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_statement_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_statement_node(test) 1042 self.start_if(first, test_ref) 1043 1044 in_conditional = self.in_conditional 1045 self.in_conditional = True 1046 self.process_statement_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_statement_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 # Store a keyword argument, either in the argument list or 1328 # in a separate keyword argument list for subsequent lookup. 1329 1330 if isinstance(arg, compiler.ast.Keyword): 1331 1332 # With knowledge of the target, store the keyword 1333 # argument directly. 1334 1335 if parameters: 1336 try: 1337 argnum = parameters.index(arg.name) 1338 except ValueError: 1339 raise TranslateError("Argument %s is not recognised." % arg.name, 1340 self.get_namespace_path(), n) 1341 args[argnum + reserved_args] = str(argexpr) 1342 1343 # Otherwise, store the details in a separate collection. 1344 1345 else: 1346 kwargs.append(str(argexpr)) 1347 kwcodes.append("{%s, %s}" % ( 1348 encode_ppos(arg.name), encode_pcode(arg.name))) 1349 1350 # Store non-keyword arguments in the argument list, rejecting 1351 # superfluous arguments. 1352 1353 else: 1354 try: 1355 args[i + reserved_args] = str(argexpr) 1356 except IndexError: 1357 raise TranslateError("Too many arguments specified.", 1358 self.get_namespace_path(), n) 1359 1360 # Reference the current target again. 1361 1362 self.in_parameter_list = in_parameter_list 1363 1364 if not self.in_parameter_list: 1365 self.function_target = function_target 1366 self.context_index = context_index 1367 self.accessor_index = accessor_index 1368 1369 # Defaults are added to the frame where arguments are missing. 1370 1371 if parameters and function_defaults is not None: 1372 1373 # Visit each default and set any missing arguments. Where keyword 1374 # arguments have been used, the defaults must be inspected and, if 1375 # necessary, inserted into gaps in the argument list. 1376 1377 for i, (argname, default) in enumerate(function_defaults): 1378 argnum = parameters.index(argname) 1379 if not args[argnum + reserved_args]: 1380 args[argnum + reserved_args] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1381 1382 elif known_parameters: 1383 1384 # No specific parameter details are provided, but no keyword 1385 # arguments are used. Thus, defaults can be supplied using position 1386 # information only. 1387 1388 i = len(n.args) 1389 pos = i - (num_parameters - num_defaults) 1390 while i < num_parameters: 1391 args[i + reserved_args] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1392 i += 1 1393 pos += 1 1394 1395 # Test for missing arguments. 1396 1397 if None in args: 1398 raise TranslateError("Not all arguments supplied.", 1399 self.get_namespace_path(), n) 1400 1401 # Encode the arguments. 1402 1403 # Where literal instantiation is occurring, add an argument indicating 1404 # the number of values. The context is excluded. 1405 1406 if literal_instantiation: 1407 argstr = "%d, %s" % (len(args) - reserved_args, ", ".join(args[reserved_args:])) 1408 else: 1409 argstr = ", ".join(args) 1410 1411 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1412 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1413 1414 # First, the invocation expression is presented. 1415 1416 stages = [] 1417 emit = stages.append 1418 1419 # Assign and yield any stored target. 1420 # The context may be set in the expression. 1421 1422 if need_target_stored: 1423 emit("%s = %s" % (target_var, expr)) 1424 target_expr = target_var 1425 1426 # Otherwise, retain the expression for later use. 1427 1428 else: 1429 target_expr = str(expr) 1430 1431 # Any specific callable is then obtained for invocation. 1432 1433 if target: 1434 1435 # An expression involving a test of the accessor providing the target. 