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 self.in_parameter_list = False 119 120 # Exception raising adjustments. 121 122 self.in_try_finally = False 123 self.in_try_except = False 124 125 # Attribute access and accessor counting. 126 127 self.attr_accesses = {} 128 self.attr_accessors = {} 129 130 # Special variable usage. 131 132 self.temp_usage = {} 133 134 # Initialise some data used for attribute access generation. 135 136 self.init_substitutions() 137 138 def __repr__(self): 139 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 140 141 def translate(self, filename, output_filename): 142 143 """ 144 Parse the file having the given 'filename', writing the translation to 145 the given 'output_filename'. 146 """ 147 148 self.parse_file(filename) 149 150 # Collect function namespaces for separate processing. 151 152 self.record_namespaces(self.astnode) 153 154 # Reset the lambda naming (in order to obtain the same names again) and 155 # translate the program. 156 157 self.reset_lambdas() 158 159 self.out_toplevel = self.out = open(output_filename, "w") 160 try: 161 self.start_output() 162 163 # Process namespaces, writing the translation. 164 165 for path, node in self.namespaces: 166 self.process_namespace(path, node) 167 168 # Process the module namespace including class namespaces. 169 170 self.process_namespace([], self.astnode) 171 172 finally: 173 self.out.close() 174 175 def have_object(self): 176 177 "Return whether a namespace is a recorded object." 178 179 return self.importer.objects.get(self.get_namespace_path()) 180 181 def get_builtin_class(self, name): 182 183 "Return a reference to the actual object providing 'name'." 184 185 return self.importer.get_object(get_builtin_class(name)) 186 187 def is_method(self, path): 188 189 "Return whether 'path' is a method." 190 191 class_name, method_name = path.rsplit(".", 1) 192 return self.importer.classes.has_key(class_name) and class_name or None 193 194 def in_method(self): 195 196 "Return whether the current namespace provides a method." 197 198 return self.in_function and self.is_method(self.get_namespace_path()) 199 200 # Namespace recording. 201 202 def record_namespaces(self, node): 203 204 "Process the program structure 'node', recording namespaces." 205 206 for n in node.getChildNodes(): 207 self.record_namespaces_in_node(n) 208 209 def record_namespaces_in_node(self, node): 210 211 "Process the program structure 'node', recording namespaces." 212 213 # Function namespaces within modules, classes and other functions. 214 # Functions appearing within conditional statements are given arbitrary 215 # names. 216 217 if isinstance(node, compiler.ast.Function): 218 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 219 220 elif isinstance(node, compiler.ast.Lambda): 221 self.record_function_node(node, self.get_lambda_name()) 222 223 # Classes are visited, but may be ignored if inside functions. 224 225 elif isinstance(node, compiler.ast.Class): 226 self.enter_namespace(node.name) 227 if self.have_object(): 228 self.record_namespaces(node) 229 self.exit_namespace() 230 231 # Conditional nodes are tracked so that function definitions may be 232 # handled. Since "for" loops are converted to "while" loops, they are 233 # included here. 234 235 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 236 in_conditional = self.in_conditional 237 self.in_conditional = True 238 self.record_namespaces(node) 239 self.in_conditional = in_conditional 240 241 # All other nodes are processed depth-first. 242 243 else: 244 self.record_namespaces(node) 245 246 def record_function_node(self, n, name): 247 248 """ 249 Record the given function, lambda, if expression or list comprehension 250 node 'n' with the given 'name'. 251 """ 252 253 self.in_function = True 254 self.enter_namespace(name) 255 256 if self.have_object(): 257 258 # Record the namespace path and the node itself. 259 260 self.namespaces.append((self.namespace_path[:], n)) 261 self.record_namespaces_in_node(n.code) 262 263 self.exit_namespace() 264 self.in_function = False 265 266 # Constant referencing. 267 268 def get_literal_instance(self, n, name=None): 269 270 """ 271 For node 'n', return a reference for the type of the given 'name', or if 272 'name' is not specified, deduce the type from the value. 273 """ 274 275 # Handle stray None constants (Sliceobj seems to produce them). 276 277 if name is None and n.value is None: 278 return self.process_name_node(compiler.ast.Name("None")) 279 280 if name in ("dict", "list", "tuple"): 281 ref = self.get_builtin_class(name) 282 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 283 else: 284 value, typename, encoding = self.get_constant_value(n.value, n.literals) 285 ref = self.get_builtin_class(typename) 286 value_type = ref.get_origin() 287 288 path = self.get_namespace_path() 289 290 # Obtain the local numbering of the constant and thus the 291 # locally-qualified name. 292 293 local_number = self.importer.all_constants[path][(value, value_type, encoding)] 294 constant_name = "$c%d" % local_number 295 objpath = self.get_object_path(constant_name) 296 297 # Obtain the unique identifier for the constant. 298 299 number = self.optimiser.constant_numbers[objpath] 300 return TrConstantValueRef(constant_name, ref.instance_of(), value, number) 301 302 # Namespace translation. 303 304 def process_namespace(self, path, node): 305 306 """ 307 Process the namespace for the given 'path' defined by the given 'node'. 308 """ 309 310 self.namespace_path = path 311 312 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 313 self.in_function = True 314 self.process_function_body_node(node) 315 else: 316 self.in_function = False 317 self.function_target = 0 318 self.max_function_target = 0 319 self.context_index = 0 320 self.max_context_index = 0 321 self.accessor_index = 0 322 self.max_accessor_index = 0 323 self.start_module() 324 self.process_structure(node) 325 self.end_module() 326 327 def process_structure(self, node): 328 329 "Process the given 'node' or result." 330 331 # Handle processing requests on results. 332 333 if isinstance(node, Result): 334 return node 335 336 # Handle processing requests on nodes. 337 338 else: 339 l = CommonModule.process_structure(self, node) 340 341 # Return indications of return statement usage. 342 343 if l and isinstance(l[-1], ReturnRef): 344 return l[-1] 345 else: 346 return None 347 348 def process_structure_node(self, n): 349 350 "Process the individual node 'n'." 351 352 # Plain statements emit their expressions. 353 354 if isinstance(n, compiler.ast.Discard): 355 expr = self.process_structure_node(n.expr) 356 self.statement(expr) 357 358 # Module import declarations. 359 360 elif isinstance(n, compiler.ast.From): 361 self.process_from_node(n) 362 363 # Nodes using operator module functions. 364 365 elif isinstance(n, compiler.ast.Operator): 366 return self.process_operator_node(n) 367 368 elif isinstance(n, compiler.ast.AugAssign): 369 self.process_augassign_node(n) 370 371 elif isinstance(n, compiler.ast.Compare): 372 return self.process_compare_node(n) 373 374 elif isinstance(n, compiler.ast.Slice): 375 return self.process_slice_node(n) 376 377 elif isinstance(n, compiler.ast.Sliceobj): 378 return self.process_sliceobj_node(n) 379 380 elif isinstance(n, compiler.ast.Subscript): 381 return self.process_subscript_node(n) 382 383 # Classes are visited, but may be ignored if inside functions. 384 385 elif isinstance(n, compiler.ast.Class): 386 self.process_class_node(n) 387 388 # Functions within namespaces have any dynamic defaults initialised. 389 390 elif isinstance(n, compiler.ast.Function): 391 self.process_function_node(n) 392 393 # Lambdas are replaced with references to separately-generated 394 # functions. 