1 #!/usr/bin/env python 2 3 """ 4 Annotate program node structures. The code in this module operates upon nodes 5 which are produced when simplifying AST node trees originating from the compiler 6 module. 7 8 Copyright (C) 2006, 2007 Paul Boddie <paul@boddie.org.uk> 9 10 This software is free software; you can redistribute it and/or 11 modify it under the terms of the GNU General Public License as 12 published by the Free Software Foundation; either version 2 of 13 the License, or (at your option) any later version. 14 15 This software is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public 21 License along with this library; see the file LICENCE.txt 22 If not, write to the Free Software Foundation, Inc., 23 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA 24 25 -------- 26 27 To use this module, the easiest approach is to use the load function: 28 29 load(filename, builtins) 30 31 To control module importing, an importer should be constructed and employed. 32 Here, the standard path for module searching is used: 33 34 importer = Importer(sys.path) 35 load(filename, builtins, importer) 36 37 Underneath the load function, the annotate function provides support for 38 annotating modules already processed by simplify and fixnames: 39 40 annotate(module, builtins) 41 42 And at the most basic level, the most intricate approach involves obtaining an 43 Annotator object: 44 45 annotator = Annotator() 46 47 Then, processing an existing module with it: 48 49 annotator.process(module) 50 51 If a module containing built-in classes and functions has already been 52 annotated, such a module should be passed in as an additional argument: 53 54 annotator.process(module, builtins) 55 """ 56 57 from simplified import * 58 import simplify, fixnames # for the load function 59 import compiler 60 import os 61 62 class System: 63 64 """ 65 A class maintaining the state of the annotation system. When the system 66 counter can no longer be incremented by any annotation operation, the 67 system may be considered stable and fully annotated. 68 """ 69 70 def __init__(self): 71 self.count = 0 72 73 def init(self, node): 74 75 "Initialise a 'node' for annotation." 76 77 if not hasattr(node, "types"): 78 node.types = [] 79 80 def annotate(self, node, types): 81 82 "Annotate the given 'node' with the given 'types'." 83 84 self.init(node) 85 self.combine(node.types, types) 86 87 def combine(self, target, types): 88 89 """ 90 Combine the 'target' list with the given 'types', counting new members. 91 """ 92 93 for type in types: 94 if type not in target: 95 target.append(type) 96 self.count += 1 97 98 system = System() 99 100 # Exceptions. 101 102 class AnnotationError(SimplifiedError): 103 104 "An error in the annotation process." 105 106 pass 107 108 class AnnotationMessage(Exception): 109 110 "A lesser annotation error." 111 112 pass 113 114 # Annotation. 115 116 class Annotator(Visitor): 117 118 """ 119 The type annotator which traverses the program nodes, typically depth-first, 120 and maintains a record of the current set of types applying to the currently 121 considered operation. Such types are also recorded on the nodes, and a 122 special "system" record is maintained to monitor the level of annotation 123 activity with a view to recognising when no more annotations are possible. 124 125 Throughout the annotation activity, type information consists of lists of 126 Attribute objects where such objects retain information about the context of 127 the type (since a value in the program may be associated with an object or 128 class) and the actual type of the value being manipulated. Upon accessing 129 attribute information on namespaces, additional accessor information is also 130 exchanged - this provides a means of distinguishing between the different 131 types possible when the means of constructing the namespace may depend on 132 run-time behaviour. 133 134 Covered: Assign, CheckExc, Conditional, Global, Import, InvokeBlock, 135 InvokeFunction, LoadAttr, LoadExc, LoadName, LoadRef, LoadTemp, 136 Module, Not, Pass, Raise, ReleaseTemp, ReturnFromBlock, 137 ReturnFromFunction, StoreAttr, StoreName, StoreTemp, Subprogram, 138 Try. 139 """ 140 141 def __init__(self, importer=None): 142 143 "Initialise the visitor with an optional 'importer'." 144 145 Visitor.__init__(self) 146 self.system = system 147 self.importer = importer or Importer() 148 149 # Satisfy visitor issues. 150 151 self.visitor = self 152 153 def process(self, module, builtins=None): 154 155 """ 156 Process the given 'module', using the optional 'builtins' to access 157 built-in classes and functions. 158 """ 159 160 self.subprograms = [] 161 self.current_subprograms = [] 162 self.current_namespaces = [] 163 self.namespace = None 164 self.module = module 165 166 # Give constants their own namespace. 167 168 for value, constant in module.simplifier.constants.items(): 169 constant.namespace = Namespace() 170 171 # Process the module, supplying builtins if possible. 172 173 self.builtins = builtins 174 self.global_namespace = Namespace() 175 176 if builtins is not None: 177 self.builtins_namespace = builtins.namespace 178 else: 179 self.builtins_namespace = self.global_namespace 180 181 return self.process_node(module, self.global_namespace) 182 183 def process_node(self, node, locals): 184 185 """ 186 Process a subprogram or module 'node', indicating the initial 'locals'. 187 Return an annotated subprogram or module. Note that this method may 188 mutate nodes in the original program. 189 """ 190 191 # Record the current subprogram and namespace. 192 193 self.current_subprograms.append(node) 194 195 # Determine the namespace. 196 197 self.current_namespaces.append(self.namespace) 198 self.namespace = locals 199 200 # Add namespace details to any structure involved. 201 202 if getattr(node, "structure", None) is not None: 203 node.structure.namespace = Namespace() 204 205 # Initialise bases where appropriate. 206 207 if hasattr(node.structure, "bases"): 208 base_refs = [] 209 for base in node.structure.bases: 210 self.dispatch(base) 211 base_refs.append(self.namespace.types) 212 node.structure.base_refs = base_refs 213 214 # Dispatch to the code itself. 