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 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 path, accessor_name, attrnames, access_number = location 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 (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 access_number = self.get_accessor_number(path, name) 727 self.update_accessor_number(path, name) 728 return (path, name, None, access_number) 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 # Produce the body and any additional return statement. 852 853 expr = self.process_structure_node(n.code) or \ 854 self.in_method() and \ 855 function_name.rsplit(".", 1)[-1] == "__init__" and \ 856 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 857 PredefinedConstantRef("None") 858 859 if not isinstance(expr, ReturnRef): 860 self.writestmt("return %s;" % expr) 861 862 self.in_conditional = in_conditional 863 864 self.end_function(function_name) 865 866 def generate_guard(self, name): 867 868 """ 869 Get the accessor details for 'name', found in the current namespace, and 870 generate any guards defined for it. 871 """ 872 873 # Obtain the location, keeping track of assignment versions. 874 875 location = self.get_accessor_location(name) 876 test = self.deducer.accessor_guard_tests.get(location) 877 878 # Generate any guard from the deduced information. 879 880 if test: 881 guard, guard_type = test 882 883 if guard == "specific": 884 ref = first(self.deducer.accessor_all_types[location]) 885 argstr = "&%s" % encode_path(ref.get_origin()) 886 elif guard == "common": 887 ref = first(self.deducer.accessor_all_general_types[location]) 888 argstr = encode_path(encode_type_attribute(ref.get_origin())) 889 else: 890 return 891 892 # Write a test that raises a TypeError upon failure. 893 894 self.writestmt("if (!__test_%s_%s(__VALUE(%s), %s)) __raise_type_error();" % ( 895 guard, guard_type, encode_path(name), argstr)) 896 897 def process_function_node(self, n): 898 899 """ 900 Process the given function, lambda, if expression or list comprehension 901 node 'n', generating any initialisation statements. 902 """ 903 904 # Where a function is declared conditionally, use a separate name for 905 # the definition, and assign the definition to the stated name. 906 907 original_name = n.name 908 909 if self.in_conditional or self.in_function: 910 name = self.get_lambda_name() 911 else: 912 name = n.name 913 914 objpath = self.get_object_path(name) 915 916 # Obtain details of the defaults. 917 918 defaults = self.process_function_defaults(n, name, objpath) 919 if defaults: 920 for default in defaults: 921 self.writeline("%s;" % default) 922 923 # Where a function is set conditionally or where the name may refer to 924 # different values, assign the name. 925 926 ref = self.importer.identify(objpath) 927 928 if self.in_conditional or self.in_function: 929 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 930 elif not ref.static(): 931 context = self.is_method(objpath) 932 933 self.process_assignment_for_object(original_name, 934 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 935 936 def process_function_defaults(self, n, name, objpath, instance_name=None): 937 938 """ 939 Process the given function or lambda node 'n', initialising defaults 940 that are dynamically set. The given 'name' indicates the name of the 941 function. The given 'objpath' indicates the origin of the function. 942 The given 'instance_name' indicates the name of any separate instance 943 of the function created to hold the defaults. 944 945 Return a list of operations setting defaults on a function instance. 946 """ 947 948 function_name = self.get_object_path(name) 949 function_defaults = self.importer.function_defaults.get(function_name) 950 if not function_defaults: 951 return None 952 953 # Determine whether any unidentified defaults are involved. 954 955 for argname, default in function_defaults: 956 if not default.static(): 957 break 958 else: 959 return None 960 961 # Handle bound methods. 962 963 if not instance_name: 964 instance_name = "&%s" % encode_path(objpath) 965 else: 966 instance_name = "__VALUE(%s)" % instance_name 967 968 # Where defaults are involved but cannot be identified, obtain a new 969 # instance of the lambda and populate the defaults. 970 971 defaults = [] 972 973 # Join the original defaults with the inspected defaults. 974 975 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 976 977 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 978 979 # Obtain any reference for the default. 980 981 if original: 982 argname, default = original 983 name_ref = self.process_structure_node(default) 984 elif inspected: 985 argname, default = inspected 986 name_ref = TrResolvedNameRef(argname, default) 987 else: 988 continue 989 990 # Generate default initialisers except when constants are employed. 