1436 # This must be emitted in order to perform the test. 1437 1438 if tests_accessor: 1439 emit(str(expr)) 1440 1441 emit(target) 1442 1443 # Methods accessed via unidentified accessors are obtained for 1444 # invocation. 1445 1446 elif function: 1447 if context_required: 1448 1449 # Avoid further context testing if appropriate. 1450 1451 if have_access_context and context_verified: 1452 emit("__get_function_member(%s)" % target_expr) 1453 1454 # Otherwise, test the context for the function/method. 1455 1456 else: 1457 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1458 else: 1459 emit("_get_function_member(%s)" % target_expr) 1460 1461 # With known parameters, the target can be tested. 1462 1463 elif known_parameters: 1464 if self.always_callable(refs): 1465 if context_verified: 1466 emit("__get_function_member(%s)" % target_expr) 1467 else: 1468 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1469 else: 1470 emit("__check_and_get_function(%s, %s)" % (context_arg, target_expr)) 1471 1472 # With a known target, the function is obtained directly and called. 1473 # By putting the invocation at the end of the final element in the 1474 # instruction sequence (the stages), the result becomes the result of 1475 # the sequence. Moreover, the parameters become part of the sequence 1476 # and thereby participate in a guaranteed evaluation order. 1477 1478 if target or function or known_parameters: 1479 stages[-1] += "(%s)" % argstr 1480 if instantiation: 1481 return InstantiationResult(instantiation, stages) 1482 else: 1483 return InvocationResult(stages) 1484 1485 # With unknown targets, the generic invocation function is applied to 1486 # the callable and argument collections. 1487 1488 else: 1489 emit("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1490 target_expr, 1491 self.always_callable(refs) and 1 or 0, 1492 len(kwargs), kwcodestr, kwargstr, 1493 len(args), "__ARGS(%s)" % argstr)) 1494 return InvocationResult(stages) 1495 1496 def next_target(self): 1497 1498 "Allocate the next function target storage." 1499 1500 self.function_target += 1 1501 self.max_function_target = max(self.function_target, self.max_function_target) 1502 1503 def next_context(self): 1504 1505 "Allocate the next context value storage." 1506 1507 self.context_index += 1 1508 self.max_context_index = max(self.context_index, self.max_context_index) 1509 1510 def next_accessor(self): 1511 1512 "Allocate the next accessor value storage." 1513 1514 self.accessor_index += 1 1515 self.max_accessor_index = max(self.accessor_index, self.max_accessor_index) 1516 1517 def always_callable(self, refs): 1518 1519 "Determine whether all 'refs' are callable." 1520 1521 if not refs: 1522 return False 1523 1524 for ref in refs: 1525 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1526 return False 1527 1528 return True 1529 1530 def need_default_arguments(self, objpath, nargs): 1531 1532 """ 1533 Return whether any default arguments are needed when invoking the object 1534 given by 'objpath'. 1535 """ 1536 1537 parameters = self.importer.function_parameters.get(objpath) 1538 return nargs < len(parameters) 1539 1540 def uses_keyword_arguments(self, n): 1541 1542 "Return whether invocation node 'n' uses keyword arguments." 1543 1544 for arg in enumerate(n.args): 1545 if isinstance(arg, compiler.ast.Keyword): 1546 return True 1547 1548 return False 1549 1550 def get_attributes_for_attrname(self, attrname): 1551 1552 "Return a set of all attributes exposed by 'attrname'." 1553 1554 usage = [(attrname, True, False)] 1555 class_types = self.deducer.get_class_types_for_usage(usage) 1556 instance_types = self.deducer.get_instance_types_for_usage(usage) 1557 module_types = self.deducer.get_module_types_for_usage(usage) 1558 attrs = set() 1559 1560 for ref in combine_types(class_types, instance_types, module_types): 1561 attrs.update(self.importer.get_attributes(ref, attrname)) 1562 1563 return attrs 1564 1565 def process_lambda_node(self, n): 1566 1567 "Process the given lambda node 'n'." 