| # Copyright (c) 2003-2010 LOGILAB S.A. (Paris, FRANCE). |
| # http://www.logilab.fr/ -- mailto:contact@logilab.fr |
| # |
| # This program is free software; you can redistribute it and/or modify it under |
| # the terms of the GNU General Public License as published by the Free Software |
| # Foundation; either version 2 of the License, or (at your option) any later |
| # version. |
| # |
| # This program is distributed in the hope that it will be useful, but WITHOUT |
| # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
| # FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. |
| # |
| # You should have received a copy of the GNU General Public License along with |
| # this program; if not, write to the Free Software Foundation, Inc., |
| # 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| """imports checkers for Python code""" |
| |
| from logilab.common.graph import get_cycles, DotBackend |
| from logilab.common.modutils import is_standard_module |
| from logilab.common.ureports import VerbatimText, Paragraph |
| |
| from logilab import astng |
| from logilab.astng import are_exclusive |
| |
| from pylint.interfaces import IASTNGChecker |
| from pylint.checkers import BaseChecker, EmptyReport |
| |
| |
| def get_first_import(node, context, name, base, level): |
| """return the node where [base.]<name> is imported or None if not found |
| """ |
| first = None |
| found = False |
| for first in context.values(): |
| if isinstance(first, astng.Import): |
| if name in [iname[0] for iname in first.names]: |
| found = True |
| break |
| elif isinstance(first, astng.From): |
| if base == first.modname and level == first.level and \ |
| name in [iname[0] for iname in first.names]: |
| found = True |
| break |
| if found and first is not node and not are_exclusive(first, node): |
| return first |
| |
| # utilities to represents import dependencies as tree and dot graph ########### |
| |
| def filter_dependencies_info(dep_info, package_dir, mode='external'): |
| """filter external or internal dependencies from dep_info (return a |
| new dictionary containing the filtered modules only) |
| """ |
| if mode == 'external': |
| filter_func = lambda x: not is_standard_module(x, (package_dir,)) |
| else: |
| assert mode == 'internal' |
| filter_func = lambda x: is_standard_module(x, (package_dir,)) |
| result = {} |
| for importee, importers in dep_info.items(): |
| if filter_func(importee): |
| result[importee] = importers |
| return result |
| |
| def make_tree_defs(mod_files_list): |
| """get a list of 2-uple (module, list_of_files_which_import_this_module), |
| it will return a dictionary to represent this as a tree |
| """ |
| tree_defs = {} |
| for mod, files in mod_files_list: |
| node = (tree_defs, ()) |
| for prefix in mod.split('.'): |
| node = node[0].setdefault(prefix, [{}, []]) |
| node[1] += files |
| return tree_defs |
| |
| def repr_tree_defs(data, indent_str=None): |
| """return a string which represents imports as a tree""" |
| lines = [] |
| nodes = data.items() |
| for i, (mod, (sub, files)) in enumerate(sorted(nodes, key=lambda x: x[0])): |
| if not files: |
| files = '' |
| else: |
| files = '(%s)' % ','.join(files) |
| if indent_str is None: |
| lines.append('%s %s' % (mod, files)) |
| sub_indent_str = ' ' |
| else: |
| lines.append('%s\-%s %s' % (indent_str, mod, files)) |
| if i == len(nodes)-1: |
| sub_indent_str = '%s ' % indent_str |
| else: |
| sub_indent_str = '%s| ' % indent_str |
| if sub: |
| lines.append(repr_tree_defs(sub, sub_indent_str)) |
| return '\n'.join(lines) |
| |
| |
| def dependencies_graph(filename, dep_info): |
| """write dependencies as a dot (graphviz) file |
| """ |
| done = {} |
| printer = DotBackend(filename[:-4], rankdir = "LR") |
| printer.emit('URL="." node[shape="box"]') |
| for modname, dependencies in dep_info.items(): |
| done[modname] = 1 |
| printer.emit_node(modname) |
| for modname in dependencies: |
| if modname not in done: |
| done[modname] = 1 |
| printer.emit_node(modname) |
| for depmodname, dependencies in dep_info.items(): |
| for modname in dependencies: |
| printer.emit_edge(modname, depmodname) |
| printer.generate(filename) |
| |
| |
| def make_graph(filename, dep_info, sect, gtype): |
| """generate a dependencies graph and add some information about it in the |
| report's section |
| """ |
| dependencies_graph(filename, dep_info) |
| sect.append(Paragraph('%simports graph has been written to %s' |
| % (gtype, filename))) |
| |
| |
