djavu-asus/elpy/rpc-venv/lib/python3.11/site-packages/mccabe.py

   1 """ Meager code path measurement tool.
   2     Ned Batchelder
   3     http://nedbatchelder.com/blog/200803/python_code_complexity_microtool.html
   4     MIT License.
   5 """
   6 from __future__ import with_statement
   7
   8 import optparse
   9 import sys
  10 import tokenize
  11
  12 from collections import defaultdict
  13 try:
  14     import ast
  15     from ast import iter_child_nodes
  16 except ImportError:   # Python 2.5
  17     from flake8.util import ast, iter_child_nodes
  18
  19 __version__ = '0.7.0'
  20
  21
  22 class ASTVisitor(object):
  23     """Performs a depth-first walk of the AST."""
  24
  25     def __init__(self):
  26         self.node = None
  27         self._cache = {}
  28
  29     def default(self, node, *args):
  30         for child in iter_child_nodes(node):
  31             self.dispatch(child, *args)
  32
  33     def dispatch(self, node, *args):
  34         self.node = node
  35         klass = node.__class__
  36         meth = self._cache.get(klass)
  37         if meth is None:
  38             className = klass.__name__
  39             meth = getattr(self.visitor, 'visit' + className, self.default)
  40             self._cache[klass] = meth
  41         return meth(node, *args)
  42
  43     def preorder(self, tree, visitor, *args):
  44         """Do preorder walk of tree using visitor"""
  45         self.visitor = visitor
  46         visitor.visit = self.dispatch
  47         self.dispatch(tree, *args)  # XXX *args make sense?
  48
  49
  50 class PathNode(object):
  51     def __init__(self, name, look="circle"):
  52         self.name = name
  53         self.look = look
  54
  55     def to_dot(self):
  56         print('node [shape=%s,label="%s"] %d;' % (
  57             self.look, self.name, self.dot_id()))
  58
  59     def dot_id(self):
  60         return id(self)
  61
  62
  63 class PathGraph(object):
  64     def __init__(self, name, entity, lineno, column=0):
  65         self.name = name
  66         self.entity = entity
  67         self.lineno = lineno
  68         self.column = column
  69         self.nodes = defaultdict(list)
  70
  71     def connect(self, n1, n2):
  72         self.nodes[n1].append(n2)
  73         # Ensure that the destination node is always counted.
  74         self.nodes[n2] = []
  75
  76     def to_dot(self):
  77         print('subgraph {')
  78         for node in self.nodes:
  79             node.to_dot()
  80         for node, nexts in self.nodes.items():
  81             for next in nexts:
  82                 print('%s -- %s;' % (node.dot_id(), next.dot_id()))
  83         print('}')
  84
  85     def complexity(self):
  86         """ Return the McCabe complexity for the graph.
  87             V-E+2
  88         """
  89         num_edges = sum([len(n) for n in self.nodes.values()])
  90         num_nodes = len(self.nodes)
  91         return num_edges - num_nodes + 2
  92
  93
  94 class PathGraphingAstVisitor(ASTVisitor):
  95     """ A visitor for a parsed Abstract Syntax Tree which finds executable
  96         statements.
  97     """
  98
  99     def __init__(self):
 100         super(PathGraphingAstVisitor, self).__init__()
 101         self.classname = ""
 102         self.graphs = {}
 103         self.reset()
 104
 105     def reset(self):
 106         self.graph = None
 107         self.tail = None
 108
 109     def dispatch_list(self, node_list):
 110         for node in node_list:
 111             self.dispatch(node)
 112
 113     def visitFunctionDef(self, node):
 114
 115         if self.classname:
 116             entity = '%s%s' % (self.classname, node.name)
 117         else:
 118             entity = node.name
 119
 120         name = '%d:%d: %r' % (node.lineno, node.col_offset, entity)
 121
 122         if self.graph is not None:
 123             # closure
 124             pathnode = self.appendPathNode(name)
 125             self.tail = pathnode
 126             self.dispatch_list(node.body)
 127             bottom = PathNode("", look='point')
 128             self.graph.connect(self.tail, bottom)
 129             self.graph.connect(pathnode, bottom)
 130             self.tail = bottom
 131         else:
 132             self.graph = PathGraph(name, entity, node.lineno, node.col_offset)
 133             pathnode = PathNode(name)
 134             self.tail = pathnode
 135             self.dispatch_list(node.body)
 136             self.graphs["%s%s" % (self.classname, node.name)] = self.graph
 137             self.reset()
 138
 139     visitAsyncFunctionDef = visitFunctionDef
 140
 141     def visitClassDef(self, node):
 142         old_classname = self.classname
 143         self.classname += node.name + "."
