1 #!/usr/bin/env python 2 3 """ 4 Inspect source files, obtaining details of classes and attributes. 5 6 Copyright (C) 2007, 2008, 2009 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 21 -------- 22 23 The results of inspecting a module are as follows: 24 25 Constants 26 --------- 27 28 All constants identified within the code shall be registered. 29 30 Classes 31 ------- 32 33 All global classes shall be registered; local classes (within functions) or 34 nested classes (within classes) are not currently registered. 35 36 Base classes must be detected and constant. 37 38 All classes without bases are made to inherit from __builtins__.object in order 39 to support some standard methods. 40 41 Functions 42 --------- 43 44 All functions and lambda definitions shall be registered. 45 46 Namespaces 47 ---------- 48 49 Modules define their own "global" namespace, within which classes, functions 50 and lambda definitions establish a hierarchy of namespaces. 51 52 Only local, global and built-in namespaces are recognised; closures are not 53 supported. 54 55 Assignments 56 ----------- 57 58 Name assignment and attribute assignment involving modules and classes cause 59 names to be associated with values within namespaces. 60 61 Any assignments within loops are considered to cause the targets of such 62 assignments to provide non-constant values. 63 64 Assignments to names are only really considered to cause the targets of such 65 assignments to provide constant values if the targets reside in the module 66 namespace or in class namespaces, subject to the above conditions. 67 68 Assignments to names within functions are not generally considered to cause the 69 targets of such assignments to provide constant values since functions can be 70 invoked many times with different inputs. However, there may be benefits in 71 considering a local to be constant within a single invocation. 72 """ 73 74 from micropython.common import * 75 from micropython.data import * 76 import compiler.ast 77 from compiler.visitor import ASTVisitor 78 79 # Program visitors. 80 81 class InspectedModule(ASTVisitor, Module): 82 83 """ 84 An inspected module, providing core details via the Module superclass, but 85 capable of being used as an AST visitor. 86 """ 87 88 def __init__(self, name, importer): 89 90 """ 91 Initialise this visitor with a module 'name' and an 'importer' which is 92 used to provide access to other modules when required. 93 """ 94 95 ASTVisitor.__init__(self) 96 Module.__init__(self, name) 97 self.visitor = self 98 99 # Import machinery links. 100 101 self.importer = importer 102 self.optimisations = importer.optimisations 103 self.builtins = self.importer.modules.get("__builtins__") 104 self.loaded = 0 105 106 # Current expression state. 107 108 self.expr = None 109 110 # Namespace state. 111 112 self.in_init = 0 # Find instance attributes in __init__ methods. 113 self.in_method = 0 # Find instance attributes in all methods. 114 self.in_loop = 0 # Note loop "membership", affecting assignments. 115 self.namespaces = [] 116 self.module = None 117 118 def parse(self, filename): 119 120 "Parse the file having the given 'filename'." 121 122 module = compiler.parseFile(filename) 123 self.process(module) 124 125 def process(self, module): 126 127 "Process the given 'module'." 128 129 self.astnode = self.module = module 130 processed = self.dispatch(module) 131 if self.has_key("__all__"): 132 all = self["__all__"] 133 if isinstance(all, compiler.ast.List): 134 for n in all.nodes: 135 self.store(n.value, self.importer.add_module(self.name + "." + n.value)) 136 return processed 137 138 def vacuum(self): 139 140 """ 141 Vacuum the module namespace, removing unreferenced objects and unused 142 names. 143 """ 144 145 for name, value in self.items(): 146 147 if self.should_optimise_unused_objects(): 148 149 # Remove entries for unreferenced objects. 