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 33 from results import Result 34 from transresults import TrConstantValueRef, TrInstanceRef, \ 35 TrLiteralSequenceRef, TrResolvedNameRef, \ 36 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 560 561 # Obtain encoded versions of each instruction, accumulating temporary 562 # variables. 563 564 for instruction in self.deducer.access_instructions[location]: 565 566 # Intercept a special instruction identifying the context. 567 568 if instruction[0] == "<context_identity>": 569 context_identity, _substituted = encode_access_instruction_arg(instruction[1], subs, instruction[0], context_index) 570 continue 571 572 # Collect the encoded instruction, noting any temporary variables 573 # required by it. 574 575 encoded, _substituted