1568 1569 name = self.get_lambda_name() 1570 function_name = self.get_object_path(name) 1571 instance_name = "__get_accessor(%d)" % self.accessor_index 1572 1573 defaults = self.process_function_defaults(n, name, function_name, instance_name) 1574 1575 # Without defaults, produce an attribute referring to the function. 1576 1577 if not defaults: 1578 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1579 1580 # With defaults, copy the function structure and set the defaults on the 1581 # copy. 1582 1583 else: 1584 self.record_temp("__tmp_values") 1585 return make_expression("""\ 1586 (__set_accessor(%d, __ATTRVALUE(__COPY(&%s, sizeof(%s)))), 1587 %s, 1588 __get_accessor(%d))""" % ( 1589 self.accessor_index, 1590 encode_path(function_name), 1591 encode_symbol("obj", function_name), 1592 ", ".join(defaults), 1593 self.accessor_index)) 1594 1595 def process_logical_node(self, n): 1596 1597 "Process the given operator node 'n'." 1598 1599 self.record_temp("__tmp_result") 1600 1601 conjunction = isinstance(n, compiler.ast.And) 1602 results = [] 1603 1604 for node in n.nodes: 1605 results.append(self.process_structure_node(node)) 1606 1607 return LogicalOperationResult(results, conjunction) 1608 1609 def process_name_node(self, n, expr=None): 1610 1611 "Process the given name node 'n' with the optional assignment 'expr'." 1612 1613 # Determine whether the name refers to a static external entity. 1614 1615 if n.name in predefined_constants: 1616 return PredefinedConstantRef(n.name, expr) 1617 1618 # Convert literal references, operator function names, and print 1619 # function names to references. 1620 1621 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1622 n.name.startswith("$seq") or n.name.startswith("$print"): 1623 1624 ref, paths = self.importer.get_module(self.name).special[n.name] 1625 return TrResolvedNameRef(n.name, ref) 1626 1627 # Get the appropriate name for the name reference, using the same method 1628 # as in the inspector. 1629 1630 path = self.get_namespace_path() 1631 objpath = self.get_object_path(n.name) 1632 1633 # Determine any assigned globals. 1634 1635 globals = self.importer.get_module(self.name).scope_globals.get(path) 1636 1637 # Explicitly declared globals. 1638 1639 if globals and n.name in globals: 1640 objpath = self.get_global_path(n.name) 1641 is_global = True 1642 1643 # Implicitly referenced globals in functions. 1644 1645 elif self.in_function: 1646 is_global = n.name not in self.importer.function_locals[path] 1647 1648 # Implicitly referenced globals elsewhere. 1649 1650 else: 1651 namespace = self.importer.identify(path) 1652 is_global = not self.importer.get_attributes(namespace, n.name) 1653 1654 # Get the static identity of the name. 1655 1656 ref = self.importer.identify(objpath) 1657 if ref and not ref.get_name(): 1658 ref = ref.alias(objpath) 1659 1660 # Obtain any resolved names for non-assignment names. 1661 1662 if not expr and not ref and self.in_function: 1663 locals = self.importer.function_locals.get(path) 1664 ref = locals and locals.get(n.name) 1665 1666 # Find any invocation or alias details. 1667 1668 name = self.get_name_for_tracking(n.name, is_global=is_global) 1669 location = not expr and self.get_access_location(name) or None 1670 1671 # Mark any local assignments as volatile in exception blocks. 1672 1673 if expr and self.in_function and not is_global and self.in_try_except: 1674 self.make_volatile(n.name) 1675 1676 # Qualified names are used for resolved static references or for 1677 # static namespace members. The reference should be configured to return 1678 # such names. 