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, special_attributes 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, n.attrname, 623 self.in_assignment) 624 625 def init_substitutions(self): 626 627 """ 628 Initialise substitutions, defining temporary variable mappings, some of 629 which are also used as substitutions, together with operation mappings 630 used as substitutions in instructions defined by the optimiser. 631 """ 632 633 self.temp_subs = { 634 635 # Substitutions used by instructions. 636 637 "<private_context>" : "__tmp_private_context", 638 "<target_accessor>" : "__tmp_target_value", 639 640 # Mappings to be replaced by those given below. 641 642 "<accessor>" : "__tmp_values", 643 "<context>" : "__tmp_contexts", 644 "<test_context_revert>" : "__tmp_contexts", 645 "<test_context_static>" : "__tmp_contexts", 646 "<set_context>" : "__tmp_contexts", 647 "<set_private_context>" : "__tmp_private_context", 648 "<set_accessor>" : "__tmp_values", 649 "<set_target_accessor>" : "__tmp_target_value", 650 } 651 652 self.op_subs = { 653 "<accessor>" : "__get_accessor", 654 "<context>" : "__get_context", 655 "<test_context_revert>" : "__test_context_revert", 656 "<test_context_static>" : "__test_context_static", 657 "<set_context>" : "__set_context", 658 "<set_private_context>" : "__set_private_context", 659 "<set_accessor>" : "__set_accessor", 660 "<set_target_accessor>" : "__set_target_accessor", 661 } 662 663 def get_referenced_attributes(self, location): 664 665 """ 666 Convert 'location' to the form used by the deducer and retrieve any 667 identified attributes. 668 """ 669 670 # Determine whether any deduced references refer to the accessed 671 # attribute. 672 673 attrnames = location.attrnames 674 attrnames = attrnames and attrnames.split(".") 675 remaining = attrnames and len(attrnames) > 1 676 677 access_location = self.deducer.const_accesses.get(location) 678 679 if remaining and not access_location: 680 return set() 681 682 return self.deducer.get_references_for_access(access_location or location) 683 684 def get_referenced_attribute_invocations(self, location): 685 686 """ 687 Convert 'location' to the form used by the deducer and retrieve any 688 identified attribute invocation details. 689 """ 690 691 access_location = self.deducer.const_accesses.get(location) 692 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 693 694 def get_accessor_kinds(self, location): 695 696 "Return the accessor kinds for 'location'." 697 698 return self.deducer.accessor_kinds.get(location) 699 700 def get_access_location(self, name, attrnames=None): 701 702 """ 703 Using the current namespace, the given 'name', and the 'attrnames' 704 employed in an access, return the access location. 705 """ 706 707 path = self.get_path_for_access() 708 709 # Get the location used by the deducer and optimiser and find any 710 # recorded access. 711 712 attrnames = attrnames and ".".join(self.attrs) 713 access_number = self.get_access_number(path, name, attrnames) 714 self.update_access_number(path, name, attrnames) 715 return AccessLocation(path, name, attrnames, access_number) 716 717 def get_access_number(self, path, name, attrnames): 718 access = name, attrnames 719 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 720 return self.attr_accesses[path][access] 721 else: 722 return 0 723 724 def update_access_number(self, path, name, attrnames): 725 access = name, attrnames 726 if name: 727 init_item(self.attr_accesses, path, dict) 728 init_item(self.attr_accesses[path], access, lambda: 0) 729 self.attr_accesses[path][access] += 1 730 731 def get_accessor_location(self, name): 732 733 """ 734 Using the current namespace and the given 'name', return the accessor 735 location. 736 """ 737 738 path = self.get_path_for_access() 739 740 # Get the location used by the deducer and optimiser and find any 741 # recorded accessor. 742 743 version = self.get_accessor_number(path, name) 744 self.update_accessor_number(path, name) 745 return Location(path, name, None, version) 746 747 def get_accessor_number(self, path, name): 748 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 749 return self.attr_accessors[path][name] 750 else: 751 return 0 752 753 def update_accessor_number(self, path, name): 754 if name: 755 init_item(self.attr_accessors, path, dict) 756 init_item(self.attr_accessors[path], name, lambda: 0) 757 self.attr_accessors[path][name] += 1 758 759 def process_class_node(self, n): 760 761 "Process the given class node 'n'." 762 763 class_name = self.get_object_path(n.name) 764 765 # Where a class is set conditionally or where the name may refer to 766 # different values, assign the name. 767 768 ref = self.importer.identify(class_name) 769 770 if not ref.static(): 771 self.process_assignment_for_object(n.name, 772 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 773 774 self.enter_namespace(n.name) 775 776 if self.have_object(): 777 self.write_comment("Class: %s" % class_name) 778 779 self.initialise_inherited_members(class_name) 780 781 self.process_structure(n) 782 self.write_comment("End class: %s" % class_name) 783 784 self.exit_namespace() 785 786 def initialise_inherited_members(self, class_name): 787 788 "Initialise members of 'class_name' inherited from its ancestors." 789 790 for name, path in self.importer.all_class_attrs[class_name].items(): 791 target = "%s.%s" % (class_name, name) 792 793 # Ignore attributes with definitions. 794 795 ref = self.importer.identify(target) 796 if ref: 797 continue 798 799 # Ignore special type attributes. 800 801 if is_type_attribute(name): 802 continue 803 804 # Reference inherited attributes. 805 806 ref = self.importer.identify(path) 807 if ref and not ref.static(): 808 parent, attrname = path.rsplit(".", 1) 809 810 # NOTE: This is a superficial test for internal attributes that 811 # NOTE: relies on such attributes being used directly and passed 812 # NOTE: to native code. 813 814 if name in special_attributes: 815 store_op = "__store_via_object_internal" 816 else: 817 store_op = "__store_via_object" 818 819 if attrname in special_attributes: 820 load_op = "__load_via_object_internal" 821 else: 822 load_op = "__load_via_object" 823 824 self.writestmt("%s(&%s, %s, %s(&%s, %s));" % ( 825 store_op, encode_path(class_name), name, 826 load_op, encode_path(parent), attrname 827 )) 828 829 def process_from_node(self, n): 830 831 "Process the given node 'n', importing from another module." 