1 #!/usr/bin/env python 2 3 """ 4 Translate programs. 5 6 Copyright (C) 2015-2018, 2021 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 after the value stack. Where the 1285 # context would be unused, it may be 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 # Introduce the value stack and any context. 1296 1297 args = ["__stack", context_arg] 1298 reserved_args = 2 1299 1300 # Complete the array with null values, permitting tests for a complete 1301 # set of arguments. 1302 1303 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1304 kwcodes = [] 1305 kwargs = [] 1306 1307 # Any invocations in the arguments will store target details in a 1308 # different location. 1309 1310 function_target = self.function_target 1311 context_index = self.context_index 1312 accessor_index = self.accessor_index 1313 1314 if need_target_stored: 1315 self.next_target() 1316 1317 if need_context_stored: 1318 self.next_context() 1319 1320 if stores_accessor: 1321 self.next_accessor() 1322 1323 in_parameter_list = self.in_parameter_list 1324 self.in_parameter_list = True 1325 1326 for i, arg in enumerate(n.args): 1327 argexpr = self.process_structure_node(arg) 1328 1329 # Obtain an appropriate argument representation. This prevents 1330 # copyable values from being mutable, but care must be taken to 1331 # prevent special internal attribute values represented using 1332 # attributes from being modified. 1333 1334 argrepr = argexpr.as_arg() 1335 1336 # Store a keyword argument, either in the argument list or 1337 # in a separate keyword argument list for subsequent lookup. 1338 1339 if isinstance(arg, compiler.ast.Keyword): 1340 1341 # With knowledge of the target, store the keyword 1342 # argument directly. 1343 1344 if parameters: 1345 try: 1346 argnum = parameters.index(arg.name) 1347 except ValueError: 1348 raise TranslateError("Argument %s is not recognised." % arg.name, 1349 self.get_namespace_path(), n) 1350 args[argnum + reserved_args] = argrepr 1351 1352 # Otherwise, store the details in a separate collection. 1353 1354 else: 1355 kwargs.append(argrepr) 1356 kwcodes.append("{%s, %s}" % ( 1357 encode_ppos(arg.name), encode_pcode(arg.name))) 1358 1359 # Store non-keyword arguments in the argument list, rejecting 1360 # superfluous arguments. 1361 1362 else: 1363 try: 1364 args[i + reserved_args] = argrepr 1365 except IndexError: 1366 raise TranslateError("Too many arguments specified.", 1367 self.get_namespace_path(), n) 1368 1369 # Reference the current target again. 1370 1371 self.in_parameter_list = in_parameter_list 1372 1373 if not self.in_parameter_list: 1374 self.function_target = function_target 1375 self.context_index = context_index 1376 self.accessor_index = accessor_index 1377 1378 # Defaults are added to the frame where arguments are missing. 1379 1380 if parameters and function_defaults is not None: 1381 1382 # Visit each default and set any missing arguments. Where keyword 1383 # arguments have been used, the defaults must be inspected and, if 1384 # necessary, inserted into gaps in the argument list. 1385 1386 for i, (argname, default) in enumerate(function_defaults): 1387 argnum = parameters.index(argname) 1388 if not args[argnum + reserved_args]: 1389 args[argnum + reserved_args] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1390 1391 elif known_parameters: 1392 1393 # No specific parameter details are provided, but no keyword 1394 # arguments are used. Thus, defaults can be supplied using position 1395 # information only. 1396 1397 i = len(n.args) 1398 pos = i - (num_parameters - num_defaults) 1399 while i < num_parameters: 1400 args[i + reserved_args] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1401 i += 1 1402 pos += 1 1403 1404 # Test for missing arguments. 1405 1406 if None in args: 1407 raise TranslateError("Not all arguments supplied.", 1408 self.get_namespace_path(), n) 1409 1410 # Encode the arguments. 