1 #!/usr/bin/env python 2 3 """ 4 Inspect and obtain module structure. 5 6 Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 7 2014, 2015, 2016 Paul Boddie <paul@boddie.org.uk> 8 9 This program is free software; you can redistribute it and/or modify it under 10 the terms of the GNU General Public License as published by the Free Software 11 Foundation; either version 3 of the License, or (at your option) any later 12 version. 13 14 This program is distributed in the hope that it will be useful, but WITHOUT 15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 16 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 17 details. 18 19 You should have received a copy of the GNU General Public License along with 20 this program. If not, see <http://www.gnu.org/licenses/>. 21 """ 22 23 from branching import BranchTracker 24 from common import get_argnames, init_item, predefined_constants 25 from modules import BasicModule, CacheWritingModule, InspectionNaming 26 from errors import InspectError 27 from referencing import Reference 28 from resolving import NameResolving 29 from results import AccessRef, InstanceRef, InvocationRef, LiteralSequenceRef, \ 30 LocalNameRef, NameRef, ResolvedNameRef 31 import compiler 32 import sys 33 34 class InspectedModule(BasicModule, CacheWritingModule, NameResolving, InspectionNaming): 35 36 "A module inspector." 37 38 def __init__(self, name, importer): 39 40 "Initialise the module with basic details." 41 42 BasicModule.__init__(self, name, importer) 43 44 self.in_class = False 45 self.in_conditional = False 46 self.global_attr_accesses = {} 47 48 # Usage tracking. 49 50 self.trackers = [] 51 self.attr_accessor_branches = {} 52 53 def __repr__(self): 54 return "InspectedModule(%r, %r)" % (self.name, self.importer) 55 56 # Principal methods. 57 58 def parse(self, filename): 59 60 "Parse the file having the given 'filename'." 61 62 self.parse_file(filename) 63 64 # Inspect the module. 65 66 self.start_tracking_in_module() 67 68 # Detect and record imports and globals declared in the module. 69 70 self.assign_general_local("__name__", self.get_constant("str", self.name)) 71 self.assign_general_local("__file__", self.get_constant("str", filename)) 72 self.process_structure(self.astnode) 73 74 # Set the class of the module after the definition has occurred. 75 76 ref = self.get_builtin("object") 77 self.set_name("__class__", ref) 78 79 # Get module-level attribute usage details. 80 81 self.stop_tracking_in_module() 82 83 # Collect external name references. 84 85 self.collect_names() 86 87 def complete(self): 88 89 "Complete the module inspection." 90 91 # Resolve names not definitively mapped to objects. 92 93 self.resolve() 94 95 # Define the invocation requirements in each namespace. 96 97 self.set_invocation_usage() 98 99 # Propagate to the importer information needed in subsequent activities. 100 101 self.propagate() 102 103 # Accessory methods. 104 105 def collect_names(self): 106 107 "Collect the names used by each scope." 108 109 for path in self.names_used.keys(): 110 self.collect_names_for_path(path) 111 112 def collect_names_for_path(self, path): 113 114 """ 115 Collect the names used by the given 'path'. These are propagated to the 116 importer in advance of any dependency resolution. 117 """ 118 119 names = self.names_used.get(path) 120 if not names: 121 return 122 123 in_function = self.function_locals.has_key(path) 124 125 for name in names: 126 if name in predefined_constants or in_function and name in self.function_locals[path]: 127 continue 128 129 # Find local definitions (within dynamic namespaces). 130 131 key = "%s.%s" % (path, name) 132 ref = self.get_resolved_object(key) 133 if ref: 134 self.set_name_reference(key, ref) 135 continue 136 137 # Find global or known built-in definitions. 138 139 ref = self.get_resolved_global_or_builtin(name) 140 if ref: 141 self.set_name_reference(key, ref) 142 continue 143 144 # Find presumed built-in definitions. 145 146 ref = self.get_builtin(name) 147 self.set_name_reference(key, ref) 148 149 def set_name_reference(self, path, ref): 150 151 "Map the given name 'path' to 'ref'." 152 153 self.importer.all_name_references[path] = self.name_references[path] = ref 154 155 def get_resolved_global_or_builtin(self, name): 156 157 "Return the resolved global or built-in object with the given 'name'." 158 159 # In some circumstances, the name is neither global nor recognised by 160 # the importer. It is then assumed to be a general built-in. 161 162 return self.get_global(name) or \ 163 self.importer.get_object("__builtins__.%s" % name) 164 165 # Module structure traversal. 166 167 def process_structure_node(self, n): 168 169 "Process the individual node 'n'." 170 171 # Module global detection. 172 173 if isinstance(n, compiler.ast.Global): 174 self.process_global_node(n) 175 176 # Module import declarations. 