215 216 node.namespace = self.namespace 217 result = self.dispatch(node) 218 result.namespace = self.namespace 219 220 # Obtain the return values. 221 222 self.last_returns = self.namespace.returns 223 self.last_raises = self.namespace.raises 224 self.returned_locals = self.namespace.return_locals 225 226 # Restore the previous subprogram and namespace. 227 228 self.namespace = self.current_namespaces.pop() 229 self.current_subprograms.pop() 230 231 return result 232 233 def annotate(self, node, types=None): 234 235 """ 236 Annotate the given 'node' in the system, using either the optional 237 'types' or the namespace's current type information. 238 """ 239 240 self.system.annotate(node, types or self.namespace.types) 241 242 def annotate_parameters(self, node, items): 243 244 """ 245 Annotate the given 'node' using the given 'items' and updating the 246 system's annotation counter. 247 """ 248 249 if not hasattr(node, "paramtypes"): 250 node.paramtypes = {} 251 252 for param, types in items: 253 if not node.paramtypes.has_key(param): 254 node.paramtypes[param] = [] 255 self.system.combine(node.paramtypes[param], types) 256 257 # Visitor methods. 258 259 def default(self, node): 260 261 """ 262 Process the given 'node', given that it does not have a specific 263 handler. 264 """ 265 266 raise AnnotationMessage, "Node '%s' not supported." % node 267 268 def dispatch(self, node, *args): 269 try: 270 return Visitor.dispatch(self, node, *args) 271 except AnnotationError, exc: 272 exc.add(node) 273 raise 274 except AnnotationMessage, exc: 275 raise AnnotationError(exc, node) 276 277 # Specific node methods. 278 279 def visitAssign(self, assign): 280 281 """ 282 Return the 'assign' node whose contents (merely a group of nodes) have 283 been processed. 284 """ 285 286 assign.code = self.dispatches(assign.code) 287 return assign 288 289 def visitCheckExc(self, checkexc): 290 291 """ 292 Return the 'checkexc' node, processing the expression to find the 293 possible types of the exception, and processing each choice to build a 294 list of checked types for the exception. 295 """ 296 297 checkexc.expr = self.dispatch(checkexc.expr) 298 expr_types = self.namespace.types 299 choice_types = [] 300 choices = [] 301 for choice in checkexc.choices: 302 choices.append(self.dispatch(choice)) 303 choice_types += self.namespace.types 304 for expr_type in expr_types: 305 if expr_type.type.get_class() not in choice_types: 306 self._prune_non_accesses(checkexc.expr, expr_type) 307 return checkexc 308 309 def visitConditional(self, conditional): 310 311 """ 312 Return the 'conditional' node, processing the test, body and else 313 clauses and recording their processed forms. The body and else clauses 314 are processed within their own namespaces, and the test is also 315 processed in its own namespace if 'isolate_test' is set on the 316 'conditional' node. 317 """ 318 319 # Conditionals keep local namespace changes isolated. 320 # With Return nodes inside the body/else sections, the changes are 321 # communicated to the caller. 322 323 is_module = self.namespace is self.module.namespace 324 325 # Where the test is closely associated with the body, save the namespace 326 # before entering the test. 327 328 if conditional.isolate_test: 329 saved_namespace = self.namespace 330 self.namespace = Namespace() 331 if is_module: 332 self.module.namespace = self.namespace 333 self.namespace.merge_namespace(saved_namespace) 334 335 conditional.test = self.dispatch(conditional.test) 336 337 # Where the test may affect the body and the else clause, save the 338 # namespace after processing the test. 339 340 if not conditional.isolate_test: 341 saved_namespace = self.namespace 342 self.namespace = Namespace() 343 if is_module: 344 self.module.namespace = self.namespace 345 self.namespace.merge_namespace(saved_namespace) 346 347 # Process the body clause. 348 349 conditional.body = self.dispatches(conditional.body) 350 body_namespace = self.namespace 351 352 # Use the saved namespace as a template for the else clause. 353 354 self.namespace = Namespace() 355 if is_module: 356 self.module.namespace = self.namespace 357 self.namespace.merge_namespace(saved_namespace) 358 359 # Process the else clause. 360 361 conditional.else_ = self.dispatches(conditional.else_) 362 else_namespace = self.namespace 363 364 # Merge the body and else namespaces. 365 366 self.namespace = Namespace() 367 if is_module: 368 self.module.namespace = self.namespace 369 self.namespace.merge_namespace(body_namespace) 370 self.namespace.merge_namespace(else_namespace) 371 372 # NOTE: Test of exception type pruning based on the test/body. 373 374 if conditional.isolate_test: 375 for exc_type in body_namespace.raises: 376 self.namespace.revoke_exception_type(exc_type) 377 378 return conditional 379 380 def visitGlobal(self, global_): 381 382 """ 383 Return the 'global_' node unprocessed since namespaces should have 384 already been altered to take global names into consideration. 385 """ 386 387 return global_ 388 389 def visitImport(self, import_): 390 391 """ 392 Return the 'import_' node, importing the module with the stated name 393 and storing details on the node. 394 """ 395 396 module = self.importer.load(import_.name, self.builtins, getattr(import_, "alias", None)) 397 if module is not None: 398 self.namespace.set_types([module]) 399 else: 400 self.namespace.set_types([]) 401 self.annotate(import_) # mainly for viewing purposes 402 return import_ 403 404 def _visitInvoke(self, invoke, invocation_types, have_args): 405 406 """ 407 Return the processed 'invoke' node, using the given 'invocation_types' 408 as the list of callables to be investigated for instantiation or for the 409 invocation of functions or blocks. If 'have_args' is a true value, any 410 invocation or instantiation will involve arguments. 411 """ 412 413 # Now locate and invoke the subprogram. This can be complicated because 414 # the target may be a class or object, and there may be many different 415 # related subprograms. 