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 refs = set([self.importer.identify(final_identity)]) 605 606 del self.attrs[0] 607 return AttrResult(output, refs, location, context_identity, context_identity_verified, accessor_test) 608 609 def init_substitutions(self): 610 611 """ 612 Initialise substitutions, defining temporary variable mappings, some of 613 which are also used as substitutions, together with operation mappings 614 used as substitutions in instructions defined by the optimiser. 615 """ 616 617 self.temp_subs = { 618 619 # Substitutions used by instructions. 620 621 "<private_context>" : "__tmp_private_context", 622 "<accessor>" : "__tmp_value", 623 "<target_accessor>" : "__tmp_target_value", 624 625 # Mappings to be replaced by those given below. 626 627 "<context>" : "__tmp_contexts", 628 "<test_context_revert>" : "__tmp_contexts", 629 "<test_context_static>" : "__tmp_contexts", 630 "<set_context>" : "__tmp_contexts", 631 "<set_private_context>" : "__tmp_private_context", 632 "<set_accessor>" : "__tmp_value", 633 "<set_target_accessor>" : "__tmp_target_value", 634 } 635 636 self.op_subs = { 637 "<context>" : "__get_context", 638 "<test_context_revert>" : "__test_context_revert", 639 "<test_context_static>" : "__test_context_static", 640 "<set_context>" : "__set_context", 641 "<set_private_context>" : "__set_private_context", 642 "<set_accessor>" : "__set_accessor", 643 "<set_target_accessor>" : "__set_target_accessor", 644 } 645 646 def get_referenced_attributes(self, location): 647 648 """ 649 Convert 'location' to the form used by the deducer and retrieve any 650 identified attributes. 651 """ 652 653 # Determine whether any deduced references refer to the accessed 654 # attribute. 655 656 attrnames = location.attrnames 657 attrnames = attrnames and attrnames.split(".") 658 remaining = attrnames and len(attrnames) > 1 659 660 access_location = self.deducer.const_accesses.get(location) 661 662 if remaining and not access_location: 663 return set() 664 665 return self.deducer.get_references_for_access(access_location or location) 666 667 def get_referenced_attribute_invocations(self, location): 668 669 """ 670 Convert 'location' to the form used by the deducer and retrieve any 671 identified attribute invocation details. 672 """ 673 674 access_location = self.deducer.const_accesses.get(location) 675 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 676 677 def get_accessor_kinds(self, location): 678 679 "Return the accessor kinds for 'location'." 680 681 return self.deducer.accessor_kinds.get(location) 682 683 def get_access_location(self, name, attrnames=None): 684 685 """ 686 Using the current namespace, the given 'name', and the 'attrnames' 687 employed in an access, return the access location. 688 """ 689 690 path = self.get_path_for_access() 691 692 # Get the location used by the deducer and optimiser and find any 693 # recorded access. 694 695 attrnames = attrnames and ".".join(self.attrs) 696 access_number = self.get_access_number(path, name, attrnames) 697 self.update_access_number(path, name, attrnames) 698 return AccessLocation(path, name, attrnames, access_number) 699 700 def get_access_number(self, path, name, attrnames): 701 access = name, attrnames 702 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 703 return self.attr_accesses[path][access] 704 else: 705 return 0 706 707 def update_access_number(self, path, name, attrnames): 708 access = name, attrnames 709 if name: 710 init_item(self.attr_accesses, path, dict) 711 init_item(self.attr_accesses[path], access, lambda: 0) 712 self.attr_accesses[path][access] += 1 713 714 def get_accessor_location(self, name): 715 716 """ 717 Using the current namespace and the given 'name', return the accessor 718 location. 719 """ 720 721 path = self.get_path_for_access() 722 723 # Get the location used by the deducer and optimiser and find any 724 # recorded accessor. 725 726 version = self.get_accessor_number(path, name) 727 self.update_accessor_number(path, name) 728 return Location(path, name, None, version) 729 730 def get_accessor_number(self, path, name): 731 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 732 return self.attr_accessors[path][name] 733 else: 734 return 0 735 736 def update_accessor_number(self, path, name): 737 if name: 738 init_item(self.attr_accessors, path, dict) 739 init_item(self.attr_accessors[path], name, lambda: 0) 740 self.attr_accessors[path][name] += 1 741 742 def process_class_node(self, n): 743 744 "Process the given class node 'n'." 745 746 class_name = self.get_object_path(n.name) 747 748 # Where a class is set conditionally or where the name may refer to 749 # different values, assign the name. 750 751 ref = self.importer.identify(class_name) 752 753 if not ref.static(): 754 self.process_assignment_for_object(n.name, 755 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 756 757 self.enter_namespace(n.name) 758 759 if self.have_object(): 760 self.write_comment("Class: %s" % class_name) 761 762 self.initialise_inherited_members(class_name) 763 764 self.process_structure(n) 765 self.write_comment("End class: %s" % class_name) 766 767 self.exit_namespace() 768 769 def initialise_inherited_members(self, class_name): 770 771 "Initialise members of 'class_name' inherited from its ancestors." 772 773 for name, path in self.importer.all_class_attrs[class_name].items(): 774 target = "%s.%s" % (class_name, name) 775 776 # Ignore attributes with definitions. 777 778 ref = self.importer.identify(target) 779 if ref: 780 continue 781 782 # Ignore special type attributes. 783 784 if is_type_attribute(name): 785 continue 786 787 # Reference inherited attributes. 