177 178 elif isinstance(n, compiler.ast.From): 179 self.process_from_node(n) 180 181 elif isinstance(n, compiler.ast.Import): 182 self.process_import_node(n) 183 184 # Nodes using operator module functions. 185 186 elif isinstance(n, compiler.ast.Operator): 187 return self.process_operator_node(n) 188 189 elif isinstance(n, compiler.ast.AugAssign): 190 self.process_augassign_node(n) 191 192 elif isinstance(n, compiler.ast.Compare): 193 return self.process_compare_node(n) 194 195 elif isinstance(n, compiler.ast.Slice): 196 return self.process_slice_node(n) 197 198 elif isinstance(n, compiler.ast.Sliceobj): 199 return self.process_sliceobj_node(n) 200 201 elif isinstance(n, compiler.ast.Subscript): 202 return self.process_subscript_node(n) 203 204 # Namespaces within modules. 205 206 elif isinstance(n, compiler.ast.Class): 207 self.process_class_node(n) 208 209 elif isinstance(n, compiler.ast.Function): 210 self.process_function_node(n, n.name) 211 212 elif isinstance(n, compiler.ast.Lambda): 213 return self.process_lambda_node(n) 214 215 # Assignments. 216 217 elif isinstance(n, compiler.ast.Assign): 218 219 # Handle each assignment node. 220 221 for node in n.nodes: 222 self.process_assignment_node(node, n.expr) 223 224 # Assignments within non-Assign nodes. 225 226 elif isinstance(n, compiler.ast.AssName): 227 self.process_assignment_node(n, None) 228 229 elif isinstance(n, compiler.ast.AssAttr): 230 self.process_attribute_access(n) 231 232 # Accesses. 233 234 elif isinstance(n, compiler.ast.Getattr): 235 return self.process_attribute_access(n) 236 237 # Name recording for later testing. 238 239 elif isinstance(n, compiler.ast.Name): 240 return self.process_name_node(n) 241 242 # Conditional statement tracking. 243 244 elif isinstance(n, compiler.ast.For): 245 self.process_for_node(n) 246 247 elif isinstance(n, compiler.ast.While): 248 self.process_while_node(n) 249 250 elif isinstance(n, compiler.ast.If): 251 self.process_if_node(n) 252 253 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 254 return self.process_logical_node(n) 255 256 # Exception control-flow tracking. 257 258 elif isinstance(n, compiler.ast.TryExcept): 259 self.process_try_node(n) 260 261 elif isinstance(n, compiler.ast.TryFinally): 262 self.process_try_finally_node(n) 263 264 # Control-flow modification statements. 265 266 elif isinstance(n, compiler.ast.Break): 267 self.trackers[-1].suspend_broken_branch() 268 269 elif isinstance(n, compiler.ast.Continue): 270 self.trackers[-1].suspend_continuing_branch() 271 272 elif isinstance(n, compiler.ast.Raise): 273 self.process_structure(n) 274 self.trackers[-1].abandon_branch() 275 276 elif isinstance(n, compiler.ast.Return): 277 self.process_structure(n) 278 self.trackers[-1].abandon_returning_branch() 279 280 # Invocations. 281 282 elif isinstance(n, compiler.ast.CallFunc): 283 return self.process_invocation_node(n) 284 285 # Constant usage. 286 287 elif isinstance(n, compiler.ast.Const): 288 return self.get_literal_instance(n, n.value.__class__.__name__) 289 290 elif isinstance(n, compiler.ast.Dict): 291 return self.get_literal_instance(n, "dict") 292 293 elif isinstance(n, compiler.ast.List): 294 return self.get_literal_instance(n, "list") 295 296 elif isinstance(n, compiler.ast.Tuple): 297 return self.get_literal_instance(n, "tuple") 298 299 # Unsupported nodes. 300 301 elif isinstance(n, compiler.ast.GenExpr): 302 raise InspectError("Generator expressions are not supported.", self.get_namespace_path(), n) 303 304 elif isinstance(n, compiler.ast.IfExp): 305 raise InspectError("If-else expressions are not supported.", self.get_namespace_path(), n) 306 307 elif isinstance(n, compiler.ast.ListComp): 308 raise InspectError("List comprehensions are not supported.", self.get_namespace_path(), n) 309 310 # All other nodes are processed depth-first. 311 312 else: 313 self.process_structure(n) 314 315 # By default, no expression details are returned. 316 317 return None 318 319 # Specific node handling. 320 321 def process_assignment_node(self, n, expr): 322 323 "Process the individual node 'n' to be assigned the contents of 'expr'." 324 325 # Names and attributes are assigned the entire expression. 326 327 if isinstance(n, compiler.ast.AssName): 328 329 name_ref = expr and self.process_structure_node(expr) 330 331 # Name assignments populate either function namespaces or the 332 # general namespace hierarchy. 333 334 self.assign_general_local(n.name, name_ref) 335 336 # Record usage of the name. 337 338 self.record_name(n.name) 339 340 elif isinstance(n, compiler.ast.AssAttr): 341 if expr: self.process_structure_node(expr) 342 self.process_attribute_access(n) 343 344 # Lists and tuples are matched against the expression and their 345 # items assigned to expression items. 346 347 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 348 self.process_assignment_node_items(n, expr) 349 350 # Slices and subscripts are permitted within assignment nodes. 