1 #!/usr/bin/env python 2 3 """ 4 Translate programs. 5 6 Copyright (C) 2015, 2016, 2017, 2018 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from common import AccessLocation, CommonModule, CommonOutput, Location, \ 23 first, get_builtin_class, init_item, is_newer, \ 24 predefined_constants 25 from encoders import encode_access_instruction, encode_access_instruction_arg, \ 26 encode_function_pointer, encode_literal_instantiator, \ 27 encode_instantiator_pointer, encode_path, encode_symbol, \ 28 encode_type_attribute, is_type_attribute 29 from errors import InspectError, TranslateError 30 from os.path import exists, join 31 from os import makedirs 32 from referencing import Reference, combine_types 33 from results import Result 34 from transresults import TrConstantValueRef, TrInstanceRef, \ 35 TrLiteralSequenceRef, TrResolvedNameRef, \ 36 AliasResult, AttrResult, Expression, InstantiationResult, \ 37 InvocationResult, LogicalOperationResult, \ 38 LogicalResult, NegationResult, PredefinedConstantRef, \ 39 ReturnRef 40 from StringIO import StringIO 41 import compiler 42 import sys 43 44 class Translator(CommonOutput): 45 46 "A program translator." 47 48 def __init__(self, importer, deducer, optimiser, output): 49 self.importer = importer 50 self.deducer = deducer 51 self.optimiser = optimiser 52 self.output = output 53 54 def to_output(self, reset=False, debug=False, gc_sections=False): 55 56 "Write a program to the configured output directory." 57 58 # Make a directory for the final sources. 59 60 output = join(self.output, "src") 61 62 if not exists(output): 63 makedirs(output) 64 65 # Clean the output directory of irrelevant data. 66 67 self.check_output("debug=%r gc_sections=%r" % (debug, gc_sections)) 68 69 for module in self.importer.modules.values(): 70 output_filename = join(output, "%s.c" % module.name) 71 72 # Do not generate modules in the native package. They are provided 73 # by native functionality source files. 74 75 parts = module.name.split(".") 76 77 if parts[0] != "native" and \ 78 (reset or is_newer(module.filename, output_filename)): 79 80 tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser) 81 tm.translate(module.filename, output_filename) 82 83 84 85 def make_expression(expr): 86 87 "Make a new expression from the existing 'expr'." 88 89 if isinstance(expr, Result): 90 return expr 91 else: 92 return Expression(str(expr)) 93 94 95 96 # The actual translation process itself. 97 98 class TranslatedModule(CommonModule): 99 100 "A module translator." 101 102 def __init__(self, name, importer, deducer, optimiser): 103 CommonModule.__init__(self, name, importer) 104 self.deducer = deducer 105 self.optimiser = optimiser 106 107 # Output stream. 108 109 self.out_toplevel = self.out = None 110 self.indent = 0 111 self.tabstop = " " 112 113 # Recorded namespaces. 114 115 self.namespaces = [] 116 self.in_conditional = False 117 118 # Exception raising adjustments. 119 120 self.in_try_finally = False 121 self.in_try_except = False 122 123 # Invocation adjustments. 124 125 self.in_argument_list = False 126 127 # Attribute access and accessor counting. 128 129 self.attr_accesses = {} 130 self.attr_accessors = {} 131 132 # Special variable usage. 133 134 self.temp_usage = {} 135 136 # Initialise some data used for attribute access generation. 137 138 self.init_substitutions() 139 140 def __repr__(self): 141 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 142 143 def translate(self, filename, output_filename): 144 145 """ 146 Parse the file having the given 'filename', writing the translation to 147 the given 'output_filename'. 148 """ 149 150 self.parse_file(filename) 151 152 # Collect function namespaces for separate processing. 153 154 self.record_namespaces(self.astnode) 155 156 # Reset the lambda naming (in order to obtain the same names again) and 157 # translate the program. 158 159 self.reset_lambdas() 160 161 self.out_toplevel = self.out = open(output_filename, "w") 162 try: 163 self.start_output() 164 165 # Process namespaces, writing the translation. 166 167 for path, node in self.namespaces: 168 self.process_namespace(path, node) 169 170 # Process the module namespace including class namespaces. 171 172 self.process_namespace([], self.astnode) 173 174 finally: 175 self.out.close() 176 177 def have_object(self): 178 179 "Return whether a namespace is a recorded object." 180 181 return self.importer.objects.get(self.get_namespace_path()) 182 183 def get_builtin_class(self, name): 184 185 "Return a reference to the actual object providing 'name'." 186 187 return self.importer.get_object(get_builtin_class(name)) 188 189 def is_method(self, path): 190 191 "Return whether 'path' is a method." 192 193 class_name, method_name = path.rsplit(".", 1) 194 return self.importer.classes.has_key(class_name) and class_name or None 195 196 def in_method(self): 197 198 "Return whether the current namespace provides a method." 199 200 return self.in_function and self.is_method(self.get_namespace_path()) 201 202 # Namespace recording. 203 204 def record_namespaces(self, node): 205 206 "Process the program structure 'node', recording namespaces." 207 208 for n in node.getChildNodes(): 209 self.record_namespaces_in_node(n) 210 211 def record_namespaces_in_node(self, node): 212 213 "Process the program structure 'node', recording namespaces." 214 215 # Function namespaces within modules, classes and other functions. 216 # Functions appearing within conditional statements are given arbitrary 217 # names. 218 219 if isinstance(node, compiler.ast.Function): 220 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 221 222 elif isinstance(node, compiler.ast.Lambda): 223 self.record_function_node(node, self.get_lambda_name()) 224 225 # Classes are visited, but may be ignored if inside functions. 226 227 elif isinstance(node, compiler.ast.Class): 228 self.enter_namespace(node.name) 229 if self.have_object(): 230 self.record_namespaces(node) 231 self.exit_namespace() 232 233 # Conditional nodes are tracked so that function definitions may be 234 # handled. Since "for" loops are converted to "while" loops, they are 235 # included here. 236 237 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 238 in_conditional = self.in_conditional 239 self.in_conditional = True 240 self.record_namespaces(node) 241 self.in_conditional = in_conditional 242 243 # All other nodes are processed depth-first. 244 245 else: 246 self.record_namespaces(node) 247 248 def record_function_node(self, n, name): 249 250 """ 251 Record the given function, lambda, if expression or list comprehension 252 node 'n' with the given 'name'. 253 """ 254 255 self.in_function = True 256 self.enter_namespace(name) 257 258 if self.have_object(): 259 260 # Record the namespace path and the node itself. 261 262 self.namespaces.append((self.namespace_path[:], n)) 263 self.record_namespaces_in_node(n.code) 264 265 self.exit_namespace() 266 self.in_function = False 267 268 # Constant referencing. 269 270 def get_literal_instance(self, n, name=None): 271 272 """ 273 For node 'n', return a reference for the type of the given 'name', or if 274 'name' is not specified, deduce the type from the value. 275 """ 276 277 # Handle stray None constants (Sliceobj seems to produce them). 