788 789 ref = self.importer.identify(path) 790 if ref and not ref.static(): 791 parent, attrname = path.rsplit(".", 1) 792 793 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 794 encode_path(class_name), name, 795 encode_path(parent), attrname 796 )) 797 798 def process_from_node(self, n): 799 800 "Process the given node 'n', importing from another module." 801 802 path = self.get_namespace_path() 803 804 # Attempt to obtain the referenced objects. 805 806 for name, alias in n.names: 807 if name == "*": 808 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 809 810 # Obtain the path of the assigned name. 811 812 objpath = self.get_object_path(alias or name) 813 814 # Obtain the identity of the name. 815 816 ref = self.importer.identify(objpath) 817 818 # Where the name is not static, assign the value. 819 820 if ref and not ref.static() and ref.get_name(): 821 self.writestmt("%s;" % 822 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 823 expr=TrResolvedNameRef(name, ref))) 824 825 def process_function_body_node(self, n): 826 827 """ 828 Process the given function, lambda, if expression or list comprehension 829 node 'n', generating the body. 830 """ 831 832 function_name = self.get_namespace_path() 833 self.start_function(function_name) 834 835 # Process the function body. 836 837 in_conditional = self.in_conditional 838 self.in_conditional = False 839 self.function_target = 0 840 self.max_function_target = 0 841 self.context_index = 0 842 self.max_context_index = 0 843 844 # Volatile locals for exception handling. 845 846 self.volatile_locals = set() 847 848 # Process any guards defined for the parameters. 849 850 for name in self.importer.function_parameters.get(function_name): 851 self.generate_guard(name) 852 853 # Also support self in methods, since some mix-in methods may only work 854 # with certain descendant classes. 855 856 if self.in_method(): 857 self.generate_guard("self") 858 859 # Make assignments for .name entries in the parameters, provided this is 860 # a method. 861 862 if self.in_method(): 863 for name in self.importer.function_attr_initialisers.get(function_name) or []: 864 self.process_assignment_node( 865 compiler.ast.AssAttr(compiler.ast.Name("self"), name, "OP_ASSIGN"), 866 compiler.ast.Name(name)) 867 868 # Produce the body and any additional return statement. 869 870 expr = self.process_structure_node(n.code) or \ 871 self.in_method() and \ 872 function_name.rsplit(".", 1)[-1] == "__init__" and \ 873 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 874 PredefinedConstantRef("None") 875 876 if not isinstance(expr, ReturnRef): 877 self.writestmt("return %s;" % expr) 878 879 self.in_conditional = in_conditional 880 881 self.end_function(function_name) 882 883 def generate_guard(self, name): 884 885 """ 886 Get the accessor details for 'name', found in the current namespace, and 887 generate any guards defined for it. 888 """ 889 890 # Obtain the location, keeping track of assignment versions. 891 892 location = self.get_accessor_location(name) 893 test = self.deducer.accessor_guard_tests.get(location) 894 895 # Generate any guard from the deduced information. 896 897 if test: 898 guard, guard_type = test 899 900 if guard == "specific": 901 ref = first(self.deducer.accessor_all_types[location]) 902 argstr = "&%s" % encode_path(ref.get_origin()) 903 elif guard == "common": 904 ref = first(self.deducer.accessor_all_general_types[location]) 905 argstr = encode_path(encode_type_attribute(ref.get_origin())) 906 else: 907 return 908 909 # Write a test that raises a TypeError upon failure. 910 911 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 912 guard, guard_type, encode_path(name), argstr)) 913 914 def process_function_node(self, n): 915 916 """ 917 Process the given function, lambda, if expression or list comprehension 918 node 'n', generating any initialisation statements. 919 """ 920 921 # Where a function is declared conditionally, use a separate name for 922 # the definition, and assign the definition to the stated name. 923 924 original_name = n.name 925 926 if self.in_conditional or self.in_function: 927 name = self.get_lambda_name() 928 else: 929 name = n.name 930 931 objpath = self.get_object_path(name) 932 933 # Obtain details of the defaults. 934 935 defaults = self.process_function_defaults(n, name, objpath) 936 if defaults: 937 for default in defaults: 938 self.writeline("%s;" % default) 939 940 # Where a function is set conditionally or where the name may refer to 941 # different values, assign the name. 942 943 ref = self.importer.identify(objpath) 944 945 if self.in_conditional or self.in_function: 946 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 947 elif not ref.static(): 948 context = self.is_method(objpath) 949 950 self.process_assignment_for_object(original_name, 951 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 952 953 def process_function_defaults(self, n, name, objpath, instance_name=None): 954 955 """ 956 Process the given function or lambda node 'n', initialising defaults 957 that are dynamically set. The given 'name' indicates the name of the 958 function. The given 'objpath' indicates the origin of the function. 959 The given 'instance_name' indicates the name of any separate instance 960 of the function created to hold the defaults. 961 962 Return a list of operations setting defaults on a function instance. 963 """ 964 965 function_name = self.get_object_path(name) 966 function_defaults = self.importer.function_defaults.get(function_name) 967 if not function_defaults: 968 return None 969 970 # Determine whether any unidentified defaults are involved. 971 972 for argname, default in function_defaults: 973 if not default.static(): 974 break 975 else: 976 return None 977 978 # Handle bound methods. 979 980 if not instance_name: 981 instance_name = "&%s" % encode_path(objpath) 982 else: 983 instance_name = "__VALUE(%s)" % instance_name 984 985 # Where defaults are involved but cannot be identified, obtain a new 986 # instance of the lambda and populate the defaults. 