1411 1412 # Where literal instantiation is occurring, add an argument indicating 1413 # the number of values. The stack and context are excluded. 1414 1415 if literal_instantiation: 1416 argstr = "%d, %s" % (len(args) - reserved_args, ", ".join(args[reserved_args:])) 1417 else: 1418 argstr = ", ".join(args) 1419 1420 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1421 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1422 1423 # First, the invocation expression is presented. 1424 1425 stages = [] 1426 emit = stages.append 1427 1428 # Assign and yield any stored target. 1429 # The context may be set in the expression. 1430 1431 if need_target_stored: 1432 emit("%s = %s" % (target_var, expr)) 1433 target_expr = target_var 1434 1435 # Otherwise, retain the expression for later use. 1436 1437 else: 1438 target_expr = str(expr) 1439 1440 # Any specific callable is then obtained for invocation. 1441 1442 if target: 1443 1444 # An expression involving a test of the accessor providing the target. 1445 # This must be emitted in order to perform the test. 1446 1447 if tests_accessor: 1448 emit(str(expr)) 1449 1450 emit(target) 1451 1452 # Methods accessed via unidentified accessors are obtained for 1453 # invocation. 1454 1455 elif function: 1456 if context_required: 1457 1458 # Avoid further context testing if appropriate. 1459 1460 if have_access_context and context_verified: 1461 emit("__get_function_member(%s)" % target_expr) 1462 1463 # Otherwise, test the context for the function/method. 1464 1465 else: 1466 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1467 else: 1468 emit("_get_function_member(%s)" % target_expr) 1469 1470 # With known parameters, the target can be tested. 1471 1472 elif known_parameters: 1473 if self.always_callable(refs): 1474 if context_verified: 1475 emit("__get_function_member(%s)" % target_expr) 1476 else: 1477 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1478 else: 1479 emit("__check_and_get_function(%s, %s)" % (context_arg, target_expr)) 1480 1481 # With a known target, the function is obtained directly and called. 1482 # By putting the invocation at the end of the final element in the 1483 # instruction sequence (the stages), the result becomes the result of 1484 # the sequence. Moreover, the parameters become part of the sequence 1485 # and thereby participate in a guaranteed evaluation order. 1486 1487 if target or function or known_parameters: 1488 stages[-1] += "(%s)" % argstr 1489 if instantiation: 1490 return InstantiationResult(instantiation, stages) 1491 else: 1492 return InvocationResult(stages) 1493 1494 # With unknown targets, the generic invocation function is applied to 1495 # the callable and argument collections. 1496 1497 else: 1498 emit("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1499 target_expr, 1500 self.always_callable(refs) and 1 or 0, 1501 len(kwargs), kwcodestr, kwargstr, 1502 len(args), "__ARGS(%s)" % argstr)) 1503 return InvocationResult(stages) 1504 1505 def next_target(self): 1506 1507 "Allocate the next function target storage." 1508 1509 self.function_target += 1 1510 self.max_function_target = max(self.function_target, self.max_function_target) 1511 1512 def next_context(self): 1513 1514 "Allocate the next context value storage." 1515 1516 self.context_index += 1 1517 self.max_context_index = max(self.context_index, self.max_context_index) 1518 1519 def next_accessor(self): 1520 1521 "Allocate the next accessor value storage." 1522 1523 self.accessor_index += 1 1524 self.max_accessor_index = max(self.accessor_index, self.max_accessor_index) 1525 1526 def always_callable(self, refs): 1527 1528 "Determine whether all 'refs' are callable." 1529 1530 if not refs: 1531 return False 1532 1533 for ref in refs: 1534 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1535 return False 1536 1537 return True 1538 1539 def need_default_arguments(self, objpath, nargs): 1540 1541 """ 1542 Return whether any default arguments are needed when invoking the object 1543 given by 'objpath'. 