278 279 if name is None and n.value is None: 280 return self.process_name_node(compiler.ast.Name("None")) 281 282 if name in ("dict", "list", "tuple"): 283 ref = self.get_builtin_class(name) 284 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 285 else: 286 value, typename, encoding = self.get_constant_value(n.value, n.literals) 287 ref = self.get_builtin_class(typename) 288 value_type = ref.get_origin() 289 290 path = self.get_namespace_path() 291 292 # Obtain the local numbering of the constant and thus the 293 # locally-qualified name. 294 295 local_number = self.importer.all_constants[path][(value, value_type, encoding)] 296 constant_name = "$c%d" % local_number 297 objpath = self.get_object_path(constant_name) 298 299 # Obtain the unique identifier for the constant. 300 301 number = self.optimiser.constant_numbers[objpath] 302 return TrConstantValueRef(constant_name, ref.instance_of(), value, number) 303 304 # Namespace translation. 305 306 def process_namespace(self, path, node): 307 308 """ 309 Process the namespace for the given 'path' defined by the given 'node'. 310 """ 311 312 self.namespace_path = path 313 314 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 315 self.in_function = True 316 self.process_function_body_node(node) 317 else: 318 self.in_function = False 319 self.function_target = 0 320 self.max_function_targets = 0 321 self.start_module() 322 self.process_structure(node) 323 self.end_module() 324 325 def process_structure(self, node): 326 327 "Process the given 'node' or result." 328 329 # Handle processing requests on results. 330 331 if isinstance(node, Result): 332 return node 333 334 # Handle processing requests on nodes. 335 336 else: 337 l = CommonModule.process_structure(self, node) 338 339 # Return indications of return statement usage. 340 341 if l and isinstance(l[-1], ReturnRef): 342 return l[-1] 343 else: 344 return None 345 346 def process_structure_node(self, n): 347 348 "Process the individual node 'n'." 349 350 # Plain statements emit their expressions. 351 352 if isinstance(n, compiler.ast.Discard): 353 expr = self.process_structure_node(n.expr) 354 self.statement(expr) 355 356 # Module import declarations. 357 358 elif isinstance(n, compiler.ast.From): 359 self.process_from_node(n) 360 361 # Nodes using operator module functions. 362 363 elif isinstance(n, compiler.ast.Operator): 364 return self.process_operator_node(n) 365 366 elif isinstance(n, compiler.ast.AugAssign): 367 self.process_augassign_node(n) 368 369 elif isinstance(n, compiler.ast.Compare): 370 return self.process_compare_node(n) 371 372 elif isinstance(n, compiler.ast.Slice): 373 return self.process_slice_node(n) 374 375 elif isinstance(n, compiler.ast.Sliceobj): 376 return self.process_sliceobj_node(n) 377 378 elif isinstance(n, compiler.ast.Subscript): 379 return self.process_subscript_node(n) 380 381 # Classes are visited, but may be ignored if inside functions. 382 383 elif isinstance(n, compiler.ast.Class): 384 self.process_class_node(n) 385 386 # Functions within namespaces have any dynamic defaults initialised. 387 388 elif isinstance(n, compiler.ast.Function): 389 self.process_function_node(n) 390 391 # Lambdas are replaced with references to separately-generated 392 # functions. 393 394 elif isinstance(n, compiler.ast.Lambda): 395 return self.process_lambda_node(n) 396 397 # Assignments. 398 399 elif isinstance(n, compiler.ast.Assign): 400 401 # Handle each assignment node. 402 403 for node in n.nodes: 404 self.process_assignment_node(node, n.expr) 405 406 # Accesses. 407 408 elif isinstance(n, compiler.ast.Getattr): 409 return self.process_attribute_access(n) 410 411 # Names. 412 413 elif isinstance(n, compiler.ast.Name): 414 return self.process_name_node(n) 415 416 # Loops and conditionals. 417 418 elif isinstance(n, compiler.ast.For): 419 self.process_for_node(n) 420 421 elif isinstance(n, compiler.ast.While): 422 self.process_while_node(n) 423 424 elif isinstance(n, compiler.ast.If): 425 self.process_if_node(n) 426 427 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 428 return self.process_logical_node(n) 429 430 elif isinstance(n, compiler.ast.Not): 431 return self.process_not_node(n) 432 433 # Exception control-flow tracking. 434 435 elif isinstance(n, compiler.ast.TryExcept): 436 self.process_try_node(n) 437 438 elif isinstance(n, compiler.ast.TryFinally): 439 self.process_try_finally_node(n) 440 441 # Control-flow modification statements. 442 443 elif isinstance(n, compiler.ast.Break): 444 self.writestmt("break;") 445 446 elif isinstance(n, compiler.ast.Continue): 447 self.writestmt("continue;") 448 449 elif isinstance(n, compiler.ast.Raise): 450 self.process_raise_node(n) 451 452 elif isinstance(n, compiler.ast.Return): 453 return self.process_return_node(n) 454 455 # Print statements. 456 457 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 458 self.statement(self.process_print_node(n)) 459 460 # Invocations. 461 462 elif isinstance(n, compiler.ast.CallFunc): 463 return self.process_invocation_node(n) 464 465 elif isinstance(n, compiler.ast.Keyword): 466 return self.process_structure_node(n.expr) 467 468 # Constant usage. 469 470 elif isinstance(n, compiler.ast.Const): 471 return self.get_literal_instance(n) 472 473 elif isinstance(n, compiler.ast.Dict): 474 return self.get_literal_instance(n, "dict") 475 476 elif isinstance(n, compiler.ast.List): 477 return self.get_literal_instance(n, "list") 478 479 elif isinstance(n, compiler.ast.Tuple): 480 return self.get_literal_instance(n, "tuple") 481 482 # All other nodes are processed depth-first. 483 484 else: 485 return self.process_structure(n) 486 487 def process_assignment_node(self, n, expr): 488 489 "Process the individual node 'n' to be assigned the contents of 'expr'." 490 491 # Names and attributes are assigned the entire expression. 492 493 if isinstance(n, compiler.ast.AssName): 494 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 495 self.statement(name_ref) 496 497 # Employ guards after assignments if required. 498 499 if expr and name_ref.is_name(): 500 self.generate_guard(name_ref.name) 501 502 elif isinstance(n, compiler.ast.AssAttr): 503 in_assignment = self.in_assignment 504 self.in_assignment = self.process_structure_node(expr) 505 self.statement(self.process_attribute_access(n)) 506 self.in_assignment = in_assignment 507 508 # Lists and tuples are matched against the expression and their 509 # items assigned to expression items. 510 511 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 512 self.process_assignment_node_items(n, expr) 513 514 # Slices and subscripts are permitted within assignment nodes. 515 516 elif isinstance(n, compiler.ast.Slice): 517 self.statement(self.process_slice_node(n, expr)) 518 519 elif isinstance(n, compiler.ast.Subscript): 520 self.statement(self.process_subscript_node(n, expr)) 521 522 def process_attribute_access(self, n): 523 524 "Process the given attribute access node 'n'." 525 526 # Obtain any completed chain and return the reference to it. 527 528 attr_expr = self.process_attribute_chain(n) 529 if self.have_access_expression(n): 530 return attr_expr 531 532 # Where the start of the chain of attributes has been reached, process 533 # the complete access. 534 535 name_ref = attr_expr and attr_expr.is_name() and attr_expr 536 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref) or None 537 538 location = self.get_access_location(name, self.attrs) 539 refs = self.get_referenced_attributes(location) 540 541 # Generate access instructions. 542 543 subs = { 544 "<expr>" : attr_expr, 545 "<name>" : attr_expr, 546 "<assexpr>" : self.in_assignment, 547 } 548 549 subs.update(self.temp_subs) 550 subs.update(self.op_subs) 551 552 output = [] 553 substituted = set() 554 555 # The context set or retrieved will be that used by any enclosing 556 # invocation. 557 558 context_index = self.function_target - 1 559 context_identity = None 560 context_identity_verified = False 561 final_identity = None 562 563 # Obtain encoded versions of each instruction, accumulating temporary 564 # variables. 