987 988 defaults = [] 989 990 # Join the original defaults with the inspected defaults. 991 992 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 993 994 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 995 996 # Obtain any reference for the default. 997 998 if original: 999 argname, default = original 1000 name_ref = self.process_structure_node(default) 1001 elif inspected: 1002 argname, default = inspected 1003 name_ref = TrResolvedNameRef(argname, default) 1004 else: 1005 continue 1006 1007 # Generate default initialisers except when constants are employed. 1008 # Constants should be used when populating the function structures. 1009 1010 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1011 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1012 1013 return defaults 1014 1015 def process_if_node(self, n): 1016 1017 """ 1018 Process the given "if" node 'n'. 1019 """ 1020 1021 first = True 1022 for test, body in n.tests: 1023 test_ref = self.process_structure_node(test) 1024 self.start_if(first, test_ref) 1025 1026 in_conditional = self.in_conditional 1027 self.in_conditional = True 1028 self.process_structure_node(body) 1029 self.in_conditional = in_conditional 1030 1031 self.end_if() 1032 first = False 1033 1034 if n.else_: 1035 self.start_else() 1036 self.process_structure_node(n.else_) 1037 self.end_else() 1038 1039 print >>self.out 1040 1041 def process_invocation_node(self, n): 1042 1043 "Process the given invocation node 'n'." 1044 1045 # Process the expression. 1046 1047 expr = self.process_structure_node(n.node) 1048 1049 # Obtain details of the invocation expression. 1050 1051 objpath = expr.get_origin() 1052 location = expr.access_location() 1053 refs = expr.references() 1054 1055 # Identified target details. 1056 1057 target = None 1058 target_structure = None 1059 1060 # Specific function target information. 1061 1062 function = None 1063 1064 # Instantiation involvement. 1065 1066 instantiation = False 1067 literal_instantiation = False 1068 1069 # Invocation requirements. 1070 1071 context_required = True 1072 have_access_context = isinstance(expr, AttrResult) 1073 context_identity = have_access_context and expr.context() 1074 context_verified = have_access_context and expr.context_verified() 1075 tests_accessor = have_access_context and expr.tests_accessor() 1076 parameters = None 1077 num_parameters = None 1078 num_defaults = None 1079 1080 # Obtain details of the callable and of its parameters. 1081 1082 # Literals may be instantiated specially. 1083 1084 if expr.is_name() and expr.name.startswith("$L") and objpath: 1085 instantiation = literal_instantiation = objpath 1086 target = encode_literal_instantiator(objpath) 1087 context_required = False 1088 1089 # Identified targets employ function pointers directly. 1090 1091 elif objpath: 1092 parameters = self.importer.function_parameters.get(objpath) 1093 function_defaults = self.importer.function_defaults.get(objpath) 1094 num_parameters = parameters and len(parameters) or 0 1095 num_defaults = function_defaults and len(function_defaults) or 0 1096 1097 # Class invocation involves instantiators. 1098 1099 if expr.has_kind("<class>"): 1100 instantiation = objpath 1101 target = encode_instantiator_pointer(objpath) 1102 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1103 target_structure = "&%s" % encode_path(init_ref) 1104 context_required = False 1105 1106 # Only plain functions and bound methods employ function pointers. 1107 1108 elif expr.has_kind("<function>"): 1109 function = objpath 1110 1111 # Test for functions and methods. 1112 1113 context_required = self.is_method(objpath) 1114 1115 accessor_kinds = location and self.get_accessor_kinds(location) 1116 1117 instance_accessor = accessor_kinds and \ 1118 len(accessor_kinds) == 1 and \ 1119 first(accessor_kinds) == "<instance>" 1120 1121 # Only identify certain bound methods or functions. 1122 1123 if not context_required or instance_accessor: 1124 target = encode_function_pointer(objpath) 1125 1126 # Access bound method defaults even if it is not clear whether 1127 # the accessor is appropriate. 1128 1129 target_structure = "&%s" % encode_path(objpath) 1130 1131 # Other targets are retrieved at run-time. 1132 1133 else: 1134 if location: 1135 attrnames = location.attrnames 1136 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1137 1138 # Determine common aspects of any identifiable targets. 1139 1140 if attrname or refs: 1141 all_params = set() 1142 all_defaults = set() 1143 min_params = set() 1144 max_params = set() 1145 1146 # Employ references from the expression or find all 1147 # possible attributes for the given attribute name. 1148 1149 refs = refs or self.get_attributes_for_attrname(attrname) 1150 1151 # Obtain parameters and defaults for each possible target. 1152 1153 for ref in refs: 1154 origin = ref.get_origin() 1155 params = self.importer.function_parameters.get(origin) 1156 1157 defaults = self.importer.function_defaults.get(origin) 1158 if defaults is not None: 1159 all_defaults.add(tuple(defaults)) 1160 1161 if params is not None: 1162 all_params.add(tuple(params)) 1163 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1164 max_params.add(len(params)) 1165 else: 1166 refs = set() 1167 break 1168 1169 # Where the parameters and defaults are always the same, 1170 # permit populating them in advance. 1171 1172 if refs: 1173 if self.uses_keyword_arguments(n): 1174 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1175 parameters = first(all_params) 1176 function_defaults = all_defaults and first(all_defaults) or [] 1177 num_parameters = parameters and len(parameters) or 0 1178 num_defaults = function_defaults and len(function_defaults) or 0 1179 else: 1180 if len(min_params) == 1 and len(max_params) == 1: 1181 num_parameters = first(max_params) 1182 num_defaults = first(max_params) - first(min_params) 1183 1184 # Some information about the target may be available and be used to 1185 # provide warnings about argument compatibility. 