395 396 elif isinstance(n, compiler.ast.Lambda): 397 return self.process_lambda_node(n) 398 399 # Assignments. 400 401 elif isinstance(n, compiler.ast.Assign): 402 403 # Handle each assignment node. 404 405 for node in n.nodes: 406 self.process_assignment_node(node, n.expr) 407 408 # Accesses. 409 410 elif isinstance(n, compiler.ast.Getattr): 411 return self.process_attribute_access(n) 412 413 # Names. 414 415 elif isinstance(n, compiler.ast.Name): 416 return self.process_name_node(n) 417 418 # Loops and conditionals. 419 420 elif isinstance(n, compiler.ast.For): 421 self.process_for_node(n) 422 423 elif isinstance(n, compiler.ast.While): 424 self.process_while_node(n) 425 426 elif isinstance(n, compiler.ast.If): 427 self.process_if_node(n) 428 429 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 430 return self.process_logical_node(n) 431 432 elif isinstance(n, compiler.ast.Not): 433 return self.process_not_node(n) 434 435 # Exception control-flow tracking. 436 437 elif isinstance(n, compiler.ast.TryExcept): 438 self.process_try_node(n) 439 440 elif isinstance(n, compiler.ast.TryFinally): 441 self.process_try_finally_node(n) 442 443 # Control-flow modification statements. 444 445 elif isinstance(n, compiler.ast.Break): 446 self.writestmt("break;") 447 448 elif isinstance(n, compiler.ast.Continue): 449 self.writestmt("continue;") 450 451 elif isinstance(n, compiler.ast.Raise): 452 self.process_raise_node(n) 453 454 elif isinstance(n, compiler.ast.Return): 455 return self.process_return_node(n) 456 457 # Print statements. 458 459 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 460 self.statement(self.process_print_node(n)) 461 462 # Invocations. 463 464 elif isinstance(n, compiler.ast.CallFunc): 465 return self.process_invocation_node(n) 466 467 elif isinstance(n, compiler.ast.Keyword): 468 return self.process_structure_node(n.expr) 469 470 # Constant usage. 471 472 elif isinstance(n, compiler.ast.Const): 473 return self.get_literal_instance(n) 474 475 elif isinstance(n, compiler.ast.Dict): 476 return self.get_literal_instance(n, "dict") 477 478 elif isinstance(n, compiler.ast.List): 479 return self.get_literal_instance(n, "list") 480 481 elif isinstance(n, compiler.ast.Tuple): 482 return self.get_literal_instance(n, "tuple") 483 484 # All other nodes are processed depth-first. 485 486 else: 487 return self.process_structure(n) 488 489 def process_assignment_node(self, n, expr): 490 491 "Process the individual node 'n' to be assigned the contents of 'expr'." 492 493 # Names and attributes are assigned the entire expression. 494 495 if isinstance(n, compiler.ast.AssName): 496 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 497 self.statement(name_ref) 498 499 # Employ guards after assignments if required. 500 501 if expr and name_ref.is_name(): 502 self.generate_guard(name_ref.name) 503 504 elif isinstance(n, compiler.ast.AssAttr): 505 in_assignment = self.in_assignment 506 self.in_assignment = self.process_structure_node(expr) 507 self.statement(self.process_attribute_access(n)) 508 self.in_assignment = in_assignment 509 510 # Lists and tuples are matched against the expression and their 511 # items assigned to expression items. 512 513 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 514 self.process_assignment_node_items(n, expr) 515 516 # Slices and subscripts are permitted within assignment nodes. 517 518 elif isinstance(n, compiler.ast.Slice): 519 self.statement(self.process_slice_node(n, expr)) 520 521 elif isinstance(n, compiler.ast.Subscript): 522 self.statement(self.process_subscript_node(n, expr)) 523 524 def process_attribute_access(self, n): 525 526 "Process the given attribute access node 'n'." 527 528 # Obtain any completed chain and return the reference to it. 529 530 attr_expr = self.process_attribute_chain(n) 531 if self.have_access_expression(n): 532 return attr_expr 533 534 # Where the start of the chain of attributes has been reached, process 535 # the complete access. 536 537 name_ref = attr_expr and attr_expr.is_name() and attr_expr 538 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref) or None 539 540 location = self.get_access_location(name, self.attrs) 541 refs = self.get_referenced_attributes(location) 542 543 # Generate access instructions. 544 545 subs = { 546 "<expr>" : attr_expr, 547 "<name>" : attr_expr, 548 "<assexpr>" : self.in_assignment, 549 } 550 551 subs.update(self.temp_subs) 552 subs.update(self.op_subs) 553 554 output = [] 555 substituted = set() 556 557 # The context set or retrieved will be that used by any enclosing 558 # invocation. 559 560 accessor_index = self.accessor_index 561 context_index = self.context_index 562 context_identity = None 563 context_identity_verified = False 564 final_identity = None 565 accessor_test = False 566 accessor_stored = False 567 568 # Obtain encoded versions of each instruction, accumulating temporary 569 # variables. 570 571 for instruction in self.deducer.access_instructions[location]: 572 573 # Intercept a special instruction identifying the context. 574 575 if instruction[0] in ("<context_identity>", "<context_identity_verified>"): 576 context_identity, _substituted = \ 577 encode_access_instruction_arg(instruction[1], subs, instruction[0], 578 accessor_index, context_index) 579 context_identity_verified = instruction[0] == "<context_identity_verified>" 580 continue 581 582 # Intercept a special instruction identifying the target. The value 583 # is not encoded since it is used internally. 584 585 elif instruction[0] == "<final_identity>": 586 final_identity = instruction[1] 587 continue 588 589 # Modify test instructions. 590 591 elif instruction[0] in typename_ops or instruction[0] in type_ops: 592 instruction = ("__to_error", instruction) 593 accessor_test = True 594 595 # Intercept accessor storage. 596 597 elif instruction[0] == "<set_accessor>": 598 accessor_stored = True 599 600 # Collect the encoded instruction, noting any temporary variables 601 # required by it. 602 603 encoded, _substituted = encode_access_instruction(instruction, subs, 604 accessor_index, context_index) 605 output.append(encoded) 606 substituted.update(_substituted) 607 608 # Record temporary name usage. 609 610 for sub in substituted: 611 if self.temp_subs.has_key(sub): 612 self.record_temp(self.temp_subs[sub]) 613 614 # Get full final identity details. 615 616 if final_identity and not refs: 617 refs = set([self.importer.identify(final_identity)]) 618 619 del self.attrs[0] 620 return AttrResult(output, refs, location, 621 context_identity, context_identity_verified, 622 accessor_test, accessor_stored) 623 624 def init_substitutions(self): 625 626 """ 627 Initialise substitutions, defining temporary variable mappings, some of 628 which are also used as substitutions, together with operation mappings 629 used as substitutions in instructions defined by the optimiser. 630 """ 631 632 self.temp_subs = { 633 634 # Substitutions used by instructions. 635 636 "<private_context>" : "__tmp_private_context", 637 "<target_accessor>" : "__tmp_target_value", 638 639 # Mappings to be replaced by those given below. 640 641 "<accessor>" : "__tmp_values", 642 "<context>" : "__tmp_contexts", 643 "<test_context_revert>" : "__tmp_contexts", 644 "<test_context_static>" : "__tmp_contexts", 645 "<set_context>" : "__tmp_contexts", 646 "<set_private_context>" : "__tmp_private_context", 647 "<set_accessor>" : "__tmp_values", 648 "<set_target_accessor>" : "__tmp_target_value", 649 } 650 651 self.op_subs = { 652 "<accessor>" : "__get_accessor", 653 "<context>" : "__get_context", 654 "<test_context_revert>" : "__test_context_revert", 655 "<test_context_static>" : "__test_context_static", 656 "<set_context>" : "__set_context", 657 "<set_private_context>" : "__set_private_context", 658 "<set_accessor>" : "__set_accessor", 659 "<set_target_accessor>" : "__set_target_accessor", 660 } 661 662 def get_referenced_attributes(self, location): 663 664 """ 665 Convert 'location' to the form used by the deducer and retrieve any 666 identified attributes. 