1679 1680 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1681 location=location) 1682 return not expr and self.get_aliases(name_ref) or name_ref 1683 1684 def get_aliases(self, name_ref): 1685 1686 "Return alias references for the given 'name_ref'." 1687 1688 location = name_ref.access_location() 1689 accessor_locations = self.deducer.access_index.get(location) 1690 1691 if not accessor_locations: 1692 return None 1693 1694 refs = set() 1695 1696 for accessor_location in accessor_locations: 1697 alias_refs = self.deducer.referenced_objects.get(accessor_location) 1698 if alias_refs: 1699 refs.update(alias_refs) 1700 1701 if refs: 1702 return AliasResult(name_ref, refs, location) 1703 else: 1704 return None 1705 1706 def make_volatile(self, name): 1707 1708 "Record 'name' as volatile in the current namespace." 1709 1710 self.volatile_locals.add(name) 1711 1712 def process_not_node(self, n): 1713 1714 "Process the given operator node 'n'." 1715 1716 return self.make_negation(self.process_structure_node(n.expr)) 1717 1718 def process_raise_node(self, n): 1719 1720 "Process the given raise node 'n'." 1721 1722 # NOTE: Determine which raise statement variants should be permitted. 1723 1724 if n.expr1: 1725 1726 # Names with accompanying arguments are treated like invocations. 1727 1728 if n.expr2: 1729 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1730 exc = self.process_structure_node(call) 1731 self.writestmt("__Raise(%s);" % exc) 1732 1733 # Raise instances, testing the kind at run-time if necessary and 1734 # instantiating any non-instance. 1735 1736 else: 1737 exc = self.process_structure_node(n.expr1) 1738 1739 if isinstance(exc, TrInstanceRef) or exc.is_well_defined_instance(): 1740 self.writestmt("__Raise(%s);" % exc) 1741 else: 1742 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1743 else: 1744 self.writestmt("__Throw(__tmp_exc);") 1745 1746 def process_return_node(self, n): 1747 1748 "Process the given return node 'n'." 1749 1750 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1751 if self.in_try_finally or self.in_try_except: 1752 self.writestmt("__Return(%s);" % expr) 1753 else: 1754 self.writestmt("return %s;" % expr) 1755 1756 return ReturnRef() 1757 1758 def process_try_node(self, n): 1759 1760 """ 1761 Process the given "try...except" node 'n'. 1762 """ 1763 1764 in_try_except = self.in_try_except 1765 self.in_try_except = True 1766 1767 # Use macros to implement exception handling. 1768 1769 self.writestmt("__Try") 1770 self.writeline("{") 1771 self.indent += 1 1772 self.process_statement_node(n.body) 1773 1774 # Put the else statement in another try block that handles any raised 1775 # exceptions and converts them to exceptions that will not be handled by 1776 # the main handling block. 1777 1778 if n.else_: 1779 self.writestmt("__Try") 1780 self.writeline("{") 1781 self.indent += 1 1782 self.process_statement_node(n.else_) 1783 self.indent -= 1 1784 self.writeline("}") 1785 self.writeline("__Catch (__tmp_exc)") 1786 self.writeline("{") 1787 self.indent += 1 1788 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1789 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1790 self.indent -= 1 1791 self.writeline("}") 1792 1793 # Complete the try block and enter the finally block, if appropriate. 1794 1795 if self.in_try_finally: 1796 self.writestmt("__Complete;") 1797 1798 self.indent -= 1 1799 self.writeline("}") 1800 1801 self.in_try_except = in_try_except 1802 1803 # Handlers are tests within a common handler block. 1804 1805 self.writeline("__Catch (__tmp_exc)") 1806 self.writeline("{") 1807 self.indent += 1 1808 1809 # Introduce an if statement to handle the completion of a try block. 