565 566 for instruction in self.deducer.access_instructions[location]: 567 568 # Intercept a special instruction identifying the context. 569 570 if instruction[0] in ("<context_identity>", "<context_identity_verified>"): 571 context_identity, _substituted = encode_access_instruction_arg(instruction[1], subs, instruction[0], context_index) 572 context_identity_verified = instruction[0] == "<context_identity_verified>" 573 continue 574 575 # Intercept a special instruction identifying the target. The value 576 # is not encoded since it is used internally. 577 578 elif instruction[0] == "<final_identity>": 579 final_identity = instruction[1] 580 continue 581 582 # Collect the encoded instruction, noting any temporary variables 583 # required by it. 584 585 encoded, _substituted = encode_access_instruction(instruction, subs, context_index) 586 output.append(encoded) 587 substituted.update(_substituted) 588 589 # Record temporary name usage. 590 591 for sub in substituted: 592 if self.temp_subs.has_key(sub): 593 self.record_temp(self.temp_subs[sub]) 594 595 # Get full final identity details. 596 597 if final_identity and not refs: 598 ref = self.importer.identify(final_identity) 599 refs = [ref] 600 601 del self.attrs[0] 602 return AttrResult(output, refs, location, context_identity, context_identity_verified) 603 604 def init_substitutions(self): 605 606 """ 607 Initialise substitutions, defining temporary variable mappings, some of 608 which are also used as substitutions, together with operation mappings 609 used as substitutions in instructions defined by the optimiser. 610 """ 611 612 self.temp_subs = { 613 614 # Substitutions used by instructions. 615 616 "<private_context>" : "__tmp_private_context", 617 "<accessor>" : "__tmp_value", 618 "<target_accessor>" : "__tmp_target_value", 619 620 # Mappings to be replaced by those given below. 621 622 "<context>" : "__tmp_contexts", 623 "<test_context_revert>" : "__tmp_contexts", 624 "<test_context_static>" : "__tmp_contexts", 625 "<set_context>" : "__tmp_contexts", 626 "<set_private_context>" : "__tmp_private_context", 627 "<set_accessor>" : "__tmp_value", 628 "<set_target_accessor>" : "__tmp_target_value", 629 } 630 631 self.op_subs = { 632 "<context>" : "__get_context", 633 "<test_context_revert>" : "__test_context_revert", 634 "<test_context_static>" : "__test_context_static", 635 "<set_context>" : "__set_context", 636 "<set_private_context>" : "__set_private_context", 637 "<set_accessor>" : "__set_accessor", 638 "<set_target_accessor>" : "__set_target_accessor", 639 } 640 641 def get_referenced_attributes(self, location): 642 643 """ 644 Convert 'location' to the form used by the deducer and retrieve any 645 identified attributes. 646 """ 647 648 # Determine whether any deduced references refer to the accessed 649 # attribute. 650 651 attrnames = location.attrnames 652 attrnames = attrnames and attrnames.split(".") 653 remaining = attrnames and len(attrnames) > 1 654 655 access_location = self.deducer.const_accesses.get(location) 656 657 if remaining and not access_location: 658 return [] 659 660 refs = [] 661 l = self.deducer.referenced_attrs.get(access_location or location) 662 if l: 663 for attrtype, objpath, attr in l: 664 refs.append(attr) 665 return refs 666 667 def get_referenced_attribute_invocations(self, location): 668 669 """ 670 Convert 'location' to the form used by the deducer and retrieve any 671 identified attribute invocation details. 672 """ 673 674 access_location = self.deducer.const_accesses.get(location) 675 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 676 677 def get_accessor_kinds(self, location): 678 679 "Return the accessor kinds for 'location'." 680 681 return self.deducer.accessor_kinds.get(location) 682 683 def get_access_location(self, name, attrnames=None): 684 685 """ 686 Using the current namespace, the given 'name', and the 'attrnames' 687 employed in an access, return the access location. 688 """ 689 690 path = self.get_path_for_access() 691 692 # Get the location used by the deducer and optimiser and find any 693 # recorded access. 694 695 attrnames = attrnames and ".".join(self.attrs) 696 access_number = self.get_access_number(path, name, attrnames) 697 self.update_access_number(path, name, attrnames) 698 return AccessLocation(path, name, attrnames, access_number) 699 700 def get_access_number(self, path, name, attrnames): 701 access = name, attrnames 702 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 703 return self.attr_accesses[path][access] 704 else: 705 return 0 706 707 def update_access_number(self, path, name, attrnames): 708 access = name, attrnames 709 if name: 710 init_item(self.attr_accesses, path, dict) 711 init_item(self.attr_accesses[path], access, lambda: 0) 712 self.attr_accesses[path][access] += 1 713 714 def get_accessor_location(self, name): 715 716 """ 717 Using the current namespace and the given 'name', return the accessor 718 location. 719 """ 720 721 path = self.get_path_for_access() 722 723 # Get the location used by the deducer and optimiser and find any 724 # recorded accessor. 725 726 version = self.get_accessor_number(path, name) 727 self.update_accessor_number(path, name) 728 return Location(path, name, None, version) 729 730 def get_accessor_number(self, path, name): 731 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 732 return self.attr_accessors[path][name] 733 else: 734 return 0 735 736 def update_accessor_number(self, path, name): 737 if name: 738 init_item(self.attr_accessors, path, dict) 739 init_item(self.attr_accessors[path], name, lambda: 0) 740 self.attr_accessors[path][name] += 1 741 742 def process_class_node(self, n): 743 744 "Process the given class node 'n'." 745 746 class_name = self.get_object_path(n.name) 747 748 # Where a class is set conditionally or where the name may refer to 749 # different values, assign the name. 750 751 ref = self.importer.identify(class_name) 752 753 if not ref.static(): 754 self.process_assignment_for_object(n.name, 755 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 756 757 self.enter_namespace(n.name) 758 759 if self.have_object(): 760 self.write_comment("Class: %s" % class_name) 761 762 self.initialise_inherited_members(class_name) 763 764 self.process_structure(n) 765 self.write_comment("End class: %s" % class_name) 766 767 self.exit_namespace() 768 769 def initialise_inherited_members(self, class_name): 770 771 "Initialise members of 'class_name' inherited from its ancestors." 772 773 for name, path in self.importer.all_class_attrs[class_name].items(): 774 target = "%s.%s" % (class_name, name) 775 776 # Ignore attributes with definitions. 777 778 ref = self.importer.identify(target) 779 if ref: 780 continue 781 782 # Ignore special type attributes. 783 784 if is_type_attribute(name): 785 continue 786 787 # Reference inherited attributes. 788 789 ref = self.importer.identify(path) 790 if ref and not ref.static(): 791 parent, attrname = path.rsplit(".", 1) 792 793 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 794 encode_path(class_name), name, 795 encode_path(parent), attrname 796 )) 797 798 def process_from_node(self, n): 799 800 "Process the given node 'n', importing from another module." 801 802 path = self.get_namespace_path() 803 804 # Attempt to obtain the referenced objects. 805 806 for name, alias in n.names: 807 if name == "*": 808 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 809 810 # Obtain the path of the assigned name. 811 812 objpath = self.get_object_path(alias or name) 813 814 # Obtain the identity of the name. 815 816 ref = self.importer.identify(objpath) 817 818 # Where the name is not static, assign the value. 