1 #!/usr/bin/env python 2 3 """ 4 Translate programs. 5 6 Copyright (C) 2015, 2016, 2017, 2018 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 from common import AccessLocation, CommonModule, CommonOutput, Location, \ 23 first, get_builtin_class, init_item, is_newer, \ 24 predefined_constants 25 from encoders import encode_access_instruction, encode_access_instruction_arg, \ 26 encode_function_pointer, encode_literal_instantiator, \ 27 encode_instantiator_pointer, encode_path, encode_symbol, \ 28 encode_type_attribute, is_type_attribute, \ 29 type_ops, typename_ops 30 from errors import InspectError, TranslateError 31 from os.path import exists, join 32 from os import makedirs 33 from referencing import Reference, combine_types 34 from results import Result 35 from transresults import TrConstantValueRef, TrInstanceRef, \ 36 TrLiteralSequenceRef, TrResolvedNameRef, \ 37 AliasResult, AttrResult, Expression, InstantiationResult, \ 38 InvocationResult, LogicalOperationResult, \ 39 LogicalResult, NegationResult, PredefinedConstantRef, \ 40 ReturnRef 41 from StringIO import StringIO 42 import compiler 43 import sys 44 45 class Translator(CommonOutput): 46 47 "A program translator." 48 49 def __init__(self, importer, deducer, optimiser, output): 50 self.importer = importer 51 self.deducer = deducer 52 self.optimiser = optimiser 53 self.output = output 54 55 def to_output(self, reset=False, debug=False, gc_sections=False): 56 57 "Write a program to the configured output directory." 58 59 # Make a directory for the final sources. 60 61 output = join(self.output, "src") 62 63 if not exists(output): 64 makedirs(output) 65 66 # Clean the output directory of irrelevant data. 67 68 self.check_output("debug=%r gc_sections=%r" % (debug, gc_sections)) 69 70 for module in self.importer.modules.values(): 71 output_filename = join(output, "%s.c" % module.name) 72 73 # Do not generate modules in the native package. They are provided 74 # by native functionality source files. 75 76 parts = module.name.split(".") 77 78 if parts[0] != "native" and \ 79 (reset or is_newer(module.filename, output_filename)): 80 81 tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser) 82 tm.translate(module.filename, output_filename) 83 84 85 86 def make_expression(expr): 87 88 "Make a new expression from the existing 'expr'." 89 90 if isinstance(expr, Result): 91 return expr 92 else: 93 return Expression(str(expr)) 94 95 96 97 # The actual translation process itself. 98 99 class TranslatedModule(CommonModule): 100 101 "A module translator." 102 103 def __init__(self, name, importer, deducer, optimiser): 104 CommonModule.__init__(self, name, importer) 105 self.deducer = deducer 106 self.optimiser = optimiser 107 108 # Output stream. 109 110 self.out_toplevel = self.out = None 111 self.indent = 0 112 self.tabstop = " " 113 114 # Recorded namespaces. 115 116 self.namespaces = [] 117 self.in_conditional = False 118 119 # Exception raising adjustments. 120 121 self.in_try_finally = False 122 self.in_try_except = False 123 124 # Attribute access and accessor counting. 125 126 self.attr_accesses = {} 127 self.attr_accessors = {} 128 129 # Special variable usage. 130 131 self.temp_usage = {} 132 133 # Initialise some data used for attribute access generation. 134 135 self.init_substitutions() 136 137 def __repr__(self): 138 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 139 140 def translate(self, filename, output_filename): 141 142 """ 143 Parse the file having the given 'filename', writing the translation to 144 the given 'output_filename'. 145 """ 146 147 self.parse_file(filename) 148 149 # Collect function namespaces for separate processing. 150 151 self.record_namespaces(self.astnode) 152 153 # Reset the lambda naming (in order to obtain the same names again) and 154 # translate the program. 155 156 self.reset_lambdas() 157 158 self.out_toplevel = self.out = open(output_filename, "w") 159 try: 160 self.start_output() 161 162 # Process namespaces, writing the translation. 163 164 for path, node in self.namespaces: 165 self.process_namespace(path, node) 166 167 # Process the module namespace including class namespaces. 168 169 self.process_namespace([], self.astnode) 170 171 finally: 172 self.out.close() 173 174 def have_object(self): 175 176 "Return whether a namespace is a recorded object." 177 178 return self.importer.objects.get(self.get_namespace_path()) 179 180 def get_builtin_class(self, name): 181 182 "Return a reference to the actual object providing 'name'." 183 184 return self.importer.get_object(get_builtin_class(name)) 185 186 def is_method(self, path): 187 188 "Return whether 'path' is a method." 189 190 class_name, method_name = path.rsplit(".", 1) 191 return self.importer.classes.has_key(class_name) and class_name or None 192 193 def in_method(self): 194 195 "Return whether the current namespace provides a method." 196 197 return self.in_function and self.is_method(self.get_namespace_path()) 198 199 # Namespace recording. 200 201 def record_namespaces(self, node): 202 203 "Process the program structure 'node', recording namespaces." 204 205 for n in node.getChildNodes(): 206 self.record_namespaces_in_node(n) 207 208 def record_namespaces_in_node(self, node): 209 210 "Process the program structure 'node', recording namespaces." 211 212 # Function namespaces within modules, classes and other functions. 213 # Functions appearing within conditional statements are given arbitrary 214 # names. 215 216 if isinstance(node, compiler.ast.Function): 217 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 218 219 elif isinstance(node, compiler.ast.Lambda): 220 self.record_function_node(node, self.get_lambda_name()) 221 222 # Classes are visited, but may be ignored if inside functions. 223 224 elif isinstance(node, compiler.ast.Class): 225 self.enter_namespace(node.name) 226 if self.have_object(): 227 self.record_namespaces(node) 228 self.exit_namespace() 229 230 # Conditional nodes are tracked so that function definitions may be 231 # handled. Since "for" loops are converted to "while" loops, they are 232 # included here. 233 234 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 235 in_conditional = self.in_conditional 236 self.in_conditional = True 237 self.record_namespaces(node) 238 self.in_conditional = in_conditional 239 240 # All other nodes are processed depth-first. 241 242 else: 243 self.record_namespaces(node) 244 245 def record_function_node(self, n, name): 246 247 """ 248 Record the given function, lambda, if expression or list comprehension 249 node 'n' with the given 'name'. 250 """ 251 252 self.in_function = True 253 self.enter_namespace(name) 254 255 if self.have_object(): 256 257 # Record the namespace path and the node itself. 258 259 self.namespaces.append((self.namespace_path[:], n)) 260 self.record_namespaces_in_node(n.code) 261 262 self.exit_namespace() 263 self.in_function = False 264 265 # Constant referencing. 266 267 def get_literal_instance(self, n, name=None): 268 269 """ 270 For node 'n', return a reference for the type of the given 'name', or if 271 'name' is not specified, deduce the type from the value. 272 """ 273 274 # Handle stray None constants (Sliceobj seems to produce them). 275 276 if name is None and n.value is None: 277 return self.process_name_node(compiler.ast.Name("None")) 278 279 if name in ("dict", "list", "tuple"): 280 ref = self.get_builtin_class(name) 281 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 282 else: 283 value, typename, encoding = self.get_constant_value(n.value, n.literals) 284 ref = self.get_builtin_class(typename) 285 value_type = ref.get_origin() 286 287 path = self.get_namespace_path() 288 289 # Obtain the local numbering of the constant and thus the 290 # locally-qualified name. 291 292 local_number = self.importer.all_constants[path][(value, value_type, encoding)] 293 constant_name = "$c%d" % local_number 294 objpath = self.get_object_path(constant_name) 295 296 # Obtain the unique identifier for the constant. 