1810 1811 self.process_try_completion() 1812 1813 # Handle exceptions in else blocks converted to __RaiseElse, converting 1814 # them back to normal exceptions. 1815 1816 if n.else_: 1817 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1818 1819 # Exception handling. 1820 1821 for name, var, handler in n.handlers: 1822 1823 # Test for specific exceptions. 1824 1825 if name is not None: 1826 name_ref = self.process_statement_node(name) 1827 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1828 else: 1829 self.writeline("else if (1)") 1830 1831 self.writeline("{") 1832 self.indent += 1 1833 1834 # Establish the local for the handler. 1835 1836 if var is not None: 1837 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1838 1839 if handler is not None: 1840 self.process_statement_node(handler) 1841 1842 self.indent -= 1 1843 self.writeline("}") 1844 1845 # Re-raise unhandled exceptions. 1846 1847 self.writeline("else __Throw(__tmp_exc);") 1848 1849 # End the handler block. 1850 1851 self.indent -= 1 1852 self.writeline("}") 1853 print >>self.out 1854 1855 def process_try_finally_node(self, n): 1856 1857 """ 1858 Process the given "try...finally" node 'n'. 1859 """ 1860 1861 in_try_finally = self.in_try_finally 1862 self.in_try_finally = True 1863 1864 # Use macros to implement exception handling. 1865 1866 self.writestmt("__Try") 1867 self.writeline("{") 1868 self.indent += 1 1869 self.process_statement_node(n.body) 1870 self.indent -= 1 1871 self.writeline("}") 1872 1873 self.in_try_finally = in_try_finally 1874 1875 # Finally clauses handle special exceptions. 1876 1877 self.writeline("__Catch (__tmp_exc)") 1878 self.writeline("{") 1879 self.indent += 1 1880 self.process_statement_node(n.final) 1881 1882 # Introduce an if statement to handle the completion of a try block. 1883 1884 self.process_try_completion() 1885 self.writeline("else __Throw(__tmp_exc);") 1886 1887 self.indent -= 1 1888 self.writeline("}") 1889 print >>self.out 1890 1891 def process_try_completion(self): 1892 1893 "Generate a test for the completion of a try block." 1894 1895 self.writestmt("if (__tmp_exc.completing)") 1896 self.writeline("{") 1897 self.indent += 1 1898 1899 # Do not return anything at the module level. 1900 1901 if self.get_namespace_path() != self.name: 1902 1903 # Only use the normal return statement if no surrounding try blocks 1904 # apply. 1905 1906 if not self.in_try_finally and not self.in_try_except: 1907 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1908 else: 1909 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1910 1911 self.indent -= 1 1912 self.writeline("}") 1913 1914 def process_while_node(self, n): 1915 1916 "Process the given while node 'n'." 1917 1918 self.writeline("while (1)") 1919 self.writeline("{") 1920 self.indent += 1 1921 test = self.process_statement_node(n.test) 1922 1923 # Emit the loop termination condition unless "while <true value>" is 1924 # indicated. 1925 1926 if not (isinstance(test, PredefinedConstantRef) and test.value): 1927 1928 # Emit a negated test of the continuation condition. 1929 1930 self.start_if(True, self.make_negation(test)) 1931 if n.else_: 1932 self.process_statement_node(n.else_) 1933 self.writestmt("break;") 1934 self.end_if() 1935 1936 in_conditional = self.in_conditional 1937 self.in_conditional = True 1938 self.process_statement_node(n.body) 1939 self.in_conditional = in_conditional 1940 1941 self.indent -= 1 1942 self.writeline("}") 1943 print >>self.out 1944 1945 # Special variable usage. 1946 1947 def get_temp_path(self): 1948 1949 """ 1950 Return the appropriate namespace path for temporary names in the current 1951 namespace. 1952 """ 1953 1954 if self.in_function: 1955 return self.get_namespace_path() 1956 else: 1957 return self.name 1958 1959 def record_temp(self, name): 1960 1961 """ 1962 Record the use of the temporary 'name' in the current namespace. At the 1963 class or module level, the temporary name is associated with the module, 1964 since the variable will then be allocated in the module's own main 1965 program. 