832 833 path = self.get_namespace_path() 834 835 # Attempt to obtain the referenced objects. 836 837 for name, alias in n.names: 838 if name == "*": 839 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 840 841 # Obtain the path of the assigned name. 842 843 objpath = self.get_object_path(alias or name) 844 845 # Obtain the identity of the name. 846 847 ref = self.importer.identify(objpath) 848 849 # Where the name is not static, assign the value. 850 851 if ref and not ref.static() and ref.get_name(): 852 self.writestmt("%s;" % 853 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 854 expr=TrResolvedNameRef(name, ref))) 855 856 def process_function_body_node(self, n): 857 858 """ 859 Process the given function, lambda, if expression or list comprehension 860 node 'n', generating the body. 861 """ 862 863 function_name = self.get_namespace_path() 864 self.start_function(function_name) 865 866 # Process the function body. 867 868 in_conditional = self.in_conditional 869 self.in_conditional = False 870 self.function_target = 0 871 self.max_function_target = 0 872 self.context_index = 0 873 self.max_context_index = 0 874 self.accessor_index = 0 875 self.max_accessor_index = 0 876 877 # Volatile locals for exception handling. 878 879 self.volatile_locals = set() 880 881 # Process any guards defined for the parameters. 882 883 for name in self.importer.function_parameters.get(function_name): 884 self.generate_guard(name) 885 886 # Also support self in methods, since some mix-in methods may only work 887 # with certain descendant classes. 888 889 if self.in_method(): 890 self.generate_guard("self") 891 892 # Make assignments for .name entries in the parameters, provided this is 893 # a method. 894 895 if self.in_method(): 896 for name in self.importer.function_attr_initialisers.get(function_name) or []: 897 self.process_assignment_node( 898 compiler.ast.AssAttr(compiler.ast.Name("self"), name, "OP_ASSIGN"), 899 compiler.ast.Name(name)) 900 901 # Record the value stack level. 902 903 self.writestmt("__section *__stack_section = __stack.stackdesc->current;") 904 self.writestmt("char *__stack_level = __stack_section->level; (void) __stack_level;") 905 906 # Produce the body and any additional return statement. 907 908 expr = self.process_structure_node(n.code) or \ 909 self.in_method() and \ 910 function_name.rsplit(".", 1)[-1] == "__init__" and \ 911 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 912 PredefinedConstantRef("None") 913 914 if not isinstance(expr, ReturnRef): 915 self.writestmt("return %s;" % expr) 916 917 self.in_conditional = in_conditional 918 919 self.end_function(function_name) 920 921 def generate_guard(self, name): 922 923 """ 924 Get the accessor details for 'name', found in the current namespace, and 925 generate any guards defined for it. 926 """ 927 928 # Obtain the location, keeping track of assignment versions. 929 930 location = self.get_accessor_location(name) 931 test = self.deducer.accessor_guard_tests.get(location) 932 933 # Generate any guard from the deduced information. 934 935 if test: 936 guard, guard_type = test 937 938 if guard == "specific": 939 ref = first(self.deducer.accessor_all_types[location]) 940 argstr = "&%s" % encode_path(ref.get_origin()) 941 elif guard == "common": 942 ref = first(self.deducer.accessor_all_general_types[location]) 943 argstr = encode_path(encode_type_attribute(ref.get_origin())) 944 else: 945 return 946 947 # Write a test that raises a TypeError upon failure. 948 949 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 950 guard, guard_type, encode_path(name), argstr)) 951 952 def process_function_node(self, n): 953 954 """ 955 Process the given function, lambda, if expression or list comprehension 956 node 'n', generating any initialisation statements. 957 """ 958 959 # Where a function is declared conditionally, use a separate name for 960 # the definition, and assign the definition to the stated name. 961 962 original_name = n.name 963 964 if self.in_conditional or self.in_function: 965 name = self.get_lambda_name() 966 else: 967 name = n.name 968 969 objpath = self.get_object_path(name) 970 971 # Obtain details of the defaults. 972 973 defaults = self.process_function_defaults(n, name, objpath) 974 if defaults: 975 for default in defaults: 976 self.writeline("%s;" % default) 977 978 # Where a function is set conditionally or where the name may refer to 979 # different values, assign the name. 980 981 ref = self.importer.identify(objpath) 982 983 if self.in_conditional or self.in_function: 984 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 985 elif not ref.static(): 986 context = self.is_method(objpath) 987 988 self.process_assignment_for_object(original_name, 989 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 990 991 def process_function_defaults(self, n, name, objpath, instance_name=None): 992 993 """ 994 Process the given function or lambda node 'n', initialising defaults 995 that are dynamically set. The given 'name' indicates the name of the 996 function. The given 'objpath' indicates the origin of the function. 997 The given 'instance_name' indicates the name of any separate instance 998 of the function created to hold the defaults. 999 1000 Return a list of operations setting defaults on a function instance. 1001 """ 1002 1003 function_name = self.get_object_path(name) 1004 function_defaults = self.importer.function_defaults.get(function_name) 1005 if not function_defaults: 1006 return None 1007 1008 # Determine whether any unidentified defaults are involved. 1009 1010 for argname, default in function_defaults: 1011 if not default.static(): 1012 break 1013 else: 1014 return None 1015 1016 # Handle bound methods. 