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, getmtime, 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, options=None): 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 # Combine cache details with any options. 45 46 full_details = options and (details + " " + options) or details 47 48 if recorded_details != full_details: 49 self.remove_output() 50 51 writefile(self.get_output_details_filename(), full_details) 52 53 def get_output_details_filename(self): 54 55 "Return the output details filename." 56 57 return join(self.output, "$details") 58 59 def get_output_details(self): 60 61 "Return details of the existing output." 62 63 details_filename = self.get_output_details_filename() 64 65 if not exists(details_filename): 66 return None 67 else: 68 return readfile(details_filename) 69 70 def remove_output(self, dirname=None): 71 72 "Remove the output." 73 74 dirname = dirname or self.output 75 76 for filename in listdir(dirname): 77 path = join(dirname, filename) 78 if isdir(path): 79 self.remove_output(path) 80 else: 81 remove(path) 82 83 def copy(source, target, only_if_newer=True): 84 85 "Copy a text file from 'source' to 'target'." 86 87 if isdir(target): 88 target = join(target, split(source)[-1]) 89 90 if only_if_newer and not is_newer(source, target): 91 return 92 93 infile = open(source) 94 outfile = open(target, "w") 95 96 try: 97 outfile.write(infile.read()) 98 finally: 99 outfile.close() 100 infile.close() 101 102 def is_newer(source, target): 103 104 "Return whether 'source' is newer than 'target'." 105 106 if exists(target): 107 target_mtime = getmtime(target) 108 source_mtime = getmtime(source) 109 return source_mtime > target_mtime 110 111 return True 112 113 class CommonModule: 114 115 "A common module representation." 116 117 def __init__(self, name, importer): 118 119 """ 120 Initialise this module with the given 'name' and an 'importer' which is 121 used to provide access to other modules when required. 122 """ 123 124 self.name = name 125 self.importer = importer 126 self.filename = None 127 128 # Inspection-related attributes. 129 130 self.astnode = None 131 self.encoding = None 132 self.temp = {} 133 self.lambdas = {} 134 135 # Constants, literals and values. 136 137 self.constants = {} 138 self.constant_values = {} 139 self.literals = {} 140 self.literal_types = {} 141 142 # Nested namespaces. 143 144 self.namespace_path = [] 145 self.in_function = False 146 147 # Retain the assignment value expression and track invocations. 148 149 self.in_assignment = None 150 self.in_invocation = None 151 152 # Attribute chain state management. 153 154 self.attrs = [] 155 self.chain_assignment = [] 156 self.chain_invocation = [] 157 158 def __repr__(self): 159 return "CommonModule(%r, %r)" % (self.name, self.importer) 160 161 def parse_file(self, filename): 162 163 "Parse the file with the given 'filename', initialising attributes." 164 165 self.filename = filename 166 167 # Use the Transformer directly to obtain encoding information. 168 169 t = Transformer() 170 f = open(filename) 171 172 try: 173 self.astnode = t.parsesuite(f.read() + "\n") 174 self.encoding = t.encoding 175 finally: 176 f.close() 177 178 # Module-relative naming. 179 180 def get_global_path(self, name): 181 return "%s.%s" % (self.name, name) 182 183 def get_namespace_path(self): 184 return ".".join([self.name] + self.namespace_path) 185 186 def get_object_path(self, name): 187 return ".".join([self.name] + self.namespace_path + [name]) 188 189 def get_parent_path(self): 190 return ".".join([self.name] + self.namespace_path[:-1]) 191 192 # Namespace management. 193 194 def enter_namespace(self, name): 195 196 "Enter the namespace having the given 'name'." 197 198 self.namespace_path.append(name) 199 200 def exit_namespace(self): 201 202 "Exit the current namespace." 203 204 self.namespace_path.pop() 205 206 # Constant reference naming. 207 208 def get_constant_name(self, value, value_type, encoding=None): 209 210 """ 211 Add a new constant to the current namespace for 'value' with 212 'value_type'. 213 """ 214 215 path = self.get_namespace_path() 216 init_item(self.constants, path, dict) 217 return "$c%d" % add_counter_item(self.constants[path], (value, value_type, encoding)) 218 219 # Literal reference naming. 220 221 def get_literal_name(self): 222 223 "Add a new literal to the current namespace." 