1 #!/usr/bin/env python 2 3 """ 4 Common functions. 5 6 Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 7 2014, 2015, 2016, 2017 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 compiler.transformer import Transformer 24 from errors import InspectError 25 from os import listdir, makedirs, remove 26 from os.path import exists, isdir, join, split 27 from results import ConstantValueRef, LiteralSequenceRef, NameRef 28 import compiler.ast 29 30 class CommonOutput: 31 32 "Common output functionality." 33 34 def check_output(self): 35 36 "Check the existing output and remove it if irrelevant." 37 38 if not exists(self.output): 39 makedirs(self.output) 40 41 details = self.importer.get_cache_details() 42 recorded_details = self.get_output_details() 43 44 if recorded_details != details: 45 self.remove_output() 46 47 writefile(self.get_output_details_filename(), details) 48 49 def get_output_details_filename(self): 50 51 "Return the output details filename." 52 53 return join(self.output, "$details") 54 55 def get_output_details(self): 56 57 "Return details of the existing output." 58 59 details_filename = self.get_output_details_filename() 60 61 if not exists(details_filename): 62 return None 63 else: 64 return readfile(details_filename) 65 66 def remove_output(self, dirname=None): 67 68 "Remove the output." 69 70 dirname = dirname or self.output 71 72 for filename in listdir(dirname): 73 path = join(dirname, filename) 74 if isdir(path): 75 self.remove_output(path) 76 else: 77 remove(path) 78 79 class CommonModule: 80 81 "A common module representation." 82 83 def __init__(self, name, importer): 84 85 """ 86 Initialise this module with the given 'name' and an 'importer' which is 87 used to provide access to other modules when required. 88 """ 89 90 self.name = name 91 self.importer = importer 92 self.filename = None 93 94 # Inspection-related attributes. 95 96 self.astnode = None 97 self.encoding = None 98 self.iterators = {} 99 self.temp = {} 100 self.lambdas = {} 101 102 # Constants, literals and values. 103 104 self.constants = {} 105 self.constant_values = {} 106 self.literals = {} 107 self.literal_types = {} 108 109 # Nested namespaces. 110 111 self.namespace_path = [] 112 self.in_function = False 113 114 # Retain the assignment value expression and track invocations. 115 116 self.in_assignment = None 117 self.in_invocation = None 118 119 # Attribute chain state management. 120 121 self.attrs = [] 122 self.chain_assignment = [] 123 self.chain_invocation = [] 124 125 def __repr__(self): 126 return "CommonModule(%r, %r)" % (self.name, self.importer) 127 128 def parse_file(self, filename): 129 130 "Parse the file with the given 'filename', initialising attributes." 131 132 self.filename = filename 133 134 # Use the Transformer directly to obtain encoding information. 135 136 t = Transformer() 137 f = open(filename) 138 139 try: 140 self.astnode = t.parsesuite(f.read() + "\n") 141 self.encoding = t.encoding 142 finally: 143 f.close() 144 145 # Module-relative naming. 146 147 def get_global_path(self, name): 148 return "%s.%s" % (self.name, name) 149 150 def get_namespace_path(self): 151 return ".".join([self.name] + self.namespace_path) 152 153 def get_object_path(self, name): 154 return ".".join([self.name] + self.namespace_path + [name]) 155 156 def get_parent_path(self): 157 return ".".join([self.name] + self.namespace_path[:-1]) 158 159 # Namespace management. 160 161 def enter_namespace(self, name): 162 163 "Enter the namespace having the given 'name'." 164 165 self.namespace_path.append(name) 166 167 def exit_namespace(self): 168 169 "Exit the current namespace." 170 171 self.namespace_path.pop() 172 173 # Constant reference naming. 174 175 def get_constant_name(self, value, value_type, encoding=None): 176 177 """ 178 Add a new constant to the current namespace for 'value' with 179 'value_type'. 180 """ 181 182 path = self.get_namespace_path() 183 init_item(self.constants, path, dict) 184 return "$c%d" % add_counter_item(self.constants[path], (value, value_type, encoding)) 185 186 # Literal reference naming. 187 188 def get_literal_name(self): 189 190 "Add a new literal to the current namespace." 191 192 path = self.get_namespace_path() 193 init_item(self.literals, path, lambda: 0) 194 return "$C%d" % self.literals[path] 195 196 def next_literal(self): 197 self.literals[self.get_namespace_path()] += 1 198 199 # Temporary iterator naming. 