1017 1018 if not instance_name: 1019 instance_name = "&%s" % encode_path(objpath) 1020 else: 1021 instance_name = "__VALUE(%s)" % instance_name 1022 1023 # Where defaults are involved but cannot be identified, obtain a new 1024 # instance of the lambda and populate the defaults. 1025 1026 defaults = [] 1027 1028 # Join the original defaults with the inspected defaults. 1029 1030 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 1031 1032 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 1033 1034 # Obtain any reference for the default. 1035 1036 if original: 1037 argname, default = original 1038 name_ref = self.process_structure_node(default) 1039 elif inspected: 1040 argname, default = inspected 1041 name_ref = TrResolvedNameRef(argname, default) 1042 else: 1043 continue 1044 1045 # Generate default initialisers except when constants are employed. 1046 # Constants should be used when populating the function structures. 1047 1048 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1049 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1050 1051 return defaults 1052 1053 def process_if_node(self, n): 1054 1055 """ 1056 Process the given "if" node 'n'. 1057 """ 1058 1059 first = True 1060 for test, body in n.tests: 1061 test_ref = self.process_structure_node(test) 1062 self.start_if(first, test_ref) 1063 1064 in_conditional = self.in_conditional 1065 self.in_conditional = True 1066 self.process_structure_node(body) 1067 self.in_conditional = in_conditional 1068 1069 self.end_if() 1070 first = False 1071 1072 if n.else_: 1073 self.start_else() 1074 self.process_structure_node(n.else_) 1075 self.end_else() 1076 1077 print >>self.out 1078 1079 def process_invocation_node(self, n): 1080 1081 "Process the given invocation node 'n'." 1082 1083 # Process the expression. 1084 1085 expr = self.process_structure_node(n.node) 1086 1087 # Obtain details of the invocation expression. 1088 1089 objpath = expr.get_origin() 1090 location = expr.access_location() 1091 refs = expr.references() 1092 1093 # Identified target details. 1094 1095 target = None 1096 target_structure = None 1097 1098 # Specific function target information. 1099 1100 function = None 1101 1102 # Instantiation involvement. 1103 1104 instantiation = False 1105 literal_instantiation = False 1106 1107 # Invocation requirements. 1108 1109 context_required = True 1110 have_access_context = isinstance(expr, AttrResult) 1111 1112 # The context identity is merely the thing providing the context. 1113 # A verified context is one that does not need further testing for 1114 # suitability. 1115 1116 context_identity = have_access_context and expr.context() 1117 context_verified = have_access_context and expr.context_verified() 1118 1119 # The presence of any test operations in the accessor expression. 1120 # With such operations present, the expression cannot be eliminated. 1121 1122 tests_accessor = have_access_context and expr.tests_accessor() 1123 stores_accessor = have_access_context and expr.stores_accessor() 1124 1125 # Parameter details and parameter list dimensions. 1126 1127 parameters = None 1128 num_parameters = None 1129 num_defaults = None 1130 1131 # Obtain details of the callable and of its parameters. 1132 1133 # Literals may be instantiated specially. 1134 1135 if expr.is_name() and expr.name.startswith("$L") and objpath: 1136 instantiation = literal_instantiation = objpath 1137 target = encode_literal_instantiator(objpath) 1138 context_required = False 1139 1140 # Identified targets employ function pointers directly. 1141 1142 elif objpath: 1143 parameters = self.importer.function_parameters.get(objpath) 1144 function_defaults = self.importer.function_defaults.get(objpath) 1145 num_parameters = parameters and len(parameters) or 0 1146 num_defaults = function_defaults and len(function_defaults) or 0 1147 1148 # Class invocation involves instantiators. 1149 1150 if expr.has_kind("<class>"): 1151 instantiation = objpath 1152 target = encode_instantiator_pointer(objpath) 1153 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1154 target_structure = "&%s" % encode_path(init_ref) 1155 context_required = False 1156 1157 # Only plain functions and bound methods employ function pointers. 1158 1159 elif expr.has_kind("<function>"): 1160 function = objpath 1161 1162 # Test for functions and methods. 1163 1164 context_required = self.is_method(objpath) 1165 1166 accessor_kinds = location and self.get_accessor_kinds(location) 1167 1168 instance_accessor = accessor_kinds and \ 1169 len(accessor_kinds) == 1 and \ 1170 first(accessor_kinds) == "<instance>" 1171 1172 # Only identify certain bound methods or functions. 1173 1174 if not context_required or instance_accessor: 1175 target = encode_function_pointer(objpath) 1176 1177 # Access bound method defaults even if it is not clear whether 1178 # the accessor is appropriate. 1179 1180 target_structure = "&%s" % encode_path(objpath) 1181 1182 # Other targets are retrieved at run-time. 1183 1184 else: 1185 if location: 1186 attrnames = location.attrnames 1187 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1188 1189 # Determine common aspects of any identifiable targets. 1190 1191 if attrname or refs: 1192 all_params = set() 1193 all_defaults = set() 1194 min_params = set() 1195 max_params = set() 1196 1197 # Employ references from the expression or find all 1198 # possible attributes for the given attribute name. 1199 1200 refs = refs or self.get_attributes_for_attrname(attrname) 1201 1202 # Obtain parameters and defaults for each possible target. 1203 1204 for ref in refs: 1205 origin = ref.get_origin() 1206 params = self.importer.function_parameters.get(origin) 1207 1208 defaults = self.importer.function_defaults.get(origin) 1209 if defaults is not None: 1210 all_defaults.add(tuple(defaults)) 1211 1212 if params is not None: 1213 all_params.add(tuple(params)) 1214 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1215 max_params.add(len(params)) 1216 else: 1217 refs = set() 1218 break 1219 1220 # Where the parameters and defaults are always the same, 1221 # permit populating them in advance. 