 144         self.dispatch_list(node.body)
 145         self.classname = old_classname
 146
 147     def appendPathNode(self, name):
 148         if not self.tail:
 149             return
 150         pathnode = PathNode(name)
 151         self.graph.connect(self.tail, pathnode)
 152         self.tail = pathnode
 153         return pathnode
 154
 155     def visitSimpleStatement(self, node):
 156         if node.lineno is None:
 157             lineno = 0
 158         else:
 159             lineno = node.lineno
 160         name = "Stmt %d" % lineno
 161         self.appendPathNode(name)
 162
 163     def default(self, node, *args):
 164         if isinstance(node, ast.stmt):
 165             self.visitSimpleStatement(node)
 166         else:
 167             super(PathGraphingAstVisitor, self).default(node, *args)
 168
 169     def visitLoop(self, node):
 170         name = "Loop %d" % node.lineno
 171         self._subgraph(node, name)
 172
 173     visitAsyncFor = visitFor = visitWhile = visitLoop
 174
 175     def visitIf(self, node):
 176         name = "If %d" % node.lineno
 177         self._subgraph(node, name)
 178
 179     def _subgraph(self, node, name, extra_blocks=()):
 180         """create the subgraphs representing any `if` and `for` statements"""
 181         if self.graph is None:
 182             # global loop
 183             self.graph = PathGraph(name, name, node.lineno, node.col_offset)
 184             pathnode = PathNode(name)
 185             self._subgraph_parse(node, pathnode, extra_blocks)
 186             self.graphs["%s%s" % (self.classname, name)] = self.graph
 187             self.reset()
 188         else:
 189             pathnode = self.appendPathNode(name)
 190             self._subgraph_parse(node, pathnode, extra_blocks)
 191
 192     def _subgraph_parse(self, node, pathnode, extra_blocks):
 193         """parse the body and any `else` block of `if` and `for` statements"""
 194         loose_ends = []
 195         self.tail = pathnode
 196         self.dispatch_list(node.body)
 197         loose_ends.append(self.tail)
 198         for extra in extra_blocks:
 199             self.tail = pathnode
 200             self.dispatch_list(extra.body)
 201             loose_ends.append(self.tail)
 202         if node.orelse:
 203             self.tail = pathnode
 204             self.dispatch_list(node.orelse)
 205             loose_ends.append(self.tail)
 206         else:
 207             loose_ends.append(pathnode)
 208         if pathnode:
 209             bottom = PathNode("", look='point')
 210             for le in loose_ends:
 211                 self.graph.connect(le, bottom)
 212             self.tail = bottom
 213
 214     def visitTryExcept(self, node):
 215         name = "TryExcept %d" % node.lineno
 216         self._subgraph(node, name, extra_blocks=node.handlers)
 217
 218     visitTry = visitTryExcept
 219
 220     def visitWith(self, node):
 221         name = "With %d" % node.lineno
 222         self.appendPathNode(name)
 223         self.dispatch_list(node.body)
 224
 225     visitAsyncWith = visitWith
 226
 227
 228 class McCabeChecker(object):
 229     """McCabe cyclomatic complexity checker."""