819 820 if ref and not ref.static() and ref.get_name(): 821 self.writestmt("%s;" % 822 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 823 expr=TrResolvedNameRef(name, ref))) 824 825 def process_function_body_node(self, n): 826 827 """ 828 Process the given function, lambda, if expression or list comprehension 829 node 'n', generating the body. 830 """ 831 832 function_name = self.get_namespace_path() 833 self.start_function(function_name) 834 835 # Process the function body. 836 837 in_conditional = self.in_conditional 838 self.in_conditional = False 839 self.function_target = 0 840 self.max_function_targets = 0 841 842 # Volatile locals for exception handling. 843 844 self.volatile_locals = set() 845 846 # Process any guards defined for the parameters. 847 848 for name in self.importer.function_parameters.get(function_name): 849 self.generate_guard(name) 850 851 # Also support self in methods, since some mix-in methods may only work 852 # with certain descendant classes. 853 854 if self.in_method(): 855 self.generate_guard("self") 856 857 # Produce the body and any additional return statement. 858 859 expr = self.process_structure_node(n.code) or \ 860 self.in_method() and \ 861 function_name.rsplit(".", 1)[-1] == "__init__" and \ 862 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 863 PredefinedConstantRef("None") 864 865 if not isinstance(expr, ReturnRef): 866 self.writestmt("return %s;" % expr) 867 868 self.in_conditional = in_conditional 869 870 self.end_function(function_name) 871 872 def generate_guard(self, name): 873 874 """ 875 Get the accessor details for 'name', found in the current namespace, and 876 generate any guards defined for it. 877 """ 878 879 # Obtain the location, keeping track of assignment versions. 880 881 location = self.get_accessor_location(name) 882 test = self.deducer.accessor_guard_tests.get(location) 883 884 # Generate any guard from the deduced information. 885 886 if test: 887 guard, guard_type = test 888 889 if guard == "specific": 890 ref = first(self.deducer.accessor_all_types[location]) 891 argstr = "&%s" % encode_path(ref.get_origin()) 892 elif guard == "common": 893 ref = first(self.deducer.accessor_all_general_types[location]) 894 argstr = encode_path(encode_type_attribute(ref.get_origin())) 895 else: 896 return 897 898 # Write a test that raises a TypeError upon failure. 899 900 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 901 guard, guard_type, encode_path(name), argstr)) 902 903 def process_function_node(self, n): 904 905 """ 906 Process the given function, lambda, if expression or list comprehension 907 node 'n', generating any initialisation statements. 908 """ 909 910 # Where a function is declared conditionally, use a separate name for 911 # the definition, and assign the definition to the stated name. 912 913 original_name = n.name 914 915 if self.in_conditional or self.in_function: 916 name = self.get_lambda_name() 917 else: 918 name = n.name 919 920 objpath = self.get_object_path(name) 921 922 # Obtain details of the defaults. 923 924 defaults = self.process_function_defaults(n, name, objpath) 925 if defaults: 926 for default in defaults: 927 self.writeline("%s;" % default) 928 929 # Where a function is set conditionally or where the name may refer to 930 # different values, assign the name. 931 932 ref = self.importer.identify(objpath) 933 934 if self.in_conditional or self.in_function: 935 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 936 elif not ref.static(): 937 context = self.is_method(objpath) 938 939 self.process_assignment_for_object(original_name, 940 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 941 942 def process_function_defaults(self, n, name, objpath, instance_name=None): 943 944 """ 945 Process the given function or lambda node 'n', initialising defaults 946 that are dynamically set. The given 'name' indicates the name of the 947 function. The given 'objpath' indicates the origin of the function. 948 The given 'instance_name' indicates the name of any separate instance 949 of the function created to hold the defaults. 950 951 Return a list of operations setting defaults on a function instance. 952 """ 953 954 function_name = self.get_object_path(name) 955 function_defaults = self.importer.function_defaults.get(function_name) 956 if not function_defaults: 957 return None 958 959 # Determine whether any unidentified defaults are involved. 960 961 for argname, default in function_defaults: 962 if not default.static(): 963 break 964 else: 965 return None 966 967 # Handle bound methods. 968 969 if not instance_name: 970 instance_name = "&%s" % encode_path(objpath) 971 else: 972 instance_name = "__VALUE(%s)" % instance_name 973 974 # Where defaults are involved but cannot be identified, obtain a new 975 # instance of the lambda and populate the defaults. 976 977 defaults = [] 978 979 # Join the original defaults with the inspected defaults. 980 981 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 982 983 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 984 985 # Obtain any reference for the default. 986 987 if original: 988 argname, default = original 989 name_ref = self.process_structure_node(default) 990 elif inspected: 991 argname, default = inspected 992 name_ref = TrResolvedNameRef(argname, default) 993 else: 994 continue 995 996 # Generate default initialisers except when constants are employed. 997 # Constants should be used when populating the function structures. 998 999 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1000 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1001 1002 return defaults 1003 1004 def process_if_node(self, n): 1005 1006 """ 1007 Process the given "if" node 'n'. 1008 """ 1009 1010 first = True 1011 for test, body in n.tests: 1012 test_ref = self.process_structure_node(test) 1013 self.start_if(first, test_ref) 1014 1015 in_conditional = self.in_conditional 1016 self.in_conditional = True 1017 self.process_structure_node(body) 1018 self.in_conditional = in_conditional 1019 1020 self.end_if() 1021 first = False 1022 1023 if n.else_: 1024 self.start_else() 1025 self.process_structure_node(n.else_) 1026 self.end_else() 1027 1028 print >>self.out 1029 1030 def process_invocation_node(self, n): 1031 1032 "Process the given invocation node 'n'." 1033 1034 # Any invocations in the expression will store target details in a 1035 # different location. 1036 1037 self.next_target() 1038 1039 in_argument_list = self.in_argument_list 1040 self.in_argument_list = False 1041 1042 # Process the expression. 1043 1044 expr = self.process_structure_node(n.node) 1045 1046 # Reference the current target again. 1047 1048 self.in_argument_list = in_argument_list 1049 self.function_target -= 1 1050 1051 # Obtain details of the invocation expression. 1052 1053 objpath = expr.get_origin() 1054 location = expr.access_location() 1055 refs = expr.references() 1056 1057 # Identified target details. 1058 1059 target = None 1060 target_structure = None 1061 1062 # Specific function target information. 1063 1064 function = None 1065 1066 # Instantiation involvement. 1067 1068 instantiation = False 1069 literal_instantiation = False 1070 1071 # Invocation requirements. 1072 1073 context_required = True 1074 have_access_context = isinstance(expr, AttrResult) 1075 context_identity = have_access_context and expr.context() 1076 context_verified = have_access_context and expr.context_verified() 1077 parameters = None 1078 num_parameters = None 1079 num_defaults = None 1080 1081 # Obtain details of the callable and of its parameters. 