150 # This, due to the nature of the referenced attribute, assumes 151 # that only explicitly mentioned classes and functions are 152 # employed in the final program. 153 154 if isinstance(value, Attr): 155 156 # Only remove entries for classes and functions, not methods. 157 158 for attr_value in value.get_values(): 159 if (isinstance(attr_value, Function) and not attr_value.is_method() or 160 isinstance(attr_value, Class)) and not attr_value.referenced: 161 pass 162 else: 163 break 164 else: 165 del self[name] 166 167 # Complain about globals not initialised at the module level. 168 169 if isinstance(value, Global): 170 print "Warning: global %r in module %r not initialised at the module level." % (name, self.name) 171 172 # Remove unreferenced objects. 173 174 if self.should_optimise_unused_objects(): 175 176 all_objects = list(self.all_objects) 177 178 for obj in all_objects: 179 180 # Only remove entries for classes and functions, not methods. 181 182 if (isinstance(obj, Function) and not obj.is_method() or 183 isinstance(obj, Class)) and not obj.referenced: 184 185 self.all_objects.remove(obj) 186 187 # Remove unused entries from classes plus associated methods. 188 189 if isinstance(obj, Class): 190 for name, attr in obj.class_attributes().items(): 191 192 # Methods can only be deleted if they are the only 193 # assigned object to the class and are unreferenced. 194 195 if name not in self.importer.names_used and \ 196 attr.assignments == 1 and isinstance(attr.get_value(), Function) and \ 197 attr.get_value().is_method() and not attr.get_value().referenced: 198 199 self.all_objects.remove(attr.get_value()) 200 del obj[name] 201 202 def finalise(self): 203 204 "Finalise the module." 205 206 for obj in self.all_objects: 207 if isinstance(obj, (Class, Function)): 208 obj.finalise_attributes() 209 210 def add_object(self, obj, any_scope=0): 211 212 """ 213 Record 'obj' if non-local or if the optional 'any_scope' is set to a 214 true value. 215 """ 216 217 if any_scope or not (self.namespaces and isinstance(self.namespaces[-1], Function)): 218 self.all_objects.add(obj) 219 220 # Optimisation tests. 221 222 def should_optimise_unused_objects(self): 223 return "unused_objects" in self.optimisations 224 225 # Namespace methods. 226 227 def store(self, name, obj): 228 229 "Record attribute or local 'name', storing 'obj'." 230 231 if not self.namespaces: 232 self.set(name, obj, not self.in_loop) 233 else: 234 self.namespaces[-1].set(name, obj, not self.in_loop) 235 236 def store_lambda(self, obj): 237 238 "Store a lambda function 'obj'." 239 240 self.add_object(obj) 241 242 def store_module_attr(self, name, module): 243 244 """ 245 Record module attribute 'name' in the given 'module' using the current 246 expression. 247 """ 248 249 module.set(name, self.expr, 0) 250 251 def store_class_attr(self, name): 252 253 """ 254 Record class attribute 'name' in the current class using the current 255 expression. 256 """ 257 258 if self.in_method and self.namespaces[-2].has_key(name): 259 self.namespaces[-2].set(name, self.expr, 0) 260 return 1 261 262 return 0 263 264 def store_instance_attr(self, name): 265 266 "Record instance attribute 'name' in the current class." 267 268 if self.in_method: 269 270 # Current namespace is the function. 271 # Previous namespace is the class. 272 273 self.namespaces[-2].add_instance_attribute(name) 274 275 def get_parent(self): 276 277 "Return the parent (or most recent) namespace currently exposed." 278 279 return (self.namespaces[-1:] or [self])[0] 280 281 # Visitor methods. 282 283 def default(self, node, *args): 284 raise InspectError(self.full_name(), node, "Node class %r is not supported." % node.__class__) 285 286 def dispatch(self, node, *args): 287 return ASTVisitor.dispatch(self, node, *args) 288 289 def NOP(self, node): 290 for n in node.getChildNodes(): 291 self.dispatch(n) 292 return None 293 294 def OP(self, node): 295 for n in node.getChildNodes(): 296 self.dispatch(n) 297 return Instance() 298 299 def _visitUnary(self, node): 300 301 "Accounting method for the unary operator 'node'." 