351 352 elif isinstance(n, compiler.ast.Slice): 353 self.process_slice_node(n, expr) 354 355 elif isinstance(n, compiler.ast.Subscript): 356 self.process_subscript_node(n, expr) 357 358 def process_attribute_access(self, n): 359 360 "Process the given attribute access node 'n'." 361 362 # Obtain any completed chain and return the reference to it. 363 364 name_ref = self.process_attribute_chain(n) 365 if self.have_access_expression(n): 366 return name_ref 367 368 # Where the start of the chain of attributes has been reached, determine 369 # the complete access. 370 371 # Given a non-access node, this chain can be handled in its entirety, 372 # either being name-based and thus an access rooted on a name, or being 373 # based on some other node and thus an anonymous access of some kind. 374 375 path = self.get_namespace_path() 376 377 # Start with the the full attribute chain. 378 379 remaining = self.attrs 380 attrnames = ".".join(remaining) 381 382 # If the accessor cannot be identified, or where attributes 383 # remain in an attribute chain, record the anonymous accesses. 384 385 if not isinstance(name_ref, NameRef): # includes ResolvedNameRef 386 387 assignment = isinstance(n, compiler.ast.AssAttr) 388 389 init_item(self.attr_accesses, path, set) 390 self.attr_accesses[path].add(attrnames) 391 392 self.record_access_details(None, attrnames, assignment) 393 del self.attrs[0] 394 return 395 396 # Name-based accesses will handle the first attribute in a 397 # chain. 398 399 else: 400 attrname = remaining[0] 401 402 # Attribute assignments are used to identify instance attributes. 403 404 if isinstance(n, compiler.ast.AssAttr) and \ 405 self.in_class and self.in_function and n.expr.name == "self": 406 407 self.set_instance_attr(attrname) 408 409 # Record attribute usage using any name local to this namespace, 410 # if assigned in the namespace, or using an external name 411 # (presently just globals within classes). 412 413 name = self.get_name_for_tracking(name_ref.name, name_ref.final()) 414 tracker = self.trackers[-1] 415 416 immediate_access = len(self.attrs) == 1 417 assignment = immediate_access and isinstance(n, compiler.ast.AssAttr) 418 419 del self.attrs[0] 420 421 # Record global-based chains for subsequent resolution. 422 423 is_global = self.in_function and not self.function_locals[path].has_key(name) or \ 424 not self.in_function 425 426 if is_global: 427 self.record_global_access_details(name, attrnames) 428 429 # Make sure the name is being tracked: global names will not 430 # already be initialised in a branch and must be added 431 # explicitly. 432 433 if not tracker.have_name(name): 434 tracker.assign_names([name]) 435 if self.in_function: 436 self.scope_globals[path].add(name) 437 438 # Record attribute usage in the tracker, and record the branch 439 # information for the access. 440 441 branches = tracker.use_attribute(name, attrname) 442 443 if not branches: 444 print >>sys.stderr, "In %s, name %s is accessed using %s before an assignment." % ( 445 path, name, attrname) 446 branches = tracker.use_attribute(name, attrname) 447 448 self.record_branches_for_access(branches, name, attrnames) 449 access_number = self.record_access_details(name, attrnames, assignment) 450 return AccessRef(name, attrnames, access_number) 451 452 def process_class_node(self, n): 453 454 "Process the given class node 'n'." 455 456 path = self.get_namespace_path() 457 458 # To avoid notions of class "versions" where the same definition 459 # might be parameterised with different state and be referenced 460 # elsewhere (as base classes, for example), classes in functions or 461 # conditions are forbidden. 462 463 if self.in_function or self.in_conditional: 464 print >>sys.stderr, "In %s, class %s in function or conditional statement ignored." % ( 465 path, n.name) 466 return 467 468 # Resolve base classes. 469 470 bases = [] 471 472 for base in n.bases: 473 base_class = self.get_class(base) 474 475 if not base_class: 476 print >>sys.stderr, "In %s, class %s has unidentifiable base class: %s" % ( 477 path, n.name, base) 478 return 479 else: 480 bases.append(base_class) 481 482 # Record bases for the class and retain the class name. 483 484 class_name = self.get_object_path(n.name) 485 486 if not bases and class_name != "__builtins__.core.object": 487 ref = self.get_object("__builtins__.object") 488 bases.append(ref) 489 490 self.importer.classes[class_name] = self.classes[class_name] = bases 491 self.importer.subclasses[class_name] = set() 492 self.scope_globals[class_name] = set() 493 494 # Set the definition before entering the namespace rather than 495 # afterwards because methods may reference it. In normal Python, 496 # a class is not accessible until the definition is complete, but 497 # methods can generally reference it since upon being called the 498 # class will already exist. 