1222 1223 if refs: 1224 if self.uses_keyword_arguments(n): 1225 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1226 parameters = first(all_params) 1227 function_defaults = all_defaults and first(all_defaults) or [] 1228 num_parameters = parameters and len(parameters) or 0 1229 num_defaults = function_defaults and len(function_defaults) or 0 1230 else: 1231 if len(min_params) == 1 and len(max_params) == 1: 1232 num_parameters = first(max_params) 1233 num_defaults = first(max_params) - first(min_params) 1234 1235 # Some information about the target may be available and be used to 1236 # provide warnings about argument compatibility. 1237 1238 if self.importer.give_warning("args"): 1239 unsuitable = self.get_referenced_attribute_invocations(location) 1240 1241 if unsuitable: 1242 for ref in unsuitable: 1243 _objpath = ref.get_origin() 1244 print >>sys.stderr, \ 1245 "In %s, at line %d, inappropriate number of " \ 1246 "arguments given. Need %d arguments to call %s." % ( 1247 self.get_namespace_path(), n.lineno, 1248 len(self.importer.function_parameters[_objpath]), 1249 _objpath) 1250 1251 # Logical statement about available parameter information. 1252 1253 known_parameters = num_parameters is not None 1254 1255 # The source of context information: target or temporary. 1256 1257 need_context_target = context_required and not have_access_context 1258 1259 need_context_stored = context_required and context_identity and \ 1260 context_identity.startswith("__get_context") 1261 1262 # Determine any readily-accessible target identity. 1263 1264 target_named = expr.is_name() and str(expr) or None 1265 target_identity = target or target_named 1266 1267 # Use of target information to populate defaults. 1268 1269 defaults_target_var = not (parameters and function_defaults is not None) and \ 1270 known_parameters and len(n.args) < num_parameters 1271 1272 # Use of a temporary target variable in these situations: 1273 # 1274 # A target provided by an expression needed for defaults. 1275 # 1276 # A target providing the context but not using a name to do so. 1277 # 1278 # A target expression involving the definition of a context which may 1279 # then be evaluated and stored to ensure that the context is available 1280 # during argument evaluation. 1281 # 1282 # An expression featuring an accessor test. 1283 1284 need_target_stored = defaults_target_var and not target_identity or \ 1285 need_context_target and not target_identity or \ 1286 need_context_stored or \ 1287 tests_accessor and not target 1288 1289 # Define stored target details. 1290 1291 target_stored = "__tmp_targets[%d]" % self.function_target 1292 target_var = need_target_stored and target_stored or target_identity 1293 1294 if need_target_stored: 1295 self.record_temp("__tmp_targets") 1296 1297 if need_context_stored: 1298 self.record_temp("__tmp_contexts") 1299 1300 if stores_accessor: 1301 self.record_temp("__tmp_values") 1302 1303 # Arguments are presented in a temporary frame array with any context 1304 # always being the first argument. Where the context would be unused, it 1305 # may be set to null. 1306 1307 if context_required: 1308 if have_access_context: 1309 context_arg = context_identity 1310 else: 1311 context_arg = "__CONTEXT_AS_VALUE(%s)" % target_var 1312 else: 1313 context_arg = "__NULL" 1314 1315 # Introduce any context. 1316 1317 args = [context_arg] 1318 reserved_args = 1 1319 1320 # Complete the array with null values, permitting tests for a complete 1321 # set of arguments. 1322 1323 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1324 kwcodes = [] 1325 kwargs = [] 1326 1327 # Any invocations in the arguments will store target details in a 1328 # different location. 1329 1330 function_target = self.function_target 1331 context_index = self.context_index 1332 accessor_index = self.accessor_index 1333 1334 if need_target_stored: 1335 self.next_target() 1336 1337 if need_context_stored: 1338 self.next_context() 1339 1340 if stores_accessor: 1341 self.next_accessor() 1342 1343 in_parameter_list = self.in_parameter_list 1344 self.in_parameter_list = True 1345 1346 for i, arg in enumerate(n.args): 1347 argexpr = self.process_structure_node(arg) 1348 1349 # Obtain an appropriate argument representation. 1350 1351 argrepr = str(argexpr) 1352 1353 # Store a keyword argument, either in the argument list or 1354 # in a separate keyword argument list for subsequent lookup. 1355 1356 if isinstance(arg, compiler.ast.Keyword): 1357 1358 # With knowledge of the target, store the keyword 1359 # argument directly. 1360 1361 if parameters: 1362 try: 1363 argnum = parameters.index(arg.name) 1364 except ValueError: 1365 raise TranslateError("Argument %s is not recognised." % arg.name, 1366 self.get_namespace_path(), n) 1367 args[argnum + reserved_args] = argrepr 1368 1369 # Otherwise, store the details in a separate collection. 1370 1371 else: 1372 kwargs.append(argrepr) 1373 kwcodes.append("{%s, %s}" % ( 1374 encode_ppos(arg.name), encode_pcode(arg.name))) 1375 1376 # Store non-keyword arguments in the argument list, rejecting 1377 # superfluous arguments. 1378 1379 else: 1380 try: 1381 args[i + reserved_args] = argrepr 1382 except IndexError: 1383 raise TranslateError("Too many arguments specified.", 1384 self.get_namespace_path(), n) 1385 1386 # Reference the current target again. 1387 1388 self.in_parameter_list = in_parameter_list 1389 1390 if not self.in_parameter_list: 1391 self.function_target = function_target 1392 self.context_index = context_index 1393 self.accessor_index = accessor_index 1394 1395 # Defaults are added to the frame where arguments are missing. 1396 1397 if parameters and function_defaults is not None: 1398 1399 # Visit each default and set any missing arguments. Where keyword 1400 # arguments have been used, the defaults must be inspected and, if 1401 # necessary, inserted into gaps in the argument list. 1402 1403 for i, (argname, default) in enumerate(function_defaults): 1404 argnum = parameters.index(argname) 1405 if not args[argnum + reserved_args]: 1406 args[argnum + reserved_args] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1407 1408 elif known_parameters: 1409 1410 # No specific parameter details are provided, but no keyword 1411 # arguments are used. Thus, defaults can be supplied using position 1412 # information only. 1413 1414 i = len(n.args) 1415 pos = i - (num_parameters - num_defaults) 1416 while i < num_parameters: 1417 args[i + reserved_args] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1418 i += 1 1419 pos += 1 1420 1421 # Test for missing arguments. 