200 201 def get_iterator_path(self): 202 return self.in_function and self.get_namespace_path() or self.name 203 204 def get_iterator_name(self): 205 path = self.get_iterator_path() 206 init_item(self.iterators, path, lambda: 0) 207 return "$i%d" % self.iterators[path] 208 209 def next_iterator(self): 210 self.iterators[self.get_iterator_path()] += 1 211 212 # Temporary variable naming. 213 214 def get_temporary_name(self): 215 path = self.get_namespace_path() 216 init_item(self.temp, path, lambda: 0) 217 return "$t%d" % self.temp[path] 218 219 def next_temporary(self): 220 self.temp[self.get_namespace_path()] += 1 221 222 # Arbitrary function naming. 223 224 def get_lambda_name(self): 225 path = self.get_namespace_path() 226 init_item(self.lambdas, path, lambda: 0) 227 name = "$l%d" % self.lambdas[path] 228 self.lambdas[path] += 1 229 return name 230 231 def reset_lambdas(self): 232 self.lambdas = {} 233 234 # Constant and literal recording. 235 236 def get_constant_value(self, value, literals=None): 237 238 """ 239 Encode the 'value' if appropriate, returning a value, a typename and any 240 encoding. 241 """ 242 243 if isinstance(value, unicode): 244 return value.encode("utf-8"), "unicode", self.encoding 245 246 # Attempt to convert plain strings to text. 247 248 elif isinstance(value, str) and self.encoding: 249 try: 250 return get_string_details(literals, self.encoding) 251 except UnicodeDecodeError: 252 pass 253 254 return value, value.__class__.__name__, None 255 256 def get_constant_reference(self, ref, value, encoding=None): 257 258 """ 259 Return a constant reference for the given 'ref' type and 'value', with 260 the optional 'encoding' applying to text values. 261 """ 262 263 constant_name = self.get_constant_name(value, ref.get_origin(), encoding) 264 265 # Return a reference for the constant. 266 267 objpath = self.get_object_path(constant_name) 268 name_ref = ConstantValueRef(constant_name, ref.instance_of(objpath), value) 269 270 # Record the value and type for the constant. 271 272 self._reserve_constant(objpath, name_ref.value, name_ref.get_origin(), encoding) 273 return name_ref 274 275 def reserve_constant(self, objpath, value, origin, encoding=None): 276 277 """ 278 Reserve a constant within 'objpath' with the given 'value' and having a 279 type with the given 'origin', with the optional 'encoding' applying to 280 text values. 281 """ 282 283 constant_name = self.get_constant_name(value, origin) 284 objpath = self.get_object_path(constant_name) 285 self._reserve_constant(objpath, value, origin, encoding) 286 287 def _reserve_constant(self, objpath, value, origin, encoding): 288 289 """ 290 Store a constant for 'objpath' with the given 'value' and 'origin', with 291 the optional 'encoding' applying to text values. 292 """ 293 294 self.constant_values[objpath] = value, origin, encoding 295 296 def get_literal_reference(self, name, ref, items, cls): 297 298 """ 299 Return a literal reference for the given type 'name', literal 'ref', 300 node 'items' and employing the given 'cls' as the class of the returned 301 reference object. 302 """ 303 304 # Construct an invocation using the items as arguments. 305 306 typename = "$L%s" % name 307 308 invocation = compiler.ast.CallFunc( 309 compiler.ast.Name(typename), 310 items 311 ) 312 313 # Get a name for the actual literal. 314 315 instname = self.get_literal_name() 316 self.next_literal() 317 318 # Record the type for the literal. 319 320 objpath = self.get_object_path(instname) 321 self.literal_types[objpath] = ref.get_origin() 322 323 # Return a wrapper for the invocation exposing the items. 324 325 return cls( 326 instname, 327 ref.instance_of(), 328 self.process_structure_node(invocation), 329 invocation.args 330 ) 331 332 # Node handling. 333 334 def process_structure(self, node): 335 336 """ 337 Within the given 'node', process the program structure. 338 339 During inspection, this will process global declarations, adjusting the 340 module namespace, and import statements, building a module dependency 341 hierarchy. 342 343 During translation, this will consult deduced program information and 344 output translated code. 345 """ 346 347 l = [] 348 for n in node.getChildNodes(): 349 l.append(self.process_structure_node(n)) 350 return l 351 352 def process_augassign_node(self, n): 353 354 "Process the given augmented assignment node 'n'." 