1082 1083 # Literals may be instantiated specially. 1084 1085 if expr.is_name() and expr.name.startswith("$L") and objpath: 1086 instantiation = literal_instantiation = objpath 1087 target = encode_literal_instantiator(objpath) 1088 context_required = False 1089 1090 # Identified targets employ function pointers directly. 1091 1092 elif objpath: 1093 parameters = self.importer.function_parameters.get(objpath) 1094 function_defaults = self.importer.function_defaults.get(objpath) 1095 num_parameters = parameters and len(parameters) or 0 1096 num_defaults = function_defaults and len(function_defaults) or 0 1097 1098 # Class invocation involves instantiators. 1099 1100 if expr.has_kind("<class>"): 1101 instantiation = objpath 1102 target = encode_instantiator_pointer(objpath) 1103 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1104 target_structure = "&%s" % encode_path(init_ref) 1105 context_required = False 1106 1107 # Only plain functions and bound methods employ function pointers. 1108 1109 elif expr.has_kind("<function>"): 1110 function = objpath 1111 1112 # Test for functions and methods. 1113 1114 context_required = self.is_method(objpath) 1115 1116 accessor_kinds = location and self.get_accessor_kinds(location) 1117 1118 instance_accessor = accessor_kinds and \ 1119 len(accessor_kinds) == 1 and \ 1120 first(accessor_kinds) == "<instance>" 1121 1122 # Only identify certain bound methods or functions. 1123 1124 if not context_required or instance_accessor: 1125 target = encode_function_pointer(objpath) 1126 1127 # Access bound method defaults even if it is not clear whether 1128 # the accessor is appropriate. 1129 1130 target_structure = "&%s" % encode_path(objpath) 1131 1132 # Other targets are retrieved at run-time. 1133 1134 else: 1135 if location: 1136 attrnames = location.attrnames 1137 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1138 1139 # Determine any common aspects of any attribute. 1140 1141 if attrname: 1142 all_params = set() 1143 all_defaults = set() 1144 min_params = set() 1145 max_params = set() 1146 refs = set() 1147 1148 # Obtain parameters and defaults for each possible target. 1149 1150 for ref in self.get_attributes_for_attrname(attrname): 1151 origin = ref.get_origin() 1152 params = self.importer.function_parameters.get(origin) 1153 1154 defaults = self.importer.function_defaults.get(origin) 1155 if defaults is not None: 1156 all_defaults.add(tuple(defaults)) 1157 1158 if params is not None: 1159 all_params.add(tuple(params)) 1160 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1161 max_params.add(len(params)) 1162 refs.add(ref) 1163 else: 1164 refs = set() 1165 break 1166 1167 # Where the parameters and defaults are always the same, 1168 # permit populating them in advance. 1169 1170 if refs: 1171 if self.uses_keyword_arguments(n): 1172 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1173 parameters = first(all_params) 1174 function_defaults = all_defaults and first(all_defaults) or [] 1175 num_parameters = parameters and len(parameters) or 0 1176 num_defaults = function_defaults and len(function_defaults) or 0 1177 else: 1178 if len(min_params) == 1 and len(max_params) == 1: 1179 num_parameters = first(max_params) 1180 num_defaults = first(max_params) - first(min_params) 1181 1182 # Some information about the target may be available and be used to 1183 # provide warnings about argument compatibility. 1184 1185 if self.importer.give_warning("args"): 1186 unsuitable = self.get_referenced_attribute_invocations(location) 1187 1188 if unsuitable: 1189 for ref in unsuitable: 1190 _objpath = ref.get_origin() 1191 print >>sys.stderr, \ 1192 "In %s, at line %d, inappropriate number of " \ 1193 "arguments given. Need %d arguments to call %s." % ( 1194 self.get_namespace_path(), n.lineno, 1195 len(self.importer.function_parameters[_objpath]), 1196 _objpath) 1197 1198 # Determine any readily-accessible target identity. 1199 1200 target_named = expr.is_name() and str(expr) or None 1201 target_stored = "__tmp_targets[%d]" % self.function_target 1202 1203 target_identity = target or target_named 1204 target_var = target_identity or target_stored 1205 context_var = target_named or target_stored 1206 1207 if not target_identity: 1208 self.record_temp("__tmp_targets") 1209 1210 if context_identity: 1211 if context_identity.startswith("__tmp_contexts"): 1212 self.record_temp("__tmp_contexts") 1213 1214 # Arguments are presented in a temporary frame array with any context 1215 # always being the first argument. Where it would be unused, it may be 1216 # set to null. 1217 1218 known_parameters = num_parameters is not None 1219 1220 if context_required: 1221 if have_access_context: 1222 args = [context_identity] 1223 else: 1224 args = ["__CONTEXT_AS_VALUE(%s)" % context_var] 1225 else: 1226 args = ["__NULL"] 1227 1228 # Complete the array with null values, permitting tests for a complete 1229 # set of arguments. 1230 1231 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1232 kwcodes = [] 1233 kwargs = [] 1234 1235 # Any invocations in the arguments will store target details in a 1236 # different location. 1237 1238 function_target = self.function_target 1239 1240 if not target_identity: 1241 self.next_target() 1242 1243 in_argument_list = self.in_argument_list 1244 self.in_argument_list = True 1245 1246 for i, arg in enumerate(n.args): 1247 argexpr = self.process_structure_node(arg) 1248 1249 # Store a keyword argument, either in the argument list or 1250 # in a separate keyword argument list for subsequent lookup. 1251 1252 if isinstance(arg, compiler.ast.Keyword): 1253 1254 # With knowledge of the target, store the keyword 1255 # argument directly. 1256 1257 if parameters: 1258 try: 1259 argnum = parameters.index(arg.name) 1260 except ValueError: 1261 raise TranslateError("Argument %s is not recognised." % arg.name, 1262 self.get_namespace_path(), n) 1263 args[argnum+1] = str(argexpr) 1264 1265 # Otherwise, store the details in a separate collection. 1266 1267 else: 1268 kwargs.append(str(argexpr)) 1269 kwcodes.append("{%s, %s}" % ( 1270 encode_ppos(arg.name), encode_pcode(arg.name))) 1271 1272 # Store non-keyword arguments in the argument list, rejecting 1273 # superfluous arguments. 1274 1275 else: 1276 try: 1277 args[i+1] = str(argexpr) 1278 except IndexError: 1279 raise TranslateError("Too many arguments specified.", 1280 self.get_namespace_path(), n) 1281 1282 # Reference the current target again. 1283 1284 self.in_argument_list = in_argument_list 1285 1286 if not self.in_argument_list: 1287 self.function_target = function_target 1288 1289 # Defaults are added to the frame where arguments are missing. 1290 1291 if parameters and function_defaults is not None: 1292 1293 # Visit each default and set any missing arguments. Where keyword 1294 # arguments have been used, the defaults must be inspected and, if 1295 # necessary, inserted into gaps in the argument list. 1296 1297 for i, (argname, default) in enumerate(function_defaults): 1298 argnum = parameters.index(argname) 1299 if not args[argnum+1]: 1300 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1301 1302 elif known_parameters: 1303 1304 # No specific parameter details are provided, but no keyword 1305 # arguments are used. Thus, defaults can be supplied using position 1306 # information only. 1307 1308 i = len(n.args) 1309 pos = i - (num_parameters - num_defaults) 1310 while i < num_parameters: 1311 args[i+1] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1312 i += 1 1313 pos += 1 1314 1315 # Test for missing arguments. 1316 1317 if None in args: 1318 raise TranslateError("Not all arguments supplied.", 1319 self.get_namespace_path(), n) 1320 1321 # Encode the arguments. 