499 500 self.set_definition(n.name, "<class>") 501 502 in_class = self.in_class 503 self.in_class = class_name 504 self.set_instance_attr("__class__", Reference("<class>", class_name)) 505 self.enter_namespace(n.name) 506 self.set_name("__fn__") # special instantiator attribute 507 self.set_name("__args__") # special instantiator attribute 508 self.assign_general_local("__name__", self.get_constant("str", class_name)) 509 self.process_structure_node(n.code) 510 self.exit_namespace() 511 self.in_class = in_class 512 513 def process_from_node(self, n): 514 515 "Process the given node 'n', importing from another module." 516 517 path = self.get_namespace_path() 518 519 module_name, names = self.get_module_name(n) 520 if module_name == self.name: 521 raise InspectError("Cannot import from the current module.", path, n) 522 523 self.queue_module(module_name) 524 525 # Attempt to obtain the referenced objects. 526 527 for name, alias in n.names: 528 if name == "*": 529 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 530 531 # Explicit names. 532 533 ref = self.import_name_from_module(name, module_name) 534 value = ResolvedNameRef(alias or name, ref) 535 self.set_general_local(alias or name, value) 536 537 def process_function_node(self, n, name): 538 539 """ 540 Process the given function or lambda node 'n' with the given 'name'. 541 """ 542 543 is_lambda = isinstance(n, compiler.ast.Lambda) 544 545 # Where a function is declared conditionally, use a separate name for 546 # the definition, and assign the definition to the stated name. 547 548 if (self.in_conditional or self.in_function) and not is_lambda: 549 original_name = name 550 name = self.get_lambda_name() 551 else: 552 original_name = None 553 554 # Initialise argument and local records. 555 556 function_name = self.get_object_path(name) 557 argnames = get_argnames(n.argnames) 558 559 # Insert "self" into methods where not explicitly declared. 560 561 if self.in_class and (not argnames or argnames[0] != "self"): 562 argnames.insert(0, "self") 563 564 self.importer.function_parameters[function_name] = \ 565 self.function_parameters[function_name] = argnames 566 567 # Define all arguments/parameters in the local namespace. 568 569 locals = self.function_locals[function_name] = {} 570 571 # Define "self" in terms of the class if in a method. 572 # This does not diminish the need for type-narrowing in the deducer. 573 574 if argnames: 575 if self.in_class and argnames[0] == "self": 576 locals[argnames[0]] = Reference("<instance>", self.in_class) 577 else: 578 locals[argnames[0]] = Reference("<var>") 579 580 for argname in argnames[1:]: 581 locals[argname] = Reference("<var>") 582 583 globals = self.scope_globals[function_name] = set() 584 585 # Process the defaults. 586 587 defaults = self.importer.function_defaults[function_name] = \ 588 self.function_defaults[function_name] = [] 589 590 for argname, default in compiler.ast.get_defaults(n): 591 if default: 592 593 # Obtain any reference for the default. 594 595 name_ref = self.process_structure_node(default) 596 defaults.append((argname, name_ref.is_name() and name_ref.reference() or Reference("<var>"))) 597 598 # Reset conditional tracking to focus on the function contents. 599 600 in_conditional = self.in_conditional 601 self.in_conditional = False 602 603 in_function = self.in_function 604 self.in_function = function_name 605 606 self.enter_namespace(name) 607 608 # Track attribute usage within the namespace. 609 610 path = self.get_namespace_path() 611 612 self.start_tracking(locals) 613 self.process_structure_node(n.code) 614 self.stop_tracking() 615 616 # Exit to the parent. 617 618 self.exit_namespace() 619 620 # Update flags. 621 622 self.in_function = in_function 623 self.in_conditional = in_conditional 624 625 # Define the function using the appropriate name. 626 627 self.set_definition(name, "<function>") 628 629 # Where a function is set conditionally, assign the name. 630 631 if original_name: 632 self.process_assignment_for_function(original_name, name) 633 634 def process_global_node(self, n): 635 636 """ 637 Process the given "global" node 'n'. 638 """ 639 640 path = self.get_namespace_path() 641 642 if path != self.name: 643 self.scope_globals[path].update(n.names) 644 645 def process_if_node(self, n): 646 647 """ 648 Process the given "if" node 'n'. 649 """ 650 651 tracker = self.trackers[-1] 652 tracker.new_branchpoint() 653 654 for test, body in n.tests: 655 self.process_structure_node(test) 656 657 tracker.new_branch() 658 659 in_conditional = self.in_conditional 660 self.in_conditional = True 661 self.process_structure_node(body) 662 self.in_conditional = in_conditional 663 664 tracker.shelve_branch() 665 666 # Maintain a branch for the else clause. 