1 #!/usr/bin/env python 2 3 """ 4 Translate programs. 5 6 Copyright (C) 2015, 2016, 2017 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 CommonModule, CommonOutput, \ 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 final_identity = None 561 562 # Obtain encoded versions of each instruction, accumulating temporary 563 # variables. 564 565 for instruction in self.deducer.access_instructions[location]: 566 567 # Intercept a special instruction identifying the context. 568 569 if instruction[0] == "<context_identity>": 570 context_identity, _substituted = encode_access_instruction_arg(instruction[1], subs, instruction[0], context_index) 571 continue 572 573 # Intercept a special instruction identifying the target. The value 574 # is not encoded since it is used internally. 575 576 if instruction[0] == "<final_identity>": 577 final_identity = instruction[1] 578 continue 579 580 # Collect the encoded instruction, noting any temporary variables 581 # required by it. 582 583 encoded, _substituted = encode_access_instruction(instruction, subs, context_index) 584 output.append(encoded) 585 substituted.update(_substituted) 586 587 # Record temporary name usage. 588 589 for sub in substituted: 590 if self.temp_subs.has_key(sub): 591 self.record_temp(self.temp_subs[sub]) 592 593 # Get full final identity details. 594 595 if final_identity and not refs: 596 ref = self.importer.identify(final_identity) 597 refs = [ref] 598 599 del self.attrs[0] 600 return AttrResult(output, refs, location, context_identity) 601 602 def init_substitutions(self): 603 604 """ 605 Initialise substitutions, defining temporary variable mappings, some of 606 which are also used as substitutions, together with operation mappings 607 used as substitutions in instructions defined by the optimiser. 608 """ 609 610 self.temp_subs = { 611 612 # Substitutions used by instructions. 613 614 "<private_context>" : "__tmp_private_context", 615 "<accessor>" : "__tmp_value", 616 "<target_accessor>" : "__tmp_target_value", 617 618 # Mappings to be replaced by those given below. 619 620 "<context>" : "__tmp_contexts", 621 "<test_context_revert>" : "__tmp_contexts", 622 "<test_context_static>" : "__tmp_contexts", 623 "<set_context>" : "__tmp_contexts", 624 "<set_private_context>" : "__tmp_private_context", 625 "<set_accessor>" : "__tmp_value", 626 "<set_target_accessor>" : "__tmp_target_value", 627 } 628 629 self.op_subs = { 630 "<context>" : "__get_context", 631 "<test_context_revert>" : "__test_context_revert", 632 "<test_context_static>" : "__test_context_static", 633 "<set_context>" : "__set_context", 634 "<set_private_context>" : "__set_private_context", 635 "<set_accessor>" : "__set_accessor", 636 "<set_target_accessor>" : "__set_target_accessor", 637 } 638 639 def get_referenced_attributes(self, location): 640 641 """ 642 Convert 'location' to the form used by the deducer and retrieve any 643 identified attributes. 644 """ 645 646 # Determine whether any deduced references refer to the accessed 647 # attribute. 648 649 path, accessor_name, attrnames, access_number = location 650 attrnames = attrnames and attrnames.split(".") 651 remaining = attrnames and len(attrnames) > 1 652 653 access_location = self.deducer.const_accesses.get(location) 654 655 if remaining and not access_location: 656 return [] 657 658 refs = [] 659 l = self.deducer.referenced_attrs.get(access_location or location) 660 if l: 661 for attrtype, objpath, attr in l: 662 refs.append(attr) 663 return refs 664 665 def get_referenced_attribute_invocations(self, location): 666 667 """ 668 Convert 'location' to the form used by the deducer and retrieve any 669 identified attribute invocation details. 670 """ 671 672 access_location = self.deducer.const_accesses.get(location) 673 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 674 675 def get_accessor_kinds(self, location): 676 677 "Return the accessor kinds for 'location'." 678 679 return self.deducer.accessor_kinds.get(location) 680 681 def get_access_location(self, name, attrnames=None): 682 683 """ 684 Using the current namespace, the given 'name', and the 'attrnames' 685 employed in an access, return the access location. 686 """ 687 688 path = self.get_path_for_access() 689 690 # Get the location used by the deducer and optimiser and find any 691 # recorded access. 692 693 attrnames = attrnames and ".".join(self.attrs) 694 access_number = self.get_access_number(path, name, attrnames) 695 self.update_access_number(path, name, attrnames) 696 return (path, name, attrnames, access_number) 697 698 def get_access_number(self, path, name, attrnames): 699 access = name, attrnames 700 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 701 return self.attr_accesses[path][access] 702 else: 703 return 0 704 705 def update_access_number(self, path, name, attrnames): 706 access = name, attrnames 707 if name: 708 init_item(self.attr_accesses, path, dict) 709 init_item(self.attr_accesses[path], access, lambda: 0) 710 self.attr_accesses[path][access] += 1 711 712 def get_accessor_location(self, name): 713 714 """ 715 Using the current namespace and the given 'name', return the accessor 716 location. 717 """ 718 719 path = self.get_path_for_access() 720 721 # Get the location used by the deducer and optimiser and find any 722 # recorded accessor. 723 724 access_number = self.get_accessor_number(path, name) 725 self.update_accessor_number(path, name) 726 return (path, name, None, access_number) 727 728 def get_accessor_number(self, path, name): 729 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 730 return self.attr_accessors[path][name] 731 else: 732 return 0 733 734 def update_accessor_number(self, path, name): 735 if name: 736 init_item(self.attr_accessors, path, dict) 737 init_item(self.attr_accessors[path], name, lambda: 0) 738 self.attr_accessors[path][name] += 1 739 740 def process_class_node(self, n): 741 742 "Process the given class node 'n'." 