 230     name = 'mccabe'
 231     version = __version__
 232     _code = 'C901'
 233     _error_tmpl = "C901 %r is too complex (%d)"
 234     max_complexity = -1
 235
 236     def __init__(self, tree, filename):
 237         self.tree = tree
 238
 239     @classmethod
 240     def add_options(cls, parser):
 241         flag = '--max-complexity'
 242         kwargs = {
 243             'default': -1,
 244             'action': 'store',
 245             'type': int,
 246             'help': 'McCabe complexity threshold',
 247             'parse_from_config': 'True',
 248         }
 249         config_opts = getattr(parser, 'config_options', None)
 250         if isinstance(config_opts, list):
 251             # Flake8 2.x
 252             kwargs.pop('parse_from_config')
 253             parser.add_option(flag, **kwargs)
 254             parser.config_options.append('max-complexity')
 255         else:
 256             parser.add_option(flag, **kwargs)
 257
 258     @classmethod
 259     def parse_options(cls, options):
 260         cls.max_complexity = int(options.max_complexity)
 261
 262     def run(self):
 263         if self.max_complexity < 0:
 264             return
 265         visitor = PathGraphingAstVisitor()
 266         visitor.preorder(self.tree, visitor)
 267         for graph in visitor.graphs.values():
 268             if graph.complexity() > self.max_complexity:
 269                 text = self._error_tmpl % (graph.entity, graph.complexity())
 270                 yield graph.lineno, graph.column, text, type(self)
 271
 272
 273 def get_code_complexity(code, threshold=7, filename='stdin'):
 274     try:
 275         tree = compile(code, filename, "exec", ast.PyCF_ONLY_AST)
 276     except SyntaxError:
 277         e = sys.exc_info()[1]
 278         sys.stderr.write("Unable to parse %s: %s\n" % (filename, e))
 279         return 0
 280
 281     complx = []
 282     McCabeChecker.max_complexity = threshold
 283     for lineno, offset, text, check in McCabeChecker(tree, filename).run():
 284         complx.append('%s:%d:1: %s' % (filename, lineno, text))
 285
 286     if len(complx) == 0:
 287         return 0
 288     print('\n'.join(complx))
 289     return len(complx)
 290
 291
 292 def get_module_complexity(module_path, threshold=7):
 293     """Returns the complexity of a module"""
 294     code = _read(module_path)
 295     return get_code_complexity(code, threshold, filename=module_path)
 296
 297
 298 def _read(filename):
 299     if (2, 5) < sys.version_info < (3, 0):
 300         with open(filename, 'rU') as f:
 301             return f.read()
 302     elif (3, 0) <= sys.version_info < (4, 0):
 303         """Read the source code."""
 304         try:
 305             with open(filename, 'rb') as f:
 306                 (encoding, _) = tokenize.detect_encoding(f.readline)
 307         except (LookupError, SyntaxError, UnicodeError):
 308             # Fall back if file encoding is improperly declared
 309             with open(filename, encoding='latin-1') as f:
 310                 return f.read()
 311         with open(filename, 'r', encoding=encoding) as f:
 312             return f.read()
 313
 314
 315 def main(argv=None):
 316     if argv is None:
 317         argv = sys.argv[1:]
 318     opar = optparse.OptionParser()
 319     opar.add_option("-d", "--dot", dest="dot",
 320                     help="output a graphviz dot file", action="store_true")
 321     opar.add_option("-m", "--min", dest="threshold",
 322                     help="minimum complexity for output", type="int",
 323                     default=1)
 324
 325     options, args = opar.parse_args(argv)
 326
 327     code = _read(args[0])
 328     tree = compile(code, args[0], "exec", ast.PyCF_ONLY_AST)
 329     visitor = PathGraphingAstVisitor()
 330     visitor.preorder(tree, visitor)
 331
 332     if options.dot:
 333         print('graph {')
 334         for graph in visitor.graphs.values():
 335             if (not options.threshold or
 336                     graph.complexity() >= options.threshold):
 337                 graph.to_dot()
 338         print('}')
 339     else:
 340         for graph in visitor.graphs.values():
 341             if graph.complexity() >= options.threshold:
 342                 print(graph.name, graph.complexity())
 343
 344
 345 if __name__ == '__main__':
 346     main(sys.argv[1:])