667 """ 668 669 # Determine whether any deduced references refer to the accessed 670 # attribute. 671 672 attrnames = location.attrnames 673 attrnames = attrnames and attrnames.split(".") 674 remaining = attrnames and len(attrnames) > 1 675 676 access_location = self.deducer.const_accesses.get(location) 677 678 if remaining and not access_location: 679 return set() 680 681 return self.deducer.get_references_for_access(access_location or location) 682 683 def get_referenced_attribute_invocations(self, location): 684 685 """ 686 Convert 'location' to the form used by the deducer and retrieve any 687 identified attribute invocation details. 688 """ 689 690 access_location = self.deducer.const_accesses.get(location) 691 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 692 693 def get_accessor_kinds(self, location): 694 695 "Return the accessor kinds for 'location'." 696 697 return self.deducer.accessor_kinds.get(location) 698 699 def get_access_location(self, name, attrnames=None): 700 701 """ 702 Using the current namespace, the given 'name', and the 'attrnames' 703 employed in an access, return the access location. 704 """ 705 706 path = self.get_path_for_access() 707 708 # Get the location used by the deducer and optimiser and find any 709 # recorded access. 710 711 attrnames = attrnames and ".".join(self.attrs) 712 access_number = self.get_access_number(path, name, attrnames) 713 self.update_access_number(path, name, attrnames) 714 return AccessLocation(path, name, attrnames, access_number) 715 716 def get_access_number(self, path, name, attrnames): 717 access = name, attrnames 718 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 719 return self.attr_accesses[path][access] 720 else: 721 return 0 722 723 def update_access_number(self, path, name, attrnames): 724 access = name, attrnames 725 if name: 726 init_item(self.attr_accesses, path, dict) 727 init_item(self.attr_accesses[path], access, lambda: 0) 728 self.attr_accesses[path][access] += 1 729 730 def get_accessor_location(self, name): 731 732 """ 733 Using the current namespace and the given 'name', return the accessor 734 location. 735 """ 736 737 path = self.get_path_for_access() 738 739 # Get the location used by the deducer and optimiser and find any 740 # recorded accessor. 741 742 version = self.get_accessor_number(path, name) 743 self.update_accessor_number(path, name) 744 return Location(path, name, None, version) 745 746 def get_accessor_number(self, path, name): 747 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 748 return self.attr_accessors[path][name] 749 else: 750 return 0 751 752 def update_accessor_number(self, path, name): 753 if name: 754 init_item(self.attr_accessors, path, dict) 755 init_item(self.attr_accessors[path], name, lambda: 0) 756 self.attr_accessors[path][name] += 1 757 758 def process_class_node(self, n): 759 760 "Process the given class node 'n'." 761 762 class_name = self.get_object_path(n.name) 763 764 # Where a class is set conditionally or where the name may refer to 765 # different values, assign the name. 766 767 ref = self.importer.identify(class_name) 768 769 if not ref.static(): 770 self.process_assignment_for_object(n.name, 771 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 772 773 self.enter_namespace(n.name) 774 775 if self.have_object(): 776 self.write_comment("Class: %s" % class_name) 777 778 self.initialise_inherited_members(class_name) 779 780 self.process_structure(n) 781 self.write_comment("End class: %s" % class_name) 782 783 self.exit_namespace() 784 785 def initialise_inherited_members(self, class_name): 786 787 "Initialise members of 'class_name' inherited from its ancestors." 788 789 for name, path in self.importer.all_class_attrs[class_name].items(): 790 target = "%s.%s" % (class_name, name) 791 792 # Ignore attributes with definitions. 793 794 ref = self.importer.identify(target) 795 if ref: 796 continue 797 798 # Ignore special type attributes. 799 800 if is_type_attribute(name): 801 continue 802 803 # Reference inherited attributes. 804 805 ref = self.importer.identify(path) 806 if ref and not ref.static(): 807 parent, attrname = path.rsplit(".", 1) 808 809 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 810 encode_path(class_name), name, 811 encode_path(parent), attrname 812 )) 813 814 def process_from_node(self, n): 815 816 "Process the given node 'n', importing from another module." 817 818 path = self.get_namespace_path() 819 820 # Attempt to obtain the referenced objects. 821 822 for name, alias in n.names: 823 if name == "*": 824 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 825 826 # Obtain the path of the assigned name. 827 828 objpath = self.get_object_path(alias or name) 829 830 # Obtain the identity of the name. 831 832 ref = self.importer.identify(objpath) 833 834 # Where the name is not static, assign the value. 835 836 if ref and not ref.static() and ref.get_name(): 837 self.writestmt("%s;" % 838 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 839 expr=TrResolvedNameRef(name, ref))) 840 841 def process_function_body_node(self, n): 842 843 """ 844 Process the given function, lambda, if expression or list comprehension 845 node 'n', generating the body. 846 """ 847 848 function_name = self.get_namespace_path() 849 self.start_function(function_name) 850 851 # Process the function body. 852 853 in_conditional = self.in_conditional 854 self.in_conditional = False 855 self.function_target = 0 856 self.max_function_target = 0 857 self.context_index = 0 858 self.max_context_index = 0 859 self.accessor_index = 0 860 self.max_accessor_index = 0 861 862 # Volatile locals for exception handling. 863 864 self.volatile_locals = set() 865 866 # Process any guards defined for the parameters. 867 868 for name in self.importer.function_parameters.get(function_name): 869 self.generate_guard(name) 870 871 # Also support self in methods, since some mix-in methods may only work 872 # with certain descendant classes. 873 874 if self.in_method(): 875 self.generate_guard("self") 876 877 # Make assignments for .name entries in the parameters, provided this is 878 # a method. 879 880 if self.in_method(): 881 for name in self.importer.function_attr_initialisers.get(function_name) or []: 882 self.process_assignment_node( 883 compiler.ast.AssAttr(compiler.ast.Name("self"), name, "OP_ASSIGN"), 884 compiler.ast.Name(name)) 885 886 # Produce the body and any additional return statement. 887 888 expr = self.process_structure_node(n.code) or \ 889 self.in_method() and \ 890 function_name.rsplit(".", 1)[-1] == "__init__" and \ 891 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 892 PredefinedConstantRef("None") 893 894 if not isinstance(expr, ReturnRef): 895 self.writestmt("return %s;" % expr) 896 897 self.in_conditional = in_conditional 898 899 self.end_function(function_name) 900 901 def generate_guard(self, name): 902 903 """ 904 Get the accessor details for 'name', found in the current namespace, and 905 generate any guards defined for it. 906 """ 907 908 # Obtain the location, keeping track of assignment versions. 909 910 location = self.get_accessor_location(name) 911 test = self.deducer.accessor_guard_tests.get(location) 912 913 # Generate any guard from the deduced information. 914 915 if test: 916 guard, guard_type = test 917 918 if guard == "specific": 919 ref = first(self.deducer.accessor_all_types[location]) 920 argstr = "&%s" % encode_path(ref.get_origin()) 921 elif guard == "common": 922 ref = first(self.deducer.accessor_all_general_types[location]) 923 argstr = encode_path(encode_type_attribute(ref.get_origin())) 924 else: 925 return 926 927 # Write a test that raises a TypeError upon failure. 