1186 1187 if self.importer.give_warning("args"): 1188 unsuitable = self.get_referenced_attribute_invocations(location) 1189 1190 if unsuitable: 1191 for ref in unsuitable: 1192 _objpath = ref.get_origin() 1193 print >>sys.stderr, \ 1194 "In %s, at line %d, inappropriate number of " \ 1195 "arguments given. Need %d arguments to call %s." % ( 1196 self.get_namespace_path(), n.lineno, 1197 len(self.importer.function_parameters[_objpath]), 1198 _objpath) 1199 1200 # Logical statement about available parameter information. 1201 1202 known_parameters = num_parameters is not None 1203 1204 # The source of context information: target or temporary. 1205 1206 need_context_target = context_required and not have_access_context 1207 1208 need_context_stored = context_required and context_identity and \ 1209 context_identity.startswith("__get_context") 1210 1211 # Determine any readily-accessible target identity. 1212 1213 target_named = expr.is_name() and str(expr) or None 1214 target_identity = target or target_named 1215 1216 # Use of target information to populate defaults. 1217 1218 defaults_target_var = not (parameters and function_defaults is not None) and \ 1219 known_parameters and len(n.args) < num_parameters 1220 1221 # Use of a temporary target variable in these situations: 1222 # 1223 # A target provided by an expression needed for defaults. 1224 # 1225 # A target providing the context but not using a name to do so. 1226 # 1227 # A target expression involving the definition of a context which may 1228 # then be evaluated and stored to ensure that the context is available 1229 # during argument evaluation. 1230 # 1231 # An expression featuring an accessor test. 1232 1233 need_target_stored = defaults_target_var and not target_identity or \ 1234 need_context_target and not target_identity or \ 1235 need_context_stored or \ 1236 tests_accessor and not target 1237 1238 # Define stored target details. 1239 1240 target_stored = "__tmp_targets[%d]" % self.function_target 1241 target_var = need_target_stored and target_stored or target_identity 1242 1243 if need_target_stored: 1244 self.record_temp("__tmp_targets") 1245 1246 if need_context_stored: 1247 self.record_temp("__tmp_contexts") 1248 1249 # Arguments are presented in a temporary frame array with any context 1250 # always being the first argument. Where it would be unused, it may be 1251 # set to null. 1252 1253 if context_required: 1254 if have_access_context: 1255 args = [context_identity] 1256 else: 1257 args = ["__CONTEXT_AS_VALUE(%s)" % target_var] 1258 else: 1259 args = ["__NULL"] 1260 1261 # Complete the array with null values, permitting tests for a complete 1262 # set of arguments. 1263 1264 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1265 kwcodes = [] 1266 kwargs = [] 1267 1268 # Any invocations in the arguments will store target details in a 1269 # different location. 1270 1271 function_target = self.function_target 1272 context_index = self.context_index 1273 1274 if need_target_stored: 1275 self.next_target() 1276 1277 if need_context_stored: 1278 self.next_context() 1279 1280 for i, arg in enumerate(n.args): 1281 argexpr = self.process_structure_node(arg) 1282 1283 # Store a keyword argument, either in the argument list or 1284 # in a separate keyword argument list for subsequent lookup. 1285 1286 if isinstance(arg, compiler.ast.Keyword): 1287 1288 # With knowledge of the target, store the keyword 1289 # argument directly. 1290 1291 if parameters: 1292 try: 1293 argnum = parameters.index(arg.name) 1294 except ValueError: 1295 raise TranslateError("Argument %s is not recognised." % arg.name, 1296 self.get_namespace_path(), n) 1297 args[argnum+1] = str(argexpr) 1298 1299 # Otherwise, store the details in a separate collection. 1300 1301 else: 1302 kwargs.append(str(argexpr)) 1303 kwcodes.append("{%s, %s}" % ( 1304 encode_ppos(arg.name), encode_pcode(arg.name))) 1305 1306 # Store non-keyword arguments in the argument list, rejecting 1307 # superfluous arguments. 1308 1309 else: 1310 try: 1311 args[i+1] = str(argexpr) 1312 except IndexError: 1313 raise TranslateError("Too many arguments specified.", 1314 self.get_namespace_path(), n) 1315 1316 # Reference the current target again. 1317 1318 self.function_target = function_target 1319 self.context_index = context_index 1320 1321 # Defaults are added to the frame where arguments are missing. 1322 1323 if parameters and function_defaults is not None: 1324 1325 # Visit each default and set any missing arguments. Where keyword 1326 # arguments have been used, the defaults must be inspected and, if 1327 # necessary, inserted into gaps in the argument list. 1328 1329 for i, (argname, default) in enumerate(function_defaults): 1330 argnum = parameters.index(argname) 1331 if not args[argnum+1]: 1332 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1333 1334 elif known_parameters: 1335 1336 # No specific parameter details are provided, but no keyword 1337 # arguments are used. Thus, defaults can be supplied using position 1338 # information only. 1339 1340 i = len(n.args) 1341 pos = i - (num_parameters - num_defaults) 1342 while i < num_parameters: 1343 args[i+1] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1344 i += 1 1345 pos += 1 1346 1347 # Test for missing arguments. 1348 1349 if None in args: 1350 raise TranslateError("Not all arguments supplied.", 1351 self.get_namespace_path(), n) 1352 1353 # Encode the arguments. 1354 1355 # Where literal instantiation is occurring, add an argument indicating 1356 # the number of values. The context is excluded. 