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 self.process_node(self.module) 78 79 # Then, process all functions and methods. 80 81 for subprogram in self.module.simplifier.subprograms: 82 83 # Internal subprograms are skipped here and processed specially via 84 # Invoke nodes. 85 86 if not getattr(subprogram, "internal", 0): 87 for specialised in subprogram.active(): 88 self.subprograms.append(self.process_node(specialised)) 89 90 # Visit structures and instances. 91 92 for structure in self.module.simplifier.structures: 93 for instance in structure.instances.values(): 94 for attrs in instance.namespace.values(): 95 self._replace(attrs) 96 97 def process_node(self, node): 98 99 """ 100 Process a subprogram or module 'node', discovering from attributes on 101 'node' any initial locals. Return a modified subprogram or module. 102 """ 103 104 # Do not process subprograms already being processed. 105 106 if node in self.current_subprograms: 107 return None 108 109 # Record the current subprogram. 110 111 self.current_subprograms.append(node) 112 113 # Dispatch to the code itself. 114 115 result = self.dispatch(node) 116 117 # Restore the previous subprogram and namespace. 118 119 self.current_subprograms.pop() 120 121 return node 122 123 # Visitor methods. 124 125 def default(self, node): 126 127 """ 128 Process the given 'node', given that it does not have a specific 129 handler. 130 """ 131 132 # Process annotations. 133 134 for name in ("non_accesses", "non_writes", "raises", "returns", "types"): 135 if hasattr(node, name): 136 attrs = getattr(node, name) 137 self._replace(attrs) 138 for name in ("accesses", "writes", "paramtypes"): 139 if hasattr(node, name): 140 d = getattr(node, name) 141 for expr, attrs in d.items(): 142 self._replace(attrs, name, d, expr) 143 144 # Visit program nodes. 145 146 for attr in ("pos_args",): 147 if hasattr(node, attr): 148 self.dispatches(getattr(node, attr)) 149 for attr in ("kw_args",): 150 if hasattr(node, attr): 151 self.dispatch_dict(getattr(node, attr)) 152 for attr in ("expr", "lvalue", "test", "star", "dstar"): 153 if hasattr(node, attr): 154 self.dispatch(getattr(node, attr)) 155 for attr in ("body", "else_", "handler", "finally_", "code", "choices", "nodes"): 156 if hasattr(node, attr): 157 self.dispatches(getattr(node, attr)) 158 if hasattr(node, "params"): 159 for param, default in node.params: 160 self.dispatch(default) 161 for attr in ("star", "dstar"): 162 if getattr(node, attr, None): 163 param, default = getattr(node, attr) 164 self.dispatch(default) 165 166 return node 167 168 def _replace(self, items, name=None, container=None, key=None): 169 for item in list(items): 170 items.remove(item) 171 if name == "accesses": 172 attr, accessor = item 173 value = attr.type 174 items.append((Attribute(self._get_replacement(attr.context), self._get_replacement(value)), self._get_replacement(accessor))) 175 else: 176 attr = item 177 value = attr.type 178 items.add(Attribute(self._get_replacement(attr.context), self._get_replacement(value))) 179 180 if name == "accesses": 181 del container[key] 182 container[self._get_replacement(key)] = items 183 184 def _get_replacement(self, value): 185 if isinstance(value, Instance): 186 distinct_instances = value.get_class().get_distinct_instances() 187 return distinct_instances[value] 188 else: 189 return value 190 191 def dispatch(self, node, *args): 192 return Visitor.dispatch(self, node, *args) 193 194 def visitInvokeFunction(self, invoke): 195 196 "Transform the 'invoke' node, performing processing on subprograms." 197 198 return self.default(invoke) 199 200 def visitInvokeRef(self, invoke): 201 202 "Transform the 'invoke' node, performing processing on subprograms." 203 204 # The special case of internal subprogram invocation is addressed by 205 # propagating namespace information to the subprogram and processing it. 206 207 subprogram = self.process_node(invoke.ref) 208 209 if subprogram is not None: 210 self.subprograms.append(subprogram) 211 return invoke 212 213 # Convenience functions. 214 215 def fix(module): 216 217 "Fix the instances in the given 'module'." 218 219 fixer = Fixer() 220 fixer.process(module) 221 222 # vim: tabstop=4 expandtab shiftwidth=4