991 # Constants should be used when populating the function structures. 992 993 if name_ref and not isinstance(name_ref, TrConstantValueRef): 994 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 995 996 return defaults 997 998 def process_if_node(self, n): 999 1000 """ 1001 Process the given "if" node 'n'. 1002 """ 1003 1004 first = True 1005 for test, body in n.tests: 1006 test_ref = self.process_structure_node(test) 1007 self.start_if(first, test_ref) 1008 1009 in_conditional = self.in_conditional 1010 self.in_conditional = True 1011 self.process_structure_node(body) 1012 self.in_conditional = in_conditional 1013 1014 self.end_if() 1015 first = False 1016 1017 if n.else_: 1018 self.start_else() 1019 self.process_structure_node(n.else_) 1020 self.end_else() 1021 1022 print >>self.out 1023 1024 def process_invocation_node(self, n): 1025 1026 "Process the given invocation node 'n'." 1027 1028 # Any invocations in the expression will store target details in a 1029 # different location. 1030 1031 self.next_target() 1032 1033 in_argument_list = self.in_argument_list 1034 self.in_argument_list = False 1035 1036 # Process the expression. 1037 1038 expr = self.process_structure_node(n.node) 1039 1040 # Reference the current target again. 1041 1042 self.in_argument_list = in_argument_list 1043 self.function_target -= 1 1044 1045 # Obtain details of the invocation expression. 1046 1047 objpath = expr.get_origin() 1048 location = expr.access_location() 1049 refs = expr.references() 1050 1051 # Identified target details. 1052 1053 target = None 1054 target_structure = None 1055 1056 # Specific function target information. 1057 1058 function = None 1059 1060 # Instantiation involvement. 1061 1062 instantiation = False 1063 literal_instantiation = False 1064 1065 # Invocation requirements. 1066 1067 context_required = True 1068 have_access_context = isinstance(expr, AttrResult) 1069 context_identity = have_access_context and expr.context() 1070 context_verified = have_access_context and expr.context_verified() 1071 parameters = None 1072 num_parameters = None 1073 num_defaults = None 1074 1075 # Obtain details of the callable and of its parameters. 1076 1077 # Literals may be instantiated specially. 1078 1079 if expr.is_name() and expr.name.startswith("$L") and objpath: 1080 instantiation = literal_instantiation = objpath 1081 target = encode_literal_instantiator(objpath) 1082 context_required = False 1083 1084 # Identified targets employ function pointers directly. 1085 1086 elif objpath: 1087 parameters = self.importer.function_parameters.get(objpath) 1088 function_defaults = self.importer.function_defaults.get(objpath) 1089 num_parameters = parameters and len(parameters) or 0 1090 num_defaults = function_defaults and len(function_defaults) or 0 1091 1092 # Class invocation involves instantiators. 1093 1094 if expr.has_kind("<class>"): 1095 instantiation = objpath 1096 target = encode_instantiator_pointer(objpath) 1097 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1098 target_structure = "&%s" % encode_path(init_ref) 1099 context_required = False 1100 1101 # Only plain functions and bound methods employ function pointers. 1102 1103 elif expr.has_kind("<function>"): 1104 function = objpath 1105 1106 # Test for functions and methods. 1107 1108 context_required = self.is_method(objpath) 1109 1110 accessor_kinds = location and self.get_accessor_kinds(location) 1111 1112 instance_accessor = accessor_kinds and \ 1113 len(accessor_kinds) == 1 and \ 1114 first(accessor_kinds) == "<instance>" 1115 1116 # Only identify certain bound methods or functions. 1117 1118 if not context_required or instance_accessor: 1119 target = encode_function_pointer(objpath) 1120 1121 # Access bound method defaults even if it is not clear whether 1122 # the accessor is appropriate. 1123 1124 target_structure = "&%s" % encode_path(objpath) 1125 1126 # Other targets are retrieved at run-time. 1127 1128 else: 1129 if location: 1130 path, name, attrnames, access_number = location 1131 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1132 1133 # Determine any common aspects of any attribute. 1134 1135 if attrname: 1136 all_params = set() 1137 all_defaults = set() 1138 min_params = set() 1139 max_params = set() 1140 refs = set() 1141 1142 # Obtain parameters and defaults for each possible target. 1143 1144 for ref in self.get_attributes_for_attrname(attrname): 1145 origin = ref.get_origin() 1146 params = self.importer.function_parameters.get(origin) 1147 1148 defaults = self.importer.function_defaults.get(origin) 1149 if defaults is not None: 1150 all_defaults.add(tuple(defaults)) 1151 1152 if params is not None: 1153 all_params.add(tuple(params)) 1154 min_params.add(len(params) - (defaults and len(defaults) or 0)) 1155 max_params.add(len(params)) 1156 refs.add(ref) 1157 else: 1158 refs = set() 1159 break 1160 1161 # Where the parameters and defaults are always the same, 1162 # permit populating them in advance. 