1544 """ 1545 1546 parameters = self.importer.function_parameters.get(objpath) 1547 return nargs < len(parameters) 1548 1549 def uses_keyword_arguments(self, n): 1550 1551 "Return whether invocation node 'n' uses keyword arguments." 1552 1553 for arg in enumerate(n.args): 1554 if isinstance(arg, compiler.ast.Keyword): 1555 return True 1556 1557 return False 1558 1559 def get_attributes_for_attrname(self, attrname): 1560 1561 "Return a set of all attributes exposed by 'attrname'." 1562 1563 usage = [(attrname, True, False)] 1564 class_types = self.deducer.get_class_types_for_usage(usage) 1565 instance_types = self.deducer.get_instance_types_for_usage(usage) 1566 module_types = self.deducer.get_module_types_for_usage(usage) 1567 attrs = set() 1568 1569 for ref in combine_types(class_types, instance_types, module_types): 1570 attrs.update(self.importer.get_attributes(ref, attrname)) 1571 1572 return attrs 1573 1574 def process_lambda_node(self, n): 1575 1576 "Process the given lambda node 'n'." 1577 1578 name = self.get_lambda_name() 1579 function_name = self.get_object_path(name) 1580 instance_name = "__get_accessor(%d)" % self.accessor_index 1581 1582 defaults = self.process_function_defaults(n, name, function_name, instance_name) 1583 1584 # Without defaults, produce an attribute referring to the function. 1585 1586 if not defaults: 1587 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1588 1589 # With defaults, copy the function structure and set the defaults on the 1590 # copy. 1591 1592 else: 1593 self.record_temp("__tmp_values") 1594 return make_expression("""\ 1595 (__set_accessor(%d, __ATTRVALUE(__COPY(&%s, sizeof(%s)))), 1596 %s, 1597 __get_accessor(%d))""" % ( 1598 self.accessor_index, 1599 encode_path(function_name), 1600 encode_symbol("obj", function_name), 1601 ", ".join(defaults), 1602 self.accessor_index)) 1603 1604 def process_logical_node(self, n): 1605 1606 "Process the given operator node 'n'." 1607 1608 self.record_temp("__tmp_result") 1609 1610 conjunction = isinstance(n, compiler.ast.And) 1611 results = [] 1612 1613 for node in n.nodes: 1614 results.append(self.process_structure_node(node)) 1615 1616 return LogicalOperationResult(results, conjunction) 1617 1618 def process_name_node(self, n, expr=None): 1619 1620 "Process the given name node 'n' with the optional assignment 'expr'." 1621 1622 # Determine whether the name refers to a static external entity. 1623 1624 if n.name in predefined_constants: 1625 return PredefinedConstantRef(n.name, expr) 1626 1627 # Convert literal references, operator function names, and print 1628 # function names to references. 1629 1630 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1631 n.name.startswith("$seq") or n.name.startswith("$print"): 1632 1633 ref, paths = self.importer.get_module(self.name).special[n.name] 1634 return TrResolvedNameRef(n.name, ref) 1635 1636 # Get the appropriate name for the name reference, using the same method 1637 # as in the inspector. 1638 1639 path = self.get_namespace_path() 1640 objpath = self.get_object_path(n.name) 1641 1642 # Determine any assigned globals. 1643 1644 globals = self.importer.get_module(self.name).scope_globals.get(path) 1645 1646 # Explicitly declared globals. 1647 1648 if globals and n.name in globals: 1649 objpath = self.get_global_path(n.name) 1650 is_global = True 1651 1652 # Implicitly referenced globals in functions. 1653 1654 elif self.in_function: 1655 is_global = n.name not in self.importer.function_locals[path] 1656 1657 # Implicitly referenced globals elsewhere. 1658 1659 else: 1660 namespace = self.importer.identify(path) 1661 is_global = not self.importer.get_attributes(namespace, n.name) 1662 1663 # Get the static identity of the name. 1664 1665 ref = self.importer.identify(objpath) 1666 if ref and not ref.get_name(): 1667 ref = ref.alias(objpath) 1668 1669 # Obtain any resolved names for non-assignment names. 