416 417 invocations = [] 418 419 # Visit each callable in turn, finding subprograms. 420 421 for attr in invocation_types: 422 423 # Deal with class invocations by providing instance objects. 424 # Here, each class is queried for the __init__ method, which may 425 # exist for some combinations of classes in a hierarchy but not for 426 # others. 427 428 if isinstance(attr.type, Class): 429 attributes = get_attributes(attr.type, "__init__") 430 431 # Deal with object invocations by using __call__ methods. 432 433 elif isinstance(attr.type, Instance): 434 attributes = get_attributes(attr.type, "__call__") 435 436 # Normal functions or methods are more straightforward. 437 # Here, we model them using an attribute with no context and with 438 # no associated accessor. 439 440 else: 441 attributes = [(attr, None)] 442 443 # Inspect each attribute and extract the subprogram. 444 445 for attribute, accessor in attributes: 446 447 # If a class is involved, presume that it must create a new 448 # object. 449 450 if isinstance(attr.type, Class): 451 452 # Instantiate the class. 453 454 instance = self.new_instance(invoke, "new", attr.type.full_name(), attr.type) 455 456 # For instantiations, switch the context. 457 458 if attribute is not None: 459 attribute = Attribute(instance, attribute.type) 460 461 # Skip cases where no callable is found. 462 463 if attribute is not None: 464 465 # If a subprogram is defined, invoke it. 466 467 self.invoke_subprogram(invoke, attribute) 468 if attribute.type not in invocations: 469 invocations.append(attribute.type) 470 471 elif not isinstance(attr.type, Class): 472 print "Invocation type is None for", accessor 473 474 else: 475 476 # Test to see if no arguments were supplied in cases where no 477 # initialiser was found. 478 479 if have_args: 480 raise AnnotationMessage, "No initialiser found for '%s' with arguments." % attr.type 481 482 # Special case: initialisation. 483 484 if isinstance(attr.type, Class): 485 486 # Associate the instance with the result of this invocation. 487 488 self.namespace.set_types([Attribute(None, instance)]) 489 self.annotate(invoke) 490 491 # Remember the invocations that were found, along with the return type 492 # information. 493 494 invoke.invocations = invocations 495 self.namespace.set_types(getattr(invoke, "types", [])) 496 return invoke 497 498 def visitInvokeBlock(self, invoke): 499 500 """ 501 Return the processed 'invoke' node, first finding the callables 502 indicated by the expression. 503 """ 504 505 invoke.expr = self.dispatch(invoke.expr) 506 invocation_types = self.namespace.types 507 return self._visitInvoke(invoke, invocation_types, have_args=0) 508 509 def visitInvokeFunction(self, invoke): 510 511 """ 512 Return the processed 'invoke' node, first finding the callables 513 indicated by the expression. 514 """ 515 516 invoke.expr = self.dispatch(invoke.expr) 517 invocation_types = self.namespace.types 518 519 # Invocation processing starts with making sure that the arguments have 520 # been processed. 521 522 return self._visitInvoke(invoke, invocation_types, have_args=self.process_args(invoke)) 523 524 def visitLoadAttr(self, loadattr): 525 526 """ 527 Return the 'loadattr' node, processing and storing the expression, and 528 using the expression's types to construct records of accesses and 529 non-accesses using the stated attribute name. 530 """ 531 532 loadattr.expr = self.dispatch(loadattr.expr) 533 types = [] 534 non_accesses = [] 535 accesses = {} 536 for attr in self.namespace.types: 537 attributes = get_attributes(attr.type, loadattr.name) 538 if not attributes: 539 if not attr in non_accesses: 540 non_accesses.append(attr) 541 combine(self.namespace.raises, self.get_builtin_instances(loadattr, "AttributeError")) 542 543 # Revoke this type from any name involved. 544 545 self._prune_non_accesses(loadattr.expr, attr) 546 547 for attribute, accessor in attributes: 548 if attribute is not None: 549 types.append(attribute) 550 if not accesses.has_key(attr.type): 551 accesses[attr.type] = [] 552 if not (attribute, accessor) in accesses[attr.type]: 553 accesses[attr.type].append((attribute, accessor)) 554 else: 555 if not attr in non_accesses: 556 non_accesses.append(attr) 557 combine(self.namespace.raises, self.get_builtin_instances(loadattr, "AttributeError")) 558 559 # Revoke this type from any name involved. 560 561 self._prune_non_accesses(loadattr.expr, attr) 562 563 if not types: 564 print "No attribute found for", loadattr.name, "given", self.namespace.types 565 self.namespace.set_types(types) 566 loadattr.non_accesses = non_accesses 567 loadattr.accesses = accesses 568 self.annotate(loadattr) 569 return loadattr 570 571 def _prune_non_accesses(self, expr, attr): 572 573 """ 574 Prune type information from 'expr' where the given 'attr' has been 575 shown to be a non-access. 576 """ 577 578 if isinstance(expr, LoadName): 579 self.namespace.revoke(expr.name, attr) 580 elif isinstance(expr, LoadExc): 581 self.namespace.revoke_exception_type(attr) 582 elif isinstance(expr, LoadTemp): 583 self.namespace.revoke_temp_type(getattr(expr, "index", None), attr) 584 585 # LoadAttr cannot be pruned since this might unintentionally prune 586 # legitimate types from other applications of the referenced type, it 587 # almost certainly doesn't take "concurrent" mutation into 588 # consideration (where in a running program, the pruned type is actually 589 # reintroduced, making the pruning invalid), and there is no easy way of 590 # preserving the meaning of a namespace without either creating lots of 591 # specialised instances, and even then... 592 593 #elif isinstance(expr, LoadAttr): 594 # for expr_attr in expr.expr.types: 595 # if hasattr(expr_attr.type, "namespace"): 596 # expr_attr.type.namespace.revoke(expr.name, attr) 597 598 def visitLoadExc(self, loadexc): 599 600 """ 601 Return the 'loadexc' node, discovering the possible exception types 602 raised. 