224 225 path = self.get_namespace_path() 226 init_item(self.literals, path, lambda: 0) 227 return "$C%d" % self.literals[path] 228 229 def next_literal(self): 230 self.literals[self.get_namespace_path()] += 1 231 232 # Temporary variable naming. 233 234 def get_temporary_name(self): 235 path = self.get_namespace_path() 236 init_item(self.temp, path, lambda: 0) 237 return "$t%d" % self.temp[path] 238 239 def next_temporary(self): 240 self.temp[self.get_namespace_path()] += 1 241 242 # Arbitrary function naming. 243 244 def get_lambda_name(self): 245 path = self.get_namespace_path() 246 init_item(self.lambdas, path, lambda: 0) 247 name = "$l%d" % self.lambdas[path] 248 self.lambdas[path] += 1 249 return name 250 251 def reset_lambdas(self): 252 self.lambdas = {} 253 254 # Constant and literal recording. 255 256 def get_constant_value(self, value, literals=None): 257 258 """ 259 Encode the 'value' if appropriate, returning a value, a typename and any 260 encoding. 261 """ 262 263 if isinstance(value, unicode): 264 return value.encode("utf-8"), "unicode", self.encoding 265 266 # Attempt to convert plain strings to text. 267 268 elif isinstance(value, str) and self.encoding: 269 try: 270 return get_string_details(literals, self.encoding) 271 except UnicodeDecodeError: 272 pass 273 274 return value, value.__class__.__name__, None 275 276 def get_constant_reference(self, ref, value, encoding=None): 277 278 """ 279 Return a constant reference for the given 'ref' type and 'value', with 280 the optional 'encoding' applying to text values. 281 """ 282 283 constant_name = self.get_constant_name(value, ref.get_origin(), encoding) 284 285 # Return a reference for the constant. 286 287 objpath = self.get_object_path(constant_name) 288 name_ref = ConstantValueRef(constant_name, ref.instance_of(objpath), value) 289 290 # Record the value and type for the constant. 291 292 self._reserve_constant(objpath, name_ref.value, name_ref.get_origin(), encoding) 293 return name_ref 294 295 def reserve_constant(self, objpath, value, origin, encoding=None): 296 297 """ 298 Reserve a constant within 'objpath' with the given 'value' and having a 299 type with the given 'origin', with the optional 'encoding' applying to 300 text values. 301 """ 302 303 constant_name = self.get_constant_name(value, origin) 304 objpath = self.get_object_path(constant_name) 305 self._reserve_constant(objpath, value, origin, encoding) 306 307 def _reserve_constant(self, objpath, value, origin, encoding): 308 309 """ 310 Store a constant for 'objpath' with the given 'value' and 'origin', with 311 the optional 'encoding' applying to text values. 312 """ 313 314 self.constant_values[objpath] = value, origin, encoding 315 316 def get_literal_reference(self, name, ref, items, cls): 317 318 """ 319 Return a literal reference for the given type 'name', literal 'ref', 320 node 'items' and employing the given 'cls' as the class of the returned 321 reference object. 322 """ 323 324 # Construct an invocation using the items as arguments. 325 326 typename = "$L%s" % name 327 328 invocation = compiler.ast.CallFunc( 329 compiler.ast.Name(typename), 330 items 331 ) 332 333 # Get a name for the actual literal. 334 335 instname = self.get_literal_name() 336 self.next_literal() 337 338 # Record the type for the literal. 339 340 objpath = self.get_object_path(instname) 341 self.literal_types[objpath] = ref.get_origin() 342 343 # Return a wrapper for the invocation exposing the items. 344 345 return cls( 346 instname, 347 ref.instance_of(), 348 self.process_structure_node(invocation), 349 invocation.args 350 ) 351 352 # Node handling. 353 354 def process_structure(self, node): 355 356 """ 357 Within the given 'node', process the program structure. 358 359 During inspection, this will process global declarations, adjusting the 360 module namespace, and import statements, building a module dependency 361 hierarchy. 362 363 During translation, this will consult deduced program information and 364 output translated code. 365 """ 366 367 l = [] 368 for n in node.getChildNodes(): 369 l.append(self.process_structure_node(n)) 370 return l 371 372 def process_augassign_node(self, n): 373 374 "Process the given augmented assignment node 'n'." 