297 298 number = self.optimiser.constant_numbers[objpath] 299 return TrConstantValueRef(constant_name, ref.instance_of(), value, number) 300 301 # Namespace translation. 302 303 def process_namespace(self, path, node): 304 305 """ 306 Process the namespace for the given 'path' defined by the given 'node'. 307 """ 308 309 self.namespace_path = path 310 311 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 312 self.in_function = True 313 self.process_function_body_node(node) 314 else: 315 self.in_function = False 316 self.function_target = 0 317 self.max_function_target = 0 318 self.context_index = 0 319 self.max_context_index = 0 320 self.start_module() 321 self.process_structure(node) 322 self.end_module() 323 324 def process_structure(self, node): 325 326 "Process the given 'node' or result." 327 328 # Handle processing requests on results. 329 330 if isinstance(node, Result): 331 return node 332 333 # Handle processing requests on nodes. 334 335 else: 336 l = CommonModule.process_structure(self, node) 337 338 # Return indications of return statement usage. 339 340 if l and isinstance(l[-1], ReturnRef): 341 return l[-1] 342 else: 343 return None 344 345 def process_structure_node(self, n): 346 347 "Process the individual node 'n'." 348 349 # Plain statements emit their expressions. 350 351 if isinstance(n, compiler.ast.Discard): 352 expr = self.process_structure_node(n.expr) 353 self.statement(expr) 354 355 # Module import declarations. 356 357 elif isinstance(n, compiler.ast.From): 358 self.process_from_node(n) 359 360 # Nodes using operator module functions. 361 362 elif isinstance(n, compiler.ast.Operator): 363 return self.process_operator_node(n) 364 365 elif isinstance(n, compiler.ast.AugAssign): 366 self.process_augassign_node(n) 367 368 elif isinstance(n, compiler.ast.Compare): 369 return self.process_compare_node(n) 370 371 elif isinstance(n, compiler.ast.Slice): 372 return self.process_slice_node(n) 373 374 elif isinstance(n, compiler.ast.Sliceobj): 375 return self.process_sliceobj_node(n) 376 377 elif isinstance(n, compiler.ast.Subscript): 378 return self.process_subscript_node(n) 379 380 # Classes are visited, but may be ignored if inside functions. 381 382 elif isinstance(n, compiler.ast.Class): 383 self.process_class_node(n) 384 385 # Functions within namespaces have any dynamic defaults initialised. 386 387 elif isinstance(n, compiler.ast.Function): 388 self.process_function_node(n) 389 390 # Lambdas are replaced with references to separately-generated 391 # functions. 392 393 elif isinstance(n, compiler.ast.Lambda): 394 return self.process_lambda_node(n) 395 396 # Assignments. 397 398 elif isinstance(n, compiler.ast.Assign): 399 400 # Handle each assignment node. 401 402 for node in n.nodes: 403 self.process_assignment_node(node, n.expr) 404 405 # Accesses. 406 407 elif isinstance(n, compiler.ast.Getattr): 408 return self.process_attribute_access(n) 409 410 # Names. 411 412 elif isinstance(n, compiler.ast.Name): 413 return self.process_name_node(n) 414 415 # Loops and conditionals. 416 417 elif isinstance(n, compiler.ast.For): 418 self.process_for_node(n) 419 420 elif isinstance(n, compiler.ast.While): 421 self.process_while_node(n) 422 423 elif isinstance(n, compiler.ast.If): 424 self.process_if_node(n) 425 426 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 427 return self.process_logical_node(n) 428 429 elif isinstance(n, compiler.ast.Not): 430 return self.process_not_node(n) 431 432 # Exception control-flow tracking. 433 434 elif isinstance(n, compiler.ast.TryExcept): 435 self.process_try_node(n) 436 437 elif isinstance(n, compiler.ast.TryFinally): 438 self.process_try_finally_node(n) 439 440 # Control-flow modification statements. 441 442 elif isinstance(n, compiler.ast.Break): 443 self.writestmt("break;") 444 445 elif isinstance(n, compiler.ast.Continue): 446 self.writestmt("continue;") 447 448 elif isinstance(n, compiler.ast.Raise): 449 self.process_raise_node(n) 450 451 elif isinstance(n, compiler.ast.Return): 452 return self.process_return_node(n) 453 454 # Print statements. 455 456 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 457 self.statement(self.process_print_node(n)) 458 459 # Invocations. 460 461 elif isinstance(n, compiler.ast.CallFunc): 462 return self.process_invocation_node(n) 463 464 elif isinstance(n, compiler.ast.Keyword): 465 return self.process_structure_node(n.expr) 466 467 # Constant usage. 468 469 elif isinstance(n, compiler.ast.Const): 470 return self.get_literal_instance(n) 471 472 elif isinstance(n, compiler.ast.Dict): 473 return self.get_literal_instance(n, "dict") 474 475 elif isinstance(n, compiler.ast.List): 476 return self.get_literal_instance(n, "list") 477 478 elif isinstance(n, compiler.ast.Tuple): 479 return self.get_literal_instance(n, "tuple") 480 481 # All other nodes are processed depth-first. 482 483 else: 484 return self.process_structure(n) 485 486 def process_assignment_node(self, n, expr): 487 488 "Process the individual node 'n' to be assigned the contents of 'expr'." 489 490 # Names and attributes are assigned the entire expression. 491 492 if isinstance(n, compiler.ast.AssName): 493 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 494 self.statement(name_ref) 495 496 # Employ guards after assignments if required. 497 498 if expr and name_ref.is_name(): 499 self.generate_guard(name_ref.name) 500 501 elif isinstance(n, compiler.ast.AssAttr): 502 in_assignment = self.in_assignment 503 self.in_assignment = self.process_structure_node(expr) 504 self.statement(self.process_attribute_access(n)) 505 self.in_assignment = in_assignment 506 507 # Lists and tuples are matched against the expression and their 508 # items assigned to expression items. 509 510 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 511 self.process_assignment_node_items(n, expr) 512 513 # Slices and subscripts are permitted within assignment nodes. 514 515 elif isinstance(n, compiler.ast.Slice): 516 self.statement(self.process_slice_node(n, expr)) 517 518 elif isinstance(n, compiler.ast.Subscript): 519 self.statement(self.process_subscript_node(n, expr)) 520 521 def process_attribute_access(self, n): 522 523 "Process the given attribute access node 'n'." 524 525 # Obtain any completed chain and return the reference to it. 526 527 attr_expr = self.process_attribute_chain(n) 528 if self.have_access_expression(n): 529 return attr_expr 530 531 # Where the start of the chain of attributes has been reached, process 532 # the complete access. 533 534 name_ref = attr_expr and attr_expr.is_name() and attr_expr 535 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref) or None 536 537 location = self.get_access_location(name, self.attrs) 538 refs = self.get_referenced_attributes(location) 539 540 # Generate access instructions. 541 542 subs = { 543 "<expr>" : attr_expr, 544 "<name>" : attr_expr, 545 "<assexpr>" : self.in_assignment, 546 } 547 548 subs.update(self.temp_subs) 549 subs.update(self.op_subs) 550 551 output = [] 552 substituted = set() 553 554 # The context set or retrieved will be that used by any enclosing 555 # invocation. 556 557 context_index = self.context_index 558 context_identity = None 559 context_identity_verified = False 560 final_identity = None 561 accessor_test = False 562 563 # Obtain encoded versions of each instruction, accumulating temporary 564 # variables. 565 566 for instruction in self.deducer.access_instructions[location]: 567 568 # Intercept a special instruction identifying the context. 569 570 if instruction[0] in ("<context_identity>", "<context_identity_verified>"): 571 context_identity, _substituted = encode_access_instruction_arg(instruction[1], subs, instruction[0], context_index) 572 context_identity_verified = instruction[0] == "<context_identity_verified>" 573 continue 574 575 # Intercept a special instruction identifying the target. The value 576 # is not encoded since it is used internally. 