355 356 op = operator_functions[n.op] 357 358 if isinstance(n.node, compiler.ast.Getattr): 359 target = compiler.ast.AssAttr(n.node.expr, n.node.attrname, "OP_ASSIGN") 360 elif isinstance(n.node, compiler.ast.Name): 361 target = compiler.ast.AssName(n.node.name, "OP_ASSIGN") 362 else: 363 target = n.node 364 365 assignment = compiler.ast.Assign( 366 [target], 367 compiler.ast.CallFunc( 368 compiler.ast.Name("$op%s" % op), 369 [n.node, n.expr])) 370 371 return self.process_structure_node(assignment) 372 373 def process_assignment_for_object(self, original_name, source): 374 375 """ 376 Return an assignment operation making 'original_name' refer to the given 377 'source'. 378 """ 379 380 assignment = compiler.ast.Assign( 381 [compiler.ast.AssName(original_name, "OP_ASSIGN")], 382 source 383 ) 384 385 return self.process_structure_node(assignment) 386 387 def process_assignment_node_items(self, n, expr): 388 389 """ 390 Process the given assignment node 'n' whose children are to be assigned 391 items of 'expr'. 392 """ 393 394 name_ref = self.process_structure_node(expr) 395 396 # Either unpack the items and present them directly to each assignment 397 # node. 398 399 if isinstance(name_ref, LiteralSequenceRef) and \ 400 self.process_literal_sequence_items(n, name_ref): 401 402 pass 403 404 # Or have the assignment nodes access each item via the sequence API. 405 406 else: 407 self.process_assignment_node_items_by_position(n, expr, name_ref) 408 409 def process_assignment_node_items_by_position(self, n, expr, name_ref): 410 411 """ 412 Process the given sequence assignment node 'n', converting the node to 413 the separate assignment of each target using positional access on a 414 temporary variable representing the sequence. Use 'expr' as the assigned 415 value and 'name_ref' as the reference providing any existing temporary 416 variable. 417 """ 418 419 assignments = [] 420 421 # Employ existing names to access the sequence. 422 # Literal sequences do not provide names of accessible objects. 423 424 if isinstance(name_ref, NameRef) and not isinstance(name_ref, LiteralSequenceRef): 425 temp = name_ref.name 426 427 # For other expressions, create a temporary name to reference the items. 428 429 else: 430 temp = self.get_temporary_name() 431 self.next_temporary() 432 433 assignments.append( 434 compiler.ast.Assign([compiler.ast.AssName(temp, "OP_ASSIGN")], expr) 435 ) 436 437 # Assign the items to the target nodes. 438 439 for i, node in enumerate(n.nodes): 440 assignments.append( 441 compiler.ast.Assign([node], compiler.ast.Subscript( 442 compiler.ast.Name(temp), "OP_APPLY", [compiler.ast.Const(i, str(i))])) 443 ) 444 445 return self.process_structure_node(compiler.ast.Stmt(assignments)) 446 447 def process_literal_sequence_items(self, n, name_ref): 448 449 """ 450 Process the given assignment node 'n', obtaining from the given 451 'name_ref' the items to be assigned to the assignment targets. 452 453 Return whether this method was able to process the assignment node as 454 a sequence of direct assignments. 455 """ 456 457 if len(n.nodes) == len(name_ref.items): 458 assigned_names, count = get_names_from_nodes(n.nodes) 459 accessed_names, _count = get_names_from_nodes(name_ref.items) 460 461 # Only assign directly between items if all assigned names are 462 # plain names (not attribute assignments), and if the assigned names 463 # do not appear in the accessed names. 464 465 if len(assigned_names) == count and \ 466 not assigned_names.intersection(accessed_names): 467 468 for node, item in zip(n.nodes, name_ref.items): 469 self.process_assignment_node(node, item) 470 471 return True 472 473 # Otherwise, use the position-based mechanism to obtain values. 474 475 else: 476 return False 477 else: 478 raise InspectError("In %s, item assignment needing %d items is given %d items." % ( 479 self.get_namespace_path(), len(n.nodes), len(name_ref.items))) 480 481 def process_compare_node(self, n): 482 483 """ 484 Process the given comparison node 'n', converting an operator sequence 485 from... 486 487 <expr1> <op1> <expr2> <op2> <expr3> 488 489 ...to... 490 491 <op1>(<expr1>, <expr2>) and <op2>(<expr2>, <expr3>) 492 """ 493 494 invocations = [] 495 last = n.expr 496 497 for op, op_node in n.ops: 498 op = operator_functions.get(op) 499 500 invocations.append(compiler.ast.CallFunc( 501 compiler.ast.Name("$op%s" % op), 502 [last, op_node])) 503 504 last = op_node 505 506 if len(invocations) > 1: 507 result = compiler.ast.And(invocations) 508 else: 509 result = invocations[0] 510 511 return self.process_structure_node(result) 512 513 def process_dict_node(self, node): 514 515 """ 516 Process the given dictionary 'node', returning a list of (key, value) 517 tuples. 