667 668 tracker.new_branch() 669 if n.else_: 670 self.process_structure_node(n.else_) 671 tracker.shelve_branch() 672 673 tracker.merge_branches() 674 675 def process_import_node(self, n): 676 677 "Process the given import node 'n'." 678 679 path = self.get_namespace_path() 680 681 # Load the mentioned module. 682 683 for name, alias in n.names: 684 if name == self.name: 685 raise InspectError("Cannot import the current module.", path, n) 686 if not alias and len(n.names) > 1: 687 raise InspectError("Imported modules must be aliased unless a simple module is imported.", path, n) 688 689 self.set_module(alias or name.split(".")[-1], name) 690 self.queue_module(name, True) 691 692 def process_invocation_node(self, n): 693 694 "Process the given invocation node 'n'." 695 696 path = self.get_namespace_path() 697 698 self.allocate_arguments(path, n.args) 699 700 try: 701 # Process the expression, obtaining any identified reference. 702 703 name_ref = self.process_structure_node(n.node) 704 705 # Process the arguments. 706 707 for arg in n.args: 708 self.process_structure_node(arg) 709 710 # Detect class invocations. 711 712 if isinstance(name_ref, ResolvedNameRef) and name_ref.has_kind("<class>"): 713 return InstanceRef(name_ref.reference().instance_of()) 714 715 elif isinstance(name_ref, NameRef): 716 return InvocationRef(name_ref) 717 718 return None 719 720 finally: 721 self.deallocate_arguments(path, n.args) 722 723 def process_lambda_node(self, n): 724 725 "Process the given lambda node 'n'." 726 727 name = self.get_lambda_name() 728 self.process_function_node(n, name) 729 730 origin = self.get_object_path(name) 731 return ResolvedNameRef(name, Reference("<function>", origin)) 732 733 def process_logical_node(self, n): 734 735 "Process the given operator node 'n'." 736 737 self.process_operator_chain(n.nodes, self.process_structure_node) 738 739 def process_name_node(self, n): 740 741 "Process the given name node 'n'." 742 743 path = self.get_namespace_path() 744 745 # Special names. 746 747 if n.name.startswith("$"): 748 value = self.get_special(n.name) 749 if value: 750 return value 751 752 # Special case for operator functions introduced through code 753 # transformations. 754 755 if n.name.startswith("$op"): 756 757 # Obtain the location of the actual function defined in the operator 758 # package. 759 760 op = n.name[len("$op"):] 761 762 # Attempt to get a reference. 763 764 ref = self.import_name_from_module(op, "operator") 765 self.add_deferred(ref) 766 767 # Record the imported name and provide the resolved name reference. 768 769 value = ResolvedNameRef(n.name, ref) 770 self.set_special(n.name, value) 771 return value 772 773 # Record usage of the name. 774 775 self.record_name(n.name) 776 777 # Search for unknown names in non-function scopes immediately. 778 # External names in functions are resolved later. 779 780 ref = self.find_name(n.name) 781 if ref: 782 return ResolvedNameRef(n.name, ref) 783 784 # Explicitly-declared global names. 785 786 elif self.in_function and n.name in self.scope_globals[path]: 787 return NameRef(n.name) 788 789 # Examine other names. 790 791 else: 792 tracker = self.trackers[-1] 793 794 # Check local names. 795 796 branches = tracker.tracking_name(n.name) 797 798 # Local name. 799 800 if branches: 801 self.record_branches_for_access(branches, n.name, None) 802 access_number = self.record_access_details(n.name, None, False) 803 return LocalNameRef(n.name, access_number) 804 805 # Possible global or built-in name. 806 807 else: 808 return NameRef(n.name) 809 810 def process_operator_chain(self, nodes, fn): 811 812 """ 813 Process the given chain of 'nodes', applying 'fn' to each node or item. 814 Each node starts a new conditional region, effectively making a deeply- 815 nested collection of if-like statements. 816 """ 817 818 tracker = self.trackers[-1] 819 820 for item in nodes: 821 tracker.new_branchpoint() 822 tracker.new_branch() 823 fn(item) 824 825 for item in nodes[:-1]: 826 tracker.shelve_branch() 827 tracker.new_branch() 828 tracker.shelve_branch() 829 tracker.merge_branches() 830 831 tracker.shelve_branch() 832 tracker.merge_branches() 833 834 def process_try_node(self, n): 835 836 """ 837 Process the given "try...except" node 'n'. 838 """ 839 840 tracker = self.trackers[-1] 841 tracker.new_branchpoint() 842 843 self.process_structure_node(n.body) 844 845 for name, var, handler in n.handlers: 846 if name is not None: 847 self.process_structure_node(name) 848 849 # Any abandoned branches from the body can now be resumed in a new 850 # branch. 851 852 tracker.resume_abandoned_branches() 853 854 # Establish the local for the handler. 855 856 if var is not None: 857 self.process_structure_node(var) 858 if handler is not None: 859 self.process_structure_node(handler) 860 861 tracker.shelve_branch() 862 863 # The else clause maintains the usage from the body but without the 864 # abandoned branches since they would never lead to the else clause 865 # being executed. 