577 578 elif instruction[0] == "<final_identity>": 579 final_identity = instruction[1] 580 continue 581 582 # Modify test instructions. 583 584 elif instruction[0] in typename_ops or instruction[0] in type_ops: 585 instruction = ("__to_error", instruction) 586 accessor_test = True 587 588 # Collect the encoded instruction, noting any temporary variables 589 # required by it. 590 591 encoded, _substituted = encode_access_instruction(instruction, subs, context_index) 592 output.append(encoded) 593 substituted.update(_substituted) 594 595 # Record temporary name usage. 596 597 for sub in substituted: 598 if self.temp_subs.has_key(sub): 599 self.record_temp(self.temp_subs[sub]) 600 601 # Get full final identity details. 602 603 if final_identity and not refs: 604 ref = self.importer.identify(final_identity) 605 refs = [ref] 606 607 del self.attrs[0] 608 return AttrResult(output, refs, location, context_identity, context_identity_verified, accessor_test) 609 610 def init_substitutions(self): 611 612 """ 613 Initialise substitutions, defining temporary variable mappings, some of 614 which are also used as substitutions, together with operation mappings 615 used as substitutions in instructions defined by the optimiser. 616 """ 617 618 self.temp_subs = { 619 620 # Substitutions used by instructions. 621 622 "<private_context>" : "__tmp_private_context", 623 "<accessor>" : "__tmp_value", 624 "<target_accessor>" : "__tmp_target_value", 625 626 # Mappings to be replaced by those given below. 627 628 "<context>" : "__tmp_contexts", 629 "<test_context_revert>" : "__tmp_contexts", 630 "<test_context_static>" : "__tmp_contexts", 631 "<set_context>" : "__tmp_contexts", 632 "<set_private_context>" : "__tmp_private_context", 633 "<set_accessor>" : "__tmp_value", 634 "<set_target_accessor>" : "__tmp_target_value", 635 } 636 637 self.op_subs = { 638 "<context>" : "__get_context", 639 "<test_context_revert>" : "__test_context_revert", 640 "<test_context_static>" : "__test_context_static", 641 "<set_context>" : "__set_context", 642 "<set_private_context>" : "__set_private_context", 643 "<set_accessor>" : "__set_accessor", 644 "<set_target_accessor>" : "__set_target_accessor", 645 } 646 647 def get_referenced_attributes(self, location): 648 649 """ 650 Convert 'location' to the form used by the deducer and retrieve any 651 identified attributes. 652 """ 653 654 # Determine whether any deduced references refer to the accessed 655 # attribute. 656 657 attrnames = location.attrnames 658 attrnames = attrnames and attrnames.split(".") 659 remaining = attrnames and len(attrnames) > 1 660 661 access_location = self.deducer.const_accesses.get(location) 662 663 if remaining and not access_location: 664 return [] 665 666 refs = [] 667 l = self.deducer.referenced_attrs.get(access_location or location) 668 if l: 669 for attrtype, objpath, attr in l: 670 refs.append(attr) 671 return refs 672 673 def get_referenced_attribute_invocations(self, location): 674 675 """ 676 Convert 'location' to the form used by the deducer and retrieve any 677 identified attribute invocation details. 678 """ 679 680 access_location = self.deducer.const_accesses.get(location) 681 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 682 683 def get_accessor_kinds(self, location): 684 685 "Return the accessor kinds for 'location'." 686 687 return self.deducer.accessor_kinds.get(location) 688 689 def get_access_location(self, name, attrnames=None): 690 691 """ 692 Using the current namespace, the given 'name', and the 'attrnames' 693 employed in an access, return the access location. 694 """ 695 696 path = self.get_path_for_access() 697 698 # Get the location used by the deducer and optimiser and find any 699 # recorded access. 700 701 attrnames = attrnames and ".".join(self.attrs) 702 access_number = self.get_access_number(path, name, attrnames) 703 self.update_access_number(path, name, attrnames) 704 return AccessLocation(path, name, attrnames, access_number) 705 706 def get_access_number(self, path, name, attrnames): 707 access = name, attrnames 708 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 709 return self.attr_accesses[path][access] 710 else: 711 return 0 712 713 def update_access_number(self, path, name, attrnames): 714 access = name, attrnames 715 if name: 716 init_item(self.attr_accesses, path, dict) 717 init_item(self.attr_accesses[path], access, lambda: 0) 718 self.attr_accesses[path][access] += 1 719 720 def get_accessor_location(self, name): 721 722 """ 723 Using the current namespace and the given 'name', return the accessor 724 location. 725 """ 726 727 path = self.get_path_for_access() 728 729 # Get the location used by the deducer and optimiser and find any 730 # recorded accessor. 731 732 version = self.get_accessor_number(path, name) 733 self.update_accessor_number(path, name) 734 return Location(path, name, None, version) 735 736 def get_accessor_number(self, path, name): 737 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 738 return self.attr_accessors[path][name] 739 else: 740 return 0 741 742 def update_accessor_number(self, path, name): 743 if name: 744 init_item(self.attr_accessors, path, dict) 745 init_item(self.attr_accessors[path], name, lambda: 0) 746 self.attr_accessors[path][name] += 1 747 748 def process_class_node(self, n): 749 750 "Process the given class node 'n'." 751 752 class_name = self.get_object_path(n.name) 753 754 # Where a class is set conditionally or where the name may refer to 755 # different values, assign the name. 756 757 ref = self.importer.identify(class_name) 758 759 if not ref.static(): 760 self.process_assignment_for_object(n.name, 761 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 762 763 self.enter_namespace(n.name) 764 765 if self.have_object(): 766 self.write_comment("Class: %s" % class_name) 767 768 self.initialise_inherited_members(class_name) 769 770 self.process_structure(n) 771 self.write_comment("End class: %s" % class_name) 772 773 self.exit_namespace() 774 775 def initialise_inherited_members(self, class_name): 776 777 "Initialise members of 'class_name' inherited from its ancestors." 778 779 for name, path in self.importer.all_class_attrs[class_name].items(): 780 target = "%s.%s" % (class_name, name) 781 782 # Ignore attributes with definitions. 783 784 ref = self.importer.identify(target) 785 if ref: 786 continue 787 788 # Ignore special type attributes. 789 790 if is_type_attribute(name): 791 continue 792 793 # Reference inherited attributes. 794 795 ref = self.importer.identify(path) 796 if ref and not ref.static(): 797 parent, attrname = path.rsplit(".", 1) 798 799 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 800 encode_path(class_name), name, 801 encode_path(parent), attrname 802 )) 803 804 def process_from_node(self, n): 805 806 "Process the given node 'n', importing from another module." 807 808 path = self.get_namespace_path() 809 810 # Attempt to obtain the referenced objects. 811 812 for name, alias in n.names: 813 if name == "*": 814 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 815 816 # Obtain the path of the assigned name. 817 818 objpath = self.get_object_path(alias or name) 819 820 # Obtain the identity of the name. 821 822 ref = self.importer.identify(objpath) 823 824 # Where the name is not static, assign the value. 825 826 if ref and not ref.static() and ref.get_name(): 827 self.writestmt("%s;" % 828 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 829 expr=TrResolvedNameRef(name, ref))) 830 831 def process_function_body_node(self, n): 832 833 """ 834 Process the given function, lambda, if expression or list comprehension 835 node 'n', generating the body. 836 """ 837 838 function_name = self.get_namespace_path() 839 self.start_function(function_name) 840 841 # Process the function body. 842 843 in_conditional = self.in_conditional 844 self.in_conditional = False 845 self.function_target = 0 846 self.max_function_target = 0 847 self.context_index = 0 848 self.max_context_index = 0 849 850 # Volatile locals for exception handling. 