1670 1671 if not expr and not ref and self.in_function: 1672 locals = self.importer.function_locals.get(path) 1673 ref = locals and locals.get(n.name) 1674 1675 # Find any invocation or alias details. 1676 1677 name = self.get_name_for_tracking(n.name, is_global=is_global) 1678 location = not expr and self.get_access_location(name) or None 1679 1680 # Mark any local assignments as volatile in exception blocks. 1681 1682 if expr and self.in_function and not is_global and self.in_try_except: 1683 self.make_volatile(n.name) 1684 1685 # Qualified names are used for resolved static references or for 1686 # static namespace members. The reference should be configured to return 1687 # such names. 1688 1689 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1690 location=location) 1691 return not expr and self.get_aliases(name_ref) or name_ref 1692 1693 def get_aliases(self, name_ref): 1694 1695 "Return alias references for the given 'name_ref'." 1696 1697 location = name_ref.access_location() 1698 accessor_locations = self.deducer.access_index.get(location) 1699 1700 if not accessor_locations: 1701 return None 1702 1703 refs = set() 1704 1705 for accessor_location in accessor_locations: 1706 alias_refs = self.deducer.referenced_objects.get(accessor_location) 1707 if alias_refs: 1708 refs.update(alias_refs) 1709 1710 if refs: 1711 return AliasResult(name_ref, refs, location) 1712 else: 1713 return None 1714 1715 def make_volatile(self, name): 1716 1717 "Record 'name' as volatile in the current namespace." 1718 1719 self.volatile_locals.add(name) 1720 1721 def process_not_node(self, n): 1722 1723 "Process the given operator node 'n'." 1724 1725 return self.make_negation(self.process_structure_node(n.expr)) 1726 1727 def process_raise_node(self, n): 1728 1729 "Process the given raise node 'n'." 1730 1731 # NOTE: Determine which raise statement variants should be permitted. 1732 1733 if n.expr1: 1734 1735 # Names with accompanying arguments are treated like invocations. 1736 1737 if n.expr2: 1738 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1739 exc = self.process_structure_node(call) 1740 self.writestmt("__Raise(%s);" % exc) 1741 1742 # Raise instances, testing the kind at run-time if necessary and 1743 # instantiating any non-instance. 1744 1745 else: 1746 exc = self.process_structure_node(n.expr1) 1747 1748 if isinstance(exc, TrInstanceRef): 1749 self.writestmt("__Raise(%s);" % exc) 1750 else: 1751 self.writestmt("__Raise(__ensure_instance(__stack, %s));" % exc) 1752 else: 1753 self.writestmt("__Throw(__tmp_exc);") 1754 1755 def process_return_node(self, n): 1756 1757 "Process the given return node 'n'." 1758 1759 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1760 if self.in_try_finally or self.in_try_except: 1761 self.writestmt("__Return(%s);" % expr) 1762 else: 1763 self.writestmt("return %s;" % expr) 1764 1765 return ReturnRef() 1766 1767 def process_try_node(self, n): 1768 1769 """ 1770 Process the given "try...except" node 'n'. 1771 """ 1772 1773 in_try_except = self.in_try_except 1774 self.in_try_except = True 1775 1776 # Use macros to implement exception handling. 1777 1778 self.writestmt("__Try") 1779 self.writeline("{") 1780 self.indent += 1 1781 self.process_structure_node(n.body) 1782 1783 # Put the else statement in another try block that handles any raised 1784 # exceptions and converts them to exceptions that will not be handled by 1785 # the main handling block. 1786 1787 if n.else_: 1788 self.writestmt("__Try") 1789 self.writeline("{") 1790 self.indent += 1 1791 self.process_structure_node(n.else_) 1792 self.indent -= 1 1793 self.writeline("}") 1794 self.writeline("__Catch (__tmp_exc)") 1795 self.writeline("{") 1796 self.indent += 1 1797 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1798 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1799 self.indent -= 1 1800 self.writeline("}") 1801 1802 # Complete the try block and enter the finally block, if appropriate. 