603 """ 604 605 self.namespace.set_types(self.namespace.raises[:]) 606 self.annotate(loadexc) 607 return loadexc 608 609 def visitLoadName(self, loadname): 610 611 """ 612 Return the 'loadname' node, processing the name information on the node 613 to determine which types are involved with the name. 614 """ 615 616 self.namespace.set_types(self.namespace.load(loadname.name)) 617 result = loadname 618 self.annotate(result) 619 return result 620 621 def visitLoadRef(self, loadref): 622 623 """ 624 Return the 'loadref' node, obtaining type information about the 625 reference stated on the node. 626 """ 627 628 self.namespace.set_types([Attribute(None, loadref.ref)]) 629 self.annotate(loadref) 630 return loadref 631 632 def visitLoadTemp(self, loadtemp): 633 634 """ 635 Return the 'loadtemp' node, obtaining type information about the 636 temporary variable accessed, and removing variable information where the 637 'release' attribute has been set on the node. 638 """ 639 640 index = getattr(loadtemp, "index", None) 641 try: 642 if getattr(loadtemp, "release", 0): 643 self.namespace.set_types(self.namespace.temp[index].pop()) 644 else: 645 self.namespace.set_types(self.namespace.temp[index][-1]) 646 except KeyError: 647 raise AnnotationMessage, "Temporary store index '%s' not defined." % index 648 self.annotate(loadtemp) 649 return loadtemp 650 651 def visitModule(self, module): 652 653 """ 654 Return the processed 'module' whose contents (merely a group of nodes) 655 are processed. 656 """ 657 658 module.code = self.dispatches(module.code) 659 return module 660 661 def visitNot(self, not_): 662 663 "Return the 'not_' node whose expression is processed." 664 665 not_.expr = self.dispatch(not_.expr) 666 return not_ 667 668 def visitPass(self, pass_): 669 670 "Return the unprocessed 'pass_' node." 671 672 return pass_ 673 674 def visitRaise(self, raise_): 675 676 """ 677 Return the 'raise_' node, processing any traceback information along 678 with the raised exception expression, converting the node into a kind of 679 invocation where the expression is found not to be an invocation itself. 680 This node affects the namespace, adding exception types to the list of 681 those raised in the namespace. 682 """ 683 684 if getattr(raise_, "traceback", None) is not None: 685 raise_.traceback = self.dispatch(raise_.traceback) 686 raise_.expr = self.dispatch(raise_.expr) 687 688 # Handle bare name exceptions by converting any classes to instances. 689 690 if not isinstance(raise_.expr, InvokeFunction): 691 raise_.pos_args = [] 692 raise_.kw_args = {} 693 raise_.star = None 694 raise_.dstar = None 695 types = [] 696 for attr in self.namespace.types: 697 if isinstance(attr.type, Class): 698 self._visitInvoke(raise_, [attr], have_args=0) 699 types += self.namespace.types 700 else: 701 types = self.namespace.types 702 703 combine(self.namespace.raises, types) 704 return raise_ 705 706 def visitReleaseTemp(self, releasetemp): 707 708 """ 709 Return the 'releasetemp' node, removing temporary variable information 710 from the current namespace. 711 """ 712 713 index = getattr(releasetemp, "index", None) 714 try: 715 self.namespace.temp[index].pop() 716 except KeyError: 717 raise AnnotationMessage, "Temporary store index '%s' not defined." % index 718 except IndexError: 719 pass #raise AnnotationMessage, "Temporary store index '%s' is empty." % index 720 return releasetemp 721 722 def visitReturn(self, return_): 723 724 """ 725 Return the 'return_' node, processing any expression and obtaining type 726 information to be accumulated in the current namespace's list of return 727 types. A snapshot of the namespace is taken for the purposes of 728 reconciling or merging namespaces where subprograms actually share 729 locals with their callers. 730 """ 731 732 if hasattr(return_, "expr"): 733 return_.expr = self.dispatch(return_.expr) 734 combine(self.namespace.returns, self.namespace.types) 735 self.annotate(return_) 736 self.namespace.snapshot() 737 return return_ 738 739 visitReturnFromBlock = visitReturn 740 visitReturnFromFunction = visitReturn 741 742 def visitStoreAttr(self, storeattr): 743 744 """ 745 Return the 'storeattr' node, processing the expression and target, and 746 using the type information obtained to build records of legitimate 747 writes to the stated attribute, along with "impossible" non-writes to 748 the attribute. 749 """ 750 751 storeattr.expr = self.dispatch(storeattr.expr) 752 expr = self.namespace.types 753 storeattr.lvalue = self.dispatch(storeattr.lvalue) 754 writes = {} 755 non_writes = [] 756 for attr in self.namespace.types: 757 # NOTE: Impose "atomic" constraints on certain types. 758 if attr is None: 759 if not attr in non_writes: 760 non_writes.append(attr) 761 continue 762 attr.type.namespace.add(storeattr.name, expr) 763 writes[attr.type] = attr.type.namespace.load(storeattr.name) 764 if not writes: 765 print "Unable to store attribute", storeattr.name, "given", self.namespace.types 766 storeattr.writes = writes 767 storeattr.non_writes = non_writes 768 return storeattr 769 770 def visitStoreName(self, storename): 771 772 """ 773 Return the 'storename' node, processing the expression on the node and 774 associating the type information obtained with the stated name in the 775 current namespace. 776 """ 777 778 storename.expr = self.dispatch(storename.expr) 779 self.namespace.store(storename.name, self.namespace.types) 780 return storename 781 782 def visitStoreTemp(self, storetemp): 783 784 """ 785 Return the 'storetemp' node, processing the expression on the node and 786 associating the type information obtained with a temporary variable in 787 the current namespace. 788 """ 789 790 storetemp.expr = self.dispatch(storetemp.expr) 791 index = getattr(storetemp, "index", None) 792 if not self.namespace.temp.has_key(index): 793 self.namespace.temp[index] = [] 794 self.namespace.temp[index].append(self.namespace.types) 795 return storetemp 796 797 def visitSubprogram(self, subprogram): 798 799 """ 800 Return the 'subprogram' node, processing its contents (a group of nodes 801 comprising the subprogram). 