743 744 class_name = self.get_object_path(n.name) 745 746 # Where a class is set conditionally or where the name may refer to 747 # different values, assign the name. 748 749 ref = self.importer.identify(class_name) 750 751 if not ref.static(): 752 self.process_assignment_for_object(n.name, 753 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 754 755 self.enter_namespace(n.name) 756 757 if self.have_object(): 758 self.write_comment("Class: %s" % class_name) 759 760 self.initialise_inherited_members(class_name) 761 762 self.process_structure(n) 763 self.write_comment("End class: %s" % class_name) 764 765 self.exit_namespace() 766 767 def initialise_inherited_members(self, class_name): 768 769 "Initialise members of 'class_name' inherited from its ancestors." 770 771 for name, path in self.importer.all_class_attrs[class_name].items(): 772 target = "%s.%s" % (class_name, name) 773 774 # Ignore attributes with definitions. 775 776 ref = self.importer.identify(target) 777 if ref: 778 continue 779 780 # Ignore special type attributes. 781 782 if is_type_attribute(name): 783 continue 784 785 # Reference inherited attributes. 786 787 ref = self.importer.identify(path) 788 if ref and not ref.static(): 789 parent, attrname = path.rsplit(".", 1) 790 791 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 792 encode_path(class_name), name, 793 encode_path(parent), attrname 794 )) 795 796 def process_from_node(self, n): 797 798 "Process the given node 'n', importing from another module." 799 800 path = self.get_namespace_path() 801 802 # Attempt to obtain the referenced objects. 803 804 for name, alias in n.names: 805 if name == "*": 806 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 807 808 # Obtain the path of the assigned name. 809 810 objpath = self.get_object_path(alias or name) 811 812 # Obtain the identity of the name. 813 814 ref = self.importer.identify(objpath) 815 816 # Where the name is not static, assign the value. 817 818 if ref and not ref.static() and ref.get_name(): 819 self.writestmt("%s;" % 820 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 821 expr=TrResolvedNameRef(name, ref))) 822 823 def process_function_body_node(self, n): 824 825 """ 826 Process the given function, lambda, if expression or list comprehension 827 node 'n', generating the body. 828 """ 829 830 function_name = self.get_namespace_path() 831 self.start_function(function_name) 832 833 # Process the function body. 834 835 in_conditional = self.in_conditional 836 self.in_conditional = False 837 self.function_target = 0 838 self.max_function_targets = 0 839 840 # Volatile locals for exception handling. 841 842 self.volatile_locals = set() 843 844 # Process any guards defined for the parameters. 845 846 for name in self.importer.function_parameters.get(function_name): 847 self.generate_guard(name) 848 849 # Produce the body and any additional return statement. 850 851 expr = self.process_structure_node(n.code) or \ 852 self.in_method() and \ 853 function_name.rsplit(".", 1)[-1] == "__init__" and \ 854 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 855 PredefinedConstantRef("None") 856 857 if not isinstance(expr, ReturnRef): 858 self.writestmt("return %s;" % expr) 859 860 self.in_conditional = in_conditional 861 862 self.end_function(function_name) 863 864 def generate_guard(self, name): 865 866 """ 867 Get the accessor details for 'name', found in the current namespace, and 868 generate any guards defined for it. 869 """ 870 871 # Obtain the location, keeping track of assignment versions. 872 873 location = self.get_accessor_location(name) 874 test = self.deducer.accessor_guard_tests.get(location) 875 876 # Generate any guard from the deduced information. 877 878 if test: 879 guard, guard_type = test 880 881 if guard == "specific": 882 ref = first(self.deducer.accessor_all_types[location]) 883 argstr = "&%s" % encode_path(ref.get_origin()) 884 elif guard == "common": 885 ref = first(self.deducer.accessor_all_general_types[location]) 886 argstr = encode_path(encode_type_attribute(ref.get_origin())) 887 else: 888 return 889 890 # Write a test that raises a TypeError upon failure. 891 892 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 893 guard, guard_type, encode_path(name), argstr)) 894 895 def process_function_node(self, n): 896 897 """ 898 Process the given function, lambda, if expression or list comprehension 899 node 'n', generating any initialisation statements. 900 """ 901 902 # Where a function is declared conditionally, use a separate name for 903 # the definition, and assign the definition to the stated name. 904 905 original_name = n.name 906 907 if self.in_conditional or self.in_function: 908 name = self.get_lambda_name() 909 else: 910 name = n.name 911 912 objpath = self.get_object_path(name) 913 914 # Obtain details of the defaults. 915 916 defaults = self.process_function_defaults(n, name, objpath) 917 if defaults: 918 for default in defaults: 919 self.writeline("%s;" % default) 920 921 # Where a function is set conditionally or where the name may refer to 922 # different values, assign the name. 923 924 ref = self.importer.identify(objpath) 925 926 if self.in_conditional or self.in_function: 927 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 928 elif not ref.static(): 929 context = self.is_method(objpath) 930 931 self.process_assignment_for_object(original_name, 932 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 933 934 def process_function_defaults(self, n, name, objpath, instance_name=None): 935 936 """ 937 Process the given function or lambda node 'n', initialising defaults 938 that are dynamically set. The given 'name' indicates the name of the 939 function. The given 'objpath' indicates the origin of the function. 