866 867 if n.else_: 868 tracker.new_branch() 869 self.process_structure_node(n.else_) 870 tracker.shelve_branch() 871 872 # Without an else clause, a null branch propagates the successful 873 # outcome. 874 875 else: 876 tracker.new_branch() 877 tracker.shelve_branch() 878 879 tracker.merge_branches() 880 881 def process_try_finally_node(self, n): 882 883 """ 884 Process the given "try...finally" node 'n'. 885 """ 886 887 tracker = self.trackers[-1] 888 self.process_structure_node(n.body) 889 890 # Any abandoned branches from the body can now be resumed. 891 892 branches = tracker.resume_all_abandoned_branches() 893 self.process_structure_node(n.final) 894 895 # At the end of the finally clause, abandoned branches are discarded. 896 897 tracker.restore_active_branches(branches) 898 899 def process_while_node(self, n): 900 901 "Process the given while node 'n'." 902 903 tracker = self.trackers[-1] 904 tracker.new_branchpoint(loop_node=True) 905 906 # Evaluate any test or iterator outside the loop. 907 908 self.process_structure_node(n.test) 909 910 # Propagate attribute usage to branches. 911 912 tracker.new_branch(loop_node=True) 913 914 # Enter the loop. 915 916 in_conditional = self.in_conditional 917 self.in_conditional = True 918 self.process_structure_node(n.body) 919 self.in_conditional = in_conditional 920 921 # Continuing branches are resumed before any test. 922 923 tracker.resume_continuing_branches() 924 925 # Evaluate any continuation test within the body. 926 927 self.process_structure_node(n.test) 928 929 tracker.shelve_branch(loop_node=True) 930 931 # Support the non-looping condition. 932 933 tracker.new_branch() 934 tracker.shelve_branch() 935 936 tracker.merge_branches() 937 938 # Evaluate any else clause outside branches. 939 940 if n.else_: 941 self.process_structure_node(n.else_) 942 943 # Connect broken branches to the code after any loop. 944 945 tracker.resume_broken_branches() 946 947 # Branch tracking methods. 948 949 def start_tracking(self, names): 950 951 """ 952 Start tracking attribute usage for names in the current namespace, 953 immediately registering the given 'names'. 954 """ 955 956 path = self.get_namespace_path() 957 parent = self.trackers[-1] 958 tracker = BranchTracker() 959 self.trackers.append(tracker) 960 961 # Record the given names established as new branches. 962 963 tracker.assign_names(names) 964 965 def assign_name(self, name, name_ref): 966 967 "Assign to 'name' the given 'name_ref' in the current namespace." 968 969 name = self.get_name_for_tracking(name) 970 self.trackers[-1].assign_names([name], [name_ref]) 971 972 def stop_tracking(self): 973 974 """ 975 Stop tracking attribute usage, recording computed usage for the current 976 namespace. 977 """ 978 979 path = self.get_namespace_path() 980 tracker = self.trackers.pop() 981 self.record_assignments_for_access(tracker) 982 983 self.attr_usage[path] = tracker.get_all_usage() 984 self.name_initialisers[path] = tracker.get_all_values() 985 986 def start_tracking_in_module(self): 987 988 "Start tracking attribute usage in the module." 989 990 tracker = BranchTracker() 991 self.trackers.append(tracker) 992 993 def stop_tracking_in_module(self): 994 995 "Stop tracking attribute usage in the module." 996 997 tracker = self.trackers[0] 998 self.record_assignments_for_access(tracker) 999 self.attr_usage[self.name] = tracker.get_all_usage() 1000 self.name_initialisers[self.name] = tracker.get_all_values() 1001 1002 def record_assignments_for_access(self, tracker): 1003 1004 """ 1005 For the current path, use the given 'tracker' to record assignment 1006 version information for attribute accesses. 1007 """ 1008 1009 path = self.get_path_for_access() 1010 1011 if not self.attr_accessor_branches.has_key(path): 1012 return 1013 1014 init_item(self.attr_accessors, path, dict) 1015 attr_accessors = self.attr_accessors[path] 1016 1017 # Obtain the branches applying during each access. 1018 1019 for access, all_branches in self.attr_accessor_branches[path].items(): 1020 name, attrnames = access 1021 init_item(attr_accessors, access, list) 1022 1023 # Obtain the assignments applying to each branch. 1024 1025 for branches in all_branches: 1026 positions = tracker.get_assignment_positions_for_branches(name, branches) 1027 1028 # Detect missing name information. 1029 1030 if None in positions: 1031 globals = self.global_attr_accesses.get(path) 1032 accesses = globals and globals.get(name) 1033 if not accesses: 1034 print >>sys.stderr, "In %s, %s may not be defined when used." % ( 1035 self.get_namespace_path(), name) 1036 positions.remove(None) 1037 1038 attr_accessors[access].append(positions) 1039 1040 def record_branches_for_access(self, branches, name, attrnames): 1041 1042 """ 1043 Record the given 'branches' for an access involving the given 'name' and 1044 'attrnames'. 