1422 1423 if None in args: 1424 raise TranslateError("Not all arguments supplied.", 1425 self.get_namespace_path(), n) 1426 1427 # Encode the arguments. 1428 1429 # Where literal instantiation is occurring, add an argument indicating 1430 # the number of values. The context is excluded. 1431 1432 if literal_instantiation: 1433 argstr = "%d, %s" % (len(args) - reserved_args, ", ".join(args[reserved_args:])) 1434 else: 1435 argstr = ", ".join(args) 1436 1437 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1438 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1439 1440 # First, the invocation expression is presented. 1441 1442 stages = [] 1443 emit = stages.append 1444 1445 # Assign and yield any stored target. 1446 # The context may be set in the expression. 1447 1448 if need_target_stored: 1449 emit("%s = %s" % (target_var, expr)) 1450 target_expr = target_var 1451 1452 # Otherwise, retain the expression for later use. 1453 1454 else: 1455 target_expr = str(expr) 1456 1457 # Any specific callable is then obtained for invocation. 1458 1459 if target: 1460 1461 # An expression involving a test of the accessor providing the target. 1462 # This must be emitted in order to perform the test. 1463 1464 if tests_accessor: 1465 emit(str(expr)) 1466 1467 emit(target) 1468 1469 # Methods accessed via unidentified accessors are obtained for 1470 # invocation. 1471 1472 elif function: 1473 if context_required: 1474 1475 # Avoid further context testing if appropriate. 1476 1477 if have_access_context and context_verified: 1478 emit("__get_function_member(%s)" % target_expr) 1479 1480 # Otherwise, test the context for the function/method. 1481 1482 else: 1483 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1484 else: 1485 emit("_get_function_member(%s)" % target_expr) 1486 1487 # With known parameters, the target can be tested. 1488 1489 elif known_parameters: 1490 if self.always_callable(refs): 1491 if context_verified: 1492 emit("__get_function_member(%s)" % target_expr) 1493 else: 1494 emit("__get_function(%s, %s)" % (context_arg, target_expr)) 1495 else: 1496 emit("__check_and_get_function(%s, %s)" % (context_arg, target_expr)) 1497 1498 # With a known target, the function is obtained directly and called. 1499 # By putting the invocation at the end of the final element in the 1500 # instruction sequence (the stages), the result becomes the result of 1501 # the sequence. Moreover, the parameters become part of the sequence 1502 # and thereby participate in a guaranteed evaluation order. 1503 1504 if target or function or known_parameters: 1505 stages[-1] += "(%s)" % argstr 1506 if instantiation: 1507 return InstantiationResult(instantiation, stages) 1508 else: 1509 return InvocationResult(stages) 1510 1511 # With unknown targets, the generic invocation function is applied to 1512 # the callable and argument collections. 1513 1514 else: 1515 emit("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1516 target_expr, 1517 self.always_callable(refs) and 1 or 0, 1518 len(kwargs), kwcodestr, kwargstr, 1519 len(args), "__ARGS(%s)" % argstr)) 1520 return InvocationResult(stages) 1521 1522 def next_target(self): 1523 1524 "Allocate the next function target storage." 1525 1526 self.function_target += 1 1527 self.max_function_target = max(self.function_target, self.max_function_target) 1528 1529 def next_context(self): 1530 1531 "Allocate the next context value storage." 1532 1533 self.context_index += 1 1534 self.max_context_index = max(self.context_index, self.max_context_index) 1535 1536 def next_accessor(self): 1537 1538 "Allocate the next accessor value storage." 1539 1540 self.accessor_index += 1 1541 self.max_accessor_index = max(self.accessor_index, self.max_accessor_index) 1542 1543 def always_callable(self, refs): 1544 1545 "Determine whether all 'refs' are callable." 1546 1547 if not refs: 1548 return False 1549 1550 for ref in refs: 1551 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1552 return False 1553 1554 return True 1555 1556 def need_default_arguments(self, objpath, nargs): 1557 1558 """ 1559 Return whether any default arguments are needed when invoking the object 1560 given by 'objpath'. 1561 """ 1562 1563 parameters = self.importer.function_parameters.get(objpath) 1564 return nargs < len(parameters) 1565 1566 def uses_keyword_arguments(self, n): 1567 1568 "Return whether invocation node 'n' uses keyword arguments." 1569 1570 for arg in enumerate(n.args): 1571 if isinstance(arg, compiler.ast.Keyword): 1572 return True 1573 1574 return False 1575 1576 def get_attributes_for_attrname(self, attrname): 1577 1578 "Return a set of all attributes exposed by 'attrname'." 1579 1580 usage = [(attrname, True, False)] 1581 class_types = self.deducer.get_class_types_for_usage(usage) 1582 instance_types = self.deducer.get_instance_types_for_usage(usage) 1583 module_types = self.deducer.get_module_types_for_usage(usage) 1584 attrs = set() 1585 1586 for ref in combine_types(class_types, instance_types, module_types): 1587 attrs.update(self.importer.get_attributes(ref, attrname)) 1588 1589 return attrs 1590 1591 def process_lambda_node(self, n): 1592 1593 "Process the given lambda node 'n'." 1594 1595 name = self.get_lambda_name() 1596 function_name = self.get_object_path(name) 1597 instance_name = "__get_accessor(%d)" % self.accessor_index 1598 1599 defaults = self.process_function_defaults(n, name, function_name, instance_name) 1600 1601 # Without defaults, produce an attribute referring to the function. 