1357 1358 if literal_instantiation: 1359 argstr = "%d, %s" % (len(args) - 1, ", ".join(args[1:])) 1360 else: 1361 argstr = ", ".join(args) 1362 1363 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1364 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1365 1366 # First, the invocation expression is presented. 1367 1368 stages = [] 1369 emit = stages.append 1370 1371 # Assign and yield any stored target. 1372 # The context may be set in the expression. 1373 1374 if need_target_stored: 1375 emit("%s = %s" % (target_var, expr)) 1376 target_expr = target_var 1377 1378 # Otherwise, retain the expression for later use. 1379 1380 else: 1381 target_expr = str(expr) 1382 1383 # Any specific callable is then obtained for invocation. 1384 1385 if target: 1386 1387 # An expression involving a test of the accessor providing the target. 1388 # This must be emitted in order to perform the test. 1389 1390 if tests_accessor: 1391 emit(str(expr)) 1392 1393 emit(target) 1394 1395 # Methods accessed via unidentified accessors are obtained for 1396 # invocation. 1397 1398 elif function: 1399 if context_required: 1400 1401 # With context_verified or context_identity... 1402 1403 if have_access_context: 1404 emit("__get_function_member(%s)" % target_expr) 1405 1406 # Otherwise, test the context for the function/method. 1407 1408 else: 1409 emit("__get_function(__CONTEXT_AS_VALUE(%s), %s)" % ( 1410 target_var, target_expr)) 1411 else: 1412 emit("_get_function_member(%s)" % target_expr) 1413 1414 # With known parameters, the target can be tested. 1415 1416 elif known_parameters: 1417 context_arg = context_required and args[0] or "__NULL" 1418 if self.always_callable(refs): 1419 if context_verified or context_identity: 1420 emit("__get_function_member(%s)" % target_expr) 1421 else: 1422 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1423 else: 1424 emit("__check_and_get_function(%s, %s)" % (context_arg, target_expr)) 1425 1426 # With a known target, the function is obtained directly and called. 1427 # By putting the invocation at the end of the final element in the 1428 # instruction sequence (the stages), the result becomes the result of 1429 # the sequence. Moreover, the parameters become part of the sequence 1430 # and thereby participate in a guaranteed evaluation order. 1431 1432 if target or function or known_parameters: 1433 stages[-1] += "(%s)" % argstr 1434 if instantiation: 1435 return InstantiationResult(instantiation, stages) 1436 else: 1437 return InvocationResult(stages) 1438 1439 # With unknown targets, the generic invocation function is applied to 1440 # the callable and argument collections. 1441 1442 else: 1443 emit("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1444 target_expr, 1445 self.always_callable(refs) and 1 or 0, 1446 len(kwargs), kwcodestr, kwargstr, 1447 len(args), "__ARGS(%s)" % argstr)) 1448 return InvocationResult(stages) 1449 1450 def next_target(self): 1451 1452 "Allocate the next function target storage." 1453 1454 self.function_target += 1 1455 self.max_function_target = max(self.function_target, self.max_function_target) 1456 1457 def next_context(self): 1458 1459 "Allocate the next context value storage." 1460 1461 self.context_index += 1 1462 self.max_context_index = max(self.context_index, self.max_context_index) 1463 1464 def always_callable(self, refs): 1465 1466 "Determine whether all 'refs' are callable." 1467 1468 if not refs: 1469 return False 1470 1471 for ref in refs: 1472 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1473 return False 1474 1475 return True 1476 1477 def need_default_arguments(self, objpath, nargs): 1478 1479 """ 1480 Return whether any default arguments are needed when invoking the object 1481 given by 'objpath'. 1482 """ 1483 1484 parameters = self.importer.function_parameters.get(objpath) 1485 return nargs < len(parameters) 1486 1487 def uses_keyword_arguments(self, n): 1488 1489 "Return whether invocation node 'n' uses keyword arguments." 1490 1491 for arg in enumerate(n.args): 1492 if isinstance(arg, compiler.ast.Keyword): 1493 return True 1494 1495 return False 1496 1497 def get_attributes_for_attrname(self, attrname): 1498 1499 "Return a set of all attributes exposed by 'attrname'." 1500 1501 usage = [(attrname, True, False)] 1502 class_types = self.deducer.get_class_types_for_usage(usage) 1503 instance_types = self.deducer.get_instance_types_for_usage(usage) 1504 module_types = self.deducer.get_module_types_for_usage(usage) 1505 attrs = set() 1506 1507 for ref in combine_types(class_types, instance_types, module_types): 1508 attrs.update(self.importer.get_attributes(ref, attrname)) 1509 1510 return attrs 1511 1512 def process_lambda_node(self, n): 1513 1514 "Process the given lambda node 'n'." 1515 1516 name = self.get_lambda_name() 1517 function_name = self.get_object_path(name) 1518 1519 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1520 1521 # Without defaults, produce an attribute referring to the function. 1522 1523 if not defaults: 1524 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1525 1526 # With defaults, copy the function structure and set the defaults on the 1527 # copy. 1528 1529 else: 1530 self.record_temp("__tmp_value") 1531 return make_expression("(__tmp_value = __ATTRVALUE(__COPY(&%s, sizeof(%s))), %s, __tmp_value)" % ( 1532 encode_path(function_name), 1533 encode_symbol("obj", function_name), 1534 ", ".join(defaults))) 1535 1536 def process_logical_node(self, n): 1537 1538 "Process the given operator node 'n'." 1539 1540 self.record_temp("__tmp_result") 1541 1542 conjunction = isinstance(n, compiler.ast.And) 1543 results = [] 1544 1545 for node in n.nodes: 1546 results.append(self.process_structure_node(node)) 1547 1548 return LogicalOperationResult(results, conjunction) 1549 1550 def process_name_node(self, n, expr=None): 1551 1552 "Process the given name node 'n' with the optional assignment 'expr'." 