
(value.source.__class__.__name__.upper() == "CLASS")):
doc = value.source.doc
if doc is None:
self.report(messages.DocstringMissing, lineno, value.name)
if isinstance(value, Assignment) and (value.name in PYTHON_BUILTINS):
self.report(messages.BuiltinOverlap, lineno, value.name)
def WITH(self, node):
"""
Handle C{with} by checking the target of the statement (which can be an
identifier, a list or tuple of targets, an attribute, etc) for
undefined names and defining any it adds to the scope and by continuing
to process the suite within the statement.
"""
# Check the "foo" part of a "with foo as bar" statement. Do this no
# matter what, since there's always a "foo" part.
self.handleNode(node.expr, node)
if node.vars is not None:
self.handleNode(node.vars, node)
self.handleChildren(node.body)
def GLOBAL(self, node):
"""
Keep track of globals declarations.
"""
if isinstance(self.scope, FunctionScope):
self.scope.globals.update(dict.fromkeys(node.names))
def LISTCOMP(self, node):
for qual in node.quals:
self.handleNode(qual, node)
self.handleNode(node.expr, node)
GENEXPRINNER = LISTCOMP
def FOR(self, node):
"""
Process bindings for loop variables.
"""
variables = []
def collectLoopVars(n):
if hasattr(n, 'name'):
variables.append(n.name)
else:
for c in n.getChildNodes():
collectLoopVars(c)
collectLoopVars(node.assign)
for varn in variables:
if (isinstance(self.scope.get(varn), Importation)
# unused ones will get an unused import warning
and self.scope[varn].used):
self.report(messages.ImportShadowedByLoopVar,
node.lineno, varn, self.scope[varn].source.lineno)
self.handleChildren(node)
def NAME(self, node):
"""
Locate the name in locals / function / globals scopes.
"""
# try local scope
importStarred = self.scope.importStarred
try:
self.scope[node.name].used = (self.scope, node.lineno)
except KeyError:
pass
else:
return
# try enclosing function scopes
for scope in self.scopeStack[-2:0:-1]:
importStarred = importStarred or scope.importStarred
if not isinstance(scope, FunctionScope):
continue
try:
scope[node.name].used = (self.scope, node.lineno)
except KeyError:
pass
else:
return
# try global scope
importStarred = importStarred or self.scopeStack[0].importStarred
try:
self.scopeStack[0][node.name].used = (self.scope, node.lineno)
except KeyError:
if not importStarred and node.name not in self.builtIns:
if (os.path.basename(self.filename) == '__init__.py' and
node.name == '__path__'):
# the special name __path__ is valid only in packages
pass
else:
self.report(messages.UndefinedName, node.lineno, node.name)
def FUNCTION(self, node):
if getattr(node, "decorators", None) is not None:
self.handleChildren(node.decorators)
self.addBinding(node.lineno, FunctionDefinition(node.name, node))
self.LAMBDA(node)
def LAMBDA(self, node):
for default in node.defaults:
self.handleNode(default, node)
def runFunction():
args = []
def addArgs(arglist):
for arg in arglist:
if isinstance(arg, tuple):
addArgs(arg)
else:
if arg in args:
self.report(messages.DuplicateArgument,
node.lineno, arg)
args.append(arg)
self.pushFunctionScope()
addArgs(node.argnames)
for name in args:
self.addBinding(node.lineno, Argument(name, node),
reportRedef=False)
self.handleNode(node.code, node)
def checkUnusedAssignments():
"""
Check to see if any assignments have not been used.
"""
for name, binding in self.scope.iteritems():
if (not binding.used and not name in self.scope.globals
and isinstance(binding, Assignment)):
self.report(messages.UnusedVariable,
binding.source.lineno, name)
self.deferAssignment(checkUnusedAssignments)
self.popScope()
self.deferFunction(runFunction)
def CLASS(self, node):
"""
Check names used in a class definition, including its decorators, base
classes, and the body of its definition. Additionally, add its name to
the current scope.
"""
if getattr(node, "decorators", None) is not None:
self.handleChildren(node.decorators)
for baseNode in node.bases:
self.handleNode(baseNode, node)
self.addBinding(node.lineno, Binding(node.name, node))
self.pushClassScope()
self.handleChildren(node.code)
self.popScope()
def ASSNAME(self, node):
if node.flags == 'OP_DELETE':
if isinstance(self.scope, FunctionScope) and \
node.name in self.scope.globals:
del self.scope.globals[node.name]
else:
self.addBinding(node.lineno, UnBinding(node.name, node))
else:
# if the name hasn't already been defined in the current scope
if isinstance(self.scope, FunctionScope) and \
node.name not in self.scope:
# for each function or module scope above us
for scope in self.scopeStack[:-1]:
if not isinstance(scope, (FunctionScope, ModuleScope)):
continue
# if the name was defined in that scope, and the name has
# been accessed already in the current scope, and hasn't
# been declared global
if (node.name in scope
and scope[node.name].used
and scope[node.name].used[0] is self.scope
and node.name not in self.scope.globals):
# then it's probably a mistake
self.report(messages.UndefinedLocal,
scope[node.name].used[1],
node.name,
scope[node.name].source.lineno)
break
if isinstance(node.parent,
(ast.For, ast.ListCompFor, ast.GenExprFor,
ast.AssTuple, ast.AssList)):
binding = Binding(node.name, node)
elif (node.name == '__all__' and
isinstance(self.scope, ModuleScope) and
isinstance(node.parent, ast.Assign)):
binding = ExportBinding(node.name, node.parent.expr)
else:
binding = Assignment(node.name, node)
if node.name in self.scope:
binding.used = self.scope[node.name].used
self.addBinding(node.lineno, binding)
def ASSIGN(self, node):
self.handleNode(node.expr, node)
for subnode in node.nodes[::-1]:
self.handleNode(subnode, node)
def IMPORT(self, node):
for name, alias in node.names:
name = alias or name
importation = Importation(name, node)
self.addBinding(node.lineno, importation)
def FROM(self, node):
if node.modname == '__future__':
if not self.futuresAllowed:
self.report(messages.LateFutureImport, node.lineno,
[n[0] for n in node.names])
else:
self.futuresAllowed = False
for name, alias in node.names:
if name == '*':
self.scope.importStarred = True
continue
name = alias or name
importation = Importation(name, node)
if node.modname == '__future__':
importation.used = (self.scope, node.lineno)
self.addBinding(node.lineno, importation)