802 """ 803 804 subprogram.code = self.dispatches(subprogram.code) 805 return subprogram 806 807 def visitTry(self, try_): 808 809 """ 810 Return the 'try_' node, processing the body clause in its own namespace 811 derived from the current namespace, processing any handler clause using 812 the namespace information accumulated in the body, and processing any 813 else and finally clauses, attempting to supply each with appropriate 814 namespace information. 815 """ 816 817 is_module = self.namespace is self.module.namespace 818 819 try_.body = self.dispatches(try_.body) 820 821 # Save the namespace from the body. 822 823 body_namespace = Namespace() 824 body_namespace.merge_namespace(self.namespace) 825 826 # Process the handler. 827 828 if hasattr(try_, "handler"): 829 try_.handler = self.dispatches(try_.handler) 830 831 # Save the namespace from the handler. 832 833 handler_namespace = Namespace() 834 handler_namespace.merge_namespace(self.namespace) 835 836 # Remember the raised exceptions encountered so far. 837 838 raises = self.namespace.raises 839 840 # Process the else clause. 841 842 if hasattr(try_, "else_"): 843 844 # Restore the body namespace for the else clause. 845 846 self.namespace = body_namespace 847 if is_module: 848 self.module.namespace = self.namespace 849 850 # Empty the raised exceptions for the else clause. 851 852 self.namespace.raises = [] 853 try_.else_ = self.dispatches(try_.else_) 854 self.namespace.raises = raises 855 856 # Merge the namespaces. 857 858 self.namespace = Namespace() 859 if is_module: 860 self.module.namespace = self.namespace 861 self.namespace.merge_namespace(body_namespace) 862 self.namespace.merge_namespace(handler_namespace) 863 864 # Process the finally clause, if any. 865 866 try_.finally_ = self.dispatches(try_.finally_) 867 return try_ 868 869 # Utility methods. 870 871 def get_builtin_instances(self, node, name): 872 return [Attribute(None, self._new_instance(node, attr.type)) for attr in self.builtins.namespace[name]] 873 874 def new_instance(self, node, reason, target, type): 875 876 "Create, on the given 'node', a new instance with the given 'type'." 877 878 if not hasattr(node, "instances"): 879 node.instances = {} 880 881 if not node.instances.has_key((reason, target, type)): 882 instance = self._new_instance(node, type) 883 node.instances[(reason, target, type)] = instance 884 885 return node.instances[(reason, target, type)] 886 887 def _new_instance(self, node, type): 888 889 "For the given 'node', obtain an instance from the given 'type'." 890 891 if not type.has_instance(node): 892 instance = Instance() 893 instance.namespace = Namespace() 894 instance.namespace.store("__class__", [Attribute(None, type)]) 895 type.add_instance(node, instance) 896 else: 897 instance = type.get_instance(node) 898 899 return instance 900 901 def invoke_subprogram(self, invoke, attribute): 902 903 """ 904 Invoke using the given 'invoke' node the subprogram represented by the 905 given 'attribute'. 906 """ 907 908 # Test for context information, making it into a real attribute. 909 910 if attribute.context is not None: 911 context = Attribute(None, attribute.context) 912 target = attribute.type 913 else: 914 context = None 915 target = attribute.type 916 917 # Test to see if anything has changed. 918 919 if hasattr(invoke, "syscount") and invoke.syscount.has_key(target) and invoke.syscount[target] == self.system.count: 920 return 921 922 # Remember the state of the system. 923 924 else: 925 if not hasattr(invoke, "syscount"): 926 invoke.syscount = {} 927 invoke.syscount[target] = self.system.count 928 929 # Provide the correct namespace for the invocation. 930 # This may be a "shared" namespace... 931 932 if getattr(invoke, "share_locals", 0): 933 namespace = Namespace() 934 namespace.merge_namespace(self.namespace, everything=0) 935 using_module_namespace = self.namespace is self.module.namespace 936 937 # Or it may be a structure... 938 939 elif getattr(target, "structure", None): 940 namespace = Namespace() 941 using_module_namespace = 0 942 943 # Or it may be a new namespace populated with the supplied parameters. 944 945 else: 946 items = self.make_items(invoke, target, context) 947 namespace = Namespace() 948 namespace.merge_items(items) 949 using_module_namespace = 0 950 951 # NOTE: Avoid PEP 227 (nested scopes) whilst permitting references to a 952 # NOTE: subprogram within itself. Do not define the name of the function 953 # NOTE: within a method definition. 954 955 if getattr(target, "name", None) is not None and not getattr(target, "is_method", 0): 956 namespace.store(target.name, [Attribute(None, target)]) 957 958 # Process the subprogram. 959 # In order to keep global accesses working, the module namespace must be 960 # adjusted. 961 962 if using_module_namespace: 963 self.module.namespace = namespace 964 965 self.process_node(target, namespace) 966 967 # NOTE: Improve and verify this. 968 # If the invocation returns a value, acquire the return types. 969 970 if getattr(target, "returns_value", 0): 971 self.namespace.set_types(self.last_returns) 972 self.annotate(invoke) 973 974 # If it is a normal block, merge the locals. 975 # This can happen in addition to the above because for things like 976 # logical expressions, the namespace can be modified whilst values are 977 # returned as results. 978 979 if getattr(invoke, "share_locals", 0): 980 self.namespace.reset() 981 982 # Merge the locals snapshots. 983 984 for locals in self.returned_locals: 985 986 # For blocks returning values (such as operations), do not merge 987 # snapshots or results. 988 989 if getattr(target, "returns_value", 0): 990 self.namespace.merge_namespace(locals, everything=0) 991 992 # For blocks not returning values (such as loops), merge 993 # snapshots and results since they contain details of genuine 994 # returns. 995 996 else: 997 self.namespace.merge_namespace(locals) 998 999 # Incorporate any raised exceptions. 1000 1001 combine(self.namespace.raises, self.last_raises) 1002 1003 # In order to keep global accesses working, the module namespace must be 1004 # adjusted. 