1966 """ 1967 1968 path = self.get_temp_path() 1969 1970 init_item(self.temp_usage, path, list) 1971 self.temp_usage[path].append(name) 1972 1973 def remove_temps(self, names): 1974 1975 """ 1976 Remove 'names' from temporary storage allocations, each instance 1977 removing each request for storage. 1978 """ 1979 1980 path = self.get_temp_path() 1981 1982 for name in names: 1983 if self.uses_temp(path, name): 1984 self.temp_usage[path].remove(name) 1985 1986 def uses_temp(self, path, name): 1987 1988 """ 1989 Return whether the given namespace 'path' employs a temporary variable 1990 with the given 'name'. Note that 'path' should only be a module or a 1991 function or method, not a class. 1992 """ 1993 1994 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1995 1996 def make_negation(self, expr): 1997 1998 "Return a negated form of 'expr'." 1999 2000 result = NegationResult(expr) 2001 2002 # Negation discards the temporary results of its operand. 2003 2004 temps = expr.discards_temporary() 2005 if temps: 2006 self.remove_temps(temps) 2007 2008 return result 2009 2010 # Output generation. 2011 2012 def start_output(self): 2013 2014 "Write the declarations at the top of each source file." 2015 2016 print >>self.out, """\ 2017 #include "types.h" 2018 #include "exceptions.h" 2019 #include "ops.h" 2020 #include "progconsts.h" 2021 #include "progops.h" 2022 #include "progtypes.h" 2023 #include "main.h" 2024 """ 2025 2026 def start_unit(self): 2027 2028 "Record output within a generated function for later use." 2029 2030 self.out = StringIO() 2031 2032 def end_unit(self): 2033 2034 "Restore the output stream." 2035 2036 out = self.out 2037 self.out = self.out_toplevel 2038 return out 2039 2040 def flush_unit(self, name, out): 2041 2042 "Add declarations and generated code." 2043 2044 self.write_temporaries(name) 2045 print >>self.out 2046 out.seek(0) 2047 self.out.write(out.read()) 2048 2049 def start_module(self): 2050 2051 "Write the start of each module's main function." 2052 2053 print >>self.out, "void __main_%s()" % encode_path(self.name) 2054 print >>self.out, "{" 2055 self.indent += 1 2056 2057 # Define temporary variables, excluded from the module structure itself. 2058 2059 tempnames = [] 2060 2061 for n in self.importer.all_module_attrs[self.name]: 2062 if n.startswith("$t"): 2063 tempnames.append(encode_path(n)) 2064 2065 if tempnames: 2066 tempnames.sort() 2067 self.writeline("__attr %s;" % ", ".join(tempnames)) 2068 2069 self.start_unit() 2070 2071 def end_module(self): 2072 2073 "End each module by closing its main function." 2074 2075 out = self.end_unit() 2076 self.flush_unit(self.name, out) 2077 2078 self.indent -= 1 2079 print >>self.out, "}" 2080 2081 def start_function(self, name): 2082 2083 "Start the function having the given 'name'." 2084 2085 self.indent += 1 2086 2087 self.start_unit() 2088 2089 def end_function(self, name): 2090 2091 "End the function having the given 'name'." 2092 2093 out = self.end_unit() 2094 2095 # Write the signature at the top indentation level. 2096 2097 self.indent -= 1 2098 self.write_parameters(name) 2099 print >>self.out, "{" 2100 2101 # Obtain local names from parameters. 2102 2103 parameters = self.importer.function_parameters[name] 2104 locals = self.importer.function_locals[name].keys() 2105 names = [] 2106 volatile_names = [] 2107 2108 for n in locals: 2109 2110 # Filter out special names and parameters. Note that self is a local 2111 # regardless of whether it originally appeared in the parameters or 2112 # not. 2113 2114 if n.startswith("$l") or n in parameters or n == "self": 2115 continue 2116 if n in self.volatile_locals: 2117 volatile_names.append(encode_path(n)) 2118 else: 2119 names.append(encode_path(n)) 2120 2121 # Emit required local names at the function indentation level. 