1803 1804 if self.in_try_finally: 1805 self.writestmt("__Complete;") 1806 1807 self.indent -= 1 1808 self.writeline("}") 1809 1810 self.in_try_except = in_try_except 1811 1812 # Handlers are tests within a common handler block. 1813 1814 self.writeline("__Catch (__tmp_exc)") 1815 self.writeline("{") 1816 self.indent += 1 1817 1818 # Introduce an if statement to handle the completion of a try block. 1819 1820 self.process_try_completion() 1821 1822 # Handle exceptions in else blocks converted to __RaiseElse, converting 1823 # them back to normal exceptions. 1824 1825 if n.else_: 1826 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1827 1828 # Exception handling. 1829 1830 for name, var, handler in n.handlers: 1831 1832 # Test for specific exceptions. 1833 1834 if name is not None: 1835 name_ref = self.process_structure_node(name) 1836 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1837 else: 1838 self.writeline("else if (1)") 1839 1840 self.writeline("{") 1841 self.indent += 1 1842 1843 # Establish the local for the handler. 1844 1845 if var is not None: 1846 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1847 1848 if handler is not None: 1849 self.process_structure_node(handler) 1850 1851 self.indent -= 1 1852 self.writeline("}") 1853 1854 # Re-raise unhandled exceptions. 1855 1856 self.writeline("else __Throw(__tmp_exc);") 1857 1858 # End the handler block. 1859 1860 self.indent -= 1 1861 self.writeline("}") 1862 print >>self.out 1863 1864 def process_try_finally_node(self, n): 1865 1866 """ 1867 Process the given "try...finally" node 'n'. 1868 """ 1869 1870 in_try_finally = self.in_try_finally 1871 self.in_try_finally = True 1872 1873 # Use macros to implement exception handling. 1874 1875 self.writestmt("__Try") 1876 self.writeline("{") 1877 self.indent += 1 1878 self.process_structure_node(n.body) 1879 self.indent -= 1 1880 self.writeline("}") 1881 1882 self.in_try_finally = in_try_finally 1883 1884 # Finally clauses handle special exceptions. 1885 1886 self.writeline("__Catch (__tmp_exc)") 1887 self.writeline("{") 1888 self.indent += 1 1889 self.process_structure_node(n.final) 1890 1891 # Introduce an if statement to handle the completion of a try block. 1892 1893 self.process_try_completion() 1894 self.writeline("else __Throw(__tmp_exc);") 1895 1896 self.indent -= 1 1897 self.writeline("}") 1898 print >>self.out 1899 1900 def process_try_completion(self): 1901 1902 "Generate a test for the completion of a try block." 1903 1904 self.writestmt("if (__tmp_exc.completing)") 1905 self.writeline("{") 1906 self.indent += 1 1907 1908 # Do not return anything at the module level. 1909 1910 if self.get_namespace_path() != self.name: 1911 1912 # Only use the normal return statement if no surrounding try blocks 1913 # apply. 1914 1915 if not self.in_try_finally and not self.in_try_except: 1916 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1917 else: 1918 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1919 1920 self.indent -= 1 1921 self.writeline("}") 1922 1923 def process_while_node(self, n): 1924 1925 "Process the given while node 'n'." 1926 1927 self.writeline("while (1)") 1928 self.writeline("{") 1929 self.indent += 1 1930 test = self.process_structure_node(n.test) 1931 1932 # Emit the loop termination condition unless "while <true value>" is 1933 # indicated. 1934 1935 if not (isinstance(test, PredefinedConstantRef) and test.value): 1936 1937 # Emit a negated test of the continuation condition. 1938 1939 self.start_if(True, self.make_negation(test)) 1940 if n.else_: 1941 self.process_structure_node(n.else_) 1942 self.writestmt("break;") 1943 self.end_if() 1944 1945 in_conditional = self.in_conditional 1946 self.in_conditional = True 1947 self.process_structure_node(n.body) 1948 self.in_conditional = in_conditional 1949 1950 self.indent -= 1 1951 self.writeline("}") 1952 print >>self.out 1953 1954 # Special variable usage. 1955 1956 def get_temp_path(self): 1957 1958 """ 1959 Return the appropriate namespace path for temporary names in the current 1960 namespace. 