375 376 op = operator_functions[n.op] 377 378 if isinstance(n.node, compiler.ast.Getattr): 379 target = compiler.ast.AssAttr(n.node.expr, n.node.attrname, "OP_ASSIGN") 380 elif isinstance(n.node, compiler.ast.Name): 381 target = compiler.ast.AssName(n.node.name, "OP_ASSIGN") 382 else: 383 target = n.node 384 385 assignment = compiler.ast.Assign( 386 [target], 387 compiler.ast.CallFunc( 388 compiler.ast.Name("$op%s" % op), 389 [n.node, n.expr])) 390 391 return self.process_structure_node(assignment) 392 393 def process_assignment_for_object(self, original_name, source): 394 395 """ 396 Return an assignment operation making 'original_name' refer to the given 397 'source'. 398 """ 399 400 assignment = compiler.ast.Assign( 401 [compiler.ast.AssName(original_name, "OP_ASSIGN")], 402 source 403 ) 404 405 return self.process_structure_node(assignment) 406 407 def process_assignment_node_items(self, n, expr): 408 409 """ 410 Process the given assignment node 'n' whose children are to be assigned 411 items of 'expr'. 412 """ 413 414 name_ref = self.process_structure_node(expr) 415 416 # Either unpack the items and present them directly to each assignment 417 # node. 418 419 if isinstance(name_ref, LiteralSequenceRef) and \ 420 self.process_literal_sequence_items(n, name_ref): 421 422 pass 423 424 # Or have the assignment nodes access each item via the sequence API. 425 426 else: 427 self.process_assignment_node_items_by_position(n, expr, name_ref) 428 429 def process_assignment_node_items_by_position(self, n, expr, name_ref): 430 431 """ 432 Process the given sequence assignment node 'n', converting the node to 433 the separate assignment of each target using positional access on a 434 temporary variable representing the sequence. Use 'expr' as the assigned 435 value and 'name_ref' as the reference providing any existing temporary 436 variable. 437 """ 438 439 assignments = [] 440 441 # Employ existing names to access the sequence. 442 # Literal sequences do not provide names of accessible objects. 443 444 if isinstance(name_ref, NameRef) and not isinstance(name_ref, LiteralSequenceRef): 445 temp = name_ref.name 446 447 # For other expressions, create a temporary name to reference the items. 448 449 else: 450 temp = self.get_temporary_name() 451 self.next_temporary() 452 453 assignments.append( 454 compiler.ast.Assign([compiler.ast.AssName(temp, "OP_ASSIGN")], expr) 455 ) 456 457 # Assign the items to the target nodes. 458 459 for i, node in enumerate(n.nodes): 460 assignments.append( 461 compiler.ast.Assign([node], compiler.ast.Subscript( 462 compiler.ast.Name(temp), "OP_APPLY", [compiler.ast.Const(i, str(i))])) 463 ) 464 465 return self.process_structure_node(compiler.ast.Stmt(assignments)) 466 467 def process_literal_sequence_items(self, n, name_ref): 468 469 """ 470 Process the given assignment node 'n', obtaining from the given 471 'name_ref' the items to be assigned to the assignment targets. 472 473 Return whether this method was able to process the assignment node as 474 a sequence of direct assignments. 475 """ 476 477 if len(n.nodes) == len(name_ref.items): 478 assigned_names, count = get_names_from_nodes(n.nodes) 479 accessed_names, _count = get_names_from_nodes(name_ref.items) 480 481 # Only assign directly between items if all assigned names are 482 # plain names (not attribute assignments), and if the assigned names 483 # do not appear in the accessed names. 484 485 if len(assigned_names) == count and \ 486 not assigned_names.intersection(accessed_names): 487 488 for node, item in zip(n.nodes, name_ref.items): 489 self.process_assignment_node(node, item) 490 491 return True 492 493 # Otherwise, use the position-based mechanism to obtain values. 494 495 else: 496 return False 497 else: 498 raise InspectError("In %s, item assignment needing %d items is given %d items." % ( 499 self.get_namespace_path(), len(n.nodes), len(name_ref.items))) 500 501 def process_compare_node(self, n): 502 503 """ 504 Process the given comparison node 'n', converting an operator sequence 505 from... 506 507 <expr1> <op1> <expr2> <op2> <expr3> 508 509 ...to... 510 511 <op1>(<expr1>, <expr2>) and <op2>(<expr2>, <expr3>) 512 """ 513 514 invocations = [] 515 last = n.expr 516 517 for op, op_node in n.ops: 518 op = operator_functions.get(op) 519 520 invocations.append(compiler.ast.CallFunc( 521 compiler.ast.Name("$op%s" % op), 522 [last, op_node])) 523 524 last = op_node 525 526 if len(invocations) > 1: 527 result = compiler.ast.And(invocations) 528 else: 529 result = invocations[0] 530 531 return self.process_structure_node(result) 532 533 def process_dict_node(self, node): 534 535 """ 536 Process the given dictionary 'node', returning a list of (key, value) 537 tuples. 