1045 """ 1046 1047 access = name, attrnames 1048 path = self.get_path_for_access() 1049 1050 init_item(self.attr_accessor_branches, path, dict) 1051 attr_accessor_branches = self.attr_accessor_branches[path] 1052 1053 init_item(attr_accessor_branches, access, list) 1054 attr_accessor_branches[access].append(branches) 1055 1056 def record_access_details(self, name, attrnames, assignment): 1057 1058 """ 1059 For the given 'name' and 'attrnames', record an access indicating 1060 whether 'assignment' is occurring. 1061 1062 These details correspond to accesses otherwise recorded by the attribute 1063 accessor and attribute access dictionaries. 1064 """ 1065 1066 access = name, attrnames 1067 path = self.get_path_for_access() 1068 1069 init_item(self.attr_access_modifiers, path, dict) 1070 init_item(self.attr_access_modifiers[path], access, list) 1071 1072 access_number = len(self.attr_access_modifiers[path][access]) 1073 self.attr_access_modifiers[path][access].append(assignment) 1074 return access_number 1075 1076 def record_global_access_details(self, name, attrnames): 1077 1078 """ 1079 Record details of a global access via the given 'name' involving the 1080 indicated 'attrnames'. 1081 """ 1082 1083 path = self.get_namespace_path() 1084 1085 init_item(self.global_attr_accesses, path, dict) 1086 init_item(self.global_attr_accesses[path], name, set) 1087 self.global_attr_accesses[path][name].add(attrnames) 1088 1089 # Namespace modification. 1090 1091 def record_name(self, name): 1092 1093 "Record the use of 'name' in a namespace." 1094 1095 path = self.get_namespace_path() 1096 init_item(self.names_used, path, set) 1097 self.names_used[path].add(name) 1098 1099 def set_module(self, name, module_name): 1100 1101 """ 1102 Set a module in the current namespace using the given 'name' associated 1103 with the corresponding 'module_name'. 1104 """ 1105 1106 if name: 1107 self.set_general_local(name, Reference("<module>", module_name)) 1108 1109 def set_definition(self, name, kind): 1110 1111 """ 1112 Set the definition having the given 'name' and 'kind'. 1113 1114 Definitions are set in the static namespace hierarchy, but they can also 1115 be recorded for function locals. 1116 """ 1117 1118 if self.is_global(name): 1119 print >>sys.stderr, "In %s, %s is defined as being global." % ( 1120 self.get_namespace_path(), name) 1121 1122 path = self.get_object_path(name) 1123 self.set_object(path, kind) 1124 1125 ref = self.get_object(path) 1126 if ref.get_kind() == "<var>": 1127 print >>sys.stderr, "In %s, %s is defined more than once." % ( 1128 self.get_namespace_path(), name) 1129 1130 if not self.is_global(name) and self.in_function: 1131 self.set_function_local(name, ref) 1132 1133 def set_function_local(self, name, ref=None): 1134 1135 "Set the local with the given 'name' and optional 'ref'." 1136 1137 locals = self.function_locals[self.get_namespace_path()] 1138 multiple = not ref or locals.has_key(name) and locals[name] != ref 1139 locals[name] = multiple and Reference("<var>") or ref 1140 1141 def assign_general_local(self, name, name_ref): 1142 1143 """ 1144 Set for 'name' the given 'name_ref', recording the name for attribute 1145 usage tracking. 1146 """ 1147 1148 self.set_general_local(name, name_ref) 1149 self.assign_name(name, name_ref) 1150 1151 def set_general_local(self, name, value=None): 1152 1153 """ 1154 Set the 'name' with optional 'value' in any kind of local namespace, 1155 where the 'value' should be a reference if specified. 1156 """ 1157 1158 init_value = self.get_initialising_value(value) 1159 1160 # Module global names. 1161 1162 if self.is_global(name): 1163 path = self.get_global_path(name) 1164 self.set_object(path, init_value) 1165 1166 # Function local names. 1167 1168 elif self.in_function: 1169 path = self.get_object_path(name) 1170 self.set_function_local(name, init_value) 1171 1172 # Other namespaces (classes). 1173 1174 else: 1175 path = self.get_object_path(name) 1176 self.set_name(name, init_value) 1177 1178 def set_name(self, name, ref=None): 1179 1180 "Attach the 'name' with optional 'ref' to the current namespace." 1181 1182 self.set_object(self.get_object_path(name), ref) 1183 1184 def set_instance_attr(self, name, ref=None): 1185 1186 """ 1187 Add an instance attribute of the given 'name' to the current class, 1188 using the optional 'ref'. 1189 """ 1190 1191 init_item(self.instance_attrs, self.in_class, set) 1192 self.instance_attrs[self.in_class].add(name) 1193 1194 if ref: 1195 init_item(self.instance_attr_constants, self.in_class, dict) 1196 self.instance_attr_constants[self.in_class][name] = ref 1197 1198 def get_initialising_value(self, value): 1199 1200 "Return a suitable initialiser reference for 'value'." 1201 1202 # Includes LiteralSequenceRef, ResolvedNameRef... 