1163 1164 if refs: 1165 if self.uses_keyword_arguments(n): 1166 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1167 parameters = first(all_params) 1168 function_defaults = all_defaults and first(all_defaults) or [] 1169 num_parameters = parameters and len(parameters) or 0 1170 num_defaults = function_defaults and len(function_defaults) or 0 1171 else: 1172 if len(min_params) == 1 and len(max_params) == 1: 1173 num_parameters = first(max_params) 1174 num_defaults = first(max_params) - first(min_params) 1175 1176 # Some information about the target may be available and be used to 1177 # provide warnings about argument compatibility. 1178 1179 if self.importer.give_warning("args"): 1180 unsuitable = self.get_referenced_attribute_invocations(location) 1181 1182 if unsuitable: 1183 for ref in unsuitable: 1184 _objpath = ref.get_origin() 1185 print >>sys.stderr, \ 1186 "In %s, at line %d, inappropriate number of " \ 1187 "arguments given. Need %d arguments to call %s." % ( 1188 self.get_namespace_path(), n.lineno, 1189 len(self.importer.function_parameters[_objpath]), 1190 _objpath) 1191 1192 # Determine any readily-accessible target identity. 1193 1194 target_named = expr.is_name() and str(expr) or None 1195 target_stored = "__tmp_targets[%d]" % self.function_target 1196 1197 target_identity = target or target_named 1198 target_var = target_identity or target_stored 1199 context_var = target_named or target_stored 1200 1201 if not target_identity: 1202 self.record_temp("__tmp_targets") 1203 1204 if context_identity: 1205 if context_identity.startswith("__tmp_contexts"): 1206 self.record_temp("__tmp_contexts") 1207 1208 # Arguments are presented in a temporary frame array with any context 1209 # always being the first argument. Where it would be unused, it may be 1210 # set to null. 1211 1212 known_parameters = num_parameters is not None 1213 1214 if context_required: 1215 if have_access_context: 1216 args = [context_identity] 1217 else: 1218 args = ["__CONTEXT_AS_VALUE(%s)" % context_var] 1219 else: 1220 args = ["__NULL"] 1221 1222 # Complete the array with null values, permitting tests for a complete 1223 # set of arguments. 1224 1225 args += [None] * (num_parameters is None and len(n.args) or num_parameters is not None and num_parameters or 0) 1226 kwcodes = [] 1227 kwargs = [] 1228 1229 # Any invocations in the arguments will store target details in a 1230 # different location. 1231 1232 function_target = self.function_target 1233 1234 if not target_identity: 1235 self.next_target() 1236 1237 in_argument_list = self.in_argument_list 1238 self.in_argument_list = True 1239 1240 for i, arg in enumerate(n.args): 1241 argexpr = self.process_structure_node(arg) 1242 1243 # Store a keyword argument, either in the argument list or 1244 # in a separate keyword argument list for subsequent lookup. 1245 1246 if isinstance(arg, compiler.ast.Keyword): 1247 1248 # With knowledge of the target, store the keyword 1249 # argument directly. 1250 1251 if parameters: 1252 try: 1253 argnum = parameters.index(arg.name) 1254 except ValueError: 1255 raise TranslateError("Argument %s is not recognised." % arg.name, 1256 self.get_namespace_path(), n) 1257 args[argnum+1] = str(argexpr) 1258 1259 # Otherwise, store the details in a separate collection. 1260 1261 else: 1262 kwargs.append(str(argexpr)) 1263 kwcodes.append("{%s, %s}" % ( 1264 encode_ppos(arg.name), encode_pcode(arg.name))) 1265 1266 # Store non-keyword arguments in the argument list, rejecting 1267 # superfluous arguments. 1268 1269 else: 1270 try: 1271 args[i+1] = str(argexpr) 1272 except IndexError: 1273 raise TranslateError("Too many arguments specified.", 1274 self.get_namespace_path(), n) 1275 1276 # Reference the current target again. 1277 1278 self.in_argument_list = in_argument_list 1279 1280 if not self.in_argument_list: 1281 self.function_target = function_target 1282 1283 # Defaults are added to the frame where arguments are missing. 1284 1285 if parameters and function_defaults: 1286 1287 # Visit each default and set any missing arguments. Where keyword 1288 # arguments have been used, the defaults must be inspected and, if 1289 # necessary, inserted into gaps in the argument list. 1290 1291 for i, (argname, default) in enumerate(function_defaults): 1292 argnum = parameters.index(argname) 1293 if not args[argnum+1]: 1294 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1295 1296 elif known_parameters: 1297 1298 # No specific parameter details are provided, but no keyword 1299 # arguments are used. Thus, defaults can be supplied using position 1300 # information only. 1301 1302 i = len(n.args) 1303 pos = i - (num_parameters - num_defaults) 1304 while i < num_parameters: 1305 args[i+1] = "__GETDEFAULT(%s.value, %d)" % (target_var, pos) 1306 i += 1 1307 pos += 1 1308 1309 # Test for missing arguments. 