1602 1603 if not defaults: 1604 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1605 1606 # With defaults, copy the function structure and set the defaults on the 1607 # copy. 1608 1609 else: 1610 self.record_temp("__tmp_values") 1611 return make_expression("""\ 1612 (__set_accessor(%d, __ATTRVALUE(__COPY(&%s, sizeof(%s)))), 1613 %s, 1614 __get_accessor(%d))""" % ( 1615 self.accessor_index, 1616 encode_path(function_name), 1617 encode_symbol("obj", function_name), 1618 ", ".join(defaults), 1619 self.accessor_index)) 1620 1621 def process_logical_node(self, n): 1622 1623 "Process the given operator node 'n'." 1624 1625 self.record_temp("__tmp_result") 1626 1627 conjunction = isinstance(n, compiler.ast.And) 1628 results = [] 1629 1630 for node in n.nodes: 1631 results.append(self.process_structure_node(node)) 1632 1633 return LogicalOperationResult(results, conjunction) 1634 1635 def process_name_node(self, n, expr=None): 1636 1637 "Process the given name node 'n' with the optional assignment 'expr'." 1638 1639 # Determine whether the name refers to a static external entity. 1640 1641 if n.name in predefined_constants: 1642 return PredefinedConstantRef(n.name, expr) 1643 1644 # Convert literal references, operator function names, and print 1645 # function names to references. 1646 1647 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1648 n.name.startswith("$seq") or n.name.startswith("$print"): 1649 1650 ref, paths = self.importer.get_module(self.name).special[n.name] 1651 return TrResolvedNameRef(n.name, ref) 1652 1653 # Get the appropriate name for the name reference, using the same method 1654 # as in the inspector. 1655 1656 path = self.get_namespace_path() 1657 objpath = self.get_object_path(n.name) 1658 1659 # Determine any assigned globals. 1660 1661 globals = self.importer.get_module(self.name).scope_globals.get(path) 1662 1663 # Explicitly declared globals. 1664 1665 if globals and n.name in globals: 1666 objpath = self.get_global_path(n.name) 1667 is_global = True 1668 1669 # Implicitly referenced globals in functions. 1670 1671 elif self.in_function: 1672 is_global = n.name not in self.importer.function_locals[path] 1673 1674 # Implicitly referenced globals elsewhere. 1675 1676 else: 1677 namespace = self.importer.identify(path) 1678 is_global = not self.importer.get_attributes(namespace, n.name) 1679 1680 # Get the static identity of the name. 1681 1682 ref = self.importer.identify(objpath) 1683 if ref and not ref.get_name(): 1684 ref = ref.alias(objpath) 1685 1686 # Obtain any resolved names for non-assignment names. 1687 1688 if not expr and not ref and self.in_function: 1689 locals = self.importer.function_locals.get(path) 1690 ref = locals and locals.get(n.name) 1691 1692 # Find any invocation or alias details. 1693 1694 name = self.get_name_for_tracking(n.name, is_global=is_global) 1695 location = not expr and self.get_access_location(name) or None 1696 1697 # Mark any local assignments as volatile in exception blocks. 1698 1699 if expr and self.in_function and not is_global and self.in_try_except: 1700 self.make_volatile(n.name) 1701 1702 # Qualified names are used for resolved static references or for 1703 # static namespace members. The reference should be configured to return 1704 # such names. 1705 1706 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1707 location=location) 1708 return not expr and self.get_aliases(name_ref) or name_ref 1709 1710 def get_aliases(self, name_ref): 1711 1712 "Return alias references for the given 'name_ref'." 1713 1714 location = name_ref.access_location() 1715 accessor_locations = self.deducer.access_index.get(location) 1716 1717 if not accessor_locations: 1718 return None 1719 1720 refs = set() 1721 1722 for accessor_location in accessor_locations: 1723 alias_refs = self.deducer.referenced_objects.get(accessor_location) 1724 if alias_refs: 1725 refs.update(alias_refs) 1726 1727 if refs: 1728 return AliasResult(name_ref, refs, location) 1729 else: 1730 return None 1731 1732 def make_volatile(self, name): 1733 1734 "Record 'name' as volatile in the current namespace." 1735 1736 self.volatile_locals.add(name) 1737 1738 def process_not_node(self, n): 1739 1740 "Process the given operator node 'n'." 1741 1742 return self.make_negation(self.process_structure_node(n.expr)) 1743 1744 def process_raise_node(self, n): 1745 1746 "Process the given raise node 'n'." 1747 1748 # NOTE: Determine which raise statement variants should be permitted. 1749 1750 if n.expr1: 1751 1752 # Names with accompanying arguments are treated like invocations. 1753 1754 if n.expr2: 1755 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1756 exc = self.process_structure_node(call) 1757 self.writestmt("__Raise(%s);" % exc) 1758 1759 # Raise instances, testing the kind at run-time if necessary and 1760 # instantiating any non-instance. 1761 1762 else: 1763 exc = self.process_structure_node(n.expr1) 1764 1765 if isinstance(exc, TrInstanceRef): 1766 self.writestmt("__Raise(%s);" % exc) 1767 else: 1768 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1769 else: 1770 self.writestmt("__Throw(__tmp_exc);") 1771 1772 def process_return_node(self, n): 1773 1774 "Process the given return node 'n'." 1775 1776 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1777 if self.in_try_finally or self.in_try_except: 1778 self.writestmt("__Return(%s);" % expr) 1779 else: 1780 self.writestmt("return __return(%s, __stack_section, __stack_level);" % expr) 1781 1782 return ReturnRef() 1783 1784 def process_try_node(self, n): 1785 1786 """ 1787 Process the given "try...except" node 'n'. 1788 """ 1789 1790 in_try_except = self.in_try_except 1791 self.in_try_except = True 1792 1793 # Use macros to implement exception handling. 1794 1795 self.writestmt("__Try") 1796 self.writeline("{") 1797 self.indent += 1 1798 self.process_structure_node(n.body) 1799 1800 # Put the else statement in another try block that handles any raised 1801 # exceptions and converts them to exceptions that will not be handled by 1802 # the main handling block. 1803 1804 if n.else_: 1805 self.writestmt("__Try") 1806 self.writeline("{") 1807 self.indent += 1 1808 self.process_structure_node(n.else_) 1809 self.indent -= 1 1810 self.writeline("}") 1811 self.writeline("__Catch (__tmp_exc)") 1812 self.writeline("{") 1813 self.indent += 1 1814 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1815 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1816 self.indent -= 1 1817 self.writeline("}") 1818 1819 # Complete the try block and enter the finally block, if appropriate. 