851 852 self.volatile_locals = set() 853 854 # Process any guards defined for the parameters. 855 856 for name in self.importer.function_parameters.get(function_name): 857 self.generate_guard(name) 858 859 # Also support self in methods, since some mix-in methods may only work 860 # with certain descendant classes. 861 862 if self.in_method(): 863 self.generate_guard("self") 864 865 # Make assignments for .name entries in the parameters, provided this is 866 # a method. 867 868 if self.in_method(): 869 for name in self.importer.function_attr_initialisers.get(function_name) or []: 870 self.process_assignment_node( 871 compiler.ast.AssAttr(compiler.ast.Name("self"), name, "OP_ASSIGN"), 872 compiler.ast.Name(name)) 873 874 # Produce the body and any additional return statement. 875 876 expr = self.process_structure_node(n.code) or \ 877 self.in_method() and \ 878 function_name.rsplit(".", 1)[-1] == "__init__" and \ 879 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 880 PredefinedConstantRef("None") 881 882 if not isinstance(expr, ReturnRef): 883 self.writestmt("return %s;" % expr) 884 885 self.in_conditional = in_conditional 886 887 self.end_function(function_name) 888 889 def generate_guard(self, name): 890 891 """ 892 Get the accessor details for 'name', found in the current namespace, and 893 generate any guards defined for it. 894 """ 895 896 # Obtain the location, keeping track of assignment versions. 897 898 location = self.get_accessor_location(name) 899 test = self.deducer.accessor_guard_tests.get(location) 900 901 # Generate any guard from the deduced information. 902 903 if test: 904 guard, guard_type = test 905 906 if guard == "specific": 907 ref = first(self.deducer.accessor_all_types[location]) 908 argstr = "&%s" % encode_path(ref.get_origin()) 909 elif guard == "common": 910 ref = first(self.deducer.accessor_all_general_types[location]) 911 argstr = encode_path(encode_type_attribute(ref.get_origin())) 912 else: 913 return 914 915 # Write a test that raises a TypeError upon failure. 916 917 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 918 guard, guard_type, encode_path(name), argstr)) 919 920 def process_function_node(self, n): 921 922 """ 923 Process the given function, lambda, if expression or list comprehension 924 node 'n', generating any initialisation statements. 925 """ 926 927 # Where a function is declared conditionally, use a separate name for 928 # the definition, and assign the definition to the stated name. 929 930 original_name = n.name 931 932 if self.in_conditional or self.in_function: 933 name = self.get_lambda_name() 934 else: 935 name = n.name 936 937 objpath = self.get_object_path(name) 938 939 # Obtain details of the defaults. 940 941 defaults = self.process_function_defaults(n, name, objpath) 942 if defaults: 943 for default in defaults: 944 self.writeline("%s;" % default) 945 946 # Where a function is set conditionally or where the name may refer to 947 # different values, assign the name. 948 949 ref = self.importer.identify(objpath) 950 951 if self.in_conditional or self.in_function: 952 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 953 elif not ref.static(): 954 context = self.is_method(objpath) 955 956 self.process_assignment_for_object(original_name, 957 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 958 959 def process_function_defaults(self, n, name, objpath, instance_name=None): 960 961 """ 962 Process the given function or lambda node 'n', initialising defaults 963 that are dynamically set. The given 'name' indicates the name of the 964 function. The given 'objpath' indicates the origin of the function. 965 The given 'instance_name' indicates the name of any separate instance 966 of the function created to hold the defaults. 967 968 Return a list of operations setting defaults on a function instance. 969 """ 970 971 function_name = self.get_object_path(name) 972 function_defaults = self.importer.function_defaults.get(function_name) 973 if not function_defaults: 974 return None 975 976 # Determine whether any unidentified defaults are involved. 977 978 for argname, default in function_defaults: 979 if not default.static(): 980 break 981 else: 982 return None 983 984 # Handle bound methods. 985 986 if not instance_name: 987 instance_name = "&%s" % encode_path(objpath) 988 else: 989 instance_name = "__VALUE(%s)" % instance_name 990 991 # Where defaults are involved but cannot be identified, obtain a new 992 # instance of the lambda and populate the defaults. 993 994 defaults = [] 995 996 # Join the original defaults with the inspected defaults. 997 998 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 999 1000 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 1001 1002 # Obtain any reference for the default. 1003 1004 if original: 1005 argname, default = original 1006 name_ref = self.process_structure_node(default) 1007 elif inspected: 1008 argname, default = inspected 1009 name_ref = TrResolvedNameRef(argname, default) 1010 else: 1011 continue 1012 1013 # Generate default initialisers except when constants are employed. 1014 # Constants should be used when populating the function structures. 1015 1016 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1017 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1018 1019 return defaults 1020 1021 def process_if_node(self, n): 1022 1023 """ 1024 Process the given "if" node 'n'. 1025 """ 1026 1027 first = True 1028 for test, body in n.tests: 1029 test_ref = self.process_structure_node(test) 1030 self.start_if(first, test_ref) 1031 1032 in_conditional = self.in_conditional 1033 self.in_conditional = True 1034 self.process_structure_node(body) 1035 self.in_conditional = in_conditional 1036 1037 self.end_if() 1038 first = False 1039 1040 if n.else_: 1041 self.start_else() 1042 self.process_structure_node(n.else_) 1043 self.end_else() 1044 1045 print >>self.out 1046 1047 def process_invocation_node(self, n): 1048 1049 "Process the given invocation node 'n'." 1050 1051 # Process the expression. 1052 1053 expr = self.process_structure_node(n.node) 1054 1055 # Obtain details of the invocation expression. 1056 1057 objpath = expr.get_origin() 1058 location = expr.access_location() 1059 refs = expr.references() 1060 1061 # Identified target details. 1062 1063 target = None 1064 target_structure = None 1065 1066 # Specific function target information. 1067 1068 function = None 1069 1070 # Instantiation involvement. 1071 1072 instantiation = False 1073 literal_instantiation = False 1074 1075 # Invocation requirements. 1076 1077 context_required = True 1078 have_access_context = isinstance(expr, AttrResult) 1079 context_identity = have_access_context and expr.context() 1080 context_verified = have_access_context and expr.context_verified() 1081 tests_accessor = have_access_context and expr.tests_accessor() 1082 parameters = None 1083 num_parameters = None 1084 num_defaults = None 1085 1086 # Obtain details of the callable and of its parameters. 1087 1088 # Literals may be instantiated specially. 1089 1090 if expr.is_name() and expr.name.startswith("$L") and objpath: 1091 instantiation = literal_instantiation = objpath 1092 target = encode_literal_instantiator(objpath) 1093 context_required = False 1094 1095 # Identified targets employ function pointers directly. 1096 1097 elif objpath: 1098 parameters = self.importer.function_parameters.get(objpath) 1099 function_defaults = self.importer.function_defaults.get(objpath) 1100 num_parameters = parameters and len(parameters) or 0 1101 num_defaults = function_defaults and len(function_defaults) or 0 1102 1103 # Class invocation involves instantiators. 