1310 1311 if None in args: 1312 raise TranslateError("Not all arguments supplied.", 1313 self.get_namespace_path(), n) 1314 1315 # Encode the arguments. 1316 1317 # Where literal instantiation is occurring, add an argument indicating 1318 # the number of values. The context is excluded. 1319 1320 if literal_instantiation: 1321 argstr = "__ARGS(%s), %d" % (", ".join(args[1:]), len(args) - 1) 1322 else: 1323 argstr = ", ".join(args) 1324 1325 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1326 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1327 1328 # First, the invocation expression is presented. 1329 1330 stages = [] 1331 1332 # Without a known specific callable, the expression provides the target. 1333 1334 if not target or context_required: 1335 1336 # The context is set in the expression. 1337 1338 if target and not target_named: 1339 1340 # Test whether the expression provides anything. 1341 1342 if expr: 1343 stages.append(str(expr)) 1344 1345 elif not target_identity: 1346 stages.append("%s = %s" % (target_var, expr)) 1347 1348 # Any specific callable is then obtained for invocation. 1349 1350 if target: 1351 stages.append(target) 1352 1353 # Methods accessed via unidentified accessors are obtained for 1354 # invocation. 1355 1356 elif function: 1357 if context_required: 1358 if have_access_context: 1359 if context_verified: 1360 stages.append("__get_function_member(%s)" % target_var) 1361 else: 1362 stages.append("__get_function(%s, %s)" % ( 1363 context_identity, target_var)) 1364 else: 1365 stages.append("__get_function(__CONTEXT_AS_VALUE(%s), %s)" % ( 1366 context_var, target_var)) 1367 else: 1368 stages.append("_get_function_member(%s)" % target_var) 1369 1370 # With known parameters, the target can be tested. 1371 1372 elif known_parameters: 1373 context_arg = context_required and args[0] or "__NULL" 1374 if self.always_callable(refs): 1375 if context_verified: 1376 stages.append("__get_function_member(%s)" % target_var) 1377 else: 1378 stages.append("__get_function(%s, %s)" % (context_arg, target_var)) 1379 else: 1380 stages.append("__check_and_get_function(%s, %s)" % (context_arg, target_var)) 1381 1382 # With a known target, the function is obtained directly and called. 1383 # By putting the invocation at the end of the final element in the 1384 # instruction sequence (the stages), the result becomes the result of 1385 # the sequence. Moreover, the parameters become part of the sequence 1386 # and thereby participate in a guaranteed evaluation order. 1387 1388 if target or function or known_parameters: 1389 stages[-1] += "(%s)" % argstr 1390 if instantiation: 1391 return InstantiationResult(instantiation, stages) 1392 else: 1393 return InvocationResult(stages) 1394 1395 # With unknown targets, the generic invocation function is applied to 1396 # the callable and argument collections. 1397 1398 else: 1399 stages.append("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1400 target_var, 1401 self.always_callable(refs) and 1 or 0, 1402 len(kwargs), kwcodestr, kwargstr, 1403 len(args), "__ARGS(%s)" % argstr)) 1404 return InvocationResult(stages) 1405 1406 def next_target(self): 1407 1408 "Allocate the next function target storage." 1409 1410 self.function_target += 1 1411 self.max_function_targets = max(self.function_target, self.max_function_targets) 1412 1413 def always_callable(self, refs): 1414 1415 "Determine whether all 'refs' are callable." 1416 1417 if not refs: 1418 return False 1419 1420 for ref in refs: 1421 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1422 return False 1423 1424 return True 1425 1426 def need_default_arguments(self, objpath, nargs): 1427 1428 """ 1429 Return whether any default arguments are needed when invoking the object 1430 given by 'objpath'. 1431 """ 1432 1433 parameters = self.importer.function_parameters.get(objpath) 1434 return nargs < len(parameters) 1435 1436 def uses_keyword_arguments(self, n): 1437 1438 "Return whether invocation node 'n' uses keyword arguments." 1439 1440 for arg in enumerate(n.args): 1441 if isinstance(arg, compiler.ast.Keyword): 1442 return True 1443 1444 return False 1445 1446 def get_attributes_for_attrname(self, attrname): 1447 1448 "Return a set of all attributes exposed by 'attrname'." 