940 The given 'instance_name' indicates the name of any separate instance 941 of the function created to hold the defaults. 942 943 Return a list of operations setting defaults on a function instance. 944 """ 945 946 function_name = self.get_object_path(name) 947 function_defaults = self.importer.function_defaults.get(function_name) 948 if not function_defaults: 949 return None 950 951 # Determine whether any unidentified defaults are involved. 952 953 for argname, default in function_defaults: 954 if not default.static(): 955 break 956 else: 957 return None 958 959 # Handle bound methods. 960 961 if not instance_name: 962 instance_name = "&%s" % encode_path(objpath) 963 else: 964 instance_name = "__VALUE(%s)" % instance_name 965 966 # Where defaults are involved but cannot be identified, obtain a new 967 # instance of the lambda and populate the defaults. 968 969 defaults = [] 970 971 # Join the original defaults with the inspected defaults. 972 973 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 974 975 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 976 977 # Obtain any reference for the default. 978 979 if original: 980 argname, default = original 981 name_ref = self.process_structure_node(default) 982 elif inspected: 983 argname, default = inspected 984 name_ref = TrResolvedNameRef(argname, default) 985 else: 986 continue 987 988 # Generate default initialisers except when constants are employed. 989 # Constants should be used when populating the function structures. 990 991 if name_ref and not isinstance(name_ref, TrConstantValueRef): 992 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 993 994 return defaults 995 996 def process_if_node(self, n): 997 998 """ 999 Process the given "if" node 'n'. 1000 """ 1001 1002 first = True 1003 for test, body in n.tests: 1004 test_ref = self.process_structure_node(test) 1005 self.start_if(first, test_ref) 1006 1007 in_conditional = self.in_conditional 1008 self.in_conditional = True 1009 self.process_structure_node(body) 1010 self.in_conditional = in_conditional 1011 1012 self.end_if() 1013 first = False 1014 1015 if n.else_: 1016 self.start_else() 1017 self.process_structure_node(n.else_) 1018 self.end_else() 1019 1020 print >>self.out 1021 1022 def process_invocation_node(self, n): 1023 1024 "Process the given invocation node 'n'." 1025 1026 # Any invocations in the expression will store target details in a 1027 # different location. 1028 1029 self.next_target() 1030 1031 in_argument_list = self.in_argument_list 1032 self.in_argument_list = False 1033 1034 # Process the expression. 1035 1036 expr = self.process_structure_node(n.node) 1037 1038 # Reference the current target again. 1039 1040 self.in_argument_list = in_argument_list 1041 self.function_target -= 1 1042 1043 # Obtain details of the invocation expression. 1044 1045 objpath = expr.get_origin() 1046 location = expr.access_location() 1047 refs = expr.references() 1048 1049 # Identified target details. 1050 1051 target = None 1052 target_structure = None 1053 1054 # Specific function target information. 1055 1056 function = None 1057 1058 # Instantiation involvement. 1059 1060 instantiation = False 1061 literal_instantiation = False 1062 1063 # Invocation requirements. 1064 1065 context_required = True 1066 have_access_context = isinstance(expr, AttrResult) 1067 context_identity = have_access_context and expr.context() 1068 parameters = None 1069 num_parameters = None 1070 num_defaults = None 1071 1072 # Obtain details of the callable and of its parameters. 1073 1074 # Literals may be instantiated specially. 1075 1076 if expr.is_name() and expr.name.startswith("$L") and objpath: 1077 instantiation = literal_instantiation = objpath 1078 target = encode_literal_instantiator(objpath) 1079 context_required = False 1080 1081 # Identified targets employ function pointers directly. 1082 1083 elif objpath: 1084 parameters = self.importer.function_parameters.get(objpath) 1085 function_defaults = self.importer.function_defaults.get(objpath) 1086 num_parameters = parameters and len(parameters) or 0 1087 num_defaults = function_defaults and len(function_defaults) or 0 1088 1089 # Class invocation involves instantiators. 1090 1091 if expr.has_kind("<class>"): 1092 instantiation = objpath 1093 target = encode_instantiator_pointer(objpath) 1094 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1095 target_structure = "&%s" % encode_path(init_ref) 1096 context_required = False 1097 1098 # Only plain functions and bound methods employ function pointers. 1099 1100 elif expr.has_kind("<function>"): 1101 function = objpath 1102 1103 # Test for functions and methods. 1104 1105 context_required = self.is_method(objpath) 1106 1107 accessor_kinds = location and self.get_accessor_kinds(location) 1108 1109 instance_accessor = accessor_kinds and \ 1110 len(accessor_kinds) == 1 and \ 1111 first(accessor_kinds) == "<instance>" 1112 1113 # Only identify certain bound methods or functions. 1114 1115 if not context_required or instance_accessor: 1116 target = encode_function_pointer(objpath) 1117 1118 # Access bound method defaults even if it is not clear whether 1119 # the accessor is appropriate. 1120 1121 target_structure = "&%s" % encode_path(objpath) 1122 1123 # Other targets are retrieved at run-time. 1124 1125 else: 1126 if location: 1127 path, name, attrnames, access_number = location 1128 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1129 1130 # Determine any common aspects of any attribute. 