538 """ 539 540 l = [] 541 for key, value in node.items: 542 l.append(( 543 self.process_structure_node(key), 544 self.process_structure_node(value))) 545 return l 546 547 def process_for_node(self, n): 548 549 """ 550 Generate attribute accesses for {n.list}.__iter__ and the next method on 551 the iterator, producing a replacement node for the original. 552 """ 553 554 t0 = self.get_temporary_name() 555 self.next_temporary() 556 t1 = self.get_temporary_name() 557 self.next_temporary() 558 i0 = self.get_temporary_name() 559 self.next_temporary() 560 561 node = compiler.ast.Stmt([ 562 563 # <t0> = {n.list} 564 # <t1> = <t0>.__iter__() 565 # <i0> = <t1>.next 566 567 compiler.ast.Assign( 568 [compiler.ast.AssName(t0, "OP_ASSIGN")], 569 n.list), 570 571 compiler.ast.Assign( 572 [compiler.ast.AssName(t1, "OP_ASSIGN")], 573 compiler.ast.CallFunc( 574 compiler.ast.Getattr(compiler.ast.Name(t0), "__iter__"), 575 [])), 576 577 compiler.ast.Assign( 578 [compiler.ast.AssName(i0, "OP_ASSIGN")], 579 compiler.ast.Getattr(compiler.ast.Name(t1), "next")), 580 581 # try: 582 # while True: 583 # <var>... = <next>() 584 # ... 585 # except StopIteration: 586 # pass 587 588 compiler.ast.TryExcept( 589 compiler.ast.While( 590 compiler.ast.Name("True"), 591 compiler.ast.Stmt([ 592 compiler.ast.Assign( 593 [n.assign], 594 compiler.ast.CallFunc( 595 compiler.ast.Name(i0), 596 [] 597 )), 598 n.body]), 599 None), 600 [(compiler.ast.Name("StopIteration"), None, compiler.ast.Stmt([compiler.ast.Pass()]))], 601 None) 602 ]) 603 604 self.process_structure_node(node) 605 606 def process_literal_sequence_node(self, n, name, ref, cls): 607 608 """ 609 Process the given literal sequence node 'n' as a function invocation, 610 with 'name' indicating the type of the sequence, and 'ref' being a 611 reference to the type. The 'cls' is used to instantiate a suitable name 612 reference. 613 """ 614 615 if name == "dict": 616 items = [] 617 for key, value in n.items: 618 items.append(compiler.ast.Tuple([key, value])) 619 else: # name in ("list", "tuple"): 620 items = n.nodes 621 622 return self.get_literal_reference(name, ref, items, cls) 623 624 def process_operator_node(self, n): 625 626 """ 627 Process the given operator node 'n' as an operator function invocation. 628 """ 629 630 op = operator_functions[n.__class__.__name__] 631 invocation = compiler.ast.CallFunc( 632 compiler.ast.Name("$op%s" % op), 633 list(n.getChildNodes()) 634 ) 635 return self.process_structure_node(invocation) 636 637 def process_print_node(self, n): 638 639 """ 640 Process the given print node 'n' as an invocation on a stream of the 641 form... 642 643 $print(dest, args, nl) 644 645 The special function name will be translated elsewhere. 646 """ 647 648 nl = isinstance(n, compiler.ast.Printnl) 649 invocation = compiler.ast.CallFunc( 650 compiler.ast.Name("$print"), 651 [n.dest or compiler.ast.Name("None"), 652 compiler.ast.List(list(n.nodes)), 653 nl and compiler.ast.Name("True") or compiler.ast.Name("False")] 654 ) 655 return self.process_structure_node(invocation) 656 657 def process_slice_node(self, n, expr=None): 658 659 """ 660 Process the given slice node 'n' as an operator function invocation. 661 """ 662 663 if n.flags == "OP_ASSIGN": op = "setslice" 664 elif n.flags == "OP_DELETE": op = "delslice" 665 else: op = "getslice" 666 667 invocation = compiler.ast.CallFunc( 668 compiler.ast.Name("$op%s" % op), 669 [n.expr, n.lower or compiler.ast.Name("None"), n.upper or compiler.ast.Name("None")] + 670 (expr and [expr] or []) 671 ) 672 673 # Fix parse tree structure. 674 675 if op == "delslice": 676 invocation = compiler.ast.Discard(invocation) 677 678 return self.process_structure_node(invocation) 679 680 def process_sliceobj_node(self, n): 681 682 """ 683 Process the given slice object node 'n' as a slice constructor. 684 """ 685 686 op = "slice" 687 invocation = compiler.ast.CallFunc( 688 compiler.ast.Name("$op%s" % op), 689 n.nodes 690 ) 691 return self.process_structure_node(invocation) 692 693 def process_subscript_node(self, n, expr=None): 694 695 """ 696 Process the given subscript node 'n' as an operator function invocation. 697 """ 698 699 if n.flags == "OP_ASSIGN": op = "setitem" 700 elif n.flags == "OP_DELETE": op = "delitem" 701 else: op = "getitem" 702 703 invocation = compiler.ast.CallFunc( 704 compiler.ast.Name("$op%s" % op), 705 [n.expr] + list(n.subs) + (expr and [expr] or []) 706 ) 707 708 # Fix parse tree structure. 