302 303 method = unary_methods[node.__class__.__name__] 304 self.importer.use_name(method) 305 return self.OP(node) 306 307 def _visitBinary(self, node): 308 309 "Accounting method for the binary operator 'node'." 310 311 left_method, right_method = binary_methods[node.__class__.__name__] 312 self.importer.use_name(left_method) 313 self.importer.use_name(right_method) 314 return self.OP(node) 315 316 def _visitFunction(self, node, name): 317 318 """ 319 Return a function object for the function defined by 'node' with the 320 given 'name'. If a lambda expression is being visited, 'name' should be 321 None. 322 """ 323 324 function = Function( 325 name, 326 self.get_parent(), 327 node.argnames, 328 node.defaults, 329 (node.flags & 4 != 0), 330 (node.flags & 8 != 0), 331 self, 332 node 333 ) 334 335 # Make a back reference from the node for code generation. 336 337 node.unit = function 338 339 # Process the defaults. 340 341 for n in node.defaults: 342 self.expr = self.dispatch(n) 343 function.store_default(self.expr) 344 345 # Enter the function. 346 347 self.namespaces.append(function) 348 349 # Current namespace is the function. 350 # Previous namespace is the class. 351 352 if len(self.namespaces) > 1 and isinstance(self.namespaces[-2], Class): 353 if name == "__init__": 354 self.in_init = 1 355 self.in_method = 1 356 357 self.dispatch(node.code) 358 self.in_init = 0 359 self.in_method = 0 360 self.namespaces.pop() 361 362 if name is not None: 363 self.store(name, function) 364 else: 365 self.store_lambda(function) 366 367 # Lambda functions are always assumed to be referenced. This is 368 # because other means of discovering the referencing of objects rely 369 # on the original names inherent in the definition of those objects. 370 371 function.set_referenced() 372 373 # Where defaults exist, an instance needs creating. Thus, it makes 374 # no sense to return a reference to the function here, since the 375 # recipient will not be referencing the function itself. 376 377 if node.defaults: 378 return Instance() # indicates no known target 379 380 self.add_object(function, any_scope=1) 381 return function 382 383 # Specific handler methods. 384 385 visitAdd = _visitBinary 386 387 visitAnd = OP 388 389 visitAssert = NOP 390 391 def visitAssign(self, node): 392 self.expr = self.dispatch(node.expr) 393 for n in node.nodes: 394 self.dispatch(n) 395 return None 396 397 def visitAssAttr(self, node): 398 expr = self.dispatch(node.expr) 399 if isinstance(expr, Attr): 400 if expr.name == "self": 401 if not self.store_class_attr(node.attrname): 402 self.store_instance_attr(node.attrname) 403 elif isinstance(expr.get_value(), Module): 404 self.store_module_attr(node.attrname, expr.get_value()) 405 print "Warning: attribute %r of module %r set outside the module." % (node.attrname, expr.get_value().name) 406 return None 407 408 def visitAssList(self, node): 409 410 # Declare names which will be used by generated code. 411 412 self.importer.use_name("__getitem__") 413 414 # Process the assignment. 415 416 for i, n in enumerate(node.nodes): 417 self.dispatch(n) 418 self.importer.make_constant(i) # for __getitem__(i) at run-time 419 return None 420 421 def visitAssName(self, node): 422 self.store(node.name, self.expr) 423 return None 424 425 visitAssTuple = visitAssList 426 427 def visitAugAssign(self, node): 428 429 # Accounting. 430 431 aug_method, (left_method, right_method) = augassign_methods[node.op] 432 self.importer.use_name(aug_method) 433 self.importer.use_name(left_method) 434 self.importer.use_name(right_method) 435 return self.OP(node) 436 437 visitBackquote = OP 438 439 visitBitand = _visitBinary 440 441 visitBitor = _visitBinary 442 443 visitBitxor = _visitBinary 444 445 visitBreak = NOP 446 447 visitCallFunc = OP 448 449 def visitClass(self, node): 450 451 """ 452 Register the class at the given 'node' subject to the restrictions 453 mentioned in the module docstring. 