1131 1132 if attrname: 1133 all_params = set() 1134 all_defaults = set() 1135 min_params = set() 1136 max_params = set() 1137 refs = set() 1138 1139 # Obtain parameters and defaults for each possible target. 1140 1141 for ref in self.get_attributes_for_attrname(attrname): 1142 origin = ref.get_origin() 1143 params = self.importer.function_parameters.get(origin) 1144 1145 defaults = self.importer.function_defaults.get(origin) 1146 if defaults is not None: 1147 all_defaults.add(tuple(defaults)) 1148 1149 if params is not None: 1150 all_params.add(tuple(params)) 1151 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1152 max_params.add(len(params)) 1153 refs.add(ref) 1154 else: 1155 refs = set() 1156 break 1157 1158 # Where the parameters and defaults are always the same, 1159 # permit populating them in advance. 1160 1161 if refs: 1162 if self.uses_keyword_arguments(n): 1163 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1164 parameters = first(all_params) 1165 function_defaults = all_defaults and first(all_defaults) or [] 1166 num_parameters = parameters and len(parameters) or 0 1167 num_defaults = function_defaults and len(function_defaults) or 0 1168 else: 1169 if len(min_params) == 1 and len(max_params) == 1: 1170 num_parameters = first(max_params) 1171 num_defaults = first(max_params) - first(min_params) 1172 1173 # Some information about the target may be available and be used to 1174 # provide warnings about argument compatibility. 1175 1176 if self.importer.give_warning("args"): 1177 unsuitable = self.get_referenced_attribute_invocations(location) 1178 1179 if unsuitable: 1180 for ref in unsuitable: 1181 _objpath = ref.get_origin() 1182 print >>sys.stderr, \ 1183 "In %s, at line %d, inappropriate number of " \ 1184 "arguments given. Need %d arguments to call %s." % ( 1185 self.get_namespace_path(), n.lineno, 1186 len(self.importer.function_parameters[_objpath]), 1187 _objpath) 1188 1189 # Determine any readily-accessible target identity. 1190 1191 target_named = expr.is_name() and str(expr) or None 1192 target_stored = "__tmp_targets[%d]" % self.function_target 1193 1194 target_identity = target or target_named 1195 target_var = target_identity or target_stored 1196 context_var = target_named or target_stored 1197 1198 if not target_identity: 1199 self.record_temp("__tmp_targets") 1200 1201 if context_identity: 1202 if context_identity.startswith("__tmp_contexts"): 1203 self.record_temp("__tmp_contexts") 1204 1205 # Arguments are presented in a temporary frame array with any context 1206 # always being the first argument. Where it would be unused, it may be 1207 # set to null. 1208 1209 known_parameters = num_parameters is not None 1210 1211 if context_required: 1212 if have_access_context: 1213 args = [context_identity] 1214 else: 1215 args = ["__CONTEXT_AS_VALUE(%s)" % context_var] 1216 else: 1217 args = ["__NULL"] 1218 1219 # Complete the array with null values, permitting tests for a complete 1220 # set of arguments. 1221 1222 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1223 kwcodes = [] 1224 kwargs = [] 1225 1226 # Any invocations in the arguments will store target details in a 1227 # different location. 1228 1229 function_target = self.function_target 1230 1231 if not target_identity: 1232 self.next_target() 1233 1234 in_argument_list = self.in_argument_list 1235 self.in_argument_list = True 1236 1237 for i, arg in enumerate(n.args): 1238 argexpr = self.process_structure_node(arg) 1239 1240 # Store a keyword argument, either in the argument list or 1241 # in a separate keyword argument list for subsequent lookup. 1242 1243 if isinstance(arg, compiler.ast.Keyword): 1244 1245 # With knowledge of the target, store the keyword 1246 # argument directly. 1247 1248 if parameters: 1249 try: 1250 argnum = parameters.index(arg.name) 1251 except ValueError: 1252 raise TranslateError("Argument %s is not recognised." % arg.name, 1253 self.get_namespace_path(), n) 1254 args[argnum+1] = str(argexpr) 1255 1256 # Otherwise, store the details in a separate collection. 1257 1258 else: 1259 kwargs.append(str(argexpr)) 1260 kwcodes.append("{%s, %s}" % ( 1261 encode_ppos(arg.name), encode_pcode(arg.name))) 1262 1263 # Store non-keyword arguments in the argument list, rejecting 1264 # superfluous arguments. 1265 1266 else: 1267 try: 1268 args[i+1] = str(argexpr) 1269 except IndexError: 1270 raise TranslateError("Too many arguments specified.", 1271 self.get_namespace_path(), n) 1272 1273 # Reference the current target again. 1274 1275 self.in_argument_list = in_argument_list 1276 1277 if not self.in_argument_list: 1278 self.function_target = function_target 1279 1280 # Defaults are added to the frame where arguments are missing. 1281 1282 if parameters and function_defaults: 1283 1284 # Visit each default and set any missing arguments. Where keyword 1285 # arguments have been used, the defaults must be inspected and, if 1286 # necessary, inserted into gaps in the argument list. 1287 1288 for i, (argname, default) in enumerate(function_defaults): 1289 argnum = parameters.index(argname) 1290 if not args[argnum+1]: 1291 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1292 1293 elif known_parameters: 1294 1295 # No specific parameter details are provided, but no keyword 1296 # arguments are used. Thus, defaults can be supplied using position 1297 # information only. 1298 1299 i = len(n.args) 1300 pos = i - (num_parameters - num_defaults) 1301 while i < num_parameters: 1302 args[i+1] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1303 i += 1 1304 pos += 1 1305 1306 # Test for missing arguments. 1307 1308 if None in args: 1309 raise TranslateError("Not all arguments supplied.", 1310 self.get_namespace_path(), n) 1311 1312 # Encode the arguments. 