1553 1554 # Determine whether the name refers to a static external entity. 1555 1556 if n.name in predefined_constants: 1557 return PredefinedConstantRef(n.name, expr) 1558 1559 # Convert literal references, operator function names, and print 1560 # function names to references. 1561 1562 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1563 n.name.startswith("$seq") or n.name.startswith("$print"): 1564 1565 ref, paths = self.importer.get_module(self.name).special[n.name] 1566 return TrResolvedNameRef(n.name, ref) 1567 1568 # Get the appropriate name for the name reference, using the same method 1569 # as in the inspector. 1570 1571 path = self.get_namespace_path() 1572 objpath = self.get_object_path(n.name) 1573 1574 # Determine any assigned globals. 1575 1576 globals = self.importer.get_module(self.name).scope_globals.get(path) 1577 1578 # Explicitly declared globals. 1579 1580 if globals and n.name in globals: 1581 objpath = self.get_global_path(n.name) 1582 is_global = True 1583 1584 # Implicitly referenced globals in functions. 1585 1586 elif self.in_function: 1587 is_global = n.name not in self.importer.function_locals[path] 1588 1589 # Implicitly referenced globals elsewhere. 1590 1591 else: 1592 namespace = self.importer.identify(path) 1593 is_global = not self.importer.get_attributes(namespace, n.name) 1594 1595 # Get the static identity of the name. 1596 1597 ref = self.importer.identify(objpath) 1598 if ref and not ref.get_name(): 1599 ref = ref.alias(objpath) 1600 1601 # Obtain any resolved names for non-assignment names. 1602 1603 if not expr and not ref and self.in_function: 1604 locals = self.importer.function_locals.get(path) 1605 ref = locals and locals.get(n.name) 1606 1607 # Find any invocation or alias details. 1608 1609 name = self.get_name_for_tracking(n.name, is_global=is_global) 1610 location = not expr and self.get_access_location(name) or None 1611 1612 # Mark any local assignments as volatile in exception blocks. 1613 1614 if expr and self.in_function and not is_global and self.in_try_except: 1615 self.make_volatile(n.name) 1616 1617 # Qualified names are used for resolved static references or for 1618 # static namespace members. The reference should be configured to return 1619 # such names. 1620 1621 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1622 location=location) 1623 return not expr and self.get_aliases(name_ref) or name_ref 1624 1625 def get_aliases(self, name_ref): 1626 1627 "Return alias references for the given 'name_ref'." 1628 1629 location = name_ref.access_location() 1630 accessor_locations = self.deducer.access_index.get(location) 1631 1632 if not accessor_locations: 1633 return None 1634 1635 refs = set() 1636 1637 for accessor_location in accessor_locations: 1638 alias_refs = self.deducer.referenced_objects.get(accessor_location) 1639 if alias_refs: 1640 refs.update(alias_refs) 1641 1642 if refs: 1643 return AliasResult(name_ref, refs, location) 1644 else: 1645 return None 1646 1647 def make_volatile(self, name): 1648 1649 "Record 'name' as volatile in the current namespace." 1650 1651 self.volatile_locals.add(name) 1652 1653 def process_not_node(self, n): 1654 1655 "Process the given operator node 'n'." 1656 1657 return self.make_negation(self.process_structure_node(n.expr)) 1658 1659 def process_raise_node(self, n): 1660 1661 "Process the given raise node 'n'." 1662 1663 # NOTE: Determine which raise statement variants should be permitted. 1664 1665 if n.expr1: 1666 1667 # Names with accompanying arguments are treated like invocations. 1668 1669 if n.expr2: 1670 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1671 exc = self.process_structure_node(call) 1672 self.writestmt("__Raise(%s);" % exc) 1673 1674 # Raise instances, testing the kind at run-time if necessary and 1675 # instantiating any non-instance. 1676 1677 else: 1678 exc = self.process_structure_node(n.expr1) 1679 1680 if isinstance(exc, TrInstanceRef): 1681 self.writestmt("__Raise(%s);" % exc) 1682 else: 1683 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1684 else: 1685 self.writestmt("__Throw(__tmp_exc);") 1686 1687 def process_return_node(self, n): 1688 1689 "Process the given return node 'n'." 1690 1691 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1692 if self.in_try_finally or self.in_try_except: 1693 self.writestmt("__Return(%s);" % expr) 1694 else: 1695 self.writestmt("return %s;" % expr) 1696 1697 return ReturnRef() 1698 1699 def process_try_node(self, n): 1700 1701 """ 1702 Process the given "try...except" node 'n'. 1703 """ 1704 1705 in_try_except = self.in_try_except 1706 self.in_try_except = True 1707 1708 # Use macros to implement exception handling. 1709 1710 self.writestmt("__Try") 1711 self.writeline("{") 1712 self.indent += 1 1713 self.process_structure_node(n.body) 1714 1715 # Put the else statement in another try block that handles any raised 1716 # exceptions and converts them to exceptions that will not be handled by 1717 # the main handling block. 1718 1719 if n.else_: 1720 self.writestmt("__Try") 1721 self.writeline("{") 1722 self.indent += 1 1723 self.process_structure_node(n.else_) 1724 self.indent -= 1 1725 self.writeline("}") 1726 self.writeline("__Catch (__tmp_exc)") 1727 self.writeline("{") 1728 self.indent += 1 1729 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1730 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1731 self.indent -= 1 1732 self.writeline("}") 1733 1734 # Complete the try block and enter the finally block, if appropriate. 1735 1736 if self.in_try_finally: 1737 self.writestmt("__Complete;") 1738 1739 self.indent -= 1 1740 self.writeline("}") 1741 1742 self.in_try_except = in_try_except 1743 1744 # Handlers are tests within a common handler block. 