518 """ 519 520 l = [] 521 for key, value in node.items: 522 l.append(( 523 self.process_structure_node(key), 524 self.process_structure_node(value))) 525 return l 526 527 def process_for_node(self, n): 528 529 """ 530 Generate attribute accesses for {n.list}.__iter__ and the next method on 531 the iterator, producing a replacement node for the original. 532 """ 533 534 node = compiler.ast.Stmt([ 535 536 # <next> = {n.list}.__iter__().next 537 538 compiler.ast.Assign( 539 [compiler.ast.AssName(self.get_iterator_name(), "OP_ASSIGN")], 540 compiler.ast.Getattr( 541 compiler.ast.CallFunc( 542 compiler.ast.Getattr(n.list, "__iter__"), 543 [] 544 ), "next")), 545 546 # try: 547 # while True: 548 # <var>... = <next>() 549 # ... 550 # except StopIteration: 551 # pass 552 553 compiler.ast.TryExcept( 554 compiler.ast.While( 555 compiler.ast.Name("True"), 556 compiler.ast.Stmt([ 557 compiler.ast.Assign( 558 [n.assign], 559 compiler.ast.CallFunc( 560 compiler.ast.Name(self.get_iterator_name()), 561 [] 562 )), 563 n.body]), 564 None), 565 [(compiler.ast.Name("StopIteration"), None, compiler.ast.Stmt([compiler.ast.Pass()]))], 566 None) 567 ]) 568 569 self.next_iterator() 570 self.process_structure_node(node) 571 572 def process_literal_sequence_node(self, n, name, ref, cls): 573 574 """ 575 Process the given literal sequence node 'n' as a function invocation, 576 with 'name' indicating the type of the sequence, and 'ref' being a 577 reference to the type. The 'cls' is used to instantiate a suitable name 578 reference. 579 """ 580 581 if name == "dict": 582 items = [] 583 for key, value in n.items: 584 items.append(compiler.ast.Tuple([key, value])) 585 else: # name in ("list", "tuple"): 586 items = n.nodes 587 588 return self.get_literal_reference(name, ref, items, cls) 589 590 def process_operator_node(self, n): 591 592 """ 593 Process the given operator node 'n' as an operator function invocation. 594 """ 595 596 op = operator_functions[n.__class__.__name__] 597 invocation = compiler.ast.CallFunc( 598 compiler.ast.Name("$op%s" % op), 599 list(n.getChildNodes()) 600 ) 601 return self.process_structure_node(invocation) 602 603 def process_print_node(self, n): 604 605 """ 606 Process the given print node 'n' as an invocation on a stream of the 607 form... 608 609 $print(dest, args, nl) 610 611 The special function name will be translated elsewhere. 612 """ 613 614 nl = isinstance(n, compiler.ast.Printnl) 615 invocation = compiler.ast.CallFunc( 616 compiler.ast.Name("$print"), 617 [n.dest or compiler.ast.Name("None"), 618 compiler.ast.List(list(n.nodes)), 619 nl and compiler.ast.Name("True") or compiler.ast.Name("False")] 620 ) 621 return self.process_structure_node(invocation) 622 623 def process_slice_node(self, n, expr=None): 624 625 """ 626 Process the given slice node 'n' as an operator function invocation. 627 """ 628 629 if n.flags == "OP_ASSIGN": op = "setslice" 630 elif n.flags == "OP_DELETE": op = "delslice" 631 else: op = "getslice" 632 633 invocation = compiler.ast.CallFunc( 634 compiler.ast.Name("$op%s" % op), 635 [n.expr, n.lower or compiler.ast.Name("None"), n.upper or compiler.ast.Name("None")] + 636 (expr and [expr] or []) 637 ) 638 639 # Fix parse tree structure. 640 641 if op == "delslice": 642 invocation = compiler.ast.Discard(invocation) 643 644 return self.process_structure_node(invocation) 645 646 def process_sliceobj_node(self, n): 647 648 """ 649 Process the given slice object node 'n' as a slice constructor. 650 """ 651 652 op = "slice" 653 invocation = compiler.ast.CallFunc( 654 compiler.ast.Name("$op%s" % op), 655 n.nodes 656 ) 657 return self.process_structure_node(invocation) 658 659 def process_subscript_node(self, n, expr=None): 660 661 """ 662 Process the given subscript node 'n' as an operator function invocation. 663 """ 664 665 if n.flags == "OP_ASSIGN": op = "setitem" 666 elif n.flags == "OP_DELETE": op = "delitem" 667 else: op = "getitem" 668 669 invocation = compiler.ast.CallFunc( 670 compiler.ast.Name("$op%s" % op), 671 [n.expr] + list(n.subs) + (expr and [expr] or []) 672 ) 673 674 # Fix parse tree structure. 