928 929 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 930 guard, guard_type, encode_path(name), argstr)) 931 932 def process_function_node(self, n): 933 934 """ 935 Process the given function, lambda, if expression or list comprehension 936 node 'n', generating any initialisation statements. 937 """ 938 939 # Where a function is declared conditionally, use a separate name for 940 # the definition, and assign the definition to the stated name. 941 942 original_name = n.name 943 944 if self.in_conditional or self.in_function: 945 name = self.get_lambda_name() 946 else: 947 name = n.name 948 949 objpath = self.get_object_path(name) 950 951 # Obtain details of the defaults. 952 953 defaults = self.process_function_defaults(n, name, objpath) 954 if defaults: 955 for default in defaults: 956 self.writeline("%s;" % default) 957 958 # Where a function is set conditionally or where the name may refer to 959 # different values, assign the name. 960 961 ref = self.importer.identify(objpath) 962 963 if self.in_conditional or self.in_function: 964 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 965 elif not ref.static(): 966 context = self.is_method(objpath) 967 968 self.process_assignment_for_object(original_name, 969 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 970 971 def process_function_defaults(self, n, name, objpath, instance_name=None): 972 973 """ 974 Process the given function or lambda node 'n', initialising defaults 975 that are dynamically set. The given 'name' indicates the name of the 976 function. The given 'objpath' indicates the origin of the function. 977 The given 'instance_name' indicates the name of any separate instance 978 of the function created to hold the defaults. 979 980 Return a list of operations setting defaults on a function instance. 981 """ 982 983 function_name = self.get_object_path(name) 984 function_defaults = self.importer.function_defaults.get(function_name) 985 if not function_defaults: 986 return None 987 988 # Determine whether any unidentified defaults are involved. 989 990 for argname, default in function_defaults: 991 if not default.static(): 992 break 993 else: 994 return None 995 996 # Handle bound methods. 997 998 if not instance_name: 999 instance_name = "&%s" % encode_path(objpath) 1000 else: 1001 instance_name = "__VALUE(%s)" % instance_name 1002 1003 # Where defaults are involved but cannot be identified, obtain a new 1004 # instance of the lambda and populate the defaults. 1005 1006 defaults = [] 1007 1008 # Join the original defaults with the inspected defaults. 1009 1010 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 1011 1012 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 1013 1014 # Obtain any reference for the default. 1015 1016 if original: 1017 argname, default = original 1018 name_ref = self.process_structure_node(default) 1019 elif inspected: 1020 argname, default = inspected 1021 name_ref = TrResolvedNameRef(argname, default) 1022 else: 1023 continue 1024 1025 # Generate default initialisers except when constants are employed. 1026 # Constants should be used when populating the function structures. 1027 1028 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1029 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1030 1031 return defaults 1032 1033 def process_if_node(self, n): 1034 1035 """ 1036 Process the given "if" node 'n'. 1037 """ 1038 1039 first = True 1040 for test, body in n.tests: 1041 test_ref = self.process_structure_node(test) 1042 self.start_if(first, test_ref) 1043 1044 in_conditional = self.in_conditional 1045 self.in_conditional = True 1046 self.process_structure_node(body) 1047 self.in_conditional = in_conditional 1048 1049 self.end_if() 1050 first = False 1051 1052 if n.else_: 1053 self.start_else() 1054 self.process_structure_node(n.else_) 1055 self.end_else() 1056 1057 print >>self.out 1058 1059 def process_invocation_node(self, n): 1060 1061 "Process the given invocation node 'n'." 1062 1063 # Process the expression. 1064 1065 expr = self.process_structure_node(n.node) 1066 1067 # Obtain details of the invocation expression. 1068 1069 objpath = expr.get_origin() 1070 location = expr.access_location() 1071 refs = expr.references() 1072 1073 # Identified target details. 1074 1075 target = None 1076 target_structure = None 1077 1078 # Specific function target information. 1079 1080 function = None 1081 1082 # Instantiation involvement. 1083 1084 instantiation = False 1085 literal_instantiation = False 1086 1087 # Invocation requirements. 1088 1089 context_required = True 1090 have_access_context = isinstance(expr, AttrResult) 1091 1092 # The context identity is merely the thing providing the context. 1093 # A verified context is one that does not need further testing for 1094 # suitability. 1095 1096 context_identity = have_access_context and expr.context() 1097 context_verified = have_access_context and expr.context_verified() 1098 1099 # The presence of any test operations in the accessor expression. 1100 # With such operations present, the expression cannot be eliminated. 1101 1102 tests_accessor = have_access_context and expr.tests_accessor() 1103 stores_accessor = have_access_context and expr.stores_accessor() 1104 1105 # Parameter details and parameter list dimensions. 1106 1107 parameters = None 1108 num_parameters = None 1109 num_defaults = None 1110 1111 # Obtain details of the callable and of its parameters. 1112 1113 # Literals may be instantiated specially. 1114 1115 if expr.is_name() and expr.name.startswith("$L") and objpath: 1116 instantiation = literal_instantiation = objpath 1117 target = encode_literal_instantiator(objpath) 1118 context_required = False 1119 1120 # Identified targets employ function pointers directly. 1121 1122 elif objpath: 1123 parameters = self.importer.function_parameters.get(objpath) 1124 function_defaults = self.importer.function_defaults.get(objpath) 1125 num_parameters = parameters and len(parameters) or 0 1126 num_defaults = function_defaults and len(function_defaults) or 0 1127 1128 # Class invocation involves instantiators. 1129 1130 if expr.has_kind("<class>"): 1131 instantiation = objpath 1132 target = encode_instantiator_pointer(objpath) 1133 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1134 target_structure = "&%s" % encode_path(init_ref) 1135 context_required = False 1136 1137 # Only plain functions and bound methods employ function pointers. 1138 1139 elif expr.has_kind("<function>"): 1140 function = objpath 1141 1142 # Test for functions and methods. 1143 1144 context_required = self.is_method(objpath) 1145 1146 accessor_kinds = location and self.get_accessor_kinds(location) 1147 1148 instance_accessor = accessor_kinds and \ 1149 len(accessor_kinds) == 1 and \ 1150 first(accessor_kinds) == "<instance>" 1151 1152 # Only identify certain bound methods or functions. 1153 1154 if not context_required or instance_accessor: 1155 target = encode_function_pointer(objpath) 1156 1157 # Access bound method defaults even if it is not clear whether 1158 # the accessor is appropriate. 1159 1160 target_structure = "&%s" % encode_path(objpath) 1161 1162 # Other targets are retrieved at run-time. 1163 1164 else: 1165 if location: 1166 attrnames = location.attrnames 1167 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1168 1169 # Determine common aspects of any identifiable targets. 1170 1171 if attrname or refs: 1172 all_params = set() 1173 all_defaults = set() 1174 min_params = set() 1175 max_params = set() 1176 1177 # Employ references from the expression or find all 1178 # possible attributes for the given attribute name. 1179 1180 refs = refs or self.get_attributes_for_attrname(attrname) 1181 1182 # Obtain parameters and defaults for each possible target. 