1005 1006 if using_module_namespace: 1007 self.module.namespace = self.namespace 1008 1009 def process_args(self, invocation): 1010 1011 """ 1012 Process the arguments associated with an 'invocation'. Return whether 1013 any arguments were processed. 1014 """ 1015 1016 invocation.pos_args = self.dispatches(invocation.pos_args) 1017 invocation.kw_args = self.dispatch_dict(invocation.kw_args) 1018 1019 # Get type information for star and dstar arguments. 1020 1021 if invocation.star is not None: 1022 param, default = invocation.star 1023 default = self.dispatch(default) 1024 invocation.star = param, default 1025 1026 if invocation.dstar is not None: 1027 param, default = invocation.dstar 1028 default = self.dispatch(default) 1029 invocation.dstar = param, default 1030 1031 if invocation.pos_args or invocation.kw_args or invocation.star or invocation.dstar: 1032 return 1 1033 else: 1034 return 0 1035 1036 def make_items(self, invocation, subprogram, context): 1037 1038 """ 1039 Make an items mapping for the 'invocation' of the 'subprogram' using the 1040 given 'context' (which may be None). 1041 """ 1042 1043 if context is not None: 1044 pos_args = [Self(context)] + invocation.pos_args 1045 else: 1046 pos_args = invocation.pos_args 1047 1048 # Duplicate the keyword arguments - we remove them in processing below. 1049 1050 kw_args = {} 1051 kw_args.update(invocation.kw_args) 1052 1053 # Sort the arguments into positional and keyword arguments. 1054 1055 params = subprogram.params 1056 items = [] 1057 star_args = [] 1058 1059 # Match each positional argument, taking excess arguments as star args. 1060 1061 for arg in pos_args: 1062 if params: 1063 param, default = params[0] 1064 if arg is None: 1065 arg = default 1066 if hasattr(arg, "types"): 1067 items.append((param, arg.types)) 1068 else: 1069 items.append((param, [])) # Annotation has not succeeded. 1070 params = params[1:] 1071 else: 1072 star_args.append(arg) 1073 1074 # Collect the remaining defaults. 1075 1076 while params: 1077 param, default = params[0] 1078 if kw_args.has_key(param): 1079 arg = kw_args[param] 1080 del kw_args[param] 1081 elif default is not None: 1082 arg = self.dispatch(default) 1083 else: 1084 raise AnnotationMessage, "No argument supplied in '%s' for parameter '%s'." % (subprogram, param) 1085 if hasattr(arg, "types"): 1086 items.append((param, arg.types)) 1087 else: 1088 items.append((param, [])) # Annotation has not succeeded. 1089 params = params[1:] 1090 1091 dstar_args = kw_args.items() 1092 1093 # Construct temporary objects. 1094 1095 if star_args: 1096 star_invocation = self.make_star_args(invocation, subprogram, star_args) 1097 self.dispatch(star_invocation) 1098 star_types = star_invocation.types 1099 else: 1100 star_types = None 1101 1102 if dstar_args: 1103 dstar_invocation = self.make_dstar_args(invocation, subprogram, dstar_args) 1104 self.dispatch(dstar_invocation) 1105 dstar_types = dstar_invocation.types 1106 else: 1107 dstar_types = None 1108 1109 # NOTE: Merge the objects properly. 1110 1111 star_types = star_types or invocation.star and invocation.star.types 1112 dstar_types = dstar_types or invocation.dstar and invocation.dstar.types 1113 1114 # Add star and dstar. 1115 1116 if star_types is not None: 1117 if subprogram.star is not None: 1118 param, default = subprogram.star 1119 items.append((param, star_types)) 1120 else: 1121 raise AnnotationMessage, "Invocation provides unwanted *args." 1122 elif subprogram.star is not None: 1123 param, default = subprogram.star 1124 if not hasattr(default, "types"): 1125 subprogram.star = param, self.dispatch(default) # NOTE: Review reprocessing. 1126 items.append((param, default.types)) 1127 1128 if dstar_types is not None: 1129 if subprogram.dstar is not None: 1130 param, default = subprogram.dstar 1131 items.append((param, dstar_types)) 1132 else: 1133 raise AnnotationMessage, "Invocation provides unwanted **args." 1134 elif subprogram.dstar is not None: 1135 param, default = subprogram.dstar 1136 if not hasattr(default, "types"): 1137 subprogram.dstar = param, self.dispatch(default) # NOTE: Review reprocessing. 1138 items.append((param, default.types)) 1139 1140 # Record the parameter types. 1141 1142 self.annotate_parameters(subprogram, items) 1143 return subprogram.paramtypes.items() 1144 1145 def make_star_args(self, invocation, subprogram, star_args): 1146 1147 "Make a subprogram which initialises a list containing 'star_args'." 1148 1149 if not hasattr(invocation, "stars"): 1150 invocation.stars = {} 1151 1152 if not invocation.stars.has_key(subprogram.full_name()): 1153 code=[ 1154 StoreTemp( 1155 expr=InvokeFunction( 1156 expr=LoadAttr( 1157 expr=LoadRef( 1158 ref=self.builtins 1159 ), 1160 name="list", 1161 nstype="module", 1162 ), 1163 args=[], 1164 star=None, 1165 dstar=None 1166 ) 1167 ) 1168 ] 1169 1170 for arg in star_args: 1171 code.append( 1172 InvokeFunction( 1173 expr=LoadAttr( 1174 expr=LoadTemp(), 1175 name="append" 1176 ), 1177 args=[arg], 1178 star=None, 1179 dstar=None 1180 ) 1181 ) 1182 1183 code += [ 1184 Return(expr=LoadTemp(release=1)) 1185 ] 1186 1187 invocation.stars[subprogram.full_name()] = InvokeBlock( 1188 produces_result=1, 1189 expr=LoadRef( 1190 ref=Subprogram( 1191 name=None, 1192 returns_value=1, 1193 params=[], 1194 star=None, 1195 dstar=None, 1196 code=code 1197 ) 1198 ) 1199 ) 1200 1201 return invocation.stars[subprogram.full_name()] 1202 1203 def make_dstar_args(self, invocation, subprogram, dstar_args): 1204 1205 """ 1206 Make a subprogram which initialises a dictionary built from the given 1207 'dstar_args'. 1208 """ 1209 1210 if not hasattr(invocation, "dstars"): 1211 invocation.dstars = {} 1212 1213 if not invocation.dstars.has_key(subprogram.full_name()): 1214 code=[ 1215 StoreTemp( 1216 expr=InvokeFunction( 1217 expr=LoadAttr( 1218 expr=LoadRef( 1219 ref=self.builtins 1220 ), 1221 name="dict", 1222 nstype="module", 1223 ) 1224 ) 1225 ) 1226 ] 1227 1228 for arg, value in dstar_args: 1229 1230 # NOTE: Constant not added to table. 