675 676 if op == "delitem": 677 invocation = compiler.ast.Discard(invocation) 678 679 return self.process_structure_node(invocation) 680 681 def process_attribute_chain(self, n): 682 683 """ 684 Process the given attribute access node 'n'. Return a reference 685 describing the expression. 686 """ 687 688 # AssAttr/Getattr are nested with the outermost access being the last 689 # access in any chain. 690 691 self.attrs.insert(0, n.attrname) 692 attrs = self.attrs 693 694 # Break attribute chains where non-access nodes are found. 695 696 if not self.have_access_expression(n): 697 self.reset_attribute_chain() 698 699 # Descend into the expression, extending backwards any existing chain, 700 # or building another for the expression. 701 702 name_ref = self.process_structure_node(n.expr) 703 704 # Restore chain information applying to this node. 705 706 if not self.have_access_expression(n): 707 self.restore_attribute_chain(attrs) 708 709 # Return immediately if the expression was another access and thus a 710 # continuation backwards along the chain. The above processing will 711 # have followed the chain all the way to its conclusion. 712 713 if self.have_access_expression(n): 714 del self.attrs[0] 715 716 return name_ref 717 718 # Attribute chain handling. 719 720 def reset_attribute_chain(self): 721 722 "Reset the attribute chain for a subexpression of an attribute access." 723 724 self.attrs = [] 725 self.chain_assignment.append(self.in_assignment) 726 self.chain_invocation.append(self.in_invocation) 727 self.in_assignment = None 728 self.in_invocation = None 729 730 def restore_attribute_chain(self, attrs): 731 732 "Restore the attribute chain for an attribute access." 733 734 self.attrs = attrs 735 self.in_assignment = self.chain_assignment.pop() 736 self.in_invocation = self.chain_invocation.pop() 737 738 def have_access_expression(self, node): 739 740 "Return whether the expression associated with 'node' is Getattr." 741 742 return isinstance(node.expr, compiler.ast.Getattr) 743 744 def get_name_for_tracking(self, name, name_ref=None): 745 746 """ 747 Return the name to be used for attribute usage observations involving 748 the given 'name' in the current namespace. 749 750 If the name is being used outside a function, and if 'name_ref' is 751 given, a path featuring the name in the global namespace is returned 752 where 'name_ref' indicates a global. Otherwise, a path computed using 753 the current namespace and the given name is returned. 754 755 The intention of this method is to provide a suitably-qualified name 756 that can be tracked across namespaces. Where globals are being 757 referenced in class namespaces, they should be referenced using their 758 path within the module, not using a path within each class. 759 760 It may not be possible to identify a global within a function at the 761 time of inspection (since a global may appear later in a file). 762 Consequently, globals are identified by their local name rather than 763 their module-qualified path. 764 """ 765 766 # For functions, use the appropriate local names. 767 768 if self.in_function: 769 return name 770 771 # For global names outside functions, use a global name. 772 773 elif name_ref and name_ref.is_global_name(): 774 return self.get_global_path(name) 775 776 # Otherwise, establish a name in the current namespace. 777 778 else: 779 return self.get_object_path(name) 780 781 def get_path_for_access(self): 782 783 "Outside functions, register accesses at the module level." 784 785 if not self.in_function: 786 return self.name 787 else: 788 return self.get_namespace_path() 789 790 def get_module_name(self, node): 791 792 """ 793 Using the given From 'node' in this module, calculate any relative import 794 information, returning a tuple containing a module to import along with any 795 names to import based on the node's name information. 796 797 Where the returned module is given as None, whole module imports should 798 be performed for the returned modules using the returned names. 799 """ 800 801 # Absolute import. 802 803 if node.level == 0: 804 return node.modname, node.names 805 806 # Relative to an ancestor of this module. 807 808 else: 809 path = self.name.split(".") 810 level = node.level 811 812 # Relative imports treat package roots as submodules. 