2122 2123 self.indent += 1 2124 2125 if names: 2126 names.sort() 2127 self.writeline("__attr %s;" % ", ".join(names)) 2128 2129 if volatile_names: 2130 volatile_names.sort() 2131 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2132 2133 self.flush_unit(name, out) 2134 2135 self.indent -= 1 2136 print >>self.out, "}" 2137 print >>self.out 2138 2139 def write_parameters(self, name): 2140 2141 """ 2142 For the function having the given 'name', write definitions of 2143 parameters found in the arguments array. 2144 """ 2145 2146 # Generate any self reference. 2147 2148 l = [] 2149 2150 if self.is_method(name): 2151 l.append("__attr self") 2152 else: 2153 l.append("__attr __self") 2154 2155 # Generate aliases for the parameters. 2156 2157 for parameter in self.importer.function_parameters[name]: 2158 l.append("%s__attr %s" % ( 2159 parameter in self.volatile_locals and "volatile " or "", 2160 encode_path(parameter))) 2161 2162 self.writeline("__attr %s(%s)" % ( 2163 encode_function_pointer(name), ", ".join(l))) 2164 2165 def write_temporaries(self, name): 2166 2167 "Write temporary storage employed by 'name'." 2168 2169 # Provide space for the recorded number of temporary variables. 2170 2171 if self.uses_temp(name, "__tmp_targets"): 2172 self.writeline("__attr __tmp_targets[%d];" % self.max_function_target) 2173 2174 if self.uses_temp(name, "__tmp_contexts"): 2175 self.writeline("__attr __tmp_contexts[%d];" % self.max_context_index) 2176 2177 if self.uses_temp(name, "__tmp_values"): 2178 self.writeline("__attr __tmp_values[%d];" % self.max_accessor_index) 2179 2180 # Add temporary variable usage details. 2181 2182 if self.uses_temp(name, "__tmp_private_context"): 2183 self.writeline("__attr __tmp_private_context;") 2184 if self.uses_temp(name, "__tmp_target_value"): 2185 self.writeline("__attr __tmp_target_value;") 2186 if self.uses_temp(name, "__tmp_result"): 2187 self.writeline("__attr __tmp_result;") 2188 2189 module = self.importer.get_module(self.name) 2190 2191 if name in module.exception_namespaces: 2192 self.writeline("__exc __tmp_exc;") 2193 2194 def start_if(self, first, test_ref): 2195 statement = "%sif" % (not first and "else " or "") 2196 2197 # Consume logical results directly. 2198 2199 if isinstance(test_ref, LogicalResult): 2200 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2201 temps = test_ref.discards_temporary() 2202 if temps: 2203 self.remove_temps(temps) 2204 else: 2205 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2206 2207 self.writeline("{") 2208 self.indent += 1 2209 2210 def end_if(self): 2211 self.indent -= 1 2212 self.writeline("}") 2213 2214 def start_else(self): 2215 self.writeline("else") 2216 self.writeline("{") 2217 self.indent += 1 2218 2219 def end_else(self): 2220 self.indent -= 1 2221 self.writeline("}") 2222 2223 def statement(self, expr): 2224 s = str(expr) 2225 if s: 2226 self.writestmt("%s;" % s) 2227 2228 def statements(self, results): 2229 for result in results: 2230 self.statement(result) 2231 2232 def writeline(self, s): 2233 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2234 2235 def writestmt(self, s): 2236 self.writeline(s) 2237 2238 def write_comment(self, s): 2239 self.writestmt("/* %s */" % s) 2240 2241 def pad(self, extra=0): 2242 return (self.indent + extra) * self.tabstop 2243 2244 def indenttext(self, s, levels): 2245 lines = s.split("\n") 2246 out = [lines[0]] 2247 for line in lines[1:]: 2248 out.append(levels * self.tabstop + line) 2249 if line.endswith("("): 2250 levels += 1 2251 elif line.startswith(")"): 2252 levels -= 1 2253 return "\n".join(out) 2254 2255 # vim: tabstop=4 expandtab shiftwidth=4