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