1231 1232 constant = Constant(name=repr(arg), value=arg, namespace=Namespace()) 1233 code += [ 1234 StoreTemp( 1235 expr=LoadRef( 1236 ref=constant 1237 ), 1238 index="const" 1239 ), 1240 StoreAttr( 1241 lvalue=LoadTemp( 1242 index="const" 1243 ), 1244 name="__class__", 1245 expr=LoadAttr( 1246 expr=LoadRef( 1247 ref=self.builtins 1248 ), 1249 name=constant.typename, 1250 nstype="module", 1251 ) 1252 ), 1253 InvokeFunction( 1254 expr=LoadAttr( 1255 expr=LoadTemp(), 1256 name="__setitem__" 1257 ), 1258 args=[ 1259 LoadTemp( 1260 index="const", 1261 release=1 1262 ), 1263 value 1264 ] 1265 ) 1266 ] 1267 1268 code += [ 1269 Return(expr=LoadTemp(release=1)) 1270 ] 1271 1272 invocation.dstars[subprogram.full_name()] = InvokeBlock( 1273 produces_result=1, 1274 expr=LoadRef( 1275 ref=Subprogram( 1276 name=None, 1277 returns_value=1, 1278 params=[], 1279 star=None, 1280 dstar=None, 1281 code=code 1282 ) 1283 ) 1284 ) 1285 1286 return invocation.dstars[subprogram.full_name()] 1287 1288 # Namespace-related abstractions. 1289 1290 class Namespace: 1291 1292 """ 1293 A local namespace which may either relate to a genuine set of function 1294 locals or the initialisation of a structure or module. 1295 """ 1296 1297 def __init__(self): 1298 1299 """ 1300 Initialise the namespace with a mapping of local names to possible 1301 types, a list of return values and of possible returned local 1302 namespaces. The namespace also tracks the "current" types and a mapping 1303 of temporary value names to types. 1304 """ 1305 1306 self.names = {} 1307 self.returns = [] 1308 self.return_locals = [] 1309 self.raises = [] 1310 self.temp = {} 1311 self.types = [] 1312 1313 def set_types(self, types): 1314 1315 "Set the current collection of 'types'." 1316 1317 self.types = types 1318 1319 def add(self, name, types): 1320 1321 "Add to the entry with the given 'name' the specified 'types'." 1322 1323 if self.names.has_key(name): 1324 combine(self.names[name], types) 1325 else: 1326 self.store(name, types) 1327 1328 def store(self, name, types): 1329 1330 "Store in (or associate with) the given 'name' the specified 'types'." 1331 1332 self.names[name] = types 1333 1334 __setitem__ = store 1335 1336 def load(self, name): 1337 1338 "Load the types associated with the given 'name'." 1339 1340 return self.names[name] 1341 1342 __getitem__ = load 1343 1344 def revoke(self, name, type): 1345 1346 "Revoke from the entry for the given 'name' the specified 'type'." 1347 1348 new_types = self.names[name][:] 1349 new_types.remove(type) 1350 self.names[name] = new_types 1351 1352 def revoke_exception_type(self, type): 1353 1354 "Revoke the given 'type' from the collection of exception types." 1355 1356 self.raises.remove(type) 1357 1358 def revoke_temp_type(self, index, type): 1359 1360 "Revoke from the temporary variable 'index' the given 'type'." 1361 1362 new_types = self.temp[index][-1][:] 1363 new_types.remove(type) 1364 self.temp[index][-1] = new_types 1365 1366 def merge_namespace(self, namespace, everything=1): 1367 1368 """ 1369 Merge items from the given 'namespace' with this namespace. When the 1370 optional 'everything' parameter is set to a false value (unlike the 1371 default), return values and locals snapshots will not be copied to this 1372 namespace. 1373 """ 1374 1375 self.merge_items(namespace.names.items()) 1376 if everything: 1377 combine(self.returns, namespace.returns) 1378 combine(self.return_locals, namespace.return_locals) 1379 combine(self.raises, namespace.raises) 1380 for name, values in namespace.temp.items(): 1381 if values: 1382 if not self.temp.has_key(name) or not self.temp[name]: 1383 self.temp[name] = [[]] 1384 combine(self.temp[name][-1], values[-1]) 1385 1386 def merge_items(self, items): 1387 1388 "Merge the given 'items' with this namespace." 1389 1390 for name, types in items: 1391 self.merge(name, types) 1392 1393 def merge(self, name, types): 1394 1395 "Merge the entry for the given 'name' and 'types' with this namespace." 1396 1397 if not self.names.has_key(name): 1398 self.names[name] = types[:] 1399 else: 1400 existing = self.names[name] 1401 combine(existing, types) 1402 1403 def snapshot(self): 1404 1405 "Make a snapshot of the locals and remember them." 1406 1407 namespace = Namespace() 1408 namespace.merge_namespace(self) 1409 self.return_locals.append(namespace) 1410 1411 def reset(self): 1412 1413 "Reset a namespace in preparation for merging with returned locals." 1414 1415 self.names = {} 1416 1417 def __repr__(self): 1418 return repr(self.names) 1419 1420 class Importer: 1421 1422 "An import machine, searching for and loading modules." 1423 1424 def __init__(self, path=None): 1425 1426 """ 1427 Initialise the importer with the given search 'path' - a list of 1428 directories to search for Python modules. 1429 """ 1430 1431 self.path = path or [os.getcwd()] 1432 self.modules = {} 1433 1434 def find_in_path(self, name): 1435 1436 """ 1437 Find the given module 'name' in the search path, returning None where no 1438 such module could be found, or a 2-tuple from the 'find' method 1439 otherwise. 1440 """ 1441 1442 for d in self.path: 1443 m = self.find(d, name) 1444 if m: return m 1445 return None 1446 1447 def find(self, d, name): 1448 1449 """ 1450 In the directory 'd', find the given module 'name', where 'name' can 1451 either refer to a single file module or to a package. Return None if the 1452 'name' cannot be associated with either a file or a package directory, 1453 or a 2-tuple from '_find_package' or '_find_module' otherwise. 1454 """ 1455 1456 m = self._find_package(d, name) 1457 if m: return m 1458 m = self._find_module(d, name) 1459 if m: return m 1460 return None 1461 1462 def _find_module(self, d, name): 1463 1464 """ 1465 In the directory 'd', find the given module 'name', returning None where 1466 no suitable file exists in the directory, or a 2-tuple consisting of 1467 None (indicating that no package directory is involved) and a filename 1468 indicating the location of the module. 1469 """ 1470 1471 name_py = name + os.extsep + "py" 1472 filename = self._find_file(d, name_py) 1473 if filename: 1474 return None, filename 1475 return None 1476 1477 def _find_package(self, d, name): 1478 1479 """ 1480 In the directory 'd', find the given package 'name', returning None 1481 where no suitable package directory exists, or a 2-tuple consisting of 1482 a directory (indicating the location of the package directory itself) 1483 and a filename indicating the location of the __init__.py module which 1484 declares the package's top-level contents. 