709 710 if op == "delitem": 711 invocation = compiler.ast.Discard(invocation) 712 713 return self.process_structure_node(invocation) 714 715 def process_attribute_chain(self, n): 716 717 """ 718 Process the given attribute access node 'n'. Return a reference 719 describing the expression. 720 """ 721 722 # AssAttr/Getattr are nested with the outermost access being the last 723 # access in any chain. 724 725 self.attrs.insert(0, n.attrname) 726 attrs = self.attrs 727 728 # Break attribute chains where non-access nodes are found. 729 730 if not self.have_access_expression(n): 731 self.reset_attribute_chain() 732 733 # Descend into the expression, extending backwards any existing chain, 734 # or building another for the expression. 735 736 name_ref = self.process_structure_node(n.expr) 737 738 # Restore chain information applying to this node. 739 740 if not self.have_access_expression(n): 741 self.restore_attribute_chain(attrs) 742 743 # Return immediately if the expression was another access and thus a 744 # continuation backwards along the chain. The above processing will 745 # have followed the chain all the way to its conclusion. 746 747 if self.have_access_expression(n): 748 del self.attrs[0] 749 750 return name_ref 751 752 # Attribute chain handling. 753 754 def reset_attribute_chain(self): 755 756 "Reset the attribute chain for a subexpression of an attribute access." 757 758 self.attrs = [] 759 self.chain_assignment.append(self.in_assignment) 760 self.chain_invocation.append(self.in_invocation) 761 self.in_assignment = None 762 self.in_invocation = None 763 764 def restore_attribute_chain(self, attrs): 765 766 "Restore the attribute chain for an attribute access." 767 768 self.attrs = attrs 769 self.in_assignment = self.chain_assignment.pop() 770 self.in_invocation = self.chain_invocation.pop() 771 772 def have_access_expression(self, node): 773 774 "Return whether the expression associated with 'node' is Getattr." 775 776 return isinstance(node.expr, compiler.ast.Getattr) 777 778 def get_name_for_tracking(self, name, name_ref=None, is_global=False): 779 780 """ 781 Return the name to be used for attribute usage observations involving 782 the given 'name' in the current namespace. 783 784 If the name is being used outside a function, and if 'name_ref' is 785 given and indicates a global or if 'is_global' is specified as a true 786 value, a path featuring the name in the global namespace is returned. 787 Otherwise, a path computed using the current namespace and the given 788 name is returned. 789 790 The intention of this method is to provide a suitably-qualified name 791 that can be tracked across namespaces. Where globals are being 792 referenced in class namespaces, they should be referenced using their 793 path within the module, not using a path within each class. 794 795 It may not be possible to identify a global within a function at the 796 time of inspection (since a global may appear later in a file). 797 Consequently, globals are identified by their local name rather than 798 their module-qualified path. 799 """ 800 801 # For functions, use the appropriate local names. 802 803 if self.in_function: 804 return name 805 806 # For global names outside functions, use a global name. 807 808 elif is_global or name_ref and name_ref.is_global_name(): 809 return self.get_global_path(name) 810 811 # Otherwise, establish a name in the current namespace. 812 813 else: 814 return self.get_object_path(name) 815 816 def get_path_for_access(self): 817 818 "Outside functions, register accesses at the module level." 819 820 if not self.in_function: 821 return self.name 822 else: 823 return self.get_namespace_path() 824 825 def get_module_name(self, node): 826 827 """ 828 Using the given From 'node' in this module, calculate any relative import 829 information, returning a tuple containing a module to import along with any 830 names to import based on the node's name information. 831 832 Where the returned module is given as None, whole module imports should 833 be performed for the returned modules using the returned names. 834 """ 835 836 # Absolute import. 837 838 if node.level == 0: 839 return node.modname, node.names 840 841 # Relative to an ancestor of this module. 842 843 else: 844 path = self.name.split(".") 845 level = node.level 846 847 # Relative imports treat package roots as submodules. 