1449 1450 usage = [(attrname, True, False)] 1451 class_types = self.deducer.get_class_types_for_usage(usage) 1452 instance_types = self.deducer.get_instance_types_for_usage(usage) 1453 module_types = self.deducer.get_module_types_for_usage(usage) 1454 attrs = set() 1455 1456 for ref in combine_types(class_types, instance_types, module_types): 1457 attrs.update(self.importer.get_attributes(ref, attrname)) 1458 1459 return attrs 1460 1461 def process_lambda_node(self, n): 1462 1463 "Process the given lambda node 'n'." 1464 1465 name = self.get_lambda_name() 1466 function_name = self.get_object_path(name) 1467 1468 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1469 1470 # Without defaults, produce an attribute referring to the function. 1471 1472 if not defaults: 1473 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1474 1475 # With defaults, copy the function structure and set the defaults on the 1476 # copy. 1477 1478 else: 1479 self.record_temp("__tmp_value") 1480 return make_expression("(__tmp_value = __ATTRVALUE(__COPY(&%s, sizeof(%s))), %s, __tmp_value)" % ( 1481 encode_path(function_name), 1482 encode_symbol("obj", function_name), 1483 ", ".join(defaults))) 1484 1485 def process_logical_node(self, n): 1486 1487 "Process the given operator node 'n'." 1488 1489 self.record_temp("__tmp_result") 1490 1491 conjunction = isinstance(n, compiler.ast.And) 1492 results = [] 1493 1494 for node in n.nodes: 1495 results.append(self.process_structure_node(node)) 1496 1497 return LogicalOperationResult(results, conjunction) 1498 1499 def process_name_node(self, n, expr=None): 1500 1501 "Process the given name node 'n' with the optional assignment 'expr'." 1502 1503 # Determine whether the name refers to a static external entity. 1504 1505 if n.name in predefined_constants: 1506 return PredefinedConstantRef(n.name, expr) 1507 1508 # Convert literal references, operator function names, and print 1509 # function names to references. 1510 1511 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1512 n.name.startswith("$print"): 1513 1514 ref, paths = self.importer.get_module(self.name).special[n.name] 1515 return TrResolvedNameRef(n.name, ref) 1516 1517 # Get the appropriate name for the name reference, using the same method 1518 # as in the inspector. 1519 1520 path = self.get_namespace_path() 1521 objpath = self.get_object_path(n.name) 1522 1523 # Determine any assigned globals. 1524 1525 globals = self.importer.get_module(self.name).scope_globals.get(path) 1526 1527 # Explicitly declared globals. 1528 1529 if globals and n.name in globals: 1530 objpath = self.get_global_path(n.name) 1531 is_global = True 1532 1533 # Implicitly referenced globals in functions. 1534 1535 elif self.in_function: 1536 is_global = n.name not in self.importer.function_locals[path] 1537 1538 # Implicitly referenced globals elsewhere. 1539 1540 else: 1541 namespace = self.importer.identify(path) 1542 is_global = not self.importer.get_attributes(namespace, n.name) 1543 1544 # Get the static identity of the name. 1545 1546 ref = self.importer.identify(objpath) 1547 if ref and not ref.get_name(): 1548 ref = ref.alias(objpath) 1549 1550 # Obtain any resolved names for non-assignment names. 1551 1552 if not expr and not ref and self.in_function: 1553 locals = self.importer.function_locals.get(path) 1554 ref = locals and locals.get(n.name) 1555 1556 # Determine whether the name refers to a parameter. The generation of 1557 # parameter references is different from other names. 1558 1559 parameters = self.importer.function_parameters.get(path) 1560 parameter = n.name == "self" and self.in_method() or \ 1561 parameters and n.name in parameters 1562 1563 # Find any invocation or alias details. 1564 1565 name = self.get_name_for_tracking(n.name, is_global=is_global) 1566 location = not expr and self.get_access_location(name) or None 1567 1568 # Mark any local assignments as volatile in exception blocks. 1569 1570 if expr and self.in_function and not is_global and self.in_try_except: 1571 self.make_volatile(n.name) 1572 1573 # Qualified names are used for resolved static references or for 1574 # static namespace members. The reference should be configured to return 1575 # such names. 1576 1577 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1578 location=location) 1579 return not expr and self.get_aliases(name_ref) or name_ref 1580 1581 def get_aliases(self, name_ref): 1582 1583 "Return alias references for the given 'name_ref'." 1584 1585 location = name_ref.access_location() 1586 1587 refs = self.deducer.referenced_objects.get(location) 1588 refs = refs or self.deducer.accessor_all_types.get(location) 1589 return AliasResult(name_ref, refs or set(), location) 1590 1591 def make_volatile(self, name): 1592 1593 "Record 'name' as volatile in the current namespace." 