1313 1314 # Where literal instantiation is occurring, add an argument indicating 1315 # the number of values. The context is excluded. 1316 1317 if literal_instantiation: 1318 argstr = "__ARGS(%s), %d" % (", ".join(args[1:]), len(args) - 1) 1319 else: 1320 argstr = ", ".join(args) 1321 1322 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1323 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1324 1325 # First, the invocation expression is presented. 1326 1327 stages = [] 1328 1329 # Without a known specific callable, the expression provides the target. 1330 1331 if not target or context_required: 1332 1333 # The context is set in the expression. 1334 1335 if target and not target_named: 1336 1337 # Test whether the expression provides anything. 1338 1339 if expr: 1340 stages.append(str(expr)) 1341 1342 elif not target_identity: 1343 stages.append("%s = %s" % (target_var, expr)) 1344 1345 # Any specific callable is then obtained for invocation. 1346 1347 if target: 1348 stages.append(target) 1349 1350 # Methods accessed via unidentified accessors are obtained for 1351 # invocation. 1352 1353 elif function: 1354 if context_required: 1355 if have_access_context: 1356 stages.append("__get_function(%s, %s)" % ( 1357 context_identity, target_var)) 1358 else: 1359 stages.append("__get_function(__CONTEXT_AS_VALUE(%s), %s)" % ( 1360 context_var, target_var)) 1361 else: 1362 stages.append("__load_via_object(__VALUE(%s), __fn__).fn" % target_var) 1363 1364 # With known parameters, the target can be tested. 1365 1366 elif known_parameters: 1367 context_arg = context_required and args[0] or "__NULL" 1368 if self.always_callable(refs): 1369 stages.append("__get_function(%s, %s)" % (context_arg, target_var)) 1370 else: 1371 stages.append("__check_and_get_function(%s, %s)" % (context_arg, target_var)) 1372 1373 # With a known target, the function is obtained directly and called. 1374 # By putting the invocation at the end of the final element in the 1375 # instruction sequence (the stages), the result becomes the result of 1376 # the sequence. Moreover, the parameters become part of the sequence 1377 # and thereby participate in a guaranteed evaluation order. 1378 1379 if target or function or known_parameters: 1380 stages[-1] += "(%s)" % argstr 1381 if instantiation: 1382 return InstantiationResult(instantiation, stages) 1383 else: 1384 return InvocationResult(stages) 1385 1386 # With unknown targets, the generic invocation function is applied to 1387 # the callable and argument collections. 1388 1389 else: 1390 stages.append("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1391 target_var, 1392 self.always_callable(refs) and 1 or 0, 1393 len(kwargs), kwcodestr, kwargstr, 1394 len(args), "__ARGS(%s)" % argstr)) 1395 return InvocationResult(stages) 1396 1397 def next_target(self): 1398 1399 "Allocate the next function target storage." 1400 1401 self.function_target += 1 1402 self.max_function_targets = max(self.function_target, self.max_function_targets) 1403 1404 def always_callable(self, refs): 1405 1406 "Determine whether all 'refs' are callable." 1407 1408 if not refs: 1409 return False 1410 1411 for ref in refs: 1412 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1413 return False 1414 1415 return True 1416 1417 def need_default_arguments(self, objpath, nargs): 1418 1419 """ 1420 Return whether any default arguments are needed when invoking the object 1421 given by 'objpath'. 1422 """ 1423 1424 parameters = self.importer.function_parameters.get(objpath) 1425 return nargs < len(parameters) 1426 1427 def uses_keyword_arguments(self, n): 1428 1429 "Return whether invocation node 'n' uses keyword arguments." 1430 1431 for arg in enumerate(n.args): 1432 if isinstance(arg, compiler.ast.Keyword): 1433 return True 1434 1435 return False 1436 1437 def get_attributes_for_attrname(self, attrname): 1438 1439 "Return a set of all attributes exposed by 'attrname'." 1440 1441 usage = [(attrname, True, False)] 1442 class_types = self.deducer.get_class_types_for_usage(usage) 1443 instance_types = self.deducer.get_instance_types_for_usage(usage) 1444 module_types = self.deducer.get_module_types_for_usage(usage) 1445 attrs = set() 1446 1447 for ref in combine_types(class_types, instance_types, module_types): 1448 attrs.update(self.importer.get_attributes(ref, attrname)) 1449 1450 return attrs 1451 1452 def process_lambda_node(self, n): 1453 1454 "Process the given lambda node 'n'." 1455 1456 name = self.get_lambda_name() 1457 function_name = self.get_object_path(name) 1458 1459 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1460 1461 # Without defaults, produce an attribute referring to the function. 1462 1463 if not defaults: 1464 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1465 1466 # With defaults, copy the function structure and set the defaults on the 1467 # copy. 1468 1469 else: 1470 self.record_temp("__tmp_value") 1471 return make_expression("(__tmp_value = __ATTRVALUE(__COPY(&%s, sizeof(%s))), %s, __tmp_value)" % ( 1472 encode_path(function_name), 1473 encode_symbol("obj", function_name), 1474 ", ".join(defaults))) 1475 1476 def process_logical_node(self, n): 1477 1478 "Process the given operator node 'n'." 1479 1480 self.record_temp("__tmp_result") 1481 1482 conjunction = isinstance(n, compiler.ast.And) 1483 results = [] 1484 1485 for node in n.nodes: 1486 results.append(self.process_structure_node(node)) 1487 1488 return LogicalOperationResult(results, conjunction) 1489 1490 def process_name_node(self, n, expr=None): 1491 1492 "Process the given name node 'n' with the optional assignment 'expr'." 1493 1494 # Determine whether the name refers to a static external entity. 1495 1496 if n.name in predefined_constants: 1497 return PredefinedConstantRef(n.name, expr) 1498 1499 # Convert literal references, operator function names, and print 1500 # function names to references. 