1 #!/usr/bin/env python 2 3 """ 4 Fix instances, removing those which are not part of the distinct set for a given 5 class. 6 7 Copyright (C) 2006, 2007 Paul Boddie <paul@boddie.org.uk> 8 9 This software is free software; you can redistribute it and/or 10 modify it under the terms of the GNU General Public License as 11 published by the Free Software Foundation; either version 2 of 12 the License, or (at your option) any later version. 13 14 This software is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public 20 License along with this library; see the file LICENCE.txt 21 If not, write to the Free Software Foundation, Inc., 22 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 23 24 -------- 25 26 To use this module, the easiest approach is to use the fix function: 27 28 fix(module) 29 30 The more complicated approach involves instantiating a Fixer object: 31 32 fixer = Fixer() 33 34 Then, applying the fixer to an existing module: 35 36 fixer.process(module) 37 """ 38 39 from simplify.simplified import * 40 41 # Fixing of instance information. 42 43 class Fixer(Visitor): 44 45 """ 46 The name fixer which traverses the program nodes in a module, typically 47 depth-first, and eliminates references to superfluous instances, replacing 48 them with those from each class's distinct list, if necessary. 49 50 See the simplify.fixnames.Fixer class for a description of the 51 """ 52 53 def __init__(self): 54 55 "Initialise the name fixer." 56 57 Visitor.__init__(self) 58 59 # Satisfy visitor issues. 60 61 self.visitor = self 62 63 def process(self, module): 64 65 "Process the given 'module'." 66 67 # The fixer maintains a list of transformed subprograms (added for each 68 # of the processing "roots" and also for each invoked internal 69 # subprogram), along with a list of current subprograms (used to avoid 70 # recursion issues) and a list of current namespaces (used to recall 71 # namespaces upon invoking internal subprograms). 72 73 self.subprograms = [] 74 self.current_subprograms = [] 75 76 self.module = module 77 78 # Visit structures and instances. 79 80 for structure in self.module.simplifier.structures: 81 for instance in structure.get_instances(): 82 for name, attrs in instance.namespace.items(): 83 instance.namespace[name] = self._replace(attrs) 84 85 self.process_node(self.module) 86 87 # Then, process all functions and methods. 88 89 for subprogram in self.module.simplifier.subprograms: 90 91 # Internal subprograms are skipped here and processed specially via 92 # Invoke nodes. 93 94 if not getattr(subprogram, "internal", 0): 95 for specialised in subprogram.active(): 96 self.subprograms.append(self.process_node(specialised)) 97 98 def process_node(self, node): 99 100 """ 101 Process a subprogram or module 'node', discovering from attributes on 102 'node' any initial locals. Return a modified subprogram or module. 103 """ 104 105 # Do not process subprograms already being processed. 106 107 if node in self.current_subprograms: 108 return None 109 110 # Record the current subprogram. 111 112 self.current_subprograms.append(node) 113 114 # Dispatch to the code itself. 115 116 result = self.dispatch(node) 117 118 # Restore the previous subprogram and namespace. 119 120 self.current_subprograms.pop() 121 122 return node 123 124 # Visitor methods. 125 126 def default(self, node): 127 128 """ 129 Process the given 'node', given that it does not have a specific 130 handler. 131 """ 132 133 # Process annotations. 134 135 for name in ("non_accesses", "non_writes", "raises", "returns", "types"): 136 if hasattr(node, name): 137 attrs = getattr(node, name) 138 setattr(node, name, self._replace(attrs)) 139 for name in ("accesses", "writes", "paramtypes"): 140 if hasattr(node, name): 141 d = getattr(node, name) 142 for expr, attrs in d.items(): 143 d[self._get_replacement(expr)] = self._replace(attrs, name) 144 145 # Visit program nodes. 146 147 for attr in ("pos_args",): 148 if hasattr(node, attr): 149 self.dispatches(getattr(node, attr)) 150 for attr in ("kw_args",): 151 if hasattr(node, attr): 152 self.dispatch_dict(getattr(node, attr)) 153 for attr in ("expr", "lvalue", "test", "star", "dstar"): 154 if hasattr(node, attr): 155 self.dispatch(getattr(node, attr)) 156 for attr in ("body", "else_", "handler", "finally_", "code", "choices", "nodes"): 157 if hasattr(node, attr): 158 self.dispatches(getattr(node, attr)) 159 if hasattr(node, "params"): 160 for param, default in node.params: 161 self.dispatch(default) 162 for attr in ("star", "dstar"): 163 if getattr(node, attr, None): 164 param, default = getattr(node, attr) 165 self.dispatch(default) 166 167 return node 168 169 def _replace(self, items, name=None): 170 if name == "accesses": 171 new_items = [] 172 else: 173 new_items = set() 174 175 for item in list(items): 176 if name == "accesses": 177 attr, accessor = item 178 value = attr.type 179 new_items.append((Attribute(self._get_replacement(attr.context), self._get_replacement(value)), self._get_replacement(accessor))) 180 else: 181 attr = item 182 value = attr.type 183 new_items.add(Attribute(self._get_replacement(attr.context), self._get_replacement(value))) 184 185 return new_items 186 187 def _get_replacement(self, value): 188 if isinstance(value, Instance): 189 distinct_instances = value.get_class().get_distinct_instances() 190 return distinct_instances[value] 191 else: 192 return value 193 194 def dispatch(self, node, *args): 195 return Visitor.dispatch(self, node, *args) 196 197 def visitInvokeFunction(self, invoke): 198 199 "Transform the 'invoke' node, performing processing on subprograms." 200 201 return self.default(invoke) 202 203 def visitInvokeRef(self, invoke): 204 205 "Transform the 'invoke' node, performing processing on subprograms." 206 207 # The special case of internal subprogram invocation is addressed by 208 # propagating namespace information to the subprogram and processing it. 209 210 subprogram = self.process_node(invoke.ref) 211 212 if subprogram is not None: 213 self.subprograms.append(subprogram) 214 return invoke 215 216 # Convenience functions. 217 218 def fix(module): 219 220 "Fix the instances in the given 'module'." 221 222 fixer = Fixer() 223 fixer.process(module) 224 225 # vim: tabstop=4 expandtab shiftwidth=4