1594 1595 self.volatile_locals.add(name) 1596 1597 def process_not_node(self, n): 1598 1599 "Process the given operator node 'n'." 1600 1601 return self.make_negation(self.process_structure_node(n.expr)) 1602 1603 def process_raise_node(self, n): 1604 1605 "Process the given raise node 'n'." 1606 1607 # NOTE: Determine which raise statement variants should be permitted. 1608 1609 if n.expr1: 1610 1611 # Names with accompanying arguments are treated like invocations. 1612 1613 if n.expr2: 1614 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1615 exc = self.process_structure_node(call) 1616 self.writestmt("__Raise(%s);" % exc) 1617 1618 # Raise instances, testing the kind at run-time if necessary and 1619 # instantiating any non-instance. 1620 1621 else: 1622 exc = self.process_structure_node(n.expr1) 1623 1624 if isinstance(exc, TrInstanceRef): 1625 self.writestmt("__Raise(%s);" % exc) 1626 else: 1627 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1628 else: 1629 self.writestmt("__Throw(__tmp_exc);") 1630 1631 def process_return_node(self, n): 1632 1633 "Process the given return node 'n'." 1634 1635 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1636 if self.in_try_finally or self.in_try_except: 1637 self.writestmt("__Return(%s);" % expr) 1638 else: 1639 self.writestmt("return %s;" % expr) 1640 1641 return ReturnRef() 1642 1643 def process_try_node(self, n): 1644 1645 """ 1646 Process the given "try...except" node 'n'. 1647 """ 1648 1649 in_try_except = self.in_try_except 1650 self.in_try_except = True 1651 1652 # Use macros to implement exception handling. 1653 1654 self.writestmt("__Try") 1655 self.writeline("{") 1656 self.indent += 1 1657 self.process_structure_node(n.body) 1658 1659 # Put the else statement in another try block that handles any raised 1660 # exceptions and converts them to exceptions that will not be handled by 1661 # the main handling block. 1662 1663 if n.else_: 1664 self.writestmt("__Try") 1665 self.writeline("{") 1666 self.indent += 1 1667 self.process_structure_node(n.else_) 1668 self.indent -= 1 1669 self.writeline("}") 1670 self.writeline("__Catch (__tmp_exc)") 1671 self.writeline("{") 1672 self.indent += 1 1673 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1674 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1675 self.indent -= 1 1676 self.writeline("}") 1677 1678 # Complete the try block and enter the finally block, if appropriate. 1679 1680 if self.in_try_finally: 1681 self.writestmt("__Complete;") 1682 1683 self.indent -= 1 1684 self.writeline("}") 1685 1686 self.in_try_except = in_try_except 1687 1688 # Handlers are tests within a common handler block. 1689 1690 self.writeline("__Catch (__tmp_exc)") 1691 self.writeline("{") 1692 self.indent += 1 1693 1694 # Introduce an if statement to handle the completion of a try block. 1695 1696 self.process_try_completion() 1697 1698 # Handle exceptions in else blocks converted to __RaiseElse, converting 1699 # them back to normal exceptions. 1700 1701 if n.else_: 1702 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1703 1704 # Exception handling. 1705 1706 for name, var, handler in n.handlers: 1707 1708 # Test for specific exceptions. 1709 1710 if name is not None: 1711 name_ref = self.process_structure_node(name) 1712 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1713 else: 1714 self.writeline("else if (1)") 1715 1716 self.writeline("{") 1717 self.indent += 1 1718 1719 # Establish the local for the handler. 1720 1721 if var is not None: 1722 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1723 1724 if handler is not None: 1725 self.process_structure_node(handler) 1726 1727 self.indent -= 1 1728 self.writeline("}") 1729 1730 # Re-raise unhandled exceptions. 1731 1732 self.writeline("else __Throw(__tmp_exc);") 1733 1734 # End the handler block. 1735 1736 self.indent -= 1 1737 self.writeline("}") 1738 print >>self.out 1739 1740 def process_try_finally_node(self, n): 1741 1742 """ 1743 Process the given "try...finally" node 'n'. 1744 """ 1745 1746 in_try_finally = self.in_try_finally 1747 self.in_try_finally = True 1748 1749 # Use macros to implement exception handling. 1750 1751 self.writestmt("__Try") 1752 self.writeline("{") 1753 self.indent += 1 1754 self.process_structure_node(n.body) 1755 self.indent -= 1 1756 self.writeline("}") 1757 1758 self.in_try_finally = in_try_finally 1759 1760 # Finally clauses handle special exceptions. 1761 1762 self.writeline("__Catch (__tmp_exc)") 1763 self.writeline("{") 1764 self.indent += 1 1765 self.process_structure_node(n.final) 1766 1767 # Introduce an if statement to handle the completion of a try block. 1768 1769 self.process_try_completion() 1770 self.writeline("else __Throw(__tmp_exc);") 1771 1772 self.indent -= 1 1773 self.writeline("}") 1774 print >>self.out 1775 1776 def process_try_completion(self): 1777 1778 "Generate a test for the completion of a try block." 