813 814 if split(self.filename)[-1] == "__init__.py": 815 level -= 1 816 817 if level > len(path): 818 raise InspectError("Relative import %r involves too many levels up from module %r" % ( 819 ("%s%s" % ("." * node.level, node.modname or "")), self.name)) 820 821 basename = ".".join(path[:len(path)-level]) 822 823 # Name imports from a module. 824 825 if node.modname: 826 return "%s.%s" % (basename, node.modname), node.names 827 828 # Relative whole module imports. 829 830 else: 831 return basename, node.names 832 833 def get_argnames(args): 834 835 """ 836 Return a list of all names provided by 'args'. Since tuples may be 837 employed, the arguments are traversed depth-first. 838 """ 839 840 l = [] 841 for arg in args: 842 if isinstance(arg, tuple): 843 l += get_argnames(arg) 844 else: 845 l.append(arg) 846 return l 847 848 def get_names_from_nodes(nodes): 849 850 """ 851 Return the names employed in the given 'nodes' along with the number of 852 nodes excluding sequences. 853 """ 854 855 names = set() 856 count = 0 857 858 for node in nodes: 859 860 # Add names and count them. 861 862 if isinstance(node, (compiler.ast.AssName, compiler.ast.Name)): 863 names.add(node.name) 864 count += 1 865 866 # Add names from sequences and incorporate their counts. 867 868 elif isinstance(node, (compiler.ast.AssList, compiler.ast.AssTuple, 869 compiler.ast.List, compiler.ast.Set, 870 compiler.ast.Tuple)): 871 _names, _count = get_names_from_nodes(node.nodes) 872 names.update(_names) 873 count += _count 874 875 # Count non-name, non-sequence nodes. 876 877 else: 878 count += 1 879 880 return names, count 881 882 # Result classes. 883 884 class InstructionSequence: 885 886 "A generic sequence of instructions." 887 888 def __init__(self, instructions): 889 self.instructions = instructions 890 891 def get_value_instruction(self): 892 return self.instructions[-1] 893 894 def get_init_instructions(self): 895 return self.instructions[:-1] 896 897 # Dictionary utilities. 898 899 def init_item(d, key, fn): 900 901 """ 902 Add to 'd' an entry for 'key' using the callable 'fn' to make an initial 903 value where no entry already exists. 904 """ 905 906 if not d.has_key(key): 907 d[key] = fn() 908 return d[key] 909 910 def dict_for_keys(d, keys): 911 912 "Return a new dictionary containing entries from 'd' for the given 'keys'." 913 914 nd = {} 915 for key in keys: 916 if d.has_key(key): 917 nd[key] = d[key] 918 return nd 919 920 def make_key(s): 921 922 "Make sequence 's' into a tuple-based key, first sorting its contents." 923 924 l = list(s) 925 l.sort() 926 return tuple(l) 927 928 def add_counter_item(d, key): 929 930 """ 931 Make a mapping in 'd' for 'key' to the number of keys added before it, thus 932 maintaining a mapping of keys to their order of insertion. 933 """ 934 935 if not d.has_key(key): 936 d[key] = len(d.keys()) 937 return d[key] 938 939 def remove_items(d1, d2): 940 941 "Remove from 'd1' all items from 'd2'." 942 943 for key in d2.keys(): 944 if d1.has_key(key): 945 del d1[key] 946 947 # Set utilities. 948 949 def first(s): 950 return list(s)[0] 951 952 def same(s1, s2): 953 return set(s1) == set(s2) 954 955 # General input/output. 956 957 def readfile(filename): 958 959 "Return the contents of 'filename'." 960 961 f = open(filename) 962 try: 963 return f.read() 964 finally: 965 f.close() 966 967 def writefile(filename, s): 968 969 "Write to 'filename' the string 's'." 970 971 f = open(filename, "w") 972 try: 973 f.write(s) 974 finally: 975 f.close() 976 977 # General encoding. 978 979 def sorted_output(x): 980 981 "Sort sequence 'x' and return a string with commas separating the values." 982 983 x = map(str, x) 984 x.sort() 985 return ", ".join(x) 986 987 def get_string_details(literals, encoding): 988 989 """ 990 Determine whether 'literals' represent Unicode strings or byte strings, 991 using 'encoding' to reproduce byte sequences. 992 993 Each literal is the full program representation including prefix and quotes 994 recoded by the parser to UTF-8. Thus, any literal found to represent a byte 995 string needs to be translated back to its original encoding. 996 997 Return a single encoded literal value, a type name, and the original 998 encoding as a tuple. 999 """ 1000 1001 typename = "unicode" 1002 1003 l = [] 1004 1005 for s in literals: 1006 out, _typename = get_literal_details(s) 1007 if _typename == "str": 1008 typename = "str" 1009 l.append(out) 1010 1011 out = "".join(l) 1012 1013 # For Unicode values, convert to the UTF-8 program representation. 