1501 1502 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1503 n.name.startswith("$print"): 1504 1505 ref, paths = self.importer.get_module(self.name).special[n.name] 1506 return TrResolvedNameRef(n.name, ref) 1507 1508 # Get the appropriate name for the name reference, using the same method 1509 # as in the inspector. 1510 1511 path = self.get_namespace_path() 1512 objpath = self.get_object_path(n.name) 1513 1514 # Determine any assigned globals. 1515 1516 globals = self.importer.get_module(self.name).scope_globals.get(path) 1517 1518 # Explicitly declared globals. 1519 1520 if globals and n.name in globals: 1521 objpath = self.get_global_path(n.name) 1522 is_global = True 1523 1524 # Implicitly referenced globals in functions. 1525 1526 elif self.in_function: 1527 is_global = n.name not in self.importer.function_locals[path] 1528 1529 # Implicitly referenced globals elsewhere. 1530 1531 else: 1532 namespace = self.importer.identify(path) 1533 is_global = not self.importer.get_attributes(namespace, n.name) 1534 1535 # Get the static identity of the name. 1536 1537 ref = self.importer.identify(objpath) 1538 if ref and not ref.get_name(): 1539 ref = ref.alias(objpath) 1540 1541 # Obtain any resolved names for non-assignment names. 1542 1543 if not expr and not ref and self.in_function: 1544 locals = self.importer.function_locals.get(path) 1545 ref = locals and locals.get(n.name) 1546 1547 # Determine whether the name refers to a parameter. The generation of 1548 # parameter references is different from other names. 1549 1550 parameters = self.importer.function_parameters.get(path) 1551 parameter = n.name == "self" and self.in_method() or \ 1552 parameters and n.name in parameters 1553 1554 # Find any invocation or alias details. 1555 1556 name = self.get_name_for_tracking(n.name, is_global=is_global) 1557 location = not expr and self.get_access_location(name) or None 1558 1559 # Mark any local assignments as volatile in exception blocks. 1560 1561 if expr and self.in_function and not is_global and self.in_try_except: 1562 self.make_volatile(n.name) 1563 1564 # Qualified names are used for resolved static references or for 1565 # static namespace members. The reference should be configured to return 1566 # such names. 1567 1568 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1569 location=location) 1570 return not expr and self.get_aliases(name_ref) or name_ref 1571 1572 def get_aliases(self, name_ref): 1573 1574 "Return alias references for the given 'name_ref'." 1575 1576 location = name_ref.access_location() 1577 1578 refs = self.deducer.referenced_objects.get(location) 1579 refs = refs or self.deducer.accessor_all_types.get(location) 1580 return AliasResult(name_ref, refs or set(), location) 1581 1582 def make_volatile(self, name): 1583 1584 "Record 'name' as volatile in the current namespace." 1585 1586 self.volatile_locals.add(name) 1587 1588 def process_not_node(self, n): 1589 1590 "Process the given operator node 'n'." 1591 1592 return self.make_negation(self.process_structure_node(n.expr)) 1593 1594 def process_raise_node(self, n): 1595 1596 "Process the given raise node 'n'." 1597 1598 # NOTE: Determine which raise statement variants should be permitted. 1599 1600 if n.expr1: 1601 1602 # Names with accompanying arguments are treated like invocations. 1603 1604 if n.expr2: 1605 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1606 exc = self.process_structure_node(call) 1607 self.writestmt("__Raise(%s);" % exc) 1608 1609 # Raise instances, testing the kind at run-time if necessary and 1610 # instantiating any non-instance. 1611 1612 else: 1613 exc = self.process_structure_node(n.expr1) 1614 1615 if isinstance(exc, TrInstanceRef): 1616 self.writestmt("__Raise(%s);" % exc) 1617 else: 1618 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1619 else: 1620 self.writestmt("__Throw(__tmp_exc);") 1621 1622 def process_return_node(self, n): 1623 1624 "Process the given return node 'n'." 1625 1626 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1627 if self.in_try_finally or self.in_try_except: 1628 self.writestmt("__Return(%s);" % expr) 1629 else: 1630 self.writestmt("return %s;" % expr) 1631 1632 return ReturnRef() 1633 1634 def process_try_node(self, n): 1635 1636 """ 1637 Process the given "try...except" node 'n'. 1638 """ 1639 1640 in_try_except = self.in_try_except 1641 self.in_try_except = True 1642 1643 # Use macros to implement exception handling. 1644 1645 self.writestmt("__Try") 1646 self.writeline("{") 1647 self.indent += 1 1648 self.process_structure_node(n.body) 1649 1650 # Put the else statement in another try block that handles any raised 1651 # exceptions and converts them to exceptions that will not be handled by 1652 # the main handling block. 1653 1654 if n.else_: 1655 self.writestmt("__Try") 1656 self.writeline("{") 1657 self.indent += 1 1658 self.process_structure_node(n.else_) 1659 self.indent -= 1 1660 self.writeline("}") 1661 self.writeline("__Catch (__tmp_exc)") 1662 self.writeline("{") 1663 self.indent += 1 1664 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1665 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1666 self.indent -= 1 1667 self.writeline("}") 1668 1669 # Complete the try block and enter the finally block, if appropriate. 1670 1671 if self.in_try_finally: 1672 self.writestmt("__Complete;") 1673 1674 self.indent -= 1 1675 self.writeline("}") 1676 1677 self.in_try_except = in_try_except 1678 1679 # Handlers are tests within a common handler block. 1680 1681 self.writeline("__Catch (__tmp_exc)") 1682 self.writeline("{") 1683 self.indent += 1 1684 1685 # Introduce an if statement to handle the completion of a try block. 