1183 1184 for ref in refs: 1185 origin = ref.get_origin() 1186 params = self.importer.function_parameters.get(origin) 1187 1188 defaults = self.importer.function_defaults.get(origin) 1189 if defaults is not None: 1190 all_defaults.add(tuple(defaults)) 1191 1192 if params is not None: 1193 all_params.add(tuple(params)) 1194 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1195 max_params.add(len(params)) 1196 else: 1197 refs = set() 1198 break 1199 1200 # Where the parameters and defaults are always the same, 1201 # permit populating them in advance. 1202 1203 if refs: 1204 if self.uses_keyword_arguments(n): 1205 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1206 parameters = first(all_params) 1207 function_defaults = all_defaults and first(all_defaults) or [] 1208 num_parameters = parameters and len(parameters) or 0 1209 num_defaults = function_defaults and len(function_defaults) or 0 1210 else: 1211 if len(min_params) == 1 and len(max_params) == 1: 1212 num_parameters = first(max_params) 1213 num_defaults = first(max_params) - first(min_params) 1214 1215 # Some information about the target may be available and be used to 1216 # provide warnings about argument compatibility. 1217 1218 if self.importer.give_warning("args"): 1219 unsuitable = self.get_referenced_attribute_invocations(location) 1220 1221 if unsuitable: 1222 for ref in unsuitable: 1223 _objpath = ref.get_origin() 1224 print >>sys.stderr, \ 1225 "In %s, at line %d, inappropriate number of " \ 1226 "arguments given. Need %d arguments to call %s." % ( 1227 self.get_namespace_path(), n.lineno, 1228 len(self.importer.function_parameters[_objpath]), 1229 _objpath) 1230 1231 # Logical statement about available parameter information. 1232 1233 known_parameters = num_parameters is not None 1234 1235 # The source of context information: target or temporary. 1236 1237 need_context_target = context_required and not have_access_context 1238 1239 need_context_stored = context_required and context_identity and \ 1240 context_identity.startswith("__get_context") 1241 1242 # Determine any readily-accessible target identity. 1243 1244 target_named = expr.is_name() and str(expr) or None 1245 target_identity = target or target_named 1246 1247 # Use of target information to populate defaults. 1248 1249 defaults_target_var = not (parameters and function_defaults is not None) and \ 1250 known_parameters and len(n.args) < num_parameters 1251 1252 # Use of a temporary target variable in these situations: 1253 # 1254 # A target provided by an expression needed for defaults. 1255 # 1256 # A target providing the context but not using a name to do so. 1257 # 1258 # A target expression involving the definition of a context which may 1259 # then be evaluated and stored to ensure that the context is available 1260 # during argument evaluation. 1261 # 1262 # An expression featuring an accessor test. 1263 1264 need_target_stored = defaults_target_var and not target_identity or \ 1265 need_context_target and not target_identity or \ 1266 need_context_stored or \ 1267 tests_accessor and not target 1268 1269 # Define stored target details. 1270 1271 target_stored = "__tmp_targets[%d]" % self.function_target 1272 target_var = need_target_stored and target_stored or target_identity 1273 1274 if need_target_stored: 1275 self.record_temp("__tmp_targets") 1276 1277 if need_context_stored: 1278 self.record_temp("__tmp_contexts") 1279 1280 if stores_accessor: 1281 self.record_temp("__tmp_values") 1282 1283 # Arguments are presented in a temporary frame array with any context 1284 # always being the first argument. Where it would be unused, it may be 1285 # set to null. 1286 1287 if context_required: 1288 if have_access_context: 1289 context_arg = context_identity 1290 else: 1291 context_arg = "__CONTEXT_AS_VALUE(%s)" % target_var 1292 else: 1293 context_arg = "__NULL" 1294 1295 args = [context_arg] 1296 reserved_args = 1 1297 1298 # Complete the array with null values, permitting tests for a complete 1299 # set of arguments. 1300 1301 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1302 kwcodes = [] 1303 kwargs = [] 1304 1305 # Any invocations in the arguments will store target details in a 1306 # different location. 1307 1308 function_target = self.function_target 1309 context_index = self.context_index 1310 accessor_index = self.accessor_index 1311 1312 if need_target_stored: 1313 self.next_target() 1314 1315 if need_context_stored: 1316 self.next_context() 1317 1318 if stores_accessor: 1319 self.next_accessor() 1320 1321 in_parameter_list = self.in_parameter_list 1322 self.in_parameter_list = True 1323 1324 for i, arg in enumerate(n.args): 1325 argexpr = self.process_structure_node(arg) 1326 1327 # Obtain an appropriate argument representation. This prevents 1328 # copyable values from being mutable, but care must be taken to 1329 # prevent special internal attribute values represented using 1330 # attributes from being modified. 1331 1332 argrepr = argexpr.as_arg() 1333 1334 # Store a keyword argument, either in the argument list or 1335 # in a separate keyword argument list for subsequent lookup. 1336 1337 if isinstance(arg, compiler.ast.Keyword): 1338 1339 # With knowledge of the target, store the keyword 1340 # argument directly. 1341 1342 if parameters: 1343 try: 1344 argnum = parameters.index(arg.name) 1345 except ValueError: 1346 raise TranslateError("Argument %s is not recognised." % arg.name, 1347 self.get_namespace_path(), n) 1348 args[argnum + reserved_args] = argrepr 1349 1350 # Otherwise, store the details in a separate collection. 1351 1352 else: 1353 kwargs.append(argrepr) 1354 kwcodes.append("{%s, %s}" % ( 1355 encode_ppos(arg.name), encode_pcode(arg.name))) 1356 1357 # Store non-keyword arguments in the argument list, rejecting 1358 # superfluous arguments. 1359 1360 else: 1361 try: 1362 args[i + reserved_args] = argrepr 1363 except IndexError: 1364 raise TranslateError("Too many arguments specified.", 1365 self.get_namespace_path(), n) 1366 1367 # Reference the current target again. 1368 1369 self.in_parameter_list = in_parameter_list 1370 1371 if not self.in_parameter_list: 1372 self.function_target = function_target 1373 self.context_index = context_index 1374 self.accessor_index = accessor_index 1375 1376 # Defaults are added to the frame where arguments are missing. 1377 1378 if parameters and function_defaults is not None: 1379 1380 # Visit each default and set any missing arguments. Where keyword 1381 # arguments have been used, the defaults must be inspected and, if 1382 # necessary, inserted into gaps in the argument list. 1383 1384 for i, (argname, default) in enumerate(function_defaults): 1385 argnum = parameters.index(argname) 1386 if not args[argnum + reserved_args]: 1387 args[argnum + reserved_args] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1388 1389 elif known_parameters: 1390 1391 # No specific parameter details are provided, but no keyword 1392 # arguments are used. Thus, defaults can be supplied using position 1393 # information only. 1394 1395 i = len(n.args) 1396 pos = i - (num_parameters - num_defaults) 1397 while i < num_parameters: 1398 args[i + reserved_args] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1399 i += 1 1400 pos += 1 1401 1402 # Test for missing arguments. 1403 1404 if None in args: 1405 raise TranslateError("Not all arguments supplied.", 1406 self.get_namespace_path(), n) 1407 1408 # Encode the arguments. 1409 1410 # Where literal instantiation is occurring, add an argument indicating 1411 # the number of values. The context is excluded. 1412 1413 if literal_instantiation: 1414 argstr = "%d, %s" % (len(args) - reserved_args, ", ".join(args[reserved_args:])) 1415 else: 1416 argstr = ", ".join(args) 1417 1418 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1419 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1420 1421 # First, the invocation expression is presented. 