848 849 if split(self.filename)[-1] == "__init__.py": 850 level -= 1 851 852 if level > len(path): 853 raise InspectError("Relative import %r involves too many levels up from module %r" % ( 854 ("%s%s" % ("." * node.level, node.modname or "")), self.name)) 855 856 basename = ".".join(path[:len(path)-level]) 857 858 # Name imports from a module. 859 860 if node.modname: 861 return "%s.%s" % (basename, node.modname), node.names 862 863 # Relative whole module imports. 864 865 else: 866 return basename, node.names 867 868 def get_argnames(args): 869 870 """ 871 Return a list of all names provided by 'args'. Since tuples may be 872 employed, the arguments are traversed depth-first. 873 """ 874 875 l = [] 876 for arg in args: 877 if isinstance(arg, tuple): 878 l += get_argnames(arg) 879 else: 880 l.append(arg) 881 return l 882 883 def get_names_from_nodes(nodes): 884 885 """ 886 Return the names employed in the given 'nodes' along with the number of 887 nodes excluding sequences. 888 """ 889 890 names = set() 891 count = 0 892 893 for node in nodes: 894 895 # Add names and count them. 896 897 if isinstance(node, (compiler.ast.AssName, compiler.ast.Name)): 898 names.add(node.name) 899 count += 1 900 901 # Add names from sequences and incorporate their counts. 902 903 elif isinstance(node, (compiler.ast.AssList, compiler.ast.AssTuple, 904 compiler.ast.List, compiler.ast.Set, 905 compiler.ast.Tuple)): 906 _names, _count = get_names_from_nodes(node.nodes) 907 names.update(_names) 908 count += _count 909 910 # Count non-name, non-sequence nodes. 911 912 else: 913 count += 1 914 915 return names, count 916 917 # Result classes. 918 919 class InstructionSequence: 920 921 "A generic sequence of instructions." 922 923 def __init__(self, instructions): 924 self.instructions = instructions 925 926 def get_value_instruction(self): 927 return self.instructions[-1] 928 929 def get_init_instructions(self): 930 return self.instructions[:-1] 931 932 # Dictionary utilities. 933 934 def init_item(d, key, fn): 935 936 """ 937 Add to 'd' an entry for 'key' using the callable 'fn' to make an initial 938 value where no entry already exists. 939 """ 940 941 if not d.has_key(key): 942 d[key] = fn() 943 return d[key] 944 945 def dict_for_keys(d, keys): 946 947 "Return a new dictionary containing entries from 'd' for the given 'keys'." 948 949 nd = {} 950 for key in keys: 951 if d.has_key(key): 952 nd[key] = d[key] 953 return nd 954 955 def make_key(s): 956 957 "Make sequence 's' into a tuple-based key, first sorting its contents." 958 959 l = list(s) 960 l.sort() 961 return tuple(l) 962 963 def add_counter_item(d, key): 964 965 """ 966 Make a mapping in 'd' for 'key' to the number of keys added before it, thus 967 maintaining a mapping of keys to their order of insertion. 968 """ 969 970 if not d.has_key(key): 971 d[key] = len(d.keys()) 972 return d[key] 973 974 def remove_items(d1, d2): 975 976 "Remove from 'd1' all items from 'd2'." 977 978 for key in d2.keys(): 979 if d1.has_key(key): 980 del d1[key] 981 982 # Set utilities. 983 984 def first(s): 985 return list(s)[0] 986 987 def same(s1, s2): 988 return set(s1) == set(s2) 989 990 # General input/output. 991 992 def readfile(filename): 993 994 "Return the contents of 'filename'." 995 996 f = open(filename) 997 try: 998 return f.read() 999 finally: 1000 f.close() 1001 1002 def writefile(filename, s): 1003 1004 "Write to 'filename' the string 's'." 1005 1006 f = open(filename, "w") 1007 try: 1008 f.write(s) 1009 finally: 1010 f.close() 1011 1012 # General encoding. 1013 1014 def sorted_output(x): 1015 1016 "Sort sequence 'x' and return a string with commas separating the values." 1017 1018 x = map(str, x) 1019 x.sort() 1020 return ", ".join(x) 1021 1022 def get_string_details(literals, encoding): 1023 1024 """ 1025 Determine whether 'literals' represent Unicode strings or byte strings, 1026 using 'encoding' to reproduce byte sequences. 1027 1028 Each literal is the full program representation including prefix and quotes 1029 recoded by the parser to UTF-8. Thus, any literal found to represent a byte 1030 string needs to be translated back to its original encoding. 1031 1032 Return a single encoded literal value, a type name, and the original 1033 encoding as a tuple. 1034 """ 1035 1036 typename = "unicode" 1037 1038 l = [] 1039 1040 for s in literals: 1041 out, _typename = get_literal_details(s) 1042 if _typename == "str": 1043 typename = "str" 1044 l.append(out) 1045 1046 out = "".join(l) 1047 1048 # For Unicode values, convert to the UTF-8 program representation. 