1104 1105 if expr.has_kind("<class>"): 1106 instantiation = objpath 1107 target = encode_instantiator_pointer(objpath) 1108 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1109 target_structure = "&%s" % encode_path(init_ref) 1110 context_required = False 1111 1112 # Only plain functions and bound methods employ function pointers. 1113 1114 elif expr.has_kind("<function>"): 1115 function = objpath 1116 1117 # Test for functions and methods. 1118 1119 context_required = self.is_method(objpath) 1120 1121 accessor_kinds = location and self.get_accessor_kinds(location) 1122 1123 instance_accessor = accessor_kinds and \ 1124 len(accessor_kinds) == 1 and \ 1125 first(accessor_kinds) == "<instance>" 1126 1127 # Only identify certain bound methods or functions. 1128 1129 if not context_required or instance_accessor: 1130 target = encode_function_pointer(objpath) 1131 1132 # Access bound method defaults even if it is not clear whether 1133 # the accessor is appropriate. 1134 1135 target_structure = "&%s" % encode_path(objpath) 1136 1137 # Other targets are retrieved at run-time. 1138 1139 else: 1140 if location: 1141 attrnames = location.attrnames 1142 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1143 1144 # Determine common aspects of any identifiable targets. 1145 1146 if attrname or refs: 1147 all_params = set() 1148 all_defaults = set() 1149 min_params = set() 1150 max_params = set() 1151 1152 # Employ references from the expression or find all 1153 # possible attributes for the given attribute name. 1154 1155 refs = refs or self.get_attributes_for_attrname(attrname) 1156 1157 # Obtain parameters and defaults for each possible target. 1158 1159 for ref in refs: 1160 origin = ref.get_origin() 1161 params = self.importer.function_parameters.get(origin) 1162 1163 defaults = self.importer.function_defaults.get(origin) 1164 if defaults is not None: 1165 all_defaults.add(tuple(defaults)) 1166 1167 if params is not None: 1168 all_params.add(tuple(params)) 1169 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1170 max_params.add(len(params)) 1171 else: 1172 refs = set() 1173 break 1174 1175 # Where the parameters and defaults are always the same, 1176 # permit populating them in advance. 1177 1178 if refs: 1179 if self.uses_keyword_arguments(n): 1180 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1181 parameters = first(all_params) 1182 function_defaults = all_defaults and first(all_defaults) or [] 1183 num_parameters = parameters and len(parameters) or 0 1184 num_defaults = function_defaults and len(function_defaults) or 0 1185 else: 1186 if len(min_params) == 1 and len(max_params) == 1: 1187 num_parameters = first(max_params) 1188 num_defaults = first(max_params) - first(min_params) 1189 1190 # Some information about the target may be available and be used to 1191 # provide warnings about argument compatibility. 1192 1193 if self.importer.give_warning("args"): 1194 unsuitable = self.get_referenced_attribute_invocations(location) 1195 1196 if unsuitable: 1197 for ref in unsuitable: 1198 _objpath = ref.get_origin() 1199 print >>sys.stderr, \ 1200 "In %s, at line %d, inappropriate number of " \ 1201 "arguments given. Need %d arguments to call %s." % ( 1202 self.get_namespace_path(), n.lineno, 1203 len(self.importer.function_parameters[_objpath]), 1204 _objpath) 1205 1206 # Logical statement about available parameter information. 1207 1208 known_parameters = num_parameters is not None 1209 1210 # The source of context information: target or temporary. 1211 1212 need_context_target = context_required and not have_access_context 1213 1214 need_context_stored = context_required and context_identity and \ 1215 context_identity.startswith("__get_context") 1216 1217 # Determine any readily-accessible target identity. 1218 1219 target_named = expr.is_name() and str(expr) or None 1220 target_identity = target or target_named 1221 1222 # Use of target information to populate defaults. 1223 1224 defaults_target_var = not (parameters and function_defaults is not None) and \ 1225 known_parameters and len(n.args) < num_parameters 1226 1227 # Use of a temporary target variable in these situations: 1228 # 1229 # A target provided by an expression needed for defaults. 1230 # 1231 # A target providing the context but not using a name to do so. 1232 # 1233 # A target expression involving the definition of a context which may 1234 # then be evaluated and stored to ensure that the context is available 1235 # during argument evaluation. 1236 # 1237 # An expression featuring an accessor test. 1238 1239 need_target_stored = defaults_target_var and not target_identity or \ 1240 need_context_target and not target_identity or \ 1241 need_context_stored or \ 1242 tests_accessor and not target 1243 1244 # Define stored target details. 1245 1246 target_stored = "__tmp_targets[%d]" % self.function_target 1247 target_var = need_target_stored and target_stored or target_identity 1248 1249 if need_target_stored: 1250 self.record_temp("__tmp_targets") 1251 1252 if need_context_stored: 1253 self.record_temp("__tmp_contexts") 1254 1255 # Arguments are presented in a temporary frame array with any context 1256 # always being the first argument. Where it would be unused, it may be 1257 # set to null. 1258 1259 if context_required: 1260 if have_access_context: 1261 args = [context_identity] 1262 else: 1263 args = ["__CONTEXT_AS_VALUE(%s)" % target_var] 1264 else: 1265 args = ["__NULL"] 1266 1267 # Complete the array with null values, permitting tests for a complete 1268 # set of arguments. 1269 1270 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1271 kwcodes = [] 1272 kwargs = [] 1273 1274 # Any invocations in the arguments will store target details in a 1275 # different location. 1276 1277 function_target = self.function_target 1278 context_index = self.context_index 1279 1280 if need_target_stored: 1281 self.next_target() 1282 1283 if need_context_stored: 1284 self.next_context() 1285 1286 for i, arg in enumerate(n.args): 1287 argexpr = self.process_structure_node(arg) 1288 1289 # Store a keyword argument, either in the argument list or 1290 # in a separate keyword argument list for subsequent lookup. 1291 1292 if isinstance(arg, compiler.ast.Keyword): 1293 1294 # With knowledge of the target, store the keyword 1295 # argument directly. 1296 1297 if parameters: 1298 try: 1299 argnum = parameters.index(arg.name) 1300 except ValueError: 1301 raise TranslateError("Argument %s is not recognised." % arg.name, 1302 self.get_namespace_path(), n) 1303 args[argnum+1] = str(argexpr) 1304 1305 # Otherwise, store the details in a separate collection. 1306 1307 else: 1308 kwargs.append(str(argexpr)) 1309 kwcodes.append("{%s, %s}" % ( 1310 encode_ppos(arg.name), encode_pcode(arg.name))) 1311 1312 # Store non-keyword arguments in the argument list, rejecting 1313 # superfluous arguments. 1314 1315 else: 1316 try: 1317 args[i+1] = str(argexpr) 1318 except IndexError: 1319 raise TranslateError("Too many arguments specified.", 1320 self.get_namespace_path(), n) 1321 1322 # Reference the current target again. 1323 1324 self.function_target = function_target 1325 self.context_index = context_index 1326 1327 # Defaults are added to the frame where arguments are missing. 1328 1329 if parameters and function_defaults is not None: 1330 1331 # Visit each default and set any missing arguments. Where keyword 1332 # arguments have been used, the defaults must be inspected and, if 1333 # necessary, inserted into gaps in the argument list. 1334 1335 for i, (argname, default) in enumerate(function_defaults): 1336 argnum = parameters.index(argname) 1337 if not args[argnum+1]: 1338 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1339 1340 elif known_parameters: 1341 1342 # No specific parameter details are provided, but no keyword 1343 # arguments are used. Thus, defaults can be supplied using position 1344 # information only. 1345 1346 i = len(n.args) 1347 pos = i - (num_parameters - num_defaults) 1348 while i < num_parameters: 1349 args[i+1] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1350 i += 1 1351 pos += 1 1352 1353 # Test for missing arguments. 