Mercurial Repositories > eric / file comparison
comparison: Plugins/CheckerPlugins/CodeStyleChecker/mccabe.py
Plugins/CheckerPlugins/CodeStyleChecker/mccabe.py
- changeset 4423
- 14f3ca3dcef6
- child 4465
- 2fbb5bdb8ddf
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| 4419:66be66ec3afc | 4423:14f3ca3dcef6 |
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| 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 collections | |
| 9 import ast | |
| 10 | |
| 11 __version__ = '0.3.1_eric6' | |
| 12 | |
| 13 | |
| 14 class ASTVisitor(object): | |
| 15 """Performs a depth-first walk of the AST.""" | |
| 16 | |
| 17 def __init__(self): | |
| 18 self.node = None | |
| 19 self._cache = {} | |
| 20 | |
| 21 def default(self, node, *args): | |
| 22 for child in ast.iter_child_nodes(node): | |
| 23 self.dispatch(child, *args) | |
| 24 | |
| 25 def dispatch(self, node, *args): | |
| 26 self.node = node | |
| 27 klass = node.__class__ | |
| 28 meth = self._cache.get(klass) | |
| 29 if meth is None: | |
| 30 className = klass.__name__ | |
| 31 meth = getattr(self.visitor, 'visit' + className, self.default) | |
| 32 self._cache[klass] = meth | |
| 33 return meth(node, *args) | |
| 34 | |
| 35 def preorder(self, tree, visitor, *args): | |
| 36 """Do preorder walk of tree using visitor""" | |
| 37 self.visitor = visitor | |
| 38 visitor.visit = self.dispatch | |
| 39 self.dispatch(tree, *args) # XXX *args make sense? | |
| 40 | |
| 41 | |
| 42 class PathNode(object): | |
| 43 def __init__(self, name, look="circle"): | |
| 44 self.name = name | |
| 45 self.look = look | |
| 46 | |
| 47 def to_dot(self): | |
| 48 print('node [shape=%s,label="%s"] %d;' % ( | |
| 49 self.look, self.name, self.dot_id())) | |
| 50 | |
| 51 def dot_id(self): | |
| 52 return id(self) | |
| 53 | |
| 54 | |
| 55 class PathGraph(object): | |
| 56 def __init__(self, name, entity, lineno): | |
| 57 self.name = name | |
| 58 self.entity = entity | |
| 59 self.lineno = lineno | |
| 60 self.nodes = collections.defaultdict(list) | |
| 61 | |
| 62 def connect(self, n1, n2): | |
| 63 self.nodes[n1].append(n2) | |
| 64 # Ensure that the destination node is always counted. | |
| 65 self.nodes[n2] = [] | |
| 66 | |
| 67 def to_dot(self): | |
| 68 print('subgraph {') | |
| 69 for node in self.nodes: | |
| 70 node.to_dot() | |
| 71 for node, nexts in self.nodes.items(): | |
| 72 for next in nexts: | |
| 73 print('%s -- %s;' % (node.dot_id(), next.dot_id())) | |
| 74 print('}') | |
| 75 | |
| 76 def complexity(self): | |
| 77 """ Return the McCabe complexity for the graph. | |
| 78 V-E+2 | |
| 79 """ | |
| 80 num_edges = sum([len(n) for n in self.nodes.values()]) | |
| 81 num_nodes = len(self.nodes) | |
| 82 return num_edges - num_nodes + 2 | |
| 83 | |
| 84 | |
| 85 class PathGraphingAstVisitor(ASTVisitor): | |
| 86 """ A visitor for a parsed Abstract Syntax Tree which finds executable | |
| 87 statements. | |
| 88 """ | |
| 89 | |
| 90 def __init__(self): | |
| 91 super(PathGraphingAstVisitor, self).__init__() | |
| 92 self.classname = "" | |
| 93 self.graphs = {} | |
| 94 self.reset() | |
| 95 | |
| 96 def reset(self): | |
| 97 self.graph = None | |
| 98 self.tail = None | |
| 99 | |
| 100 def dispatch_list(self, node_list): | |
| 101 for node in node_list: | |
| 102 self.dispatch(node) | |
| 103 | |
| 104 def visitFunctionDef(self, node): | |
| 105 | |
| 106 if self.classname: | |
| 107 entity = '%s%s' % (self.classname, node.name) | |
| 108 else: | |
| 109 entity = node.name | |
| 110 | |
| 111 name = '%d:1: %r' % (node.lineno, entity) | |
| 112 | |
| 113 if self.graph is not None: | |