1820 1821 if self.in_try_finally: 1822 self.writestmt("__Complete;") 1823 1824 self.indent -= 1 1825 self.writeline("}") 1826 1827 self.in_try_except = in_try_except 1828 1829 # Handlers are tests within a common handler block. 1830 1831 self.writeline("__Catch (__tmp_exc)") 1832 self.writeline("{") 1833 self.indent += 1 1834 1835 # Introduce an if statement to handle the completion of a try block. 1836 1837 self.process_try_completion() 1838 1839 # Handle exceptions in else blocks converted to __RaiseElse, converting 1840 # them back to normal exceptions. 1841 1842 if n.else_: 1843 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1844 1845 # Exception handling. 1846 1847 for name, var, handler in n.handlers: 1848 1849 # Test for specific exceptions. 1850 1851 if name is not None: 1852 name_ref = self.process_structure_node(name) 1853 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1854 else: 1855 self.writeline("else if (1)") 1856 1857 self.writeline("{") 1858 self.indent += 1 1859 1860 # Establish the local for the handler. 1861 1862 if var is not None: 1863 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1864 1865 if handler is not None: 1866 self.process_structure_node(handler) 1867 1868 self.indent -= 1 1869 self.writeline("}") 1870 1871 # Re-raise unhandled exceptions. 1872 1873 self.writeline("else __Throw(__tmp_exc);") 1874 1875 # End the handler block. 1876 1877 self.indent -= 1 1878 self.writeline("}") 1879 print >>self.out 1880 1881 def process_try_finally_node(self, n): 1882 1883 """ 1884 Process the given "try...finally" node 'n'. 1885 """ 1886 1887 in_try_finally = self.in_try_finally 1888 self.in_try_finally = True 1889 1890 # Use macros to implement exception handling. 1891 1892 self.writestmt("__Try") 1893 self.writeline("{") 1894 self.indent += 1 1895 self.process_structure_node(n.body) 1896 self.indent -= 1 1897 self.writeline("}") 1898 1899 self.in_try_finally = in_try_finally 1900 1901 # Finally clauses handle special exceptions. 1902 1903 self.writeline("__Catch (__tmp_exc)") 1904 self.writeline("{") 1905 self.indent += 1 1906 self.process_structure_node(n.final) 1907 1908 # Introduce an if statement to handle the completion of a try block. 1909 1910 self.process_try_completion() 1911 self.writeline("else __Throw(__tmp_exc);") 1912 1913 self.indent -= 1 1914 self.writeline("}") 1915 print >>self.out 1916 1917 def process_try_completion(self): 1918 1919 "Generate a test for the completion of a try block." 1920 1921 self.writestmt("if (__tmp_exc.completing)") 1922 self.writeline("{") 1923 self.indent += 1 1924 1925 # Do not return anything at the module level. 1926 1927 if self.get_namespace_path() != self.name: 1928 1929 # Only use the normal return statement if no surrounding try blocks 1930 # apply. 1931 1932 if not self.in_try_finally and not self.in_try_except: 1933 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1934 else: 1935 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1936 1937 self.indent -= 1 1938 self.writeline("}") 1939 1940 def process_while_node(self, n): 1941 1942 "Process the given while node 'n'." 1943 1944 self.writeline("while (1)") 1945 self.writeline("{") 1946 self.indent += 1 1947 test = self.process_structure_node(n.test) 1948 1949 # Emit the loop termination condition unless "while <true value>" is 1950 # indicated. 1951 1952 if not (isinstance(test, PredefinedConstantRef) and test.value): 1953 1954 # Emit a negated test of the continuation condition. 1955 1956 self.start_if(True, self.make_negation(test)) 1957 if n.else_: 1958 self.process_structure_node(n.else_) 1959 self.writestmt("break;") 1960 self.end_if() 1961 1962 in_conditional = self.in_conditional 1963 self.in_conditional = True 1964 self.process_structure_node(n.body) 1965 self.in_conditional = in_conditional 1966 1967 self.indent -= 1 1968 self.writeline("}") 1969 print >>self.out 1970 1971 # Special variable usage. 1972 1973 def get_temp_path(self): 1974 1975 """ 1976 Return the appropriate namespace path for temporary names in the current 1977 namespace. 1978 """ 1979 1980 if self.in_function: 1981 return self.get_namespace_path() 1982 else: 1983 return self.name 1984 1985 def record_temp(self, name): 1986 1987 """ 1988 Record the use of the temporary 'name' in the current namespace. At the 1989 class or module level, the temporary name is associated with the module, 1990 since the variable will then be allocated in the module's own main 1991 program. 1992 """ 1993 1994 path = self.get_temp_path() 1995 1996 init_item(self.temp_usage, path, list) 1997 self.temp_usage[path].append(name) 1998 1999 def remove_temps(self, names): 2000 2001 """ 2002 Remove 'names' from temporary storage allocations, each instance 2003 removing each request for storage. 2004 """ 2005 2006 path = self.get_temp_path() 2007 2008 for name in names: 2009 if self.uses_temp(path, name): 2010 self.temp_usage[path].remove(name) 2011 2012 def uses_temp(self, path, name): 2013 2014 """ 2015 Return whether the given namespace 'path' employs a temporary variable 2016 with the given 'name'. Note that 'path' should only be a module or a 2017 function or method, not a class. 2018 """ 2019 2020 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 2021 2022 def make_negation(self, expr): 2023 2024 "Return a negated form of 'expr'." 2025 2026 result = NegationResult(expr) 2027 2028 # Negation discards the temporary results of its operand. 2029 2030 temps = expr.discards_temporary() 2031 if temps: 2032 self.remove_temps(temps) 2033 2034 return result 2035 2036 # Output generation. 2037 2038 def start_output(self): 2039 2040 "Write the declarations at the top of each source file." 2041 2042 print >>self.out, """\ 2043 #include "types.h" 2044 #include "exceptions.h" 2045 #include "ops.h" 2046 #include "progconsts.h" 2047 #include "progops.h" 2048 #include "progtypes.h" 2049 #include "main.h" 2050 """ 2051 2052 def start_unit(self): 2053 2054 "Record output within a generated function for later use." 2055 2056 self.out = StringIO() 2057 2058 def end_unit(self): 2059 2060 "Restore the output stream." 