1354 1355 if None in args: 1356 raise TranslateError("Not all arguments supplied.", 1357 self.get_namespace_path(), n) 1358 1359 # Encode the arguments. 1360 1361 # Where literal instantiation is occurring, add an argument indicating 1362 # the number of values. The context is excluded. 1363 1364 if literal_instantiation: 1365 argstr = "%d, %s" % (len(args) - 1, ", ".join(args[1:])) 1366 else: 1367 argstr = ", ".join(args) 1368 1369 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1370 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1371 1372 # First, the invocation expression is presented. 1373 1374 stages = [] 1375 emit = stages.append 1376 1377 # Assign and yield any stored target. 1378 # The context may be set in the expression. 1379 1380 if need_target_stored: 1381 emit("%s = %s" % (target_var, expr)) 1382 target_expr = target_var 1383 1384 # Otherwise, retain the expression for later use. 1385 1386 else: 1387 target_expr = str(expr) 1388 1389 # Any specific callable is then obtained for invocation. 1390 1391 if target: 1392 1393 # An expression involving a test of the accessor providing the target. 1394 # This must be emitted in order to perform the test. 1395 1396 if tests_accessor: 1397 emit(str(expr)) 1398 1399 emit(target) 1400 1401 # Methods accessed via unidentified accessors are obtained for 1402 # invocation. 1403 1404 elif function: 1405 if context_required: 1406 if have_access_context: 1407 if context_verified: 1408 emit("__get_function_member(%s)" % target_expr) 1409 else: 1410 emit("__get_function(%s, %s)" % ( 1411 context_identity, target_expr)) 1412 else: 1413 emit("__get_function(__CONTEXT_AS_VALUE(%s), %s)" % ( 1414 target_var, target_expr)) 1415 else: 1416 emit("_get_function_member(%s)" % target_expr) 1417 1418 # With known parameters, the target can be tested. 1419 1420 elif known_parameters: 1421 context_arg = context_required and args[0] or "__NULL" 1422 if self.always_callable(refs): 1423 if context_verified: 1424 emit("__get_function_member(%s)" % target_expr) 1425 else: 1426 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1427 else: 1428 emit("__check_and_get_function(%s, %s)" % (context_arg, target_expr)) 1429 1430 # With a known target, the function is obtained directly and called. 1431 # By putting the invocation at the end of the final element in the 1432 # instruction sequence (the stages), the result becomes the result of 1433 # the sequence. Moreover, the parameters become part of the sequence 1434 # and thereby participate in a guaranteed evaluation order. 1435 1436 if target or function or known_parameters: 1437 stages[-1] += "(%s)" % argstr 1438 if instantiation: 1439 return InstantiationResult(instantiation, stages) 1440 else: 1441 return InvocationResult(stages) 1442 1443 # With unknown targets, the generic invocation function is applied to 1444 # the callable and argument collections. 1445 1446 else: 1447 emit("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1448 target_expr, 1449 self.always_callable(refs) and 1 or 0, 1450 len(kwargs), kwcodestr, kwargstr, 1451 len(args), "__ARGS(%s)" % argstr)) 1452 return InvocationResult(stages) 1453 1454 def next_target(self): 1455 1456 "Allocate the next function target storage." 1457 1458 self.function_target += 1 1459 self.max_function_target = max(self.function_target, self.max_function_target) 1460 1461 def next_context(self): 1462 1463 "Allocate the next context value storage." 1464 1465 self.context_index += 1 1466 self.max_context_index = max(self.context_index, self.max_context_index) 1467 1468 def always_callable(self, refs): 1469 1470 "Determine whether all 'refs' are callable." 1471 1472 if not refs: 1473 return False 1474 1475 for ref in refs: 1476 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1477 return False 1478 1479 return True 1480 1481 def need_default_arguments(self, objpath, nargs): 1482 1483 """ 1484 Return whether any default arguments are needed when invoking the object 1485 given by 'objpath'. 1486 """ 1487 1488 parameters = self.importer.function_parameters.get(objpath) 1489 return nargs < len(parameters) 1490 1491 def uses_keyword_arguments(self, n): 1492 1493 "Return whether invocation node 'n' uses keyword arguments." 1494 1495 for arg in enumerate(n.args): 1496 if isinstance(arg, compiler.ast.Keyword): 1497 return True 1498 1499 return False 1500 1501 def get_attributes_for_attrname(self, attrname): 1502 1503 "Return a set of all attributes exposed by 'attrname'." 1504 1505 usage = [(attrname, True, False)] 1506 class_types = self.deducer.get_class_types_for_usage(usage) 1507 instance_types = self.deducer.get_instance_types_for_usage(usage) 1508 module_types = self.deducer.get_module_types_for_usage(usage) 1509 attrs = set() 1510 1511 for ref in combine_types(class_types, instance_types, module_types): 1512 attrs.update(self.importer.get_attributes(ref, attrname)) 1513 1514 return attrs 1515 1516 def process_lambda_node(self, n): 1517 1518 "Process the given lambda node 'n'." 1519 1520 name = self.get_lambda_name() 1521 function_name = self.get_object_path(name) 1522 1523 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1524 1525 # Without defaults, produce an attribute referring to the function. 1526 1527 if not defaults: 1528 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1529 1530 # With defaults, copy the function structure and set the defaults on the 1531 # copy. 1532 1533 else: 1534 self.record_temp("__tmp_value") 1535 return make_expression("(__tmp_value = __ATTRVALUE(__COPY(&%s, sizeof(%s))), %s, __tmp_value)" % ( 1536 encode_path(function_name), 1537 encode_symbol("obj", function_name), 1538 ", ".join(defaults))) 1539 1540 def process_logical_node(self, n): 1541 1542 "Process the given operator node 'n'." 1543 1544 self.record_temp("__tmp_result") 1545 1546 conjunction = isinstance(n, compiler.ast.And) 1547 results = [] 1548 1549 for node in n.nodes: 1550 results.append(self.process_structure_node(node)) 1551 1552 return LogicalOperationResult(results, conjunction) 1553 1554 def process_name_node(self, n, expr=None): 1555 1556 "Process the given name node 'n' with the optional assignment 'expr'." 1557 1558 # Determine whether the name refers to a static external entity. 1559 1560 if n.name in predefined_constants: 1561 return PredefinedConstantRef(n.name, expr) 1562 1563 # Convert literal references, operator function names, and print 1564 # function names to references. 1565 1566 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1567 n.name.startswith("$print"): 1568 1569 ref, paths = self.importer.get_module(self.name).special[n.name] 1570 return TrResolvedNameRef(n.name, ref) 1571 1572 # Get the appropriate name for the name reference, using the same method 1573 # as in the inspector. 1574 1575 path = self.get_namespace_path() 1576 objpath = self.get_object_path(n.name) 1577 1578 # Determine any assigned globals. 1579 1580 globals = self.importer.get_module(self.name).scope_globals.get(path) 1581 1582 # Explicitly declared globals. 1583 1584 if globals and n.name in globals: 1585 objpath = self.get_global_path(n.name) 1586 is_global = True 1587 1588 # Implicitly referenced globals in functions. 1589 1590 elif self.in_function: 1591 is_global = n.name not in self.importer.function_locals[path] 1592 1593 # Implicitly referenced globals elsewhere. 1594 1595 else: 1596 namespace = self.importer.identify(path) 1597 is_global = not self.importer.get_attributes(namespace, n.name) 1598 1599 # Get the static identity of the name. 1600 1601 ref = self.importer.identify(objpath) 1602 if ref and not ref.get_name(): 1603 ref = ref.alias(objpath) 1604 1605 # Obtain any resolved names for non-assignment names. 