| 114 # closure | |
| 115 pathnode = self.appendPathNode(name) | |
| 116 self.tail = pathnode | |
| 117 self.dispatch_list(node.body) | |
| 118 bottom = PathNode("", look='point') | |
| 119 self.graph.connect(self.tail, bottom) | |
| 120 self.graph.connect(pathnode, bottom) | |
| 121 self.tail = bottom | |
| 122 else: | |
| 123 self.graph = PathGraph(name, entity, node.lineno) | |
| 124 pathnode = PathNode(name) | |
| 125 self.tail = pathnode | |
| 126 self.dispatch_list(node.body) | |
| 127 self.graphs["%s%s" % (self.classname, node.name)] = self.graph | |
| 128 self.reset() | |
| 129 | |
| 130 def visitClassDef(self, node): | |
| 131 old_classname = self.classname | |
| 132 self.classname += node.name + "." | |
| 133 self.dispatch_list(node.body) | |
| 134 self.classname = old_classname | |
| 135 | |
| 136 def appendPathNode(self, name): | |
| 137 if not self.tail: | |
| 138 return | |
| 139 pathnode = PathNode(name) | |
| 140 self.graph.connect(self.tail, pathnode) | |
| 141 self.tail = pathnode | |
| 142 return pathnode | |
| 143 | |
| 144 def visitSimpleStatement(self, node): | |
| 145 if node.lineno is None: | |
| 146 lineno = 0 | |
| 147 else: | |
| 148 lineno = node.lineno | |
| 149 name = "Stmt %d" % lineno | |
| 150 self.appendPathNode(name) | |
| 151 | |
| 152 visitAssert = visitAssign = visitAugAssign = visitDelete = visitPrint = \ | |
| 153 visitRaise = visitYield = visitImport = visitCall = visitSubscript = \ | |
| 154 visitPass = visitContinue = visitBreak = visitGlobal = visitReturn = \ | |
| 155 visitSimpleStatement | |
| 156 | |
| 157 def visitLoop(self, node): | |
| 158 name = "Loop %d" % node.lineno | |
| 159 self._subgraph(node, name) | |
| 160 | |
| 161 visitFor = visitWhile = visitLoop | |
| 162 | |
| 163 def visitIf(self, node): | |
| 164 name = "If %d" % node.lineno | |
| 165 self._subgraph(node, name) | |
| 166 | |
| 167 def _subgraph(self, node, name, extra_blocks=()): | |
| 168 """create the subgraphs representing any `if` and `for` statements""" | |
| 169 if self.graph is None: | |
| 170 # global loop | |
| 171 self.graph = PathGraph(name, name, node.lineno) | |
| 172 pathnode = PathNode(name) | |
| 173 self._subgraph_parse(node, pathnode, extra_blocks) | |
| 174 self.graphs["%s%s" % (self.classname, name)] = self.graph | |
| 175 self.reset() | |
| 176 else: | |
| 177 pathnode = self.appendPathNode(name) | |
| 178 self._subgraph_parse(node, pathnode, extra_blocks) | |
| 179 | |
| 180 def _subgraph_parse(self, node, pathnode, extra_blocks): | |
| 181 """parse the body and any `else` block of `if` and `for` statements""" | |
| 182 loose_ends = [] | |
| 183 self.tail = pathnode | |
| 184 self.dispatch_list(node.body) | |
| 185 loose_ends.append(self.tail) | |
| 186 for extra in extra_blocks: | |
| 187 self.tail = pathnode | |
| 188 self.dispatch_list(extra.body) | |
| 189 loose_ends.append(self.tail) | |
| 190 if node.orelse: | |
| 191 self.tail = pathnode | |
| 192 self.dispatch_list(node.orelse) | |
| 193 loose_ends.append(self.tail) | |
| 194 else: | |
| 195 loose_ends.append(pathnode) | |
| 196 if pathnode: | |
| 197 bottom = PathNode("", look='point') | |
| 198 for le in loose_ends: | |
| 199 self.graph.connect(le, bottom) | |
| 200 self.tail = bottom | |
| 201 | |
| 202 def visitTryExcept(self, node): | |
| 203 name = "TryExcept %d" % node.lineno | |
| 204 self._subgraph(node, name, extra_blocks=node.handlers) | |
| 205 | |
| 206 visitTry = visitTryExcept | |
| 207 | |
| 208 def visitWith(self, node): | |
| 209 name = "With %d" % node.lineno | |
| 210 self.appendPathNode(name) | |
| 211 self.dispatch_list(node.body) |