1422 1423 stages = [] 1424 emit = stages.append 1425 1426 # Assign and yield any stored target. 1427 # The context may be set in the expression. 1428 1429 if need_target_stored: 1430 emit("%s = %s" % (target_var, expr)) 1431 target_expr = target_var 1432 1433 # Otherwise, retain the expression for later use. 1434 1435 else: 1436 target_expr = str(expr) 1437 1438 # Any specific callable is then obtained for invocation. 1439 1440 if target: 1441 1442 # An expression involving a test of the accessor providing the target. 1443 # This must be emitted in order to perform the test. 1444 1445 if tests_accessor: 1446 emit(str(expr)) 1447 1448 emit(target) 1449 1450 # Methods accessed via unidentified accessors are obtained for 1451 # invocation. 1452 1453 elif function: 1454 if context_required: 1455 1456 # Avoid further context testing if appropriate. 1457 1458 if have_access_context and context_verified: 1459 emit("__get_function_member(%s)" % target_expr) 1460 1461 # Otherwise, test the context for the function/method. 1462 1463 else: 1464 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1465 else: 1466 emit("_get_function_member(%s)" % target_expr) 1467 1468 # With known parameters, the target can be tested. 1469 1470 elif known_parameters: 1471 if self.always_callable(refs): 1472 if context_verified: 1473 emit("__get_function_member(%s)" % target_expr) 1474 else: 1475 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1476 else: 1477 emit("__check_and_get_function(%s, %s)" % (context_arg, target_expr)) 1478 1479 # With a known target, the function is obtained directly and called. 1480 # By putting the invocation at the end of the final element in the 1481 # instruction sequence (the stages), the result becomes the result of 1482 # the sequence. Moreover, the parameters become part of the sequence 1483 # and thereby participate in a guaranteed evaluation order. 1484 1485 if target or function or known_parameters: 1486 stages[-1] += "(%s)" % argstr 1487 if instantiation: 1488 return InstantiationResult(instantiation, stages) 1489 else: 1490 return InvocationResult(stages) 1491 1492 # With unknown targets, the generic invocation function is applied to 1493 # the callable and argument collections. 1494 1495 else: 1496 emit("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1497 target_expr, 1498 self.always_callable(refs) and 1 or 0, 1499 len(kwargs), kwcodestr, kwargstr, 1500 len(args), "__ARGS(%s)" % argstr)) 1501 return InvocationResult(stages) 1502 1503 def next_target(self): 1504 1505 "Allocate the next function target storage." 1506 1507 self.function_target += 1 1508 self.max_function_target = max(self.function_target, self.max_function_target) 1509 1510 def next_context(self): 1511 1512 "Allocate the next context value storage." 1513 1514 self.context_index += 1 1515 self.max_context_index = max(self.context_index, self.max_context_index) 1516 1517 def next_accessor(self): 1518 1519 "Allocate the next accessor value storage." 1520 1521 self.accessor_index += 1 1522 self.max_accessor_index = max(self.accessor_index, self.max_accessor_index) 1523 1524 def always_callable(self, refs): 1525 1526 "Determine whether all 'refs' are callable." 1527 1528 if not refs: 1529 return False 1530 1531 for ref in refs: 1532 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1533 return False 1534 1535 return True 1536 1537 def need_default_arguments(self, objpath, nargs): 1538 1539 """ 1540 Return whether any default arguments are needed when invoking the object 1541 given by 'objpath'. 1542 """ 1543 1544 parameters = self.importer.function_parameters.get(objpath) 1545 return nargs < len(parameters) 1546 1547 def uses_keyword_arguments(self, n): 1548 1549 "Return whether invocation node 'n' uses keyword arguments." 1550 1551 for arg in enumerate(n.args): 1552 if isinstance(arg, compiler.ast.Keyword): 1553 return True 1554 1555 return False 1556 1557 def get_attributes_for_attrname(self, attrname): 1558 1559 "Return a set of all attributes exposed by 'attrname'." 1560 1561 usage = [(attrname, True, False)] 1562 class_types = self.deducer.get_class_types_for_usage(usage) 1563 instance_types = self.deducer.get_instance_types_for_usage(usage) 1564 module_types = self.deducer.get_module_types_for_usage(usage) 1565 attrs = set() 1566 1567 for ref in combine_types(class_types, instance_types, module_types): 1568 attrs.update(self.importer.get_attributes(ref, attrname)) 1569 1570 return attrs 1571 1572 def process_lambda_node(self, n): 1573 1574 "Process the given lambda node 'n'." 1575 1576 name = self.get_lambda_name() 1577 function_name = self.get_object_path(name) 1578 instance_name = "__get_accessor(%d)" % self.accessor_index 1579 1580 defaults = self.process_function_defaults(n, name, function_name, instance_name) 1581 1582 # Without defaults, produce an attribute referring to the function. 1583 1584 if not defaults: 1585 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1586 1587 # With defaults, copy the function structure and set the defaults on the 1588 # copy. 1589 1590 else: 1591 self.record_temp("__tmp_values") 1592 return make_expression("""\ 1593 (__set_accessor(%d, __ATTRVALUE(__COPY(&%s, sizeof(%s)))), 1594 %s, 1595 __get_accessor(%d))""" % ( 1596 self.accessor_index, 1597 encode_path(function_name), 1598 encode_symbol("obj", function_name), 1599 ", ".join(defaults), 1600 self.accessor_index)) 1601 1602 def process_logical_node(self, n): 1603 1604 "Process the given operator node 'n'." 1605 1606 self.record_temp("__tmp_result") 1607 1608 conjunction = isinstance(n, compiler.ast.And) 1609 results = [] 1610 1611 for node in n.nodes: 1612 results.append(self.process_structure_node(node)) 1613 1614 return LogicalOperationResult(results, conjunction) 1615 1616 def process_name_node(self, n, expr=None): 1617 1618 "Process the given name node 'n' with the optional assignment 'expr'." 1619 1620 # Determine whether the name refers to a static external entity. 1621 1622 if n.name in predefined_constants: 1623 return PredefinedConstantRef(n.name, expr) 1624 1625 # Convert literal references, operator function names, and print 1626 # function names to references. 1627 1628 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1629 n.name.startswith("$seq") or n.name.startswith("$print"): 1630 1631 ref, paths = self.importer.get_module(self.name).special[n.name] 1632 return TrResolvedNameRef(n.name, ref) 1633 1634 # Get the appropriate name for the name reference, using the same method 1635 # as in the inspector. 1636 1637 path = self.get_namespace_path() 1638 objpath = self.get_object_path(n.name) 1639 1640 # Determine any assigned globals. 1641 1642 globals = self.importer.get_module(self.name).scope_globals.get(path) 1643 1644 # Explicitly declared globals. 1645 1646 if globals and n.name in globals: 1647 objpath = self.get_global_path(n.name) 1648 is_global = True 1649 1650 # Implicitly referenced globals in functions. 1651 1652 elif self.in_function: 1653 is_global = n.name not in self.importer.function_locals[path] 1654 1655 # Implicitly referenced globals elsewhere. 1656 1657 else: 1658 namespace = self.importer.identify(path) 1659 is_global = not self.importer.get_attributes(namespace, n.name) 1660 1661 # Get the static identity of the name. 1662 1663 ref = self.importer.identify(objpath) 1664 if ref and not ref.get_name(): 1665 ref = ref.alias(objpath) 1666 1667 # Obtain any resolved names for non-assignment names. 1668 1669 if not expr and not ref and self.in_function: 1670 locals = self.importer.function_locals.get(path) 1671 ref = locals and locals.get(n.name) 1672 1673 # Find any invocation or alias details. 