1322 1323 # Where literal instantiation is occurring, add an argument indicating 1324 # the number of values. The context is excluded. 1325 1326 if literal_instantiation: 1327 argstr = "%d, %s" % (len(args) - 1, ", ".join(args[1:])) 1328 else: 1329 argstr = ", ".join(args) 1330 1331 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1332 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1333 1334 # First, the invocation expression is presented. 1335 1336 stages = [] 1337 1338 # Without a known specific callable, the expression provides the target. 1339 1340 if not target or context_required: 1341 1342 # The context is set in the expression. 1343 1344 if target and not target_named: 1345 1346 # Test whether the expression provides anything. 1347 1348 if expr: 1349 stages.append(str(expr)) 1350 1351 elif not target_identity: 1352 stages.append("%s = %s" % (target_var, expr)) 1353 1354 # Any specific callable is then obtained for invocation. 1355 1356 if target: 1357 stages.append(target) 1358 1359 # Methods accessed via unidentified accessors are obtained for 1360 # invocation. 1361 1362 elif function: 1363 if context_required: 1364 if have_access_context: 1365 if context_verified: 1366 stages.append("__get_function_member(%s)" % target_var) 1367 else: 1368 stages.append("__get_function(%s, %s)" % ( 1369 context_identity, target_var)) 1370 else: 1371 stages.append("__get_function(__CONTEXT_AS_VALUE(%s), %s)" % ( 1372 context_var, target_var)) 1373 else: 1374 stages.append("_get_function_member(%s)" % target_var) 1375 1376 # With known parameters, the target can be tested. 1377 1378 elif known_parameters: 1379 context_arg = context_required and args[0] or "__NULL" 1380 if self.always_callable(refs): 1381 if context_verified: 1382 stages.append("__get_function_member(%s)" % target_var) 1383 else: 1384 stages.append("__get_function(%s, %s)" % (context_arg, target_var)) 1385 else: 1386 stages.append("__check_and_get_function(%s, %s)" % (context_arg, target_var)) 1387 1388 # With a known target, the function is obtained directly and called. 1389 # By putting the invocation at the end of the final element in the 1390 # instruction sequence (the stages), the result becomes the result of 1391 # the sequence. Moreover, the parameters become part of the sequence 1392 # and thereby participate in a guaranteed evaluation order. 1393 1394 if target or function or known_parameters: 1395 stages[-1] += "(%s)" % argstr 1396 if instantiation: 1397 return InstantiationResult(instantiation, stages) 1398 else: 1399 return InvocationResult(stages) 1400 1401 # With unknown targets, the generic invocation function is applied to 1402 # the callable and argument collections. 1403 1404 else: 1405 stages.append("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1406 target_var, 1407 self.always_callable(refs) and 1 or 0, 1408 len(kwargs), kwcodestr, kwargstr, 1409 len(args), "__ARGS(%s)" % argstr)) 1410 return InvocationResult(stages) 1411 1412 def next_target(self): 1413 1414 "Allocate the next function target storage." 1415 1416 self.function_target += 1 1417 self.max_function_targets = max(self.function_target, self.max_function_targets) 1418 1419 def always_callable(self, refs): 1420 1421 "Determine whether all 'refs' are callable." 1422 1423 if not refs: 1424 return False 1425 1426 for ref in refs: 1427 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1428 return False 1429 1430 return True 1431 1432 def need_default_arguments(self, objpath, nargs): 1433 1434 """ 1435 Return whether any default arguments are needed when invoking the object 1436 given by 'objpath'. 1437 """ 1438 1439 parameters = self.importer.function_parameters.get(objpath) 1440 return nargs < len(parameters) 1441 1442 def uses_keyword_arguments(self, n): 1443 1444 "Return whether invocation node 'n' uses keyword arguments." 1445 1446 for arg in enumerate(n.args): 1447 if isinstance(arg, compiler.ast.Keyword): 1448 return True 1449 1450 return False 1451 1452 def get_attributes_for_attrname(self, attrname): 1453 1454 "Return a set of all attributes exposed by 'attrname'." 1455 1456 usage = [(attrname, True, False)] 1457 class_types = self.deducer.get_class_types_for_usage(usage) 1458 instance_types = self.deducer.get_instance_types_for_usage(usage) 1459 module_types = self.deducer.get_module_types_for_usage(usage) 1460 attrs = set() 1461 1462 for ref in combine_types(class_types, instance_types, module_types): 1463 attrs.update(self.importer.get_attributes(ref, attrname)) 1464 1465 return attrs 1466 1467 def process_lambda_node(self, n): 1468 1469 "Process the given lambda node 'n'." 1470 1471 name = self.get_lambda_name() 1472 function_name = self.get_object_path(name) 1473 1474 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1475 1476 # Without defaults, produce an attribute referring to the function. 1477 1478 if not defaults: 1479 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1480 1481 # With defaults, copy the function structure and set the defaults on the 1482 # copy. 1483 1484 else: 1485 self.record_temp("__tmp_value") 1486 return make_expression("(__tmp_value = __ATTRVALUE(__COPY(&%s, sizeof(%s))), %s, __tmp_value)" % ( 1487 encode_path(function_name), 1488 encode_symbol("obj", function_name), 1489 ", ".join(defaults))) 1490 1491 def process_logical_node(self, n): 1492 1493 "Process the given operator node 'n'." 1494 1495 self.record_temp("__tmp_result") 1496 1497 conjunction = isinstance(n, compiler.ast.And) 1498 results = [] 1499 1500 for node in n.nodes: 1501 results.append(self.process_structure_node(node)) 1502 1503 return LogicalOperationResult(results, conjunction) 1504 1505 def process_name_node(self, n, expr=None): 1506 1507 "Process the given name node 'n' with the optional assignment 'expr'." 1508 1509 # Determine whether the name refers to a static external entity. 1510 1511 if n.name in predefined_constants: 1512 return PredefinedConstantRef(n.name, expr) 1513 1514 # Convert literal references, operator function names, and print 1515 # function names to references. 1516 1517 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1518 n.name.startswith("$print"): 1519 1520 ref, paths = self.importer.get_module(self.name).special[n.name] 1521 return TrResolvedNameRef(n.name, ref) 1522 1523 # Get the appropriate name for the name reference, using the same method 1524 # as in the inspector. 1525 1526 path = self.get_namespace_path() 1527 objpath = self.get_object_path(n.name) 1528 1529 # Determine any assigned globals. 1530 1531 globals = self.importer.get_module(self.name).scope_globals.get(path) 1532 1533 # Explicitly declared globals. 1534 1535 if globals and n.name in globals: 1536 objpath = self.get_global_path(n.name) 1537 is_global = True 1538 1539 # Implicitly referenced globals in functions. 1540 1541 elif self.in_function: 1542 is_global = n.name not in self.importer.function_locals[path] 1543 1544 # Implicitly referenced globals elsewhere. 1545 1546 else: 1547 namespace = self.importer.identify(path) 1548 is_global = not self.importer.get_attributes(namespace, n.name) 1549 1550 # Get the static identity of the name. 1551 1552 ref = self.importer.identify(objpath) 1553 if ref and not ref.get_name(): 1554 ref = ref.alias(objpath) 1555 1556 # Obtain any resolved names for non-assignment names. 1557 1558 if not expr and not ref and self.in_function: 1559 locals = self.importer.function_locals.get(path) 1560 ref = locals and locals.get(n.name) 1561 1562 # Find any invocation or alias details. 