1049 1050 if typename == "unicode": 1051 return out.encode("utf-8"), typename, encoding 1052 1053 # For byte string values, convert back to the original encoding. 1054 1055 else: 1056 return out.encode(encoding), typename, encoding 1057 1058 def get_literal_details(s): 1059 1060 """ 1061 Determine whether 's' represents a Unicode string or a byte string, where 1062 's' contains the full program representation of a literal including prefix 1063 and quotes, recoded by the parser to UTF-8. 1064 1065 Find and convert Unicode values starting with <backslash>u or <backslash>U, 1066 and byte or Unicode values starting with <backslash><octal digit> or 1067 <backslash>x. 1068 1069 Literals prefixed with "u" cause <backslash><octal digit> and <backslash>x 1070 to be considered as Unicode values. Otherwise, they produce byte values and 1071 cause unprefixed strings to be considered as byte strings. 1072 1073 Literals prefixed with "r" do not have their backslash-encoded values 1074 converted unless also prefixed with "u", in which case only the above value 1075 formats are converted, not any of the other special sequences for things 1076 like newlines. 1077 1078 Return the literal value as a Unicode object together with the appropriate 1079 type name in a tuple. 1080 """ 1081 1082 l = [] 1083 1084 # Identify the quote character and use it to identify the prefix. 1085 1086 quote_type = s[-1] 1087 prefix_end = s.find(quote_type) 1088 prefix = s[:prefix_end].lower() 1089 1090 if prefix not in ("", "b", "br", "r", "u", "ur"): 1091 raise ValueError, "String literal does not have a supported prefix: %s" % s 1092 1093 if "b" in prefix: 1094 typename = "str" 1095 else: 1096 typename = "unicode" 1097 1098 # Identify triple quotes or single quotes. 1099 1100 if len(s) >= 6 and s[-2] == quote_type and s[-3] == quote_type: 1101 quote = s[prefix_end:prefix_end+3] 1102 current = prefix_end + 3 1103 end = len(s) - 3 1104 else: 1105 quote = s[prefix_end] 1106 current = prefix_end + 1 1107 end = len(s) - 1 1108 1109 # Conversions of some quoted values. 1110 1111 searches = { 1112 "u" : (6, 16), 1113 "U" : (10, 16), 1114 "x" : (4, 16), 1115 } 1116 1117 octal_digits = map(str, range(0, 8)) 1118 1119 # Translations of some quoted values. 1120 1121 escaped = { 1122 "\\" : "\\", "'" : "'", '"' : '"', 1123 "a" : "\a", "b" : "\b", "f" : "\f", 1124 "n" : "\n", "r" : "\r", "t" : "\t", 1125 } 1126 1127 while current < end: 1128 1129 # Look for quoted values. 1130 1131 index = s.find("\\", current) 1132 if index == -1 or index + 1 == end: 1133 l.append(s[current:end]) 1134 break 1135 1136 # Add the preceding text. 1137 1138 l.append(s[current:index]) 1139 1140 # Handle quoted text. 1141 1142 term = s[index+1] 1143 1144 # Add Unicode values. Where a string is u-prefixed, even \o and \x 1145 # produce Unicode values. 1146 1147 if typename == "unicode" and ( 1148 term in ("u", "U") or 1149 "u" in prefix and (term == "x" or term in octal_digits)): 1150 1151 needed, base = searches.get(term, (4, 8)) 1152 value = convert_quoted_value(s, index, needed, end, base, unichr) 1153 l.append(value) 1154 current = index + needed 1155 1156 # Add raw byte values, changing the string type. 1157 1158 elif "r" not in prefix and ( 1159 term == "x" or term in octal_digits): 1160 1161 needed, base = searches.get(term, (4, 8)) 1162 value = convert_quoted_value(s, index, needed, end, base, chr) 1163 l.append(value) 1164 typename = "str" 1165 current = index + needed 1166 1167 # Add other escaped values. 1168 1169 elif "r" not in prefix and escaped.has_key(term): 1170 l.append(escaped[term]) 1171 current = index + 2 1172 1173 # Add other text as found. 1174 1175 else: 1176 l.append(s[index:index+2]) 1177 current = index + 2 1178 1179 # Collect the components into a single Unicode object. Since the literal 1180 # text was already in UTF-8 form, interpret plain strings as UTF-8 1181 # sequences. 1182 1183 out = [] 1184 1185 for value in l: 1186 if isinstance(value, unicode): 1187 out.append(value) 1188 else: 1189 out.append(unicode(value, "utf-8")) 1190 1191 return "".join(out), typename 1192 1193 def convert_quoted_value(s, index, needed, end, base, fn): 1194 1195 """ 1196 Interpret a quoted value in 's' at 'index' with the given 'needed' number of 1197 positions, and with the given 'end' indicating the first position after the 1198 end of the actual string content. 