| # the import checker itself ################################################### |
| |
| MSGS = { |
| 'F0401': ('Unable to import %s', |
| 'Used when pylint has been unable to import a module.'), |
| 'R0401': ('Cyclic import (%s)', |
| 'Used when a cyclic import between two or more modules is \ |
| detected.'), |
| |
| 'W0401': ('Wildcard import %s', |
| 'Used when `from module import *` is detected.'), |
| 'W0402': ('Uses of a deprecated module %r', |
| 'Used a module marked as deprecated is imported.'), |
| 'W0403': ('Relative import %r, should be %r', |
| 'Used when an import relative to the package directory is \ |
| detected.'), |
| 'W0404': ('Reimport %r (imported line %s)', |
| 'Used when a module is reimported multiple times.'), |
| 'W0406': ('Module import itself', |
| 'Used when a module is importing itself.'), |
| |
| 'W0410': ('__future__ import is not the first non docstring statement', |
| 'Python 2.5 and greater require __future__ import to be the \ |
| first non docstring statement in the module.'), |
| } |
| |
| class ImportsChecker(BaseChecker): |
| """checks for |
| * external modules dependencies |
| * relative / wildcard imports |
| * cyclic imports |
| * uses of deprecated modules |
| """ |
| |
| __implements__ = IASTNGChecker |
| |
| name = 'imports' |
| msgs = MSGS |
| priority = -2 |
| |
| options = (('deprecated-modules', |
| {'default' : ('regsub', 'string', 'TERMIOS', |
| 'Bastion', 'rexec'), |
| 'type' : 'csv', |
| 'metavar' : '<modules>', |
| 'help' : 'Deprecated modules which should not be used, \ |
| separated by a comma'} |
| ), |
| ('import-graph', |
| {'default' : '', |
| 'type' : 'string', |
| 'metavar' : '<file.dot>', |
| 'help' : 'Create a graph of every (i.e. internal and \ |
| external) dependencies in the given file (report RP0402 must not be disabled)'} |
| ), |
| ('ext-import-graph', |
| {'default' : '', |
| 'type' : 'string', |
| 'metavar' : '<file.dot>', |
| 'help' : 'Create a graph of external dependencies in the \ |
| given file (report RP0402 must not be disabled)'} |
| ), |
| ('int-import-graph', |
| {'default' : '', |
| 'type' : 'string', |
| 'metavar' : '<file.dot>', |
| 'help' : 'Create a graph of internal dependencies in the \ |
| given file (report RP0402 must not be disabled)'} |
| ), |
| |
| ) |
| |
| def __init__(self, linter=None): |
| BaseChecker.__init__(self, linter) |
| self.stats = None |
| self.import_graph = None |
| self.__int_dep_info = self.__ext_dep_info = None |
| self.reports = (('RP0401', 'External dependencies', |
| self.report_external_dependencies), |
| ('RP0402', 'Modules dependencies graph', |
| self.report_dependencies_graph), |
| ) |
| |
| def open(self): |
| """called before visiting project (i.e set of modules)""" |
| self.linter.add_stats(dependencies={}) |
| self.linter.add_stats(cycles=[]) |
| self.stats = self.linter.stats |
| self.import_graph = {} |
| |
| def close(self): |
| """called before visiting project (i.e set of modules)""" |
| # don't try to compute cycles if the associated message is disabled |
| if self.linter.is_message_enabled('R0401'): |
| for cycle in get_cycles(self.import_graph): |
| self.add_message('R0401', args=' -> '.join(cycle)) |
| |
| def visit_import(self, node): |
| """triggered when an import statement is seen""" |
| modnode = node.root() |
| for name, _ in node.names: |
| importedmodnode = self.get_imported_module(modnode, node, name) |
| if importedmodnode is None: |
| continue |
| self._check_relative_import(modnode, node, importedmodnode, name) |
| self._add_imported_module(node, importedmodnode.name) |
| self._check_deprecated_module(node, name) |
| self._check_reimport(node, name) |
| |
| |
| def visit_from(self, node): |
| """triggered when a from statement is seen""" |
| basename = node.modname |
| if basename == '__future__': |
| # check if this is the first non-docstring statement in the module |
| prev = node.previous_sibling() |
| if prev: |
| # consecutive future statements are possible |
| if not (isinstance(prev, astng.From) |
| and prev.modname == '__future__'): |
| self.add_message('W0410', node=node) |
| return |
| modnode = node.root() |
| importedmodnode = self.get_imported_module(modnode, node, basename) |
| if importedmodnode is None: |
| return |
| self._check_relative_import(modnode, node, importedmodnode, basename) |
| self._check_deprecated_module(node, basename) |
| for name, _ in node.names: |
| if name == '*': |
| self.add_message('W0401', args=basename, node=node) |
| continue |