1686 1687 self.process_try_completion() 1688 1689 # Handle exceptions in else blocks converted to __RaiseElse, converting 1690 # them back to normal exceptions. 1691 1692 if n.else_: 1693 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1694 1695 # Exception handling. 1696 1697 for name, var, handler in n.handlers: 1698 1699 # Test for specific exceptions. 1700 1701 if name is not None: 1702 name_ref = self.process_structure_node(name) 1703 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1704 else: 1705 self.writeline("else if (1)") 1706 1707 self.writeline("{") 1708 self.indent += 1 1709 1710 # Establish the local for the handler. 1711 1712 if var is not None: 1713 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1714 1715 if handler is not None: 1716 self.process_structure_node(handler) 1717 1718 self.indent -= 1 1719 self.writeline("}") 1720 1721 # Re-raise unhandled exceptions. 1722 1723 self.writeline("else __Throw(__tmp_exc);") 1724 1725 # End the handler block. 1726 1727 self.indent -= 1 1728 self.writeline("}") 1729 print >>self.out 1730 1731 def process_try_finally_node(self, n): 1732 1733 """ 1734 Process the given "try...finally" node 'n'. 1735 """ 1736 1737 in_try_finally = self.in_try_finally 1738 self.in_try_finally = True 1739 1740 # Use macros to implement exception handling. 1741 1742 self.writestmt("__Try") 1743 self.writeline("{") 1744 self.indent += 1 1745 self.process_structure_node(n.body) 1746 self.indent -= 1 1747 self.writeline("}") 1748 1749 self.in_try_finally = in_try_finally 1750 1751 # Finally clauses handle special exceptions. 1752 1753 self.writeline("__Catch (__tmp_exc)") 1754 self.writeline("{") 1755 self.indent += 1 1756 self.process_structure_node(n.final) 1757 1758 # Introduce an if statement to handle the completion of a try block. 1759 1760 self.process_try_completion() 1761 self.writeline("else __Throw(__tmp_exc);") 1762 1763 self.indent -= 1 1764 self.writeline("}") 1765 print >>self.out 1766 1767 def process_try_completion(self): 1768 1769 "Generate a test for the completion of a try block." 1770 1771 self.writestmt("if (__tmp_exc.completing)") 1772 self.writeline("{") 1773 self.indent += 1 1774 1775 # Do not return anything at the module level. 1776 1777 if self.get_namespace_path() != self.name: 1778 1779 # Only use the normal return statement if no surrounding try blocks 1780 # apply. 1781 1782 if not self.in_try_finally and not self.in_try_except: 1783 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1784 else: 1785 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1786 1787 self.indent -= 1 1788 self.writeline("}") 1789 1790 def process_while_node(self, n): 1791 1792 "Process the given while node 'n'." 1793 1794 self.writeline("while (1)") 1795 self.writeline("{") 1796 self.indent += 1 1797 test = self.process_structure_node(n.test) 1798 1799 # Emit the loop termination condition unless "while <true value>" is 1800 # indicated. 1801 1802 if not (isinstance(test, PredefinedConstantRef) and test.value): 1803 1804 # Emit a negated test of the continuation condition. 1805 1806 self.start_if(True, self.make_negation(test)) 1807 if n.else_: 1808 self.process_structure_node(n.else_) 1809 self.writestmt("break;") 1810 self.end_if() 1811 1812 in_conditional = self.in_conditional 1813 self.in_conditional = True 1814 self.process_structure_node(n.body) 1815 self.in_conditional = in_conditional 1816 1817 self.indent -= 1 1818 self.writeline("}") 1819 print >>self.out 1820 1821 # Special variable usage. 1822 1823 def get_temp_path(self): 1824 1825 """ 1826 Return the appropriate namespace path for temporary names in the current 1827 namespace. 1828 """ 1829 1830 if self.in_function: 1831 return self.get_namespace_path() 1832 else: 1833 return self.name 1834 1835 def record_temp(self, name): 1836 1837 """ 1838 Record the use of the temporary 'name' in the current namespace. At the 1839 class or module level, the temporary name is associated with the module, 1840 since the variable will then be allocated in the module's own main 1841 program. 1842 """ 1843 1844 path = self.get_temp_path() 1845 1846 init_item(self.temp_usage, path, list) 1847 self.temp_usage[path].append(name) 1848 1849 def remove_temps(self, names): 1850 1851 """ 1852 Remove 'names' from temporary storage allocations, each instance 1853 removing each request for storage. 1854 """ 1855 1856 path = self.get_temp_path() 1857 1858 for name in names: 1859 if self.uses_temp(path, name): 1860 self.temp_usage[path].remove(name) 1861 1862 def uses_temp(self, path, name): 1863 1864 """ 1865 Return whether the given namespace 'path' employs a temporary variable 1866 with the given 'name'. Note that 'path' should only be a module or a 1867 function or method, not a class. 1868 """ 1869 1870 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1871 1872 def make_negation(self, expr): 1873 1874 "Return a negated form of 'expr'." 1875 1876 result = NegationResult(expr) 1877 1878 # Negation discards the temporary results of its operand. 1879 1880 temps = expr.discards_temporary() 1881 if temps: 1882 self.remove_temps(temps) 1883 1884 return result 1885 1886 # Output generation. 1887 1888 def start_output(self): 1889 1890 "Write the declarations at the top of each source file." 1891 1892 print >>self.out, """\ 1893 #include "types.h" 1894 #include "exceptions.h" 1895 #include "ops.h" 1896 #include "progconsts.h" 1897 #include "progops.h" 1898 #include "progtypes.h" 1899 #include "main.h" 1900 """ 1901 1902 def start_unit(self): 1903 1904 "Record output within a generated function for later use." 1905 1906 self.out = StringIO() 1907 1908 def end_unit(self): 1909 1910 "Restore the output stream." 