1779 1780 self.writestmt("if (__tmp_exc.completing)") 1781 self.writeline("{") 1782 self.indent += 1 1783 1784 # Do not return anything at the module level. 1785 1786 if self.get_namespace_path() != self.name: 1787 1788 # Only use the normal return statement if no surrounding try blocks 1789 # apply. 1790 1791 if not self.in_try_finally and not self.in_try_except: 1792 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1793 else: 1794 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1795 1796 self.indent -= 1 1797 self.writeline("}") 1798 1799 def process_while_node(self, n): 1800 1801 "Process the given while node 'n'." 1802 1803 self.writeline("while (1)") 1804 self.writeline("{") 1805 self.indent += 1 1806 test = self.process_structure_node(n.test) 1807 1808 # Emit the loop termination condition unless "while <true value>" is 1809 # indicated. 1810 1811 if not (isinstance(test, PredefinedConstantRef) and test.value): 1812 1813 # Emit a negated test of the continuation condition. 1814 1815 self.start_if(True, self.make_negation(test)) 1816 if n.else_: 1817 self.process_structure_node(n.else_) 1818 self.writestmt("break;") 1819 self.end_if() 1820 1821 in_conditional = self.in_conditional 1822 self.in_conditional = True 1823 self.process_structure_node(n.body) 1824 self.in_conditional = in_conditional 1825 1826 self.indent -= 1 1827 self.writeline("}") 1828 print >>self.out 1829 1830 # Special variable usage. 1831 1832 def get_temp_path(self): 1833 1834 """ 1835 Return the appropriate namespace path for temporary names in the current 1836 namespace. 1837 """ 1838 1839 if self.in_function: 1840 return self.get_namespace_path() 1841 else: 1842 return self.name 1843 1844 def record_temp(self, name): 1845 1846 """ 1847 Record the use of the temporary 'name' in the current namespace. At the 1848 class or module level, the temporary name is associated with the module, 1849 since the variable will then be allocated in the module's own main 1850 program. 1851 """ 1852 1853 path = self.get_temp_path() 1854 1855 init_item(self.temp_usage, path, list) 1856 self.temp_usage[path].append(name) 1857 1858 def remove_temps(self, names): 1859 1860 """ 1861 Remove 'names' from temporary storage allocations, each instance 1862 removing each request for storage. 1863 """ 1864 1865 path = self.get_temp_path() 1866 1867 for name in names: 1868 if self.uses_temp(path, name): 1869 self.temp_usage[path].remove(name) 1870 1871 def uses_temp(self, path, name): 1872 1873 """ 1874 Return whether the given namespace 'path' employs a temporary variable 1875 with the given 'name'. Note that 'path' should only be a module or a 1876 function or method, not a class. 1877 """ 1878 1879 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1880 1881 def make_negation(self, expr): 1882 1883 "Return a negated form of 'expr'." 1884 1885 result = NegationResult(expr) 1886 1887 # Negation discards the temporary results of its operand. 1888 1889 temps = expr.discards_temporary() 1890 if temps: 1891 self.remove_temps(temps) 1892 1893 return result 1894 1895 # Output generation. 1896 1897 def start_output(self): 1898 1899 "Write the declarations at the top of each source file." 1900 1901 print >>self.out, """\ 1902 #include "types.h" 1903 #include "exceptions.h" 1904 #include "ops.h" 1905 #include "progconsts.h" 1906 #include "progops.h" 1907 #include "progtypes.h" 1908 #include "main.h" 1909 """ 1910 1911 def start_unit(self): 1912 1913 "Record output within a generated function for later use." 1914 1915 self.out = StringIO() 1916 1917 def end_unit(self): 1918 1919 "Restore the output stream." 1920 1921 out = self.out 1922 self.out = self.out_toplevel 1923 return out 1924 1925 def flush_unit(self, name, out): 1926 1927 "Add declarations and generated code." 1928 1929 self.write_temporaries(name) 1930 print >>self.out 1931 out.seek(0) 1932 self.out.write(out.read()) 1933 1934 def start_module(self): 1935 1936 "Write the start of each module's main function." 1937 1938 print >>self.out, "void __main_%s()" % encode_path(self.name) 1939 print >>self.out, "{" 1940 self.indent += 1 1941 1942 # Define temporary variables, excluded from the module structure itself. 1943 1944 tempnames = [] 1945 1946 for n in self.importer.all_module_attrs[self.name]: 1947 if n.startswith("$t"): 1948 tempnames.append(encode_path(n)) 1949 1950 if tempnames: 1951 tempnames.sort() 1952 self.writeline("__attr %s;" % ", ".join(tempnames)) 1953 1954 self.start_unit() 1955 1956 def end_module(self): 1957 1958 "End each module by closing its main function." 