1674 1675 name = self.get_name_for_tracking(n.name, is_global=is_global) 1676 location = not expr and self.get_access_location(name) or None 1677 1678 # Mark any local assignments as volatile in exception blocks. 1679 1680 if expr and self.in_function and not is_global and self.in_try_except: 1681 self.make_volatile(n.name) 1682 1683 # Qualified names are used for resolved static references or for 1684 # static namespace members. The reference should be configured to return 1685 # such names. 1686 1687 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1688 location=location) 1689 return not expr and self.get_aliases(name_ref) or name_ref 1690 1691 def get_aliases(self, name_ref): 1692 1693 "Return alias references for the given 'name_ref'." 1694 1695 location = name_ref.access_location() 1696 accessor_locations = self.deducer.access_index.get(location) 1697 1698 if not accessor_locations: 1699 return None 1700 1701 refs = set() 1702 1703 for accessor_location in accessor_locations: 1704 alias_refs = self.deducer.referenced_objects.get(accessor_location) 1705 if alias_refs: 1706 refs.update(alias_refs) 1707 1708 if refs: 1709 return AliasResult(name_ref, refs, location) 1710 else: 1711 return None 1712 1713 def make_volatile(self, name): 1714 1715 "Record 'name' as volatile in the current namespace." 1716 1717 self.volatile_locals.add(name) 1718 1719 def process_not_node(self, n): 1720 1721 "Process the given operator node 'n'." 1722 1723 return self.make_negation(self.process_structure_node(n.expr)) 1724 1725 def process_raise_node(self, n): 1726 1727 "Process the given raise node 'n'." 1728 1729 # NOTE: Determine which raise statement variants should be permitted. 1730 1731 if n.expr1: 1732 1733 # Names with accompanying arguments are treated like invocations. 1734 1735 if n.expr2: 1736 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1737 exc = self.process_structure_node(call) 1738 self.writestmt("__Raise(%s);" % exc) 1739 1740 # Raise instances, testing the kind at run-time if necessary and 1741 # instantiating any non-instance. 1742 1743 else: 1744 exc = self.process_structure_node(n.expr1) 1745 1746 if isinstance(exc, TrInstanceRef): 1747 self.writestmt("__Raise(%s);" % exc) 1748 else: 1749 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1750 else: 1751 self.writestmt("__Throw(__tmp_exc);") 1752 1753 def process_return_node(self, n): 1754 1755 "Process the given return node 'n'." 1756 1757 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1758 if self.in_try_finally or self.in_try_except: 1759 self.writestmt("__Return(%s);" % expr) 1760 else: 1761 self.writestmt("return %s;" % expr) 1762 1763 return ReturnRef() 1764 1765 def process_try_node(self, n): 1766 1767 """ 1768 Process the given "try...except" node 'n'. 1769 """ 1770 1771 in_try_except = self.in_try_except 1772 self.in_try_except = True 1773 1774 # Use macros to implement exception handling. 1775 1776 self.writestmt("__Try") 1777 self.writeline("{") 1778 self.indent += 1 1779 self.process_structure_node(n.body) 1780 1781 # Put the else statement in another try block that handles any raised 1782 # exceptions and converts them to exceptions that will not be handled by 1783 # the main handling block. 1784 1785 if n.else_: 1786 self.writestmt("__Try") 1787 self.writeline("{") 1788 self.indent += 1 1789 self.process_structure_node(n.else_) 1790 self.indent -= 1 1791 self.writeline("}") 1792 self.writeline("__Catch (__tmp_exc)") 1793 self.writeline("{") 1794 self.indent += 1 1795 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1796 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1797 self.indent -= 1 1798 self.writeline("}") 1799 1800 # Complete the try block and enter the finally block, if appropriate. 1801 1802 if self.in_try_finally: 1803 self.writestmt("__Complete;") 1804 1805 self.indent -= 1 1806 self.writeline("}") 1807 1808 self.in_try_except = in_try_except 1809 1810 # Handlers are tests within a common handler block. 1811 1812 self.writeline("__Catch (__tmp_exc)") 1813 self.writeline("{") 1814 self.indent += 1 1815 1816 # Introduce an if statement to handle the completion of a try block. 1817 1818 self.process_try_completion() 1819 1820 # Handle exceptions in else blocks converted to __RaiseElse, converting 1821 # them back to normal exceptions. 1822 1823 if n.else_: 1824 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1825 1826 # Exception handling. 1827 1828 for name, var, handler in n.handlers: 1829 1830 # Test for specific exceptions. 1831 1832 if name is not None: 1833 name_ref = self.process_structure_node(name) 1834 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1835 else: 1836 self.writeline("else if (1)") 1837 1838 self.writeline("{") 1839 self.indent += 1 1840 1841 # Establish the local for the handler. 1842 1843 if var is not None: 1844 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1845 1846 if handler is not None: 1847 self.process_structure_node(handler) 1848 1849 self.indent -= 1 1850 self.writeline("}") 1851 1852 # Re-raise unhandled exceptions. 1853 1854 self.writeline("else __Throw(__tmp_exc);") 1855 1856 # End the handler block. 1857 1858 self.indent -= 1 1859 self.writeline("}") 1860 print >>self.out 1861 1862 def process_try_finally_node(self, n): 1863 1864 """ 1865 Process the given "try...finally" node 'n'. 1866 """ 1867 1868 in_try_finally = self.in_try_finally 1869 self.in_try_finally = True 1870 1871 # Use macros to implement exception handling. 1872 1873 self.writestmt("__Try") 1874 self.writeline("{") 1875 self.indent += 1 1876 self.process_structure_node(n.body) 1877 self.indent -= 1 1878 self.writeline("}") 1879 1880 self.in_try_finally = in_try_finally 1881 1882 # Finally clauses handle special exceptions. 1883 1884 self.writeline("__Catch (__tmp_exc)") 1885 self.writeline("{") 1886 self.indent += 1 1887 self.process_structure_node(n.final) 1888 1889 # Introduce an if statement to handle the completion of a try block. 1890 1891 self.process_try_completion() 1892 self.writeline("else __Throw(__tmp_exc);") 1893 1894 self.indent -= 1 1895 self.writeline("}") 1896 print >>self.out 1897 1898 def process_try_completion(self): 1899 1900 "Generate a test for the completion of a try block." 1901 1902 self.writestmt("if (__tmp_exc.completing)") 1903 self.writeline("{") 1904 self.indent += 1 1905 1906 # Do not return anything at the module level. 1907 1908 if self.get_namespace_path() != self.name: 1909 1910 # Only use the normal return statement if no surrounding try blocks 1911 # apply. 1912 1913 if not self.in_try_finally and not self.in_try_except: 1914 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1915 else: 1916 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1917 1918 self.indent -= 1 1919 self.writeline("}") 1920 1921 def process_while_node(self, n): 1922 1923 "Process the given while node 'n'." 1924 1925 self.writeline("while (1)") 1926 self.writeline("{") 1927 self.indent += 1 1928 test = self.process_structure_node(n.test) 1929 1930 # Emit the loop termination condition unless "while <true value>" is 1931 # indicated. 1932 1933 if not (isinstance(test, PredefinedConstantRef) and test.value): 1934 1935 # Emit a negated test of the continuation condition. 1936 1937 self.start_if(True, self.make_negation(test)) 1938 if n.else_: 1939 self.process_structure_node(n.else_) 1940 self.writestmt("break;") 1941 self.end_if() 1942 1943 in_conditional = self.in_conditional 1944 self.in_conditional = True 1945 self.process_structure_node(n.body) 1946 self.in_conditional = in_conditional 1947 1948 self.indent -= 1 1949 self.writeline("}") 1950 print >>self.out 1951 1952 # Special variable usage. 1953 1954 def get_temp_path(self): 1955 1956 """ 1957 Return the appropriate namespace path for temporary names in the current 1958 namespace. 