1745 1746 self.writeline("__Catch (__tmp_exc)") 1747 self.writeline("{") 1748 self.indent += 1 1749 1750 # Introduce an if statement to handle the completion of a try block. 1751 1752 self.process_try_completion() 1753 1754 # Handle exceptions in else blocks converted to __RaiseElse, converting 1755 # them back to normal exceptions. 1756 1757 if n.else_: 1758 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1759 1760 # Exception handling. 1761 1762 for name, var, handler in n.handlers: 1763 1764 # Test for specific exceptions. 1765 1766 if name is not None: 1767 name_ref = self.process_structure_node(name) 1768 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1769 else: 1770 self.writeline("else if (1)") 1771 1772 self.writeline("{") 1773 self.indent += 1 1774 1775 # Establish the local for the handler. 1776 1777 if var is not None: 1778 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1779 1780 if handler is not None: 1781 self.process_structure_node(handler) 1782 1783 self.indent -= 1 1784 self.writeline("}") 1785 1786 # Re-raise unhandled exceptions. 1787 1788 self.writeline("else __Throw(__tmp_exc);") 1789 1790 # End the handler block. 1791 1792 self.indent -= 1 1793 self.writeline("}") 1794 print >>self.out 1795 1796 def process_try_finally_node(self, n): 1797 1798 """ 1799 Process the given "try...finally" node 'n'. 1800 """ 1801 1802 in_try_finally = self.in_try_finally 1803 self.in_try_finally = True 1804 1805 # Use macros to implement exception handling. 1806 1807 self.writestmt("__Try") 1808 self.writeline("{") 1809 self.indent += 1 1810 self.process_structure_node(n.body) 1811 self.indent -= 1 1812 self.writeline("}") 1813 1814 self.in_try_finally = in_try_finally 1815 1816 # Finally clauses handle special exceptions. 1817 1818 self.writeline("__Catch (__tmp_exc)") 1819 self.writeline("{") 1820 self.indent += 1 1821 self.process_structure_node(n.final) 1822 1823 # Introduce an if statement to handle the completion of a try block. 1824 1825 self.process_try_completion() 1826 self.writeline("else __Throw(__tmp_exc);") 1827 1828 self.indent -= 1 1829 self.writeline("}") 1830 print >>self.out 1831 1832 def process_try_completion(self): 1833 1834 "Generate a test for the completion of a try block." 1835 1836 self.writestmt("if (__tmp_exc.completing)") 1837 self.writeline("{") 1838 self.indent += 1 1839 1840 # Do not return anything at the module level. 1841 1842 if self.get_namespace_path() != self.name: 1843 1844 # Only use the normal return statement if no surrounding try blocks 1845 # apply. 1846 1847 if not self.in_try_finally and not self.in_try_except: 1848 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1849 else: 1850 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1851 1852 self.indent -= 1 1853 self.writeline("}") 1854 1855 def process_while_node(self, n): 1856 1857 "Process the given while node 'n'." 1858 1859 self.writeline("while (1)") 1860 self.writeline("{") 1861 self.indent += 1 1862 test = self.process_structure_node(n.test) 1863 1864 # Emit the loop termination condition unless "while <true value>" is 1865 # indicated. 1866 1867 if not (isinstance(test, PredefinedConstantRef) and test.value): 1868 1869 # Emit a negated test of the continuation condition. 1870 1871 self.start_if(True, self.make_negation(test)) 1872 if n.else_: 1873 self.process_structure_node(n.else_) 1874 self.writestmt("break;") 1875 self.end_if() 1876 1877 in_conditional = self.in_conditional 1878 self.in_conditional = True 1879 self.process_structure_node(n.body) 1880 self.in_conditional = in_conditional 1881 1882 self.indent -= 1 1883 self.writeline("}") 1884 print >>self.out 1885 1886 # Special variable usage. 1887 1888 def get_temp_path(self): 1889 1890 """ 1891 Return the appropriate namespace path for temporary names in the current 1892 namespace. 1893 """ 1894 1895 if self.in_function: 1896 return self.get_namespace_path() 1897 else: 1898 return self.name 1899 1900 def record_temp(self, name): 1901 1902 """ 1903 Record the use of the temporary 'name' in the current namespace. At the 1904 class or module level, the temporary name is associated with the module, 1905 since the variable will then be allocated in the module's own main 1906 program. 1907 """ 1908 1909 path = self.get_temp_path() 1910 1911 init_item(self.temp_usage, path, list) 1912 self.temp_usage[path].append(name) 1913 1914 def remove_temps(self, names): 1915 1916 """ 1917 Remove 'names' from temporary storage allocations, each instance 1918 removing each request for storage. 1919 """ 1920 1921 path = self.get_temp_path() 1922 1923 for name in names: 1924 if self.uses_temp(path, name): 1925 self.temp_usage[path].remove(name) 1926 1927 def uses_temp(self, path, name): 1928 1929 """ 1930 Return whether the given namespace 'path' employs a temporary variable 1931 with the given 'name'. Note that 'path' should only be a module or a 1932 function or method, not a class. 1933 """ 1934 1935 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1936 1937 def make_negation(self, expr): 1938 1939 "Return a negated form of 'expr'." 1940 1941 result = NegationResult(expr) 1942 1943 # Negation discards the temporary results of its operand. 1944 1945 temps = expr.discards_temporary() 1946 if temps: 1947 self.remove_temps(temps) 1948 1949 return result 1950 1951 # Output generation. 1952 1953 def start_output(self): 1954 1955 "Write the declarations at the top of each source file." 1956 1957 print >>self.out, """\ 1958 #include "types.h" 1959 #include "exceptions.h" 1960 #include "ops.h" 1961 #include "progconsts.h" 1962 #include "progops.h" 1963 #include "progtypes.h" 1964 #include "main.h" 1965 """ 1966 1967 def start_unit(self): 1968 1969 "Record output within a generated function for later use." 1970 1971 self.out = StringIO() 1972 1973 def end_unit(self): 1974 1975 "Restore the output stream." 