1959 1960 out = self.end_unit() 1961 self.flush_unit(self.name, out) 1962 1963 self.indent -= 1 1964 print >>self.out, "}" 1965 1966 def start_function(self, name): 1967 1968 "Start the function having the given 'name'." 1969 1970 self.indent += 1 1971 1972 self.start_unit() 1973 1974 def end_function(self, name): 1975 1976 "End the function having the given 'name'." 1977 1978 out = self.end_unit() 1979 1980 # Write the signature at the top indentation level. 1981 1982 self.indent -= 1 1983 self.write_parameters(name) 1984 print >>self.out, "{" 1985 1986 # Obtain local names from parameters. 1987 1988 parameters = self.importer.function_parameters[name] 1989 locals = self.importer.function_locals[name].keys() 1990 names = [] 1991 volatile_names = [] 1992 1993 for n in locals: 1994 1995 # Filter out special names and parameters. Note that self is a local 1996 # regardless of whether it originally appeared in the parameters or 1997 # not. 1998 1999 if n.startswith("$l") or n in parameters or n == "self": 2000 continue 2001 if n in self.volatile_locals: 2002 volatile_names.append(encode_path(n)) 2003 else: 2004 names.append(encode_path(n)) 2005 2006 # Emit required local names at the function indentation level. 2007 2008 self.indent += 1 2009 2010 if names: 2011 names.sort() 2012 self.writeline("__attr %s;" % ", ".join(names)) 2013 2014 if volatile_names: 2015 volatile_names.sort() 2016 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 2017 2018 self.flush_unit(name, out) 2019 2020 self.indent -= 1 2021 print >>self.out, "}" 2022 print >>self.out 2023 2024 def write_parameters(self, name): 2025 2026 """ 2027 For the function having the given 'name', write definitions of 2028 parameters found in the arguments array. 2029 """ 2030 2031 # Generate any self reference. 2032 2033 l = [] 2034 2035 if self.is_method(name): 2036 l.append("__attr self") 2037 else: 2038 l.append("__attr __self") 2039 2040 # Generate aliases for the parameters. 2041 2042 for parameter in self.importer.function_parameters[name]: 2043 l.append("%s__attr %s" % ( 2044 parameter in self.volatile_locals and "volatile " or "", 2045 encode_path(parameter))) 2046 2047 self.writeline("__attr %s(%s)" % ( 2048 encode_function_pointer(name), ", ".join(l))) 2049 2050 def write_temporaries(self, name): 2051 2052 "Write temporary storage employed by 'name'." 2053 2054 # Provide space for the given number of targets. 2055 2056 targets = self.max_function_targets 2057 2058 if self.uses_temp(name, "__tmp_targets"): 2059 self.writeline("__attr __tmp_targets[%d];" % targets) 2060 if self.uses_temp(name, "__tmp_contexts"): 2061 self.writeline("__attr __tmp_contexts[%d];" % targets) 2062 2063 # Add temporary variable usage details. 2064 2065 if self.uses_temp(name, "__tmp_private_context"): 2066 self.writeline("__attr __tmp_private_context;") 2067 if self.uses_temp(name, "__tmp_value"): 2068 self.writeline("__attr __tmp_value;") 2069 if self.uses_temp(name, "__tmp_target_value"): 2070 self.writeline("__attr __tmp_target_value;") 2071 if self.uses_temp(name, "__tmp_result"): 2072 self.writeline("__attr __tmp_result;") 2073 2074 module = self.importer.get_module(self.name) 2075 2076 if name in module.exception_namespaces: 2077 self.writeline("__exc __tmp_exc;") 2078 2079 def start_if(self, first, test_ref): 2080 statement = "%sif" % (not first and "else " or "") 2081 2082 # Consume logical results directly. 2083 2084 if isinstance(test_ref, LogicalResult): 2085 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2086 temps = test_ref.discards_temporary() 2087 if temps: 2088 self.remove_temps(temps) 2089 else: 2090 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2091 2092 self.writeline("{") 2093 self.indent += 1 2094 2095 def end_if(self): 2096 self.indent -= 1 2097 self.writeline("}") 2098 2099 def start_else(self): 2100 self.writeline("else") 2101 self.writeline("{") 2102 self.indent += 1 2103 2104 def end_else(self): 2105 self.indent -= 1 2106 self.writeline("}") 2107 2108 def statement(self, expr): 2109 s = str(expr) 2110 if s: 2111 self.writestmt("%s;" % s) 2112 2113 def statements(self, results): 2114 for result in results: 2115 self.statement(result) 2116 2117 def writeline(self, s): 2118 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2119 2120 def writestmt(self, s): 2121 self.writeline(s) 2122 2123 def write_comment(self, s): 2124 self.writestmt("/* %s */" % s) 2125 2126 def pad(self, extra=0): 2127 return (self.indent + extra) * self.tabstop 2128 2129 def indenttext(self, s, levels): 2130 lines = s.split("\n") 2131 out = [lines[0]] 2132 for line in lines[1:]: 2133 out.append(levels * self.tabstop + line) 2134 if line.endswith("("): 2135 levels += 1 2136 elif line.startswith(")"): 2137 levels -= 1 2138 return "\n".join(out) 2139 2140 # vim: tabstop=4 expandtab shiftwidth=4