1199 1200 Use 'base' as the numerical base when interpreting the value, and use 'fn' 1201 to convert the value to an appropriate type. 1202 """ 1203 1204 s = s[index:min(index+needed, end)] 1205 1206 # Not a complete occurrence. 1207 1208 if len(s) < needed: 1209 return s 1210 1211 # Test for a well-formed value. 1212 1213 try: 1214 first = base == 8 and 1 or 2 1215 value = int(s[first:needed], base) 1216 except ValueError: 1217 return s 1218 else: 1219 return fn(value) 1220 1221 # Attribute chain decoding. 1222 1223 def get_attrnames(attrnames): 1224 1225 """ 1226 Split the qualified attribute chain 'attrnames' into its components, 1227 handling special attributes starting with "#" that indicate type 1228 conformance. 1229 """ 1230 1231 if attrnames.startswith("#"): 1232 return [attrnames] 1233 else: 1234 return attrnames.split(".") 1235 1236 def get_attrname_from_location(location): 1237 1238 """ 1239 Extract the first attribute from the attribute names employed in a 1240 'location'. 1241 """ 1242 1243 path, name, attrnames, access = location 1244 if not attrnames: 1245 return attrnames 1246 return get_attrnames(attrnames)[0] 1247 1248 def get_name_path(path, name): 1249 1250 "Return a suitable qualified name from the given 'path' and 'name'." 1251 1252 if "." in name: 1253 return name 1254 else: 1255 return "%s.%s" % (path, name) 1256 1257 # Usage-related functions. 1258 1259 def get_types_for_usage(attrnames, objects): 1260 1261 """ 1262 Identify the types that can support the given 'attrnames', using the 1263 given 'objects' as the catalogue of type details. 1264 """ 1265 1266 types = [] 1267 for name, _attrnames in objects.items(): 1268 if set(attrnames).issubset(_attrnames): 1269 types.append(name) 1270 return types 1271 1272 def get_invoked_attributes(usage): 1273 1274 "Obtain invoked attribute from the given 'usage'." 1275 1276 invoked = [] 1277 if usage: 1278 for attrname, invocation, assignment in usage: 1279 if invocation: 1280 invoked.append(attrname) 1281 return invoked 1282 1283 def get_assigned_attributes(usage): 1284 1285 "Obtain assigned attribute from the given 'usage'." 1286 1287 assigned = [] 1288 if usage: 1289 for attrname, invocation, assignment in usage: 1290 if assignment: 1291 assigned.append(attrname) 1292 return assigned 1293 1294 # Type and module functions. 1295 # NOTE: This makes assumptions about the __builtins__ structure. 1296 1297 def get_builtin_module(name): 1298 1299 "Return the module name containing the given type 'name'." 1300 1301 if name == "string": 1302 modname = "str" 1303 elif name == "utf8string": 1304 modname = "unicode" 1305 elif name == "NoneType": 1306 modname = "none" 1307 else: 1308 modname = name 1309 1310 return "__builtins__.%s" % modname 1311 1312 def get_builtin_type(name): 1313 1314 "Return the type name provided by the given Python value 'name'." 1315 1316 if name == "str": 1317 return "string" 1318 elif name == "unicode": 1319 return "utf8string" 1320 else: 1321 return name 1322 1323 def get_builtin_class(name): 1324 1325 "Return the full name of the built-in class having the given 'name'." 1326 1327 typename = get_builtin_type(name) 1328 module = get_builtin_module(typename) 1329 return "%s.%s" % (module, typename) 1330 1331 # Useful data. 1332 1333 predefined_constants = "False", "None", "NotImplemented", "True" 1334 1335 operator_functions = { 1336 1337 # Fundamental operations. 1338 1339 "is" : "is_", 1340 "is not" : "is_not", 1341 1342 # Binary operations. 1343 1344 "in" : "in_", 1345 "not in" : "not_in", 1346 "Add" : "add", 1347 "Bitand" : "and_", 1348 "Bitor" : "or_", 1349 "Bitxor" : "xor", 1350 "Div" : "div", 1351 "FloorDiv" : "floordiv", 1352 "LeftShift" : "lshift", 1353 "Mod" : "mod", 1354 "Mul" : "mul", 1355 "Power" : "pow", 1356 "RightShift" : "rshift", 1357 "Sub" : "sub", 1358 1359 # Unary operations. 1360 1361 "Invert" : "invert", 1362 "UnaryAdd" : "pos", 1363 "UnarySub" : "neg", 1364 1365 # Augmented assignment. 1366 1367 "+=" : "iadd", 1368 "-=" : "isub", 1369 "*=" : "imul", 1370 "/=" : "idiv", 1371 "//=" : "ifloordiv", 1372 "%=" : "imod", 1373 "**=" : "ipow", 1374 "<<=" : "ilshift", 1375 ">>=" : "irshift", 1376 "&=" : "iand", 1377 "^=" : "ixor", 1378 "|=" : "ior", 1379 1380 # Comparisons. 1381 1382 "==" : "eq", 1383 "!=" : "ne", 1384 "<" : "lt", 1385 "<=" : "le", 1386 ">=" : "ge", 1387 ">" : "gt", 1388 } 1389 1390 # vim: tabstop=4 expandtab shiftwidth=4