1976 1977 out = self.out 1978 self.out = self.out_toplevel 1979 return out 1980 1981 def flush_unit(self, name, out): 1982 1983 "Add declarations and generated code." 1984 1985 self.write_temporaries(name) 1986 print >>self.out 1987 out.seek(0) 1988 self.out.write(out.read()) 1989 1990 def start_module(self): 1991 1992 "Write the start of each module's main function." 1993 1994 print >>self.out, "void __main_%s()" % encode_path(self.name) 1995 print >>self.out, "{" 1996 self.indent += 1 1997 1998 # Define temporary variables, excluded from the module structure itself. 1999 2000 tempnames = [] 2001 2002 for n in self.importer.all_module_attrs[self.name]: 2003 if n.startswith("$t"): 2004 tempnames.append(encode_path(n)) 2005 2006 if tempnames: 2007 tempnames.sort() 2008 self.writeline("__attr %s;" % ", ".join(tempnames)) 2009 2010 self.start_unit() 2011 2012 def end_module(self): 2013 2014 "End each module by closing its main function." 2015 2016 out = self.end_unit() 2017 self.flush_unit(self.name, out) 2018 2019 self.indent -= 1 2020 print >>self.out, "}" 2021 2022 def start_function(self, name): 2023 2024 "Start the function having the given 'name'." 2025 2026 self.indent += 1 2027 2028 self.start_unit() 2029 2030 def end_function(self, name): 2031 2032 "End the function having the given 'name'." 2033 2034 out = self.end_unit() 2035 2036 # Write the signature at the top indentation level. 2037 2038 self.indent -= 1 2039 self.write_parameters(name) 2040 print >>self.out, "{" 2041 2042 # Obtain local names from parameters. 2043 2044 parameters = self.importer.function_parameters[name] 2045 locals = self.importer.function_locals[name].keys() 2046 names = [] 2047 volatile_names = [] 2048 2049 for n in locals: 2050 2051 # Filter out special names and parameters. Note that self is a local 2052 # regardless of whether it originally appeared in the parameters or 2053 # not. 2054 2055 if n.startswith("$l") or n in parameters or n == "self": 2056 continue 2057 if n in self.volatile_locals: 2058 volatile_names.append(encode_path(n)) 2059 else: 2060 names.append(encode_path(n)) 2061 2062 # Emit required local names at the function indentation level. 2063 2064 self.indent += 1 2065 2066 if names: 2067 names.sort() 2068 self.writeline("__attr %s;" % ", ".join(names)) 2069 2070 if volatile_names: 2071 volatile_names.sort() 2072 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2073 2074 self.flush_unit(name, out) 2075 2076 self.indent -= 1 2077 print >>self.out, "}" 2078 print >>self.out 2079 2080 def write_parameters(self, name): 2081 2082 """ 2083 For the function having the given 'name', write definitions of 2084 parameters found in the arguments array. 2085 """ 2086 2087 # Generate any self reference. 2088 2089 l = [] 2090 2091 if self.is_method(name): 2092 l.append("__attr self") 2093 else: 2094 l.append("__attr __self") 2095 2096 # Generate aliases for the parameters. 2097 2098 for parameter in self.importer.function_parameters[name]: 2099 l.append("%s__attr %s" % ( 2100 parameter in self.volatile_locals and "volatile " or "", 2101 encode_path(parameter))) 2102 2103 self.writeline("__attr %s(%s)" % ( 2104 encode_function_pointer(name), ", ".join(l))) 2105 2106 def write_temporaries(self, name): 2107 2108 "Write temporary storage employed by 'name'." 2109 2110 # Provide space for the given number of targets. 2111 2112 targets = self.max_function_target 2113 2114 if self.uses_temp(name, "__tmp_targets"): 2115 self.writeline("__attr __tmp_targets[%d];" % targets) 2116 2117 index = self.max_context_index 2118 2119 if self.uses_temp(name, "__tmp_contexts"): 2120 self.writeline("__attr __tmp_contexts[%d];" % index) 2121 2122 # Add temporary variable usage details. 2123 2124 if self.uses_temp(name, "__tmp_private_context"): 2125 self.writeline("__attr __tmp_private_context;") 2126 if self.uses_temp(name, "__tmp_value"): 2127 self.writeline("__attr __tmp_value;") 2128 if self.uses_temp(name, "__tmp_target_value"): 2129 self.writeline("__attr __tmp_target_value;") 2130 if self.uses_temp(name, "__tmp_result"): 2131 self.writeline("__attr __tmp_result;") 2132 2133 module = self.importer.get_module(self.name) 2134 2135 if name in module.exception_namespaces: 2136 self.writeline("__exc __tmp_exc;") 2137 2138 def start_if(self, first, test_ref): 2139 statement = "%sif" % (not first and "else " or "") 2140 2141 # Consume logical results directly. 2142 2143 if isinstance(test_ref, LogicalResult): 2144 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2145 temps = test_ref.discards_temporary() 2146 if temps: 2147 self.remove_temps(temps) 2148 else: 2149 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2150 2151 self.writeline("{") 2152 self.indent += 1 2153 2154 def end_if(self): 2155 self.indent -= 1 2156 self.writeline("}") 2157 2158 def start_else(self): 2159 self.writeline("else") 2160 self.writeline("{") 2161 self.indent += 1 2162 2163 def end_else(self): 2164 self.indent -= 1 2165 self.writeline("}") 2166 2167 def statement(self, expr): 2168 s = str(expr) 2169 if s: 2170 self.writestmt("%s;" % s) 2171 2172 def statements(self, results): 2173 for result in results: 2174 self.statement(result) 2175 2176 def writeline(self, s): 2177 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2178 2179 def writestmt(self, s): 2180 self.writeline(s) 2181 2182 def write_comment(self, s): 2183 self.writestmt("/* %s */" % s) 2184 2185 def pad(self, extra=0): 2186 return (self.indent + extra) * self.tabstop 2187 2188 def indenttext(self, s, levels): 2189 lines = s.split("\n") 2190 out = [lines[0]] 2191 for line in lines[1:]: 2192 out.append(levels * self.tabstop + line) 2193 if line.endswith("("): 2194 levels += 1 2195 elif line.startswith(")"): 2196 levels -= 1 2197 return "\n".join(out) 2198 2199 # vim: tabstop=4 expandtab shiftwidth=4