1203 1204 if isinstance(value, (NameRef, AccessRef, InstanceRef)): 1205 return value.reference() 1206 1207 # In general, invocations do not produce known results. However, the 1208 # name initialisers are resolved once a module has been inspected. 1209 1210 elif isinstance(value, InvocationRef): 1211 return value.reference() 1212 1213 else: 1214 return value 1215 1216 # Static, program-relative naming. 1217 1218 def find_name(self, name): 1219 1220 """ 1221 Return the qualified name for the given 'name' used in the current 1222 non-function namespace. 1223 """ 1224 1225 path = self.get_namespace_path() 1226 ref = None 1227 1228 if not self.in_function and name not in predefined_constants: 1229 if self.in_class: 1230 ref = self.get_object(self.get_object_path(name)) 1231 if not ref: 1232 ref = self.get_global_or_builtin(name) 1233 1234 return ref 1235 1236 def get_class(self, node): 1237 1238 """ 1239 Use the given 'node' to obtain the identity of a class. Return a 1240 reference for the class. Unresolved dependencies are permitted and must 1241 be resolved later. 1242 """ 1243 1244 ref = self._get_class(node) 1245 return ref.has_kind(["<class>", "<depends>"]) and ref or None 1246 1247 def _get_class(self, node): 1248 1249 """ 1250 Use the given 'node' to find a class definition. Return a reference to 1251 the class. 1252 """ 1253 1254 if isinstance(node, compiler.ast.Getattr): 1255 1256 # Obtain the identity of the access target. 1257 1258 ref = self._get_class(node.expr) 1259 1260 # Where the target is a class or module, obtain the identity of the 1261 # attribute. 1262 1263 if ref.has_kind(["<function>", "<var>"]): 1264 return None 1265 else: 1266 attrname = "%s.%s" % (ref.get_origin(), node.attrname) 1267 return self.get_object(attrname) 1268 1269 # Names can be module-level or built-in. 1270 1271 elif isinstance(node, compiler.ast.Name): 1272 1273 # Record usage of the name and attempt to identify it. 1274 1275 self.record_name(node.name) 1276 return self.get_global_or_builtin(node.name) 1277 else: 1278 return None 1279 1280 def get_constant(self, name, value): 1281 1282 "Return a constant reference for the given type 'name' and 'value'." 1283 1284 ref = self.get_builtin_class(name) 1285 return self.get_constant_reference(ref, value) 1286 1287 def get_literal_instance(self, n, name): 1288 1289 "For node 'n', return a reference to an instance of 'name'." 1290 1291 # Get a reference to the built-in class. 1292 1293 ref = self.get_builtin_class(name) 1294 1295 # Obtain the details of the literal itself. 1296 # An alias to the type is generated for sequences. 1297 1298 if name in ("dict", "list", "tuple"): 1299 self.set_special_literal(name, ref) 1300 return self.process_literal_sequence_node(n, name, ref, LiteralSequenceRef) 1301 1302 # Constant values are independently recorded. 1303 1304 else: 1305 return self.get_constant_reference(ref, n.value) 1306 1307 # Special names. 1308 1309 def get_special(self, name): 1310 1311 "Return any stored value for the given special 'name'." 1312 1313 return self.special.get(name) 1314 1315 def set_special(self, name, value): 1316 1317 """ 1318 Set a special 'name' that merely tracks the use of an implicit object 1319 'value'. 1320 """ 1321 1322 self.special[name] = value 1323 1324 def set_special_literal(self, name, ref): 1325 1326 """ 1327 Set a special name for the literal type 'name' having type 'ref'. Such 1328 special names provide a way of referring to literal object types. 1329 """ 1330 1331 literal_name = "$L%s" % name 1332 value = ResolvedNameRef(literal_name, ref) 1333 self.set_special(literal_name, value) 1334 1335 # Functions and invocations. 1336 1337 def set_invocation_usage(self): 1338 1339 """ 1340 Discard the current invocation storage figures, retaining the maximum 1341 values. 1342 """ 1343 1344 for path, (current, maximum) in self.function_targets.items(): 1345 self.importer.function_targets[path] = self.function_targets[path] = maximum 1346 1347 for path, (current, maximum) in self.function_arguments.items(): 1348 self.importer.function_arguments[path] = self.function_arguments[path] = maximum 1349 1350 def allocate_arguments(self, path, args): 1351 1352 """ 1353 Allocate temporary argument storage using current and maximum 1354 requirements for the given 'path' and 'args'. 1355 """ 1356 1357 init_item(self.function_targets, path, lambda: [0, 0]) 1358 t = self.function_targets[path] 1359 t[0] += 1 1360 t[1] = max(t[0], t[1]) 1361 1362 init_item(self.function_arguments, path, lambda: [0, 0]) 1363 t = self.function_arguments[path] 1364 t[0] += len(args) + 1 1365 t[1] = max(t[0], t[1]) 1366 1367 def deallocate_arguments(self, path, args): 1368 1369 "Deallocate temporary argument storage for the given 'path' and 'args'." 1370 1371 self.function_targets[path][0] -= 1 1372 self.function_arguments[path][0] -= len(args) + 1 1373 1374 # vim: tabstop=4 expandtab shiftwidth=4