1606 1607 if not expr and not ref and self.in_function: 1608 locals = self.importer.function_locals.get(path) 1609 ref = locals and locals.get(n.name) 1610 1611 # Find any invocation or alias details. 1612 1613 name = self.get_name_for_tracking(n.name, is_global=is_global) 1614 location = not expr and self.get_access_location(name) or None 1615 1616 # Mark any local assignments as volatile in exception blocks. 1617 1618 if expr and self.in_function and not is_global and self.in_try_except: 1619 self.make_volatile(n.name) 1620 1621 # Qualified names are used for resolved static references or for 1622 # static namespace members. The reference should be configured to return 1623 # such names. 1624 1625 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1626 location=location) 1627 return not expr and self.get_aliases(name_ref) or name_ref 1628 1629 def get_aliases(self, name_ref): 1630 1631 "Return alias references for the given 'name_ref'." 1632 1633 location = name_ref.access_location() 1634 accessor_locations = self.deducer.access_index.get(location) 1635 1636 if not accessor_locations: 1637 return None 1638 1639 refs = set() 1640 1641 for accessor_location in accessor_locations: 1642 alias_refs = self.deducer.referenced_objects.get(accessor_location) 1643 if alias_refs: 1644 refs.update(alias_refs) 1645 1646 if refs: 1647 return AliasResult(name_ref, refs, location) 1648 else: 1649 return None 1650 1651 def make_volatile(self, name): 1652 1653 "Record 'name' as volatile in the current namespace." 1654 1655 self.volatile_locals.add(name) 1656 1657 def process_not_node(self, n): 1658 1659 "Process the given operator node 'n'." 1660 1661 return self.make_negation(self.process_structure_node(n.expr)) 1662 1663 def process_raise_node(self, n): 1664 1665 "Process the given raise node 'n'." 1666 1667 # NOTE: Determine which raise statement variants should be permitted. 1668 1669 if n.expr1: 1670 1671 # Names with accompanying arguments are treated like invocations. 1672 1673 if n.expr2: 1674 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1675 exc = self.process_structure_node(call) 1676 self.writestmt("__Raise(%s);" % exc) 1677 1678 # Raise instances, testing the kind at run-time if necessary and 1679 # instantiating any non-instance. 1680 1681 else: 1682 exc = self.process_structure_node(n.expr1) 1683 1684 if isinstance(exc, TrInstanceRef): 1685 self.writestmt("__Raise(%s);" % exc) 1686 else: 1687 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1688 else: 1689 self.writestmt("__Throw(__tmp_exc);") 1690 1691 def process_return_node(self, n): 1692 1693 "Process the given return node 'n'." 1694 1695 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1696 if self.in_try_finally or self.in_try_except: 1697 self.writestmt("__Return(%s);" % expr) 1698 else: 1699 self.writestmt("return %s;" % expr) 1700 1701 return ReturnRef() 1702 1703 def process_try_node(self, n): 1704 1705 """ 1706 Process the given "try...except" node 'n'. 1707 """ 1708 1709 in_try_except = self.in_try_except 1710 self.in_try_except = True 1711 1712 # Use macros to implement exception handling. 1713 1714 self.writestmt("__Try") 1715 self.writeline("{") 1716 self.indent += 1 1717 self.process_structure_node(n.body) 1718 1719 # Put the else statement in another try block that handles any raised 1720 # exceptions and converts them to exceptions that will not be handled by 1721 # the main handling block. 1722 1723 if n.else_: 1724 self.writestmt("__Try") 1725 self.writeline("{") 1726 self.indent += 1 1727 self.process_structure_node(n.else_) 1728 self.indent -= 1 1729 self.writeline("}") 1730 self.writeline("__Catch (__tmp_exc)") 1731 self.writeline("{") 1732 self.indent += 1 1733 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1734 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1735 self.indent -= 1 1736 self.writeline("}") 1737 1738 # Complete the try block and enter the finally block, if appropriate. 1739 1740 if self.in_try_finally: 1741 self.writestmt("__Complete;") 1742 1743 self.indent -= 1 1744 self.writeline("}") 1745 1746 self.in_try_except = in_try_except 1747 1748 # Handlers are tests within a common handler block. 1749 1750 self.writeline("__Catch (__tmp_exc)") 1751 self.writeline("{") 1752 self.indent += 1 1753 1754 # Introduce an if statement to handle the completion of a try block. 1755 1756 self.process_try_completion() 1757 1758 # Handle exceptions in else blocks converted to __RaiseElse, converting 1759 # them back to normal exceptions. 1760 1761 if n.else_: 1762 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1763 1764 # Exception handling. 1765 1766 for name, var, handler in n.handlers: 1767 1768 # Test for specific exceptions. 1769 1770 if name is not None: 1771 name_ref = self.process_structure_node(name) 1772 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1773 else: 1774 self.writeline("else if (1)") 1775 1776 self.writeline("{") 1777 self.indent += 1 1778 1779 # Establish the local for the handler. 1780 1781 if var is not None: 1782 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1783 1784 if handler is not None: 1785 self.process_structure_node(handler) 1786 1787 self.indent -= 1 1788 self.writeline("}") 1789 1790 # Re-raise unhandled exceptions. 1791 1792 self.writeline("else __Throw(__tmp_exc);") 1793 1794 # End the handler block. 1795 1796 self.indent -= 1 1797 self.writeline("}") 1798 print >>self.out 1799 1800 def process_try_finally_node(self, n): 1801 1802 """ 1803 Process the given "try...finally" node 'n'. 1804 """ 1805 1806 in_try_finally = self.in_try_finally 1807 self.in_try_finally = True 1808 1809 # Use macros to implement exception handling. 1810 1811 self.writestmt("__Try") 1812 self.writeline("{") 1813 self.indent += 1 1814 self.process_structure_node(n.body) 1815 self.indent -= 1 1816 self.writeline("}") 1817 1818 self.in_try_finally = in_try_finally 1819 1820 # Finally clauses handle special exceptions. 1821 1822 self.writeline("__Catch (__tmp_exc)") 1823 self.writeline("{") 1824 self.indent += 1 1825 self.process_structure_node(n.final) 1826 1827 # Introduce an if statement to handle the completion of a try block. 1828 1829 self.process_try_completion() 1830 self.writeline("else __Throw(__tmp_exc);") 1831 1832 self.indent -= 1 1833 self.writeline("}") 1834 print >>self.out 1835 1836 def process_try_completion(self): 1837 1838 "Generate a test for the completion of a try block." 1839 1840 self.writestmt("if (__tmp_exc.completing)") 1841 self.writeline("{") 1842 self.indent += 1 1843 1844 # Do not return anything at the module level. 1845 1846 if self.get_namespace_path() != self.name: 1847 1848 # Only use the normal return statement if no surrounding try blocks 1849 # apply. 1850 1851 if not self.in_try_finally and not self.in_try_except: 1852 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1853 else: 1854 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1855 1856 self.indent -= 1 1857 self.writeline("}") 1858 1859 def process_while_node(self, n): 1860 1861 "Process the given while node 'n'." 1862 1863 self.writeline("while (1)") 1864 self.writeline("{") 1865 self.indent += 1 1866 test = self.process_structure_node(n.test) 1867 1868 # Emit the loop termination condition unless "while <true value>" is 1869 # indicated. 1870 1871 if not (isinstance(test, PredefinedConstantRef) and test.value): 1872 1873 # Emit a negated test of the continuation condition. 1874 1875 self.start_if(True, self.make_negation(test)) 1876 if n.else_: 1877 self.process_structure_node(n.else_) 1878 self.writestmt("break;") 1879 self.end_if() 1880 1881 in_conditional = self.in_conditional 1882 self.in_conditional = True 1883 self.process_structure_node(n.body) 1884 self.in_conditional = in_conditional 1885 1886 self.indent -= 1 1887 self.writeline("}") 1888 print >>self.out 1889 1890 # Special variable usage. 1891 1892 def get_temp_path(self): 1893 1894 """ 1895 Return the appropriate namespace path for temporary names in the current 1896 namespace. 