454 """ 455 456 if self.namespaces: 457 print "Class %r in %r is not global: ignored." % (node.name, self.namespaces[-1].full_name()) 458 return None 459 else: 460 cls = Class(node.name, self.get_parent(), self, node) 461 462 # Visit the base class expressions, attempting to find concrete 463 # definitions of classes. 464 465 for base in node.bases: 466 expr = self.dispatch(base) 467 if isinstance(expr, Attr): 468 if expr.assignments != 1: 469 raise InspectError(self.full_name(), node, 470 "Base class %r for %r is not constant." % (base, cls.full_name())) 471 else: 472 cls.add_base(expr.get_value()) 473 else: # if expr is None: 474 raise InspectError(self.full_name(), node, 475 "Base class %r for %r is not found: it may be hidden in some way." % (base, cls.full_name())) 476 477 # NOTE: Potentially dubious measure to permit __init__ availability. 478 # If no bases exist, adopt the 'object' class. 479 480 if not node.bases and not (self.name == "__builtins__" and node.name == "object") : 481 expr = self.dispatch(compiler.ast.Name("object")) 482 cls.add_base(expr.get_value()) 483 484 # Make a back reference from the node for code generation. 485 486 node.unit = cls 487 488 # Make an entry for the class. 489 490 self.store(node.name, cls) 491 self.add_object(cls) 492 493 # Process the class body. 494 495 self.namespaces.append(cls) 496 self.dispatch(node.code) 497 self.namespaces.pop() 498 499 return cls 500 501 def visitCompare(self, node): 502 503 # Accounting. 504 # NOTE: Replicates some code in micropython.ast.visitCompare. 505 506 for op in node.ops: 507 op_name, next_node = op 508 methods = comparison_methods[op_name] 509 if methods is not None: 510 self.importer.use_name(methods[0]) 511 self.importer.use_name(methods[1]) 512 elif op_name.endswith("in"): 513 self.importer.use_name("__contains__") 514 515 return self.OP(node) 516 517 def visitConst(self, node): 518 519 # Register the constant, if necessary, returning the resulting object. 520 521 return self.importer.make_constant(node.value) 522 523 visitContinue = NOP 524 525 visitDecorators = NOP 526 527 visitDict = OP 528 529 visitDiscard = NOP 530 531 visitDiv = _visitBinary 532 533 visitEllipsis = NOP 534 535 visitExec = NOP 536 537 visitExpression = OP 538 539 visitFloorDiv = _visitBinary 540 541 def visitFor(self, node): 542 543 # Declare names which will be used by generated code. 544 545 self.importer.use_name("__iter__") 546 self.importer.use_name("next") 547 548 # Enter the loop. 549 550 self.in_loop = 1 551 self.NOP(node) 552 self.in_loop = 0 553 return None 554 555 def visitFrom(self, node): 556 module = self.importer.load(node.modname, 1) 557 558 if module is not None: 559 module.set_referenced() 560 561 #if module is None: 562 # print "Warning:", node.modname, "not imported." 563 564 for name, alias in node.names: 565 if name != "*": 566 if module is not None and module.namespace.has_key(name): 567 attr = module[name] 568 self.store(alias or name, attr) 569 if isinstance(attr.get_value(), Module) and not attr.get_value().loaded: 570 self.importer.load(attr.get_value().name) 571 572 # Support the import of names from missing modules. 573 574 else: 575 self.store(alias or name, UnresolvedName(name, node.modname, self)) 576 else: 577 if module is not None: 578 for n in module.namespace.keys(): 579 attr = module[n] 580 self.store(n, attr) 581 if isinstance(attr.get_value(), Module) and not attr.get_value().loaded: 582 self.importer.load(attr.get_value().name) 583 584 return None 585 586 def visitFunction(self, node): 587 return self._visitFunction(node, node.name) 588 589 visitGenExpr = OP 590 591 visitGenExprFor = NOP 592 593 visitGenExprIf = NOP 594 595 visitGenExprInner = NOP 596 597 def visitGetattr(self, node): 598 expr = self.dispatch(node.expr) 599 attrname = node.attrname 600 601 if isinstance(expr, Attr): 602 value = expr.get_value() 603 if isinstance(value, (Class, Module)): 604 attr = value.namespace.get(attrname) 605 elif isinstance(value, UnresolvedName): 606 attr = UnresolvedName(attrname, value.full_name(), self) 607 else: 608 attr = None 609 elif self.builtins is not None: 610 attr = self.builtins.get(attrname) 611 else: 612 attr = UnresolvedName(attrname, value.full_name(), self) 613 614 # Accounting. 