1563 1564 name = self.get_name_for_tracking(n.name, is_global=is_global) 1565 location = not expr and self.get_access_location(name) or None 1566 1567 # Mark any local assignments as volatile in exception blocks. 1568 1569 if expr and self.in_function and not is_global and self.in_try_except: 1570 self.make_volatile(n.name) 1571 1572 # Qualified names are used for resolved static references or for 1573 # static namespace members. The reference should be configured to return 1574 # such names. 1575 1576 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1577 location=location) 1578 return not expr and self.get_aliases(name_ref) or name_ref 1579 1580 def get_aliases(self, name_ref): 1581 1582 "Return alias references for the given 'name_ref'." 1583 1584 location = name_ref.access_location() 1585 1586 refs = self.deducer.referenced_objects.get(location) 1587 refs = refs or self.deducer.accessor_all_types.get(location) 1588 return AliasResult(name_ref, refs or set(), location) 1589 1590 def make_volatile(self, name): 1591 1592 "Record 'name' as volatile in the current namespace." 1593 1594 self.volatile_locals.add(name) 1595 1596 def process_not_node(self, n): 1597 1598 "Process the given operator node 'n'." 1599 1600 return self.make_negation(self.process_structure_node(n.expr)) 1601 1602 def process_raise_node(self, n): 1603 1604 "Process the given raise node 'n'." 1605 1606 # NOTE: Determine which raise statement variants should be permitted. 1607 1608 if n.expr1: 1609 1610 # Names with accompanying arguments are treated like invocations. 1611 1612 if n.expr2: 1613 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1614 exc = self.process_structure_node(call) 1615 self.writestmt("__Raise(%s);" % exc) 1616 1617 # Raise instances, testing the kind at run-time if necessary and 1618 # instantiating any non-instance. 1619 1620 else: 1621 exc = self.process_structure_node(n.expr1) 1622 1623 if isinstance(exc, TrInstanceRef): 1624 self.writestmt("__Raise(%s);" % exc) 1625 else: 1626 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1627 else: 1628 self.writestmt("__Throw(__tmp_exc);") 1629 1630 def process_return_node(self, n): 1631 1632 "Process the given return node 'n'." 1633 1634 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1635 if self.in_try_finally or self.in_try_except: 1636 self.writestmt("__Return(%s);" % expr) 1637 else: 1638 self.writestmt("return %s;" % expr) 1639 1640 return ReturnRef() 1641 1642 def process_try_node(self, n): 1643 1644 """ 1645 Process the given "try...except" node 'n'. 1646 """ 1647 1648 in_try_except = self.in_try_except 1649 self.in_try_except = True 1650 1651 # Use macros to implement exception handling. 1652 1653 self.writestmt("__Try") 1654 self.writeline("{") 1655 self.indent += 1 1656 self.process_structure_node(n.body) 1657 1658 # Put the else statement in another try block that handles any raised 1659 # exceptions and converts them to exceptions that will not be handled by 1660 # the main handling block. 1661 1662 if n.else_: 1663 self.writestmt("__Try") 1664 self.writeline("{") 1665 self.indent += 1 1666 self.process_structure_node(n.else_) 1667 self.indent -= 1 1668 self.writeline("}") 1669 self.writeline("__Catch (__tmp_exc)") 1670 self.writeline("{") 1671 self.indent += 1 1672 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1673 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1674 self.indent -= 1 1675 self.writeline("}") 1676 1677 # Complete the try block and enter the finally block, if appropriate. 1678 1679 if self.in_try_finally: 1680 self.writestmt("__Complete;") 1681 1682 self.indent -= 1 1683 self.writeline("}") 1684 1685 self.in_try_except = in_try_except 1686 1687 # Handlers are tests within a common handler block. 1688 1689 self.writeline("__Catch (__tmp_exc)") 1690 self.writeline("{") 1691 self.indent += 1 1692 1693 # Introduce an if statement to handle the completion of a try block. 1694 1695 self.process_try_completion() 1696 1697 # Handle exceptions in else blocks converted to __RaiseElse, converting 1698 # them back to normal exceptions. 1699 1700 if n.else_: 1701 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1702 1703 # Exception handling. 1704 1705 for name, var, handler in n.handlers: 1706 1707 # Test for specific exceptions. 1708 1709 if name is not None: 1710 name_ref = self.process_structure_node(name) 1711 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1712 else: 1713 self.writeline("else if (1)") 1714 1715 self.writeline("{") 1716 self.indent += 1 1717 1718 # Establish the local for the handler. 1719 1720 if var is not None: 1721 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1722 1723 if handler is not None: 1724 self.process_structure_node(handler) 1725 1726 self.indent -= 1 1727 self.writeline("}") 1728 1729 # Re-raise unhandled exceptions. 1730 1731 self.writeline("else __Throw(__tmp_exc);") 1732 1733 # End the handler block. 1734 1735 self.indent -= 1 1736 self.writeline("}") 1737 print >>self.out 1738 1739 def process_try_finally_node(self, n): 1740 1741 """ 1742 Process the given "try...finally" node 'n'. 1743 """ 1744 1745 in_try_finally = self.in_try_finally 1746 self.in_try_finally = True 1747 1748 # Use macros to implement exception handling. 1749 1750 self.writestmt("__Try") 1751 self.writeline("{") 1752 self.indent += 1 1753 self.process_structure_node(n.body) 1754 self.indent -= 1 1755 self.writeline("}") 1756 1757 self.in_try_finally = in_try_finally 1758 1759 # Finally clauses handle special exceptions. 1760 1761 self.writeline("__Catch (__tmp_exc)") 1762 self.writeline("{") 1763 self.indent += 1 1764 self.process_structure_node(n.final) 1765 1766 # Introduce an if statement to handle the completion of a try block. 1767 1768 self.process_try_completion() 1769 self.writeline("else __Throw(__tmp_exc);") 1770 1771 self.indent -= 1 1772 self.writeline("}") 1773 print >>self.out 1774 1775 def process_try_completion(self): 1776 1777 "Generate a test for the completion of a try block." 1778 1779 self.writestmt("if (__tmp_exc.completing)") 1780 self.writeline("{") 1781 self.indent += 1 1782 1783 # Do not return anything at the module level. 1784 1785 if self.get_namespace_path() != self.name: 1786 1787 # Only use the normal return statement if no surrounding try blocks 1788 # apply. 1789 1790 if not self.in_try_finally and not self.in_try_except: 1791 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1792 else: 1793 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1794 1795 self.indent -= 1 1796 self.writeline("}") 1797 1798 def process_while_node(self, n): 1799 1800 "Process the given while node 'n'." 1801 1802 self.writeline("while (1)") 1803 self.writeline("{") 1804 self.indent += 1 1805 test = self.process_structure_node(n.test) 1806 1807 # Emit the loop termination condition unless "while <true value>" is 1808 # indicated. 1809 1810 if not (isinstance(test, PredefinedConstantRef) and test.value): 1811 1812 # Emit a negated test of the continuation condition. 1813 1814 self.start_if(True, self.make_negation(test)) 1815 if n.else_: 1816 self.process_structure_node(n.else_) 1817 self.writestmt("break;") 1818 self.end_if() 1819 1820 in_conditional = self.in_conditional 1821 self.in_conditional = True 1822 self.process_structure_node(n.body) 1823 self.in_conditional = in_conditional 1824 1825 self.indent -= 1 1826 self.writeline("}") 1827 print >>self.out 1828 1829 # Special variable usage. 1830 1831 def get_temp_path(self): 1832 1833 """ 1834 Return the appropriate namespace path for temporary names in the current 1835 namespace. 