1897 """ 1898 1899 if self.in_function: 1900 return self.get_namespace_path() 1901 else: 1902 return self.name 1903 1904 def record_temp(self, name): 1905 1906 """ 1907 Record the use of the temporary 'name' in the current namespace. At the 1908 class or module level, the temporary name is associated with the module, 1909 since the variable will then be allocated in the module's own main 1910 program. 1911 """ 1912 1913 path = self.get_temp_path() 1914 1915 init_item(self.temp_usage, path, list) 1916 self.temp_usage[path].append(name) 1917 1918 def remove_temps(self, names): 1919 1920 """ 1921 Remove 'names' from temporary storage allocations, each instance 1922 removing each request for storage. 1923 """ 1924 1925 path = self.get_temp_path() 1926 1927 for name in names: 1928 if self.uses_temp(path, name): 1929 self.temp_usage[path].remove(name) 1930 1931 def uses_temp(self, path, name): 1932 1933 """ 1934 Return whether the given namespace 'path' employs a temporary variable 1935 with the given 'name'. Note that 'path' should only be a module or a 1936 function or method, not a class. 1937 """ 1938 1939 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1940 1941 def make_negation(self, expr): 1942 1943 "Return a negated form of 'expr'." 1944 1945 result = NegationResult(expr) 1946 1947 # Negation discards the temporary results of its operand. 1948 1949 temps = expr.discards_temporary() 1950 if temps: 1951 self.remove_temps(temps) 1952 1953 return result 1954 1955 # Output generation. 1956 1957 def start_output(self): 1958 1959 "Write the declarations at the top of each source file." 1960 1961 print >>self.out, """\ 1962 #include "types.h" 1963 #include "exceptions.h" 1964 #include "ops.h" 1965 #include "progconsts.h" 1966 #include "progops.h" 1967 #include "progtypes.h" 1968 #include "main.h" 1969 """ 1970 1971 def start_unit(self): 1972 1973 "Record output within a generated function for later use." 1974 1975 self.out = StringIO() 1976 1977 def end_unit(self): 1978 1979 "Restore the output stream." 1980 1981 out = self.out 1982 self.out = self.out_toplevel 1983 return out 1984 1985 def flush_unit(self, name, out): 1986 1987 "Add declarations and generated code." 1988 1989 self.write_temporaries(name) 1990 print >>self.out 1991 out.seek(0) 1992 self.out.write(out.read()) 1993 1994 def start_module(self): 1995 1996 "Write the start of each module's main function." 1997 1998 print >>self.out, "void __main_%s()" % encode_path(self.name) 1999 print >>self.out, "{" 2000 self.indent += 1 2001 2002 # Define temporary variables, excluded from the module structure itself. 2003 2004 tempnames = [] 2005 2006 for n in self.importer.all_module_attrs[self.name]: 2007 if n.startswith("$t"): 2008 tempnames.append(encode_path(n)) 2009 2010 if tempnames: 2011 tempnames.sort() 2012 self.writeline("__attr %s;" % ", ".join(tempnames)) 2013 2014 self.start_unit() 2015 2016 def end_module(self): 2017 2018 "End each module by closing its main function." 2019 2020 out = self.end_unit() 2021 self.flush_unit(self.name, out) 2022 2023 self.indent -= 1 2024 print >>self.out, "}" 2025 2026 def start_function(self, name): 2027 2028 "Start the function having the given 'name'." 2029 2030 self.indent += 1 2031 2032 self.start_unit() 2033 2034 def end_function(self, name): 2035 2036 "End the function having the given 'name'." 2037 2038 out = self.end_unit() 2039 2040 # Write the signature at the top indentation level. 2041 2042 self.indent -= 1 2043 self.write_parameters(name) 2044 print >>self.out, "{" 2045 2046 # Obtain local names from parameters. 2047 2048 parameters = self.importer.function_parameters[name] 2049 locals = self.importer.function_locals[name].keys() 2050 names = [] 2051 volatile_names = [] 2052 2053 for n in locals: 2054 2055 # Filter out special names and parameters. Note that self is a local 2056 # regardless of whether it originally appeared in the parameters or 2057 # not. 2058 2059 if n.startswith("$l") or n in parameters or n == "self": 2060 continue 2061 if n in self.volatile_locals: 2062 volatile_names.append(encode_path(n)) 2063 else: 2064 names.append(encode_path(n)) 2065 2066 # Emit required local names at the function indentation level. 2067 2068 self.indent += 1 2069 2070 if names: 2071 names.sort() 2072 self.writeline("__attr %s;" % ", ".join(names)) 2073 2074 if volatile_names: 2075 volatile_names.sort() 2076 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2077 2078 self.flush_unit(name, out) 2079 2080 self.indent -= 1 2081 print >>self.out, "}" 2082 print >>self.out 2083 2084 def write_parameters(self, name): 2085 2086 """ 2087 For the function having the given 'name', write definitions of 2088 parameters found in the arguments array. 2089 """ 2090 2091 # Generate any self reference. 2092 2093 l = [] 2094 2095 if self.is_method(name): 2096 l.append("__attr self") 2097 else: 2098 l.append("__attr __self") 2099 2100 # Generate aliases for the parameters. 2101 2102 for parameter in self.importer.function_parameters[name]: 2103 l.append("%s__attr %s" % ( 2104 parameter in self.volatile_locals and "volatile " or "", 2105 encode_path(parameter))) 2106 2107 self.writeline("__attr %s(%s)" % ( 2108 encode_function_pointer(name), ", ".join(l))) 2109 2110 def write_temporaries(self, name): 2111 2112 "Write temporary storage employed by 'name'." 2113 2114 # Provide space for the given number of targets. 2115 2116 targets = self.max_function_target 2117 2118 if self.uses_temp(name, "__tmp_targets"): 2119 self.writeline("__attr __tmp_targets[%d];" % targets) 2120 2121 index = self.max_context_index 2122 2123 if self.uses_temp(name, "__tmp_contexts"): 2124 self.writeline("__attr __tmp_contexts[%d];" % index) 2125 2126 # Add temporary variable usage details. 2127 2128 if self.uses_temp(name, "__tmp_private_context"): 2129 self.writeline("__attr __tmp_private_context;") 2130 if self.uses_temp(name, "__tmp_value"): 2131 self.writeline("__attr __tmp_value;") 2132 if self.uses_temp(name, "__tmp_target_value"): 2133 self.writeline("__attr __tmp_target_value;") 2134 if self.uses_temp(name, "__tmp_result"): 2135 self.writeline("__attr __tmp_result;") 2136 2137 module = self.importer.get_module(self.name) 2138 2139 if name in module.exception_namespaces: 2140 self.writeline("__exc __tmp_exc;") 2141 2142 def start_if(self, first, test_ref): 2143 statement = "%sif" % (not first and "else " or "") 2144 2145 # Consume logical results directly. 2146 2147 if isinstance(test_ref, LogicalResult): 2148 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2149 temps = test_ref.discards_temporary() 2150 if temps: 2151 self.remove_temps(temps) 2152 else: 2153 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2154 2155 self.writeline("{") 2156 self.indent += 1 2157 2158 def end_if(self): 2159 self.indent -= 1 2160 self.writeline("}") 2161 2162 def start_else(self): 2163 self.writeline("else") 2164 self.writeline("{") 2165 self.indent += 1 2166 2167 def end_else(self): 2168 self.indent -= 1 2169 self.writeline("}") 2170 2171 def statement(self, expr): 2172 s = str(expr) 2173 if s: 2174 self.writestmt("%s;" % s) 2175 2176 def statements(self, results): 2177 for result in results: 2178 self.statement(result) 2179 2180 def writeline(self, s): 2181 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2182 2183 def writestmt(self, s): 2184 self.writeline(s) 2185 2186 def write_comment(self, s): 2187 self.writestmt("/* %s */" % s) 2188 2189 def pad(self, extra=0): 2190 return (self.indent + extra) * self.tabstop 2191 2192 def indenttext(self, s, levels): 2193 lines = s.split("\n") 2194 out = [lines[0]] 2195 for line in lines[1:]: 2196 out.append(levels * self.tabstop + line) 2197 if line.endswith("("): 2198 levels += 1 2199 elif line.startswith(")"): 2200 levels -= 1 2201 return "\n".join(out) 2202 2203 # vim: tabstop=4 expandtab shiftwidth=4