1014 1015 if typename == "unicode": 1016 return out.encode("utf-8"), typename, encoding 1017 1018 # For byte string values, convert back to the original encoding. 1019 1020 else: 1021 return out.encode(encoding), typename, encoding 1022 1023 def get_literal_details(s): 1024 1025 """ 1026 Determine whether 's' represents a Unicode string or a byte string, where 1027 's' contains the full program representation of a literal including prefix 1028 and quotes, recoded by the parser to UTF-8. 1029 1030 Find and convert Unicode values starting with <backslash>u or <backslash>U, 1031 and byte or Unicode values starting with <backslash><octal digit> or 1032 <backslash>x. 1033 1034 Literals prefixed with "u" cause <backslash><octal digit> and <backslash>x 1035 to be considered as Unicode values. Otherwise, they produce byte values and 1036 cause unprefixed strings to be considered as byte strings. 1037 1038 Literals prefixed with "r" do not have their backslash-encoded values 1039 converted unless also prefixed with "u", in which case only the above value 1040 formats are converted, not any of the other special sequences for things 1041 like newlines. 1042 1043 Return the literal value as a Unicode object together with the appropriate 1044 type name in a tuple. 1045 """ 1046 1047 l = [] 1048 1049 # Identify the quote character and use it to identify the prefix. 1050 1051 quote_type = s[-1] 1052 prefix_end = s.find(quote_type) 1053 prefix = s[:prefix_end].lower() 1054 1055 if prefix not in ("", "b", "br", "r", "u", "ur"): 1056 raise ValueError, "String literal does not have a supported prefix: %s" % s 1057 1058 if "b" in prefix: 1059 typename = "str" 1060 else: 1061 typename = "unicode" 1062 1063 # Identify triple quotes or single quotes. 1064 1065 if len(s) >= 6 and s[-2] == quote_type and s[-3] == quote_type: 1066 quote = s[prefix_end:prefix_end+3] 1067 current = prefix_end + 3 1068 end = len(s) - 3 1069 else: 1070 quote = s[prefix_end] 1071 current = prefix_end + 1 1072 end = len(s) - 1 1073 1074 # Conversions of some quoted values. 1075 1076 searches = { 1077 "u" : (6, 16), 1078 "U" : (10, 16), 1079 "x" : (4, 16), 1080 } 1081 1082 octal_digits = map(str, range(0, 8)) 1083 1084 # Translations of some quoted values. 1085 1086 escaped = { 1087 "\\" : "\\", "'" : "'", '"' : '"', 1088 "a" : "\a", "b" : "\b", "f" : "\f", 1089 "n" : "\n", "r" : "\r", "t" : "\t", 1090 } 1091 1092 while current < end: 1093 1094 # Look for quoted values. 1095 1096 index = s.find("\\", current) 1097 if index == -1 or index + 1 == end: 1098 l.append(s[current:end]) 1099 break 1100 1101 # Add the preceding text. 1102 1103 l.append(s[current:index]) 1104 1105 # Handle quoted text. 1106 1107 term = s[index+1] 1108 1109 # Add Unicode values. Where a string is u-prefixed, even \o and \x 1110 # produce Unicode values. 1111 1112 if typename == "unicode" and ( 1113 term in ("u", "U") or 1114 "u" in prefix and (term == "x" or term in octal_digits)): 1115 1116 needed, base = searches.get(term, (4, 8)) 1117 value = convert_quoted_value(s, index, needed, end, base, unichr) 1118 l.append(value) 1119 current = index + needed 1120 1121 # Add raw byte values, changing the string type. 1122 1123 elif "r" not in prefix and ( 1124 term == "x" or term in octal_digits): 1125 1126 needed, base = searches.get(term, (4, 8)) 1127 value = convert_quoted_value(s, index, needed, end, base, chr) 1128 l.append(value) 1129 typename = "str" 1130 current = index + needed 1131 1132 # Add other escaped values. 1133 1134 elif "r" not in prefix and escaped.has_key(term): 1135 l.append(escaped[term]) 1136 current = index + 2 1137 1138 # Add other text as found. 1139 1140 else: 1141 l.append(s[index:index+2]) 1142 current = index + 2 1143 1144 # Collect the components into a single Unicode object. Since the literal 1145 # text was already in UTF-8 form, interpret plain strings as UTF-8 1146 # sequences. 1147 1148 out = [] 1149 1150 for value in l: 1151 if isinstance(value, unicode): 1152 out.append(value) 1153 else: 1154 out.append(unicode(value, "utf-8")) 1155 1156 return "".join(out), typename 1157 1158 def convert_quoted_value(s, index, needed, end, base, fn): 1159 1160 """ 1161 Interpret a quoted value in 's' at 'index' with the given 'needed' number of 1162 positions, and with the given 'end' indicating the first position after the 1163 end of the actual string content. 