1836 """ 1837 1838 if self.in_function: 1839 return self.get_namespace_path() 1840 else: 1841 return self.name 1842 1843 def record_temp(self, name): 1844 1845 """ 1846 Record the use of the temporary 'name' in the current namespace. At the 1847 class or module level, the temporary name is associated with the module, 1848 since the variable will then be allocated in the module's own main 1849 program. 1850 """ 1851 1852 path = self.get_temp_path() 1853 1854 init_item(self.temp_usage, path, list) 1855 self.temp_usage[path].append(name) 1856 1857 def remove_temps(self, names): 1858 1859 """ 1860 Remove 'names' from temporary storage allocations, each instance 1861 removing each request for storage. 1862 """ 1863 1864 path = self.get_temp_path() 1865 1866 for name in names: 1867 if self.uses_temp(path, name): 1868 self.temp_usage[path].remove(name) 1869 1870 def uses_temp(self, path, name): 1871 1872 """ 1873 Return whether the given namespace 'path' employs a temporary variable 1874 with the given 'name'. Note that 'path' should only be a module or a 1875 function or method, not a class. 1876 """ 1877 1878 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1879 1880 def make_negation(self, expr): 1881 1882 "Return a negated form of 'expr'." 1883 1884 result = NegationResult(expr) 1885 1886 # Negation discards the temporary results of its operand. 1887 1888 temps = expr.discards_temporary() 1889 if temps: 1890 self.remove_temps(temps) 1891 1892 return result 1893 1894 # Output generation. 1895 1896 def start_output(self): 1897 1898 "Write the declarations at the top of each source file." 1899 1900 print >>self.out, """\ 1901 #include "types.h" 1902 #include "exceptions.h" 1903 #include "ops.h" 1904 #include "progconsts.h" 1905 #include "progops.h" 1906 #include "progtypes.h" 1907 #include "main.h" 1908 """ 1909 1910 def start_unit(self): 1911 1912 "Record output within a generated function for later use." 1913 1914 self.out = StringIO() 1915 1916 def end_unit(self): 1917 1918 "Restore the output stream." 1919 1920 out = self.out 1921 self.out = self.out_toplevel 1922 return out 1923 1924 def flush_unit(self, name, out): 1925 1926 "Add declarations and generated code." 1927 1928 self.write_temporaries(name) 1929 print >>self.out 1930 out.seek(0) 1931 self.out.write(out.read()) 1932 1933 def start_module(self): 1934 1935 "Write the start of each module's main function." 1936 1937 print >>self.out, "void __main_%s()" % encode_path(self.name) 1938 print >>self.out, "{" 1939 self.indent += 1 1940 1941 # Define temporary variables, excluded from the module structure itself. 1942 1943 tempnames = [] 1944 1945 for n in self.importer.all_module_attrs[self.name]: 1946 if n.startswith("$t"): 1947 tempnames.append(encode_path(n)) 1948 1949 if tempnames: 1950 tempnames.sort() 1951 self.writeline("__attr %s;" % ", ".join(tempnames)) 1952 1953 self.start_unit() 1954 1955 def end_module(self): 1956 1957 "End each module by closing its main function." 1958 1959 out = self.end_unit() 1960 self.flush_unit(self.name, out) 1961 1962 self.indent -= 1 1963 print >>self.out, "}" 1964 1965 def start_function(self, name): 1966 1967 "Start the function having the given 'name'." 1968 1969 self.indent += 1 1970 1971 self.start_unit() 1972 1973 def end_function(self, name): 1974 1975 "End the function having the given 'name'." 1976 1977 out = self.end_unit() 1978 1979 # Write the signature at the top indentation level. 1980 1981 self.indent -= 1 1982 self.write_parameters(name) 1983 print >>self.out, "{" 1984 1985 # Obtain local names from parameters. 1986 1987 parameters = self.importer.function_parameters[name] 1988 locals = self.importer.function_locals[name].keys() 1989 names = [] 1990 volatile_names = [] 1991 1992 for n in locals: 1993 1994 # Filter out special names and parameters. Note that self is a local 1995 # regardless of whether it originally appeared in the parameters or 1996 # not. 1997 1998 if n.startswith("$l") or n in parameters or n == "self": 1999 continue 2000 if n in self.volatile_locals: 2001 volatile_names.append(encode_path(n)) 2002 else: 2003 names.append(encode_path(n)) 2004 2005 # Emit required local names at the function indentation level. 2006 2007 self.indent += 1 2008 2009 if names: 2010 names.sort() 2011 self.writeline("__attr %s;" % ", ".join(names)) 2012 2013 if volatile_names: 2014 volatile_names.sort() 2015 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2016 2017 self.flush_unit(name, out) 2018 2019 self.indent -= 1 2020 print >>self.out, "}" 2021 print >>self.out 2022 2023 def write_parameters(self, name): 2024 2025 """ 2026 For the function having the given 'name', write definitions of 2027 parameters found in the arguments array. 2028 """ 2029 2030 # Generate any self reference. 2031 2032 l = [] 2033 2034 if self.is_method(name): 2035 l.append("__attr self") 2036 else: 2037 l.append("__attr __self") 2038 2039 # Generate aliases for the parameters. 2040 2041 for parameter in self.importer.function_parameters[name]: 2042 l.append("%s__attr %s" % ( 2043 parameter in self.volatile_locals and "volatile " or "", 2044 encode_path(parameter))) 2045 2046 self.writeline("__attr %s(%s)" % ( 2047 encode_function_pointer(name), ", ".join(l))) 2048 2049 def write_temporaries(self, name): 2050 2051 "Write temporary storage employed by 'name'." 2052 2053 # Provide space for the given number of targets. 2054 2055 targets = self.max_function_targets 2056 2057 if self.uses_temp(name, "__tmp_targets"): 2058 self.writeline("__attr __tmp_targets[%d];" % targets) 2059 if self.uses_temp(name, "__tmp_contexts"): 2060 self.writeline("__attr __tmp_contexts[%d];" % targets) 2061 2062 # Add temporary variable usage details. 2063 2064 if self.uses_temp(name, "__tmp_private_context"): 2065 self.writeline("__attr __tmp_private_context;") 2066 if self.uses_temp(name, "__tmp_value"): 2067 self.writeline("__attr __tmp_value;") 2068 if self.uses_temp(name, "__tmp_target_value"): 2069 self.writeline("__attr __tmp_target_value;") 2070 if self.uses_temp(name, "__tmp_result"): 2071 self.writeline("__attr __tmp_result;") 2072 2073 module = self.importer.get_module(self.name) 2074 2075 if name in module.exception_namespaces: 2076 self.writeline("__exc __tmp_exc;") 2077 2078 def start_if(self, first, test_ref): 2079 statement = "%sif" % (not first and "else " or "") 2080 2081 # Consume logical results directly. 2082 2083 if isinstance(test_ref, LogicalResult): 2084 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2085 temps = test_ref.discards_temporary() 2086 if temps: 2087 self.remove_temps(temps) 2088 else: 2089 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2090 2091 self.writeline("{") 2092 self.indent += 1 2093 2094 def end_if(self): 2095 self.indent -= 1 2096 self.writeline("}") 2097 2098 def start_else(self): 2099 self.writeline("else") 2100 self.writeline("{") 2101 self.indent += 1 2102 2103 def end_else(self): 2104 self.indent -= 1 2105 self.writeline("}") 2106 2107 def statement(self, expr): 2108 s = str(expr) 2109 if s: 2110 self.writestmt("%s;" % s) 2111 2112 def statements(self, results): 2113 for result in results: 2114 self.statement(result) 2115 2116 def writeline(self, s): 2117 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2118 2119 def writestmt(self, s): 2120 self.writeline(s) 2121 2122 def write_comment(self, s): 2123 self.writestmt("/* %s */" % s) 2124 2125 def pad(self, extra=0): 2126 return (self.indent + extra) * self.tabstop 2127 2128 def indenttext(self, s, levels): 2129 lines = s.split("\n") 2130 out = [lines[0]] 2131 for line in lines[1:]: 2132 out.append(levels * self.tabstop + line) 2133 if line.endswith("("): 2134 levels += 1 2135 elif line.startswith(")"): 2136 levels -= 1 2137 return "\n".join(out) 2138 2139 # vim: tabstop=4 expandtab shiftwidth=4