2061 2062 out = self.out 2063 self.out = self.out_toplevel 2064 return out 2065 2066 def flush_unit(self, name, out): 2067 2068 "Add declarations and generated code." 2069 2070 self.write_temporaries(name) 2071 print >>self.out 2072 out.seek(0) 2073 self.out.write(out.read()) 2074 2075 def start_module(self): 2076 2077 "Write the start of each module's main function." 2078 2079 print >>self.out, "void __main_%s()" % encode_path(self.name) 2080 print >>self.out, "{" 2081 self.indent += 1 2082 2083 # Define temporary variables, excluded from the module structure itself. 2084 2085 tempnames = [] 2086 2087 for n in self.importer.all_module_attrs[self.name]: 2088 if n.startswith("$t"): 2089 tempnames.append(encode_path(n)) 2090 2091 if tempnames: 2092 tempnames.sort() 2093 self.writeline("__attr %s;" % ", ".join(tempnames)) 2094 2095 self.start_unit() 2096 2097 def end_module(self): 2098 2099 "End each module by closing its main function." 2100 2101 out = self.end_unit() 2102 self.flush_unit(self.name, out) 2103 2104 self.indent -= 1 2105 print >>self.out, "}" 2106 2107 def start_function(self, name): 2108 2109 "Start the function having the given 'name'." 2110 2111 self.indent += 1 2112 2113 self.start_unit() 2114 2115 def end_function(self, name): 2116 2117 "End the function having the given 'name'." 2118 2119 out = self.end_unit() 2120 2121 # Write the signature at the top indentation level. 2122 2123 self.indent -= 1 2124 self.write_parameters(name) 2125 print >>self.out, "{" 2126 2127 # Obtain local names from parameters. 2128 2129 parameters = self.importer.function_parameters[name] 2130 locals = self.importer.function_locals[name].keys() 2131 names = [] 2132 volatile_names = [] 2133 2134 for n in locals: 2135 2136 # Filter out special names and parameters. Note that self is a local 2137 # regardless of whether it originally appeared in the parameters or 2138 # not. 2139 2140 if n.startswith("$l") or n in parameters or n == "self": 2141 continue 2142 if n in self.volatile_locals: 2143 volatile_names.append(encode_path(n)) 2144 else: 2145 names.append(encode_path(n)) 2146 2147 # Emit required local names at the function indentation level. 2148 2149 self.indent += 1 2150 2151 if names: 2152 names.sort() 2153 for n in names: 2154 self.writeline("__attr %s = (__attr) {.rawvalue = 0};" % n) 2155 2156 if volatile_names: 2157 volatile_names.sort() 2158 for n in volatile_names: 2159 self.writeline("volatile __attr %s = (__attr) {.rawvalue = 0};" % n) 2160 2161 self.flush_unit(name, out) 2162 2163 self.indent -= 1 2164 print >>self.out, "}" 2165 print >>self.out 2166 2167 def write_parameters(self, name): 2168 2169 """ 2170 For the function having the given 'name', write definitions of 2171 parameters found in the arguments array. 2172 """ 2173 2174 # Generate any self reference. 2175 2176 l = [] 2177 2178 if self.is_method(name): 2179 l.append("__attr self") 2180 else: 2181 l.append("__attr __self") 2182 2183 # Generate aliases for the parameters. 2184 2185 for parameter in self.importer.function_parameters[name]: 2186 l.append("%s__attr %s" % ( 2187 parameter in self.volatile_locals and "volatile " or "", 2188 encode_path(parameter))) 2189 2190 self.writeline("__attr %s(%s)" % ( 2191 encode_function_pointer(name), ", ".join(l))) 2192 2193 def write_temporaries(self, name): 2194 2195 "Write temporary storage employed by 'name'." 2196 2197 # Provide space for the recorded number of temporary variables. 2198 2199 if self.uses_temp(name, "__tmp_targets"): 2200 self.writeline("__attr __tmp_targets[%d];" % self.max_function_target) 2201 2202 if self.uses_temp(name, "__tmp_contexts"): 2203 self.writeline("__attr __tmp_contexts[%d];" % self.max_context_index) 2204 2205 if self.uses_temp(name, "__tmp_values"): 2206 self.writeline("__attr __tmp_values[%d];" % self.max_accessor_index) 2207 2208 # Add temporary variable usage details. 2209 2210 if self.uses_temp(name, "__tmp_private_context"): 2211 self.writeline("__attr __tmp_private_context;") 2212 if self.uses_temp(name, "__tmp_target_value"): 2213 self.writeline("__attr __tmp_target_value;") 2214 if self.uses_temp(name, "__tmp_result"): 2215 self.writeline("__attr __tmp_result;") 2216 2217 module = self.importer.get_module(self.name) 2218 2219 if name in module.exception_namespaces: 2220 self.writeline("__exc __tmp_exc;") 2221 2222 def start_if(self, first, test_ref): 2223 statement = "%sif" % (not first and "else " or "") 2224 2225 # Consume logical results directly. 2226 2227 if isinstance(test_ref, LogicalResult): 2228 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2229 temps = test_ref.discards_temporary() 2230 if temps: 2231 self.remove_temps(temps) 2232 else: 2233 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2234 2235 self.writeline("{") 2236 self.indent += 1 2237 2238 def end_if(self): 2239 self.indent -= 1 2240 self.writeline("}") 2241 2242 def start_else(self): 2243 self.writeline("else") 2244 self.writeline("{") 2245 self.indent += 1 2246 2247 def end_else(self): 2248 self.indent -= 1 2249 self.writeline("}") 2250 2251 def statement(self, expr): 2252 s = str(expr) 2253 if s: 2254 self.writestmt("%s;" % s) 2255 2256 def statements(self, results): 2257 for result in results: 2258 self.statement(result) 2259 2260 def writeline(self, s): 2261 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2262 2263 def writestmt(self, s): 2264 self.writeline(s) 2265 2266 def write_comment(self, s): 2267 self.writestmt("/* %s */" % s) 2268 2269 def pad(self, extra=0): 2270 return (self.indent + extra) * self.tabstop 2271 2272 def indenttext(self, s, levels): 2273 lines = s.split("\n") 2274 out = [lines[0]] 2275 for line in lines[1:]: 2276 out.append(levels * self.tabstop + line) 2277 if line.endswith("("): 2278 levels += 1 2279 elif line.startswith(")"): 2280 levels -= 1 2281 return "\n".join(out) 2282 2283 # vim: tabstop=4 expandtab shiftwidth=4