615 616 if attr is not None: 617 attr.set_referenced() 618 619 self.importer.use_name(attrname) 620 621 return attr 622 623 def visitGlobal(self, node): 624 if self.namespaces: 625 for name in node.names: 626 ns = self.namespaces[-1] 627 if not ns.make_global(name): 628 raise InspectError(ns.full_name(), node, "Name %r is global and local in %r" % (name, ns.full_name())) 629 630 # Record a global entry for the name in the module. 631 632 if not self.has_key(name): 633 self[name] = Global() 634 635 def visitIf(self, node): 636 for test, body in node.tests: 637 self.dispatch(test) 638 self.dispatch(body) 639 if node.else_ is not None: 640 self.dispatch(node.else_) 641 return None 642 643 visitIfExp = NOP 644 645 def visitImport(self, node): 646 for name, alias in node.names: 647 if alias is not None: 648 module = self.importer.load(name, 1) or UnresolvedName(None, name, self) 649 self.store(alias, module) 650 else: 651 module = self.importer.load(name) or UnresolvedName(None, name.split(".")[0], self) 652 self.store(name.split(".")[0], module) 653 module.set_referenced() 654 655 return None 656 657 visitInvert = _visitUnary 658 659 def visitKeyword(self, node): 660 self.dispatch(node.expr) 661 self.importer.make_constant(node.name) 662 self.keyword_names.add(node.name) 663 return None 664 665 def visitLambda(self, node): 666 return self._visitFunction(node, None) 667 668 visitLeftShift = _visitBinary 669 670 visitList = OP 671 672 visitListComp = OP 673 674 visitListCompFor = NOP 675 676 visitListCompIf = NOP 677 678 visitMod = _visitBinary 679 680 def visitModule(self, node): 681 682 # Make a back reference from the node for code generation. 683 684 node.unit = self 685 return self.dispatch(node.node) 686 687 visitMul = _visitBinary 688 689 def visitName(self, node): 690 name = node.name 691 692 if self.importer.predefined_constants.has_key(name): 693 attr = self.importer.get_predefined_constant(name) 694 elif self.namespaces and self.namespaces[-1].has_key(name): 695 attr = self.namespaces[-1][name] 696 elif self.has_key(name): 697 attr = self[name] 698 elif self.builtins is not None and self.builtins.has_key(name): 699 attr = self.builtins[name] 700 else: 701 attr = None 702 703 # Accounting. 704 705 if attr is not None: 706 attr.set_referenced() 707 708 self.importer.use_name(name) 709 710 return attr 711 712 visitNot = OP 713 714 visitOr = OP 715 716 visitPass = NOP 717 718 visitPower = _visitBinary 719 720 visitPrint = NOP 721 722 visitPrintnl = NOP 723 724 visitRaise = NOP 725 726 visitReturn = NOP 727 728 visitRightShift = _visitBinary 729 730 visitSlice = OP 731 732 visitSliceobj = OP 733 734 def visitStmt(self, node): 735 for n in node.nodes: 736 self.dispatch(n) 737 return None 738 739 visitSub = _visitBinary 740 741 def visitSubscript(self, node): 742 self.importer.use_name("__getitem__") 743 self.OP(node) 744 745 def visitTryExcept(self, node): 746 self.dispatch(node.body) 747 for name, var, n in node.handlers: 748 749 # Establish the local for the handler. 750 751 if var is not None: 752 self.dispatch(var) 753 if n is not None: 754 self.dispatch(n) 755 if node.else_ is not None: 756 self.dispatch(node.else_) 757 return None 758 759 visitTryFinally = NOP 760 761 visitTuple = OP 762 763 visitUnaryAdd = _visitUnary 764 765 visitUnarySub = _visitUnary 766 767 def visitWhile(self, node): 768 self.in_loop = 1 769 self.NOP(node) 770 self.in_loop = 0 771 return None 772 773 visitWith = NOP 774 775 visitYield = NOP 776 777 class Global: 778 779 """ 780 A reference to an object assigned to a global from outside the module 781 top-level. 782 """ 783 784 pass 785 786 # vim: tabstop=4 expandtab shiftwidth=4