1959 """ 1960 1961 if self.in_function: 1962 return self.get_namespace_path() 1963 else: 1964 return self.name 1965 1966 def record_temp(self, name): 1967 1968 """ 1969 Record the use of the temporary 'name' in the current namespace. At the 1970 class or module level, the temporary name is associated with the module, 1971 since the variable will then be allocated in the module's own main 1972 program. 1973 """ 1974 1975 path = self.get_temp_path() 1976 1977 init_item(self.temp_usage, path, list) 1978 self.temp_usage[path].append(name) 1979 1980 def remove_temps(self, names): 1981 1982 """ 1983 Remove 'names' from temporary storage allocations, each instance 1984 removing each request for storage. 1985 """ 1986 1987 path = self.get_temp_path() 1988 1989 for name in names: 1990 if self.uses_temp(path, name): 1991 self.temp_usage[path].remove(name) 1992 1993 def uses_temp(self, path, name): 1994 1995 """ 1996 Return whether the given namespace 'path' employs a temporary variable 1997 with the given 'name'. Note that 'path' should only be a module or a 1998 function or method, not a class. 1999 """ 2000 2001 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 2002 2003 def make_negation(self, expr): 2004 2005 "Return a negated form of 'expr'." 2006 2007 result = NegationResult(expr) 2008 2009 # Negation discards the temporary results of its operand. 2010 2011 temps = expr.discards_temporary() 2012 if temps: 2013 self.remove_temps(temps) 2014 2015 return result 2016 2017 # Output generation. 2018 2019 def start_output(self): 2020 2021 "Write the declarations at the top of each source file." 2022 2023 print >>self.out, """\ 2024 #include "types.h" 2025 #include "exceptions.h" 2026 #include "ops.h" 2027 #include "progconsts.h" 2028 #include "progops.h" 2029 #include "progtypes.h" 2030 #include "main.h" 2031 """ 2032 2033 def start_unit(self): 2034 2035 "Record output within a generated function for later use." 2036 2037 self.out = StringIO() 2038 2039 def end_unit(self): 2040 2041 "Restore the output stream." 2042 2043 out = self.out 2044 self.out = self.out_toplevel 2045 return out 2046 2047 def flush_unit(self, name, out): 2048 2049 "Add declarations and generated code." 2050 2051 self.write_temporaries(name) 2052 print >>self.out 2053 out.seek(0) 2054 self.out.write(out.read()) 2055 2056 def start_module(self): 2057 2058 "Write the start of each module's main function." 2059 2060 print >>self.out, "void __main_%s()" % encode_path(self.name) 2061 print >>self.out, "{" 2062 self.indent += 1 2063 2064 # Define temporary variables, excluded from the module structure itself. 2065 2066 tempnames = [] 2067 2068 for n in self.importer.all_module_attrs[self.name]: 2069 if n.startswith("$t"): 2070 tempnames.append(encode_path(n)) 2071 2072 if tempnames: 2073 tempnames.sort() 2074 self.writeline("__attr %s;" % ", ".join(tempnames)) 2075 2076 self.start_unit() 2077 2078 def end_module(self): 2079 2080 "End each module by closing its main function." 2081 2082 out = self.end_unit() 2083 self.flush_unit(self.name, out) 2084 2085 self.indent -= 1 2086 print >>self.out, "}" 2087 2088 def start_function(self, name): 2089 2090 "Start the function having the given 'name'." 2091 2092 self.indent += 1 2093 2094 self.start_unit() 2095 2096 def end_function(self, name): 2097 2098 "End the function having the given 'name'." 2099 2100 out = self.end_unit() 2101 2102 # Write the signature at the top indentation level. 2103 2104 self.indent -= 1 2105 self.write_parameters(name) 2106 print >>self.out, "{" 2107 2108 # Obtain local names from parameters. 2109 2110 parameters = self.importer.function_parameters[name] 2111 locals = self.importer.function_locals[name].keys() 2112 names = [] 2113 volatile_names = [] 2114 2115 for n in locals: 2116 2117 # Filter out special names and parameters. Note that self is a local 2118 # regardless of whether it originally appeared in the parameters or 2119 # not. 2120 2121 if n.startswith("$l") or n in parameters or n == "self": 2122 continue 2123 if n in self.volatile_locals: 2124 volatile_names.append(encode_path(n)) 2125 else: 2126 names.append(encode_path(n)) 2127 2128 # Emit required local names at the function indentation level. 2129 2130 self.indent += 1 2131 2132 if names: 2133 names.sort() 2134 self.writeline("__attr %s;" % ", ".join(names)) 2135 2136 if volatile_names: 2137 volatile_names.sort() 2138 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2139 2140 self.flush_unit(name, out) 2141 2142 self.indent -= 1 2143 print >>self.out, "}" 2144 print >>self.out 2145 2146 def write_parameters(self, name): 2147 2148 """ 2149 For the function having the given 'name', write definitions of 2150 parameters found in the arguments array. 2151 """ 2152 2153 # Generate any self reference. 2154 2155 l = [] 2156 2157 if self.is_method(name): 2158 l.append("__attr self") 2159 else: 2160 l.append("__attr __self") 2161 2162 # Generate aliases for the parameters. 2163 2164 for parameter in self.importer.function_parameters[name]: 2165 l.append("%s__attr %s" % ( 2166 parameter in self.volatile_locals and "volatile " or "", 2167 encode_path(parameter))) 2168 2169 self.writeline("__attr %s(%s)" % ( 2170 encode_function_pointer(name), ", ".join(l))) 2171 2172 def write_temporaries(self, name): 2173 2174 "Write temporary storage employed by 'name'." 2175 2176 # Provide space for the recorded number of temporary variables. 2177 2178 if self.uses_temp(name, "__tmp_targets"): 2179 self.writeline("__attr __tmp_targets[%d];" % self.max_function_target) 2180 2181 if self.uses_temp(name, "__tmp_contexts"): 2182 self.writeline("__attr __tmp_contexts[%d];" % self.max_context_index) 2183 2184 if self.uses_temp(name, "__tmp_values"): 2185 self.writeline("__attr __tmp_values[%d];" % self.max_accessor_index) 2186 2187 # Add temporary variable usage details. 2188 2189 if self.uses_temp(name, "__tmp_private_context"): 2190 self.writeline("__attr __tmp_private_context;") 2191 if self.uses_temp(name, "__tmp_target_value"): 2192 self.writeline("__attr __tmp_target_value;") 2193 if self.uses_temp(name, "__tmp_result"): 2194 self.writeline("__attr __tmp_result;") 2195 2196 module = self.importer.get_module(self.name) 2197 2198 if name in module.exception_namespaces: 2199 self.writeline("__exc __tmp_exc;") 2200 2201 def start_if(self, first, test_ref): 2202 statement = "%sif" % (not first and "else " or "") 2203 2204 # Consume logical results directly. 2205 2206 if isinstance(test_ref, LogicalResult): 2207 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2208 temps = test_ref.discards_temporary() 2209 if temps: 2210 self.remove_temps(temps) 2211 else: 2212 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2213 2214 self.writeline("{") 2215 self.indent += 1 2216 2217 def end_if(self): 2218 self.indent -= 1 2219 self.writeline("}") 2220 2221 def start_else(self): 2222 self.writeline("else") 2223 self.writeline("{") 2224 self.indent += 1 2225 2226 def end_else(self): 2227 self.indent -= 1 2228 self.writeline("}") 2229 2230 def statement(self, expr): 2231 s = str(expr) 2232 if s: 2233 self.writestmt("%s;" % s) 2234 2235 def statements(self, results): 2236 for result in results: 2237 self.statement(result) 2238 2239 def writeline(self, s): 2240 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2241 2242 def writestmt(self, s): 2243 self.writeline(s) 2244 2245 def write_comment(self, s): 2246 self.writestmt("/* %s */" % s) 2247 2248 def pad(self, extra=0): 2249 return (self.indent + extra) * self.tabstop 2250 2251 def indenttext(self, s, levels): 2252 lines = s.split("\n") 2253 out = [lines[0]] 2254 for line in lines[1:]: 2255 out.append(levels * self.tabstop + line) 2256 if line.endswith("("): 2257 levels += 1 2258 elif line.startswith(")"): 2259 levels -= 1 2260 return "\n".join(out) 2261 2262 # vim: tabstop=4 expandtab shiftwidth=4