| self._add_imported_module(node, '%s.%s' % (importedmodnode.name, name)) |
| self._check_reimport(node, name, basename, node.level) |
| |
| def get_imported_module(self, modnode, importnode, modname): |
| try: |
| return importnode.do_import_module(modname) |
| except astng.InferenceError, ex: |
| if str(ex) != modname: |
| args = '%r (%s)' % (modname, ex) |
| else: |
| args = repr(modname) |
| self.add_message("F0401", args=args, node=importnode) |
| |
| def _check_relative_import(self, modnode, importnode, importedmodnode, |
| importedasname): |
| """check relative import. node is either an Import or From node, modname |
| the imported module name. |
| """ |
| if 'W0403' not in self.active_msgs: |
| return |
| if importedmodnode.file is None: |
| return False # built-in module |
| if modnode is importedmodnode: |
| return False # module importing itself |
| if modnode.absolute_import_activated() or getattr(importnode, 'level', None): |
| return False |
| if importedmodnode.name != importedasname: |
| # this must be a relative import... |
| self.add_message('W0403', args=(importedasname, importedmodnode.name), |
| node=importnode) |
| |
| def _add_imported_module(self, node, importedmodname): |
| """notify an imported module, used to analyze dependencies""" |
| context_name = node.root().name |
| if context_name == importedmodname: |
| # module importing itself ! |
| self.add_message('W0406', node=node) |
| elif not is_standard_module(importedmodname): |
| # handle dependencies |
| importedmodnames = self.stats['dependencies'].setdefault( |
| importedmodname, set()) |
| if not context_name in importedmodnames: |
| importedmodnames.add(context_name) |
| if is_standard_module( importedmodname, (self.package_dir(),) ): |
| # update import graph |
| mgraph = self.import_graph.setdefault(context_name, set()) |
| if not importedmodname in mgraph: |
| mgraph.add(importedmodname) |
| |
| def _check_deprecated_module(self, node, mod_path): |
| """check if the module is deprecated""" |
| for mod_name in self.config.deprecated_modules: |
| if mod_path == mod_name or mod_path.startswith(mod_name + '.'): |
| self.add_message('W0402', node=node, args=mod_path) |
| |
| def _check_reimport(self, node, name, basename=None, level=0): |
| """check if the import is necessary (i.e. not already done)""" |
| if 'W0404' not in self.active_msgs: |
| return |
| frame = node.frame() |
| root = node.root() |
| contexts = [(frame, level)] |
| if root is not frame: |
| contexts.append((root, 0)) |
| for context, level in contexts: |
| first = get_first_import(node, context, name, basename, level) |
| if first is not None: |
| self.add_message('W0404', node=node, |
| args=(name, first.fromlineno)) |
| |
| |
| def report_external_dependencies(self, sect, _, dummy): |
| """return a verbatim layout for displaying dependencies""" |
| dep_info = make_tree_defs(self._external_dependencies_info().items()) |
| if not dep_info: |
| raise EmptyReport() |
| tree_str = repr_tree_defs(dep_info) |
| sect.append(VerbatimText(tree_str)) |
| |
| def report_dependencies_graph(self, sect, _, dummy): |
| """write dependencies as a dot (graphviz) file""" |
| dep_info = self.stats['dependencies'] |
| if not dep_info or not (self.config.import_graph |
| or self.config.ext_import_graph |
| or self.config.int_import_graph): |
| raise EmptyReport() |
| filename = self.config.import_graph |
| if filename: |
| make_graph(filename, dep_info, sect, '') |
| filename = self.config.ext_import_graph |
| if filename: |
| make_graph(filename, self._external_dependencies_info(), |
| sect, 'external ') |
| filename = self.config.int_import_graph |
| if filename: |
| make_graph(filename, self._internal_dependencies_info(), |
| sect, 'internal ') |
| |
| def _external_dependencies_info(self): |
| """return cached external dependencies information or build and |
| cache them |
| """ |
| if self.__ext_dep_info is None: |
| self.__ext_dep_info = filter_dependencies_info( |
| self.stats['dependencies'], self.package_dir(), 'external') |
| return self.__ext_dep_info |
| |
| def _internal_dependencies_info(self): |
| """return cached internal dependencies information or build and |
| cache them |
| """ |
| if self.__int_dep_info is None: |
| self.__int_dep_info = filter_dependencies_info( |
| self.stats['dependencies'], self.package_dir(), 'internal') |
| return self.__int_dep_info |
| |
| |
| def register(linter): |
| """required method to auto register this checker """ |
| linter.register_checker(ImportsChecker(linter)) |
