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