1164 1165 Use 'base' as the numerical base when interpreting the value, and use 'fn' 1166 to convert the value to an appropriate type. 1167 """ 1168 1169 s = s[index:min(index+needed, end)] 1170 1171 # Not a complete occurrence. 1172 1173 if len(s) < needed: 1174 return s 1175 1176 # Test for a well-formed value. 1177 1178 try: 1179 first = base == 8 and 1 or 2 1180 value = int(s[first:needed], base) 1181 except ValueError: 1182 return s 1183 else: 1184 return fn(value) 1185 1186 # Attribute chain decoding. 1187 1188 def get_attrnames(attrnames): 1189 1190 """ 1191 Split the qualified attribute chain 'attrnames' into its components, 1192 handling special attributes starting with "#" that indicate type 1193 conformance. 1194 """ 1195 1196 if attrnames.startswith("#"): 1197 return [attrnames] 1198 else: 1199 return attrnames.split(".") 1200 1201 def get_attrname_from_location(location): 1202 1203 """ 1204 Extract the first attribute from the attribute names employed in a 1205 'location'. 1206 """ 1207 1208 path, name, attrnames, access = location 1209 if not attrnames: 1210 return attrnames 1211 return get_attrnames(attrnames)[0] 1212 1213 def get_name_path(path, name): 1214 1215 "Return a suitable qualified name from the given 'path' and 'name'." 1216 1217 if "." in name: 1218 return name 1219 else: 1220 return "%s.%s" % (path, name) 1221 1222 # Usage-related functions. 1223 1224 def get_types_for_usage(attrnames, objects): 1225 1226 """ 1227 Identify the types that can support the given 'attrnames', using the 1228 given 'objects' as the catalogue of type details. 1229 """ 1230 1231 types = [] 1232 for name, _attrnames in objects.items(): 1233 if set(attrnames).issubset(_attrnames): 1234 types.append(name) 1235 return types 1236 1237 def get_invoked_attributes(usage): 1238 1239 "Obtain invoked attribute from the given 'usage'." 1240 1241 invoked = [] 1242 if usage: 1243 for attrname, invocation, assignment in usage: 1244 if invocation: 1245 invoked.append(attrname) 1246 return invoked 1247 1248 def get_assigned_attributes(usage): 1249 1250 "Obtain assigned attribute from the given 'usage'." 1251 1252 assigned = [] 1253 if usage: 1254 for attrname, invocation, assignment in usage: 1255 if assignment: 1256 assigned.append(attrname) 1257 return assigned 1258 1259 # Type and module functions. 1260 # NOTE: This makes assumptions about the __builtins__ structure. 1261 1262 def get_builtin_module(name): 1263 1264 "Return the module name containing the given type 'name'." 1265 1266 if name == "string": 1267 modname = "str" 1268 elif name == "utf8string": 1269 modname = "unicode" 1270 elif name == "NoneType": 1271 modname = "none" 1272 else: 1273 modname = name 1274 1275 return "__builtins__.%s" % modname 1276 1277 def get_builtin_type(name): 1278 1279 "Return the type name provided by the given Python value 'name'." 1280 1281 if name == "str": 1282 return "string" 1283 elif name == "unicode": 1284 return "utf8string" 1285 else: 1286 return name 1287 1288 def get_builtin_class(name): 1289 1290 "Return the full name of the built-in class having the given 'name'." 1291 1292 typename = get_builtin_type(name) 1293 module = get_builtin_module(typename) 1294 return "%s.%s" % (module, typename) 1295 1296 # Useful data. 1297 1298 predefined_constants = "False", "None", "NotImplemented", "True" 1299 1300 operator_functions = { 1301 1302 # Fundamental operations. 1303 1304 "is" : "is_", 1305 "is not" : "is_not", 1306 1307 # Binary operations. 1308 1309 "in" : "in_", 1310 "not in" : "not_in", 1311 "Add" : "add", 1312 "Bitand" : "and_", 1313 "Bitor" : "or_", 1314 "Bitxor" : "xor", 1315 "Div" : "div", 1316 "FloorDiv" : "floordiv", 1317 "LeftShift" : "lshift", 1318 "Mod" : "mod", 1319 "Mul" : "mul", 1320 "Power" : "pow", 1321 "RightShift" : "rshift", 1322 "Sub" : "sub", 1323 1324 # Unary operations. 1325 1326 "Invert" : "invert", 1327 "UnaryAdd" : "pos", 1328 "UnarySub" : "neg", 1329 1330 # Augmented assignment. 1331 1332 "+=" : "iadd", 1333 "-=" : "isub", 1334 "*=" : "imul", 1335 "/=" : "idiv", 1336 "//=" : "ifloordiv", 1337 "%=" : "imod", 1338 "**=" : "ipow", 1339 "<<=" : "ilshift", 1340 ">>=" : "irshift", 1341 "&=" : "iand", 1342 "^=" : "ixor", 1343 "|=" : "ior", 1344 1345 # Comparisons. 1346 1347 "==" : "eq", 1348 "!=" : "ne", 1349 "<" : "lt", 1350 "<=" : "le", 1351 ">=" : "ge", 1352 ">" : "gt", 1353 } 1354 1355 # vim: tabstop=4 expandtab shiftwidth=4