1911 1912 out = self.out 1913 self.out = self.out_toplevel 1914 return out 1915 1916 def flush_unit(self, name, out): 1917 1918 "Add declarations and generated code." 1919 1920 self.write_temporaries(name) 1921 print >>self.out 1922 out.seek(0) 1923 self.out.write(out.read()) 1924 1925 def start_module(self): 1926 1927 "Write the start of each module's main function." 1928 1929 print >>self.out, "void __main_%s()" % encode_path(self.name) 1930 print >>self.out, "{" 1931 self.indent += 1 1932 1933 # Define temporary variables, excluded from the module structure itself. 1934 1935 tempnames = [] 1936 1937 for n in self.importer.all_module_attrs[self.name]: 1938 if n.startswith("$t"): 1939 tempnames.append(encode_path(n)) 1940 1941 if tempnames: 1942 tempnames.sort() 1943 self.writeline("__attr %s;" % ", ".join(tempnames)) 1944 1945 self.start_unit() 1946 1947 def end_module(self): 1948 1949 "End each module by closing its main function." 1950 1951 out = self.end_unit() 1952 self.flush_unit(self.name, out) 1953 1954 self.indent -= 1 1955 print >>self.out, "}" 1956 1957 def start_function(self, name): 1958 1959 "Start the function having the given 'name'." 1960 1961 self.indent += 1 1962 1963 self.start_unit() 1964 1965 def end_function(self, name): 1966 1967 "End the function having the given 'name'." 1968 1969 out = self.end_unit() 1970 1971 # Write the signature at the top indentation level. 1972 1973 self.indent -= 1 1974 self.write_parameters(name) 1975 print >>self.out, "{" 1976 1977 # Obtain local names from parameters. 1978 1979 parameters = self.importer.function_parameters[name] 1980 locals = self.importer.function_locals[name].keys() 1981 names = [] 1982 volatile_names = [] 1983 1984 for n in locals: 1985 1986 # Filter out special names and parameters. Note that self is a local 1987 # regardless of whether it originally appeared in the parameters or 1988 # not. 1989 1990 if n.startswith("$l") or n in parameters or n == "self": 1991 continue 1992 if n in self.volatile_locals: 1993 volatile_names.append(encode_path(n)) 1994 else: 1995 names.append(encode_path(n)) 1996 1997 # Emit required local names at the function indentation level. 1998 1999 self.indent += 1 2000 2001 if names: 2002 names.sort() 2003 self.writeline("__attr %s;" % ", ".join(names)) 2004 2005 if volatile_names: 2006 volatile_names.sort() 2007 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2008 2009 self.flush_unit(name, out) 2010 2011 self.indent -= 1 2012 print >>self.out, "}" 2013 print >>self.out 2014 2015 def write_parameters(self, name): 2016 2017 """ 2018 For the function having the given 'name', write definitions of 2019 parameters found in the arguments array. 2020 """ 2021 2022 # Generate any self reference. 2023 2024 l = [] 2025 2026 if self.is_method(name): 2027 l.append("__attr self") 2028 else: 2029 l.append("__attr __self") 2030 2031 # Generate aliases for the parameters. 2032 2033 for parameter in self.importer.function_parameters[name]: 2034 l.append("%s__attr %s" % ( 2035 parameter in self.volatile_locals and "volatile " or "", 2036 encode_path(parameter))) 2037 2038 self.writeline("__attr %s(%s)" % ( 2039 encode_function_pointer(name), ", ".join(l))) 2040 2041 def write_temporaries(self, name): 2042 2043 "Write temporary storage employed by 'name'." 2044 2045 # Provide space for the given number of targets. 2046 2047 targets = self.max_function_targets 2048 2049 if self.uses_temp(name, "__tmp_targets"): 2050 self.writeline("__attr __tmp_targets[%d];" % targets) 2051 if self.uses_temp(name, "__tmp_contexts"): 2052 self.writeline("__attr __tmp_contexts[%d];" % targets) 2053 2054 # Add temporary variable usage details. 2055 2056 if self.uses_temp(name, "__tmp_private_context"): 2057 self.writeline("__attr __tmp_private_context;") 2058 if self.uses_temp(name, "__tmp_value"): 2059 self.writeline("__attr __tmp_value;") 2060 if self.uses_temp(name, "__tmp_target_value"): 2061 self.writeline("__attr __tmp_target_value;") 2062 if self.uses_temp(name, "__tmp_result"): 2063 self.writeline("__attr __tmp_result;") 2064 2065 module = self.importer.get_module(self.name) 2066 2067 if name in module.exception_namespaces: 2068 self.writeline("__exc __tmp_exc;") 2069 2070 def start_if(self, first, test_ref): 2071 statement = "%sif" % (not first and "else " or "") 2072 2073 # Consume logical results directly. 2074 2075 if isinstance(test_ref, LogicalResult): 2076 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2077 temps = test_ref.discards_temporary() 2078 if temps: 2079 self.remove_temps(temps) 2080 else: 2081 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2082 2083 self.writeline("{") 2084 self.indent += 1 2085 2086 def end_if(self): 2087 self.indent -= 1 2088 self.writeline("}") 2089 2090 def start_else(self): 2091 self.writeline("else") 2092 self.writeline("{") 2093 self.indent += 1 2094 2095 def end_else(self): 2096 self.indent -= 1 2097 self.writeline("}") 2098 2099 def statement(self, expr): 2100 s = str(expr) 2101 if s: 2102 self.writestmt("%s;" % s) 2103 2104 def statements(self, results): 2105 for result in results: 2106 self.statement(result) 2107 2108 def writeline(self, s): 2109 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2110 2111 def writestmt(self, s): 2112 self.writeline(s) 2113 2114 def write_comment(self, s): 2115 self.writestmt("/* %s */" % s) 2116 2117 def pad(self, extra=0): 2118 return (self.indent + extra) * self.tabstop 2119 2120 def indenttext(self, s, levels): 2121 lines = s.split("\n") 2122 out = [lines[0]] 2123 for line in lines[1:]: 2124 out.append(levels * self.tabstop + line) 2125 if line.endswith("("): 2126 levels += 1 2127 elif line.startswith(")"): 2128 levels -= 1 2129 return "\n".join(out) 2130 2131 # vim: tabstop=4 expandtab shiftwidth=4