1485 """ 1486 1487 filename = self._find_file(d, name) 1488 if filename: 1489 init_py = "__init__" + os.path.extsep + "py" 1490 init_py_filename = self._find_file(filename, init_py) 1491 if init_py_filename: 1492 return filename, init_py_filename 1493 return None 1494 1495 def _find_file(self, d, filename): 1496 1497 """ 1498 Return the filename obtained when searching the directory 'd' for the 1499 given 'filename', or None if no actual file exists for the filename. 1500 """ 1501 1502 filename = os.path.join(d, filename) 1503 if os.path.exists(filename): 1504 return filename 1505 else: 1506 return None 1507 1508 def load(self, name, builtins, alias=None): 1509 1510 """ 1511 Load the module or package with the given 'name' and using the specified 1512 'builtins'. Return an Attribute object referencing the loaded module or 1513 package, or None if no such module or package exists. 1514 """ 1515 1516 path = name.split(".") 1517 m = self.find_in_path(path[0]) 1518 if not m: 1519 return None # NOTE: Import error. 1520 d, filename = m 1521 top = module = self.modules.get(path[0], load(filename, builtins, path[0], self)) 1522 self.modules[path[0]] = module 1523 1524 if len(path) > 1: 1525 path_so_far = path[:1] 1526 for p in path[1:]: 1527 path_so_far.append(p) 1528 m = self.find(d, p) 1529 if not m: 1530 return None # NOTE: Import error. 1531 d, filename = m 1532 module_name = ".".join(path_so_far) 1533 submodule = self.modules.get(module_name, load(filename, builtins, module_name, self)) 1534 self.modules[module_name] = submodule 1535 1536 # Store the submodule within its parent module. 1537 1538 module.namespace[p] = [Attribute(None, submodule)] 1539 module = submodule 1540 1541 if alias: 1542 return Attribute(None, module) 1543 else: 1544 return Attribute(None, top) 1545 1546 def combine(target, additions): 1547 1548 """ 1549 Merge into the 'target' sequence the given 'additions', preventing duplicate 1550 items. 1551 """ 1552 1553 for addition in additions: 1554 if addition not in target: 1555 target.append(addition) 1556 1557 def find_attributes(structure, name): 1558 1559 """ 1560 Find for the given 'structure' all attributes for the given 'name', visiting 1561 base classes where appropriate and returning the attributes in order of 1562 descending precedence for all possible base classes. 1563 1564 The elements in the result list are 2-tuples which contain the attribute and 1565 the structure involved in accessing the attribute. 1566 """ 1567 1568 # First attempt to search the instance/class namespace. 1569 1570 try: 1571 l = structure.namespace.load(name) 1572 attributes = [] 1573 for attribute in l: 1574 attributes.append((attribute, structure)) 1575 1576 # If that does not work, attempt to investigate any class or base classes. 1577 1578 except KeyError: 1579 attributes = [] 1580 1581 # Investigate any instance's implementing class. 1582 1583 if isinstance(structure, Instance): 1584 for attr in structure.namespace.load("__class__"): 1585 cls = attr.type 1586 l = get_attributes(cls, name) 1587 combine(attributes, l) 1588 1589 # Investigate any class's base classes. 1590 1591 elif isinstance(structure, Class): 1592 1593 # If no base classes exist, return an indicator that no attribute 1594 # exists. 1595 1596 if not structure.base_refs: 1597 return [(None, structure)] 1598 1599 # Otherwise, find all possible base classes. 1600 1601 for base_refs in structure.base_refs: 1602 base_attributes = [] 1603 1604 # For each base class, find attributes either in the base 1605 # class or its own base classes. 1606 1607 for base_ref in base_refs: 1608 l = get_attributes(base_ref, name) 1609 combine(base_attributes, l) 1610 1611 combine(attributes, base_attributes) 1612 1613 return attributes 1614 1615 def get_attributes(structure, name): 1616 1617 """ 1618 Return all possible attributes for the given 'structure' having the given 1619 'name', wrapping each attribute in an Attribute object which includes 1620 context information for the attribute access. 1621 1622 The elements in the result list are 2-tuples which contain the attribute and 1623 the structure involved in accessing the attribute. 1624 """ 1625 1626 if isinstance(structure, Attribute): 1627 structure = structure.type 1628 results = [] 1629 for attribute, accessor in find_attributes(structure, name): 1630 1631 # Detect class attribute access via instances. 1632 1633 if attribute is not None and isinstance(structure, Instance) and isinstance(accessor, Class): 1634 attribute = accessor.get_attribute_for_instance(attribute, structure) 1635 1636 # Produce an attribute with the appropriate context. 1637 1638 if attribute is not None and isinstance(structure, Structure): 1639 results.append((Attribute(structure, attribute.type), accessor)) 1640 else: 1641 results.append((attribute, accessor)) 1642 1643 return results 1644 1645 # Convenience functions. 1646 1647 def load(name, builtins=None, module_name=None, importer=None): 1648 1649 """ 1650 Load the module with the given 'name' (which may be a full module path), 1651 using the optional 'builtins' to resolve built-in names, and using the 1652 optional 'importer' to provide a means of finding and loading modules. 1653 """ 1654 1655 module = simplify.simplify(name, builtins is None, module_name) 1656 fixnames.fix(module, builtins) 1657 annotate(module, builtins, importer) 1658 return module 1659 1660 def annotate(module, builtins=None, importer=None): 1661 1662 """ 1663 Annotate the given 'module', also employing the optional 'builtins' module, 1664 if specified. If the optional 'importer' is given, use that to find and load 1665 modules. 1666 """ 1667 1668 annotator = Annotator(importer) 1669 if builtins is not None: 1670 annotator.process(module, builtins) 1671 else: 1672 annotator.process(module) 1673 1674 # vim: tabstop=4 expandtab shiftwidth=4