1961 """ 1962 1963 if self.in_function: 1964 return self.get_namespace_path() 1965 else: 1966 return self.name 1967 1968 def record_temp(self, name): 1969 1970 """ 1971 Record the use of the temporary 'name' in the current namespace. At the 1972 class or module level, the temporary name is associated with the module, 1973 since the variable will then be allocated in the module's own main 1974 program. 1975 """ 1976 1977 path = self.get_temp_path() 1978 1979 init_item(self.temp_usage, path, list) 1980 self.temp_usage[path].append(name) 1981 1982 def remove_temps(self, names): 1983 1984 """ 1985 Remove 'names' from temporary storage allocations, each instance 1986 removing each request for storage. 1987 """ 1988 1989 path = self.get_temp_path() 1990 1991 for name in names: 1992 if self.uses_temp(path, name): 1993 self.temp_usage[path].remove(name) 1994 1995 def uses_temp(self, path, name): 1996 1997 """ 1998 Return whether the given namespace 'path' employs a temporary variable 1999 with the given 'name'. Note that 'path' should only be a module or a 2000 function or method, not a class. 2001 """ 2002 2003 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 2004 2005 def make_negation(self, expr): 2006 2007 "Return a negated form of 'expr'." 2008 2009 result = NegationResult(expr) 2010 2011 # Negation discards the temporary results of its operand. 2012 2013 temps = expr.discards_temporary() 2014 if temps: 2015 self.remove_temps(temps) 2016 2017 return result 2018 2019 # Output generation. 2020 2021 def start_output(self): 2022 2023 "Write the declarations at the top of each source file." 2024 2025 print >>self.out, """\ 2026 #include "types.h" 2027 #include "exceptions.h" 2028 #include "ops.h" 2029 #include "progconsts.h" 2030 #include "progops.h" 2031 #include "progtypes.h" 2032 #include "main.h" 2033 """ 2034 2035 def start_unit(self): 2036 2037 "Record output within a generated function for later use." 2038 2039 self.out = StringIO() 2040 2041 def end_unit(self): 2042 2043 "Restore the output stream." 2044 2045 out = self.out 2046 self.out = self.out_toplevel 2047 return out 2048 2049 def flush_unit(self, name, out): 2050 2051 "Add declarations and generated code." 2052 2053 self.write_temporaries(name) 2054 print >>self.out 2055 out.seek(0) 2056 self.out.write(out.read()) 2057 2058 def start_module(self): 2059 2060 "Write the start of each module's main function." 2061 2062 print >>self.out, "void __main_%s(__attr __stack)" % encode_path(self.name) 2063 print >>self.out, "{" 2064 self.indent += 1 2065 2066 # Define temporary variables, excluded from the module structure itself. 2067 2068 tempnames = [] 2069 2070 for n in self.importer.all_module_attrs[self.name]: 2071 if n.startswith("$t"): 2072 tempnames.append(encode_path(n)) 2073 2074 if tempnames: 2075 tempnames.sort() 2076 self.writeline("__attr %s;" % ", ".join(tempnames)) 2077 2078 self.start_unit() 2079 2080 def end_module(self): 2081 2082 "End each module by closing its main function." 2083 2084 out = self.end_unit() 2085 self.flush_unit(self.name, out) 2086 2087 self.indent -= 1 2088 print >>self.out, "}" 2089 2090 def start_function(self, name): 2091 2092 "Start the function having the given 'name'." 2093 2094 self.indent += 1 2095 2096 self.start_unit() 2097 2098 def end_function(self, name): 2099 2100 "End the function having the given 'name'." 2101 2102 out = self.end_unit() 2103 2104 # Write the signature at the top indentation level. 2105 2106 self.indent -= 1 2107 self.write_parameters(name) 2108 print >>self.out, "{" 2109 2110 # Obtain local names from parameters. 2111 2112 parameters = self.importer.function_parameters[name] 2113 locals = self.importer.function_locals[name].keys() 2114 names = [] 2115 volatile_names = [] 2116 2117 for n in locals: 2118 2119 # Filter out special names and parameters. Note that self is a local 2120 # regardless of whether it originally appeared in the parameters or 2121 # not. 2122 2123 if n.startswith("$l") or n in parameters or n == "self": 2124 continue 2125 if n in self.volatile_locals: 2126 volatile_names.append(encode_path(n)) 2127 else: 2128 names.append(encode_path(n)) 2129 2130 # Emit required local names at the function indentation level. 2131 2132 self.indent += 1 2133 2134 if names: 2135 names.sort() 2136 self.writeline("__attr %s;" % ", ".join(names)) 2137 2138 if volatile_names: 2139 volatile_names.sort() 2140 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2141 2142 self.flush_unit(name, out) 2143 2144 self.indent -= 1 2145 print >>self.out, "}" 2146 print >>self.out 2147 2148 def write_parameters(self, name): 2149 2150 """ 2151 For the function having the given 'name', write definitions of 2152 parameters found in the arguments array. 2153 """ 2154 2155 l = [] 2156 2157 # Generate the parallel value stack reference. 2158 2159 l.append("__attr __stack") 2160 2161 # Generate any self reference. 2162 2163 if self.is_method(name): 2164 l.append("__attr self") 2165 else: 2166 l.append("__attr __self") 2167 2168 # Generate aliases for the parameters. 2169 2170 for parameter in self.importer.function_parameters[name]: 2171 l.append("%s__attr %s" % ( 2172 parameter in self.volatile_locals and "volatile " or "", 2173 encode_path(parameter))) 2174 2175 self.writeline("__attr %s(%s)" % ( 2176 encode_function_pointer(name), ", ".join(l))) 2177 2178 def write_temporaries(self, name): 2179 2180 "Write temporary storage employed by 'name'." 2181 2182 # Provide space for the recorded number of temporary variables. 2183 2184 if self.uses_temp(name, "__tmp_targets"): 2185 self.writeline("__attr __tmp_targets[%d];" % self.max_function_target) 2186 2187 if self.uses_temp(name, "__tmp_contexts"): 2188 self.writeline("__attr __tmp_contexts[%d];" % self.max_context_index) 2189 2190 if self.uses_temp(name, "__tmp_values"): 2191 self.writeline("__attr __tmp_values[%d];" % self.max_accessor_index) 2192 2193 # Add temporary variable usage details. 2194 2195 if self.uses_temp(name, "__tmp_private_context"): 2196 self.writeline("__attr __tmp_private_context;") 2197 if self.uses_temp(name, "__tmp_target_value"): 2198 self.writeline("__attr __tmp_target_value;") 2199 if self.uses_temp(name, "__tmp_result"): 2200 self.writeline("__attr __tmp_result;") 2201 2202 module = self.importer.get_module(self.name) 2203 2204 if name in module.exception_namespaces: 2205 self.writeline("__exc __tmp_exc;") 2206 2207 def start_if(self, first, test_ref): 2208 statement = "%sif" % (not first and "else " or "") 2209 2210 # Consume logical results directly. 2211 2212 if isinstance(test_ref, LogicalResult): 2213 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2214 temps = test_ref.discards_temporary() 2215 if temps: 2216 self.remove_temps(temps) 2217 else: 2218 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2219 2220 self.writeline("{") 2221 self.indent += 1 2222 2223 def end_if(self): 2224 self.indent -= 1 2225 self.writeline("}") 2226 2227 def start_else(self): 2228 self.writeline("else") 2229 self.writeline("{") 2230 self.indent += 1 2231 2232 def end_else(self): 2233 self.indent -= 1 2234 self.writeline("}") 2235 2236 def statement(self, expr): 2237 s = str(expr) 2238 if s: 2239 self.writestmt("%s;" % s) 2240 2241 def statements(self, results): 2242 for result in results: 2243 self.statement(result) 2244 2245 def writeline(self, s): 2246 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2247 2248 def writestmt(self, s): 2249 self.writeline(s) 2250 2251 def write_comment(self, s): 2252 self.writestmt("/* %s */" % s) 2253 2254 def pad(self, extra=0): 2255 return (self.indent + extra) * self.tabstop 2256 2257 def indenttext(self, s, levels): 2258 lines = s.split("\n") 2259 out = [lines[0]] 2260 for line in lines[1:]: 2261 out.append(levels * self.tabstop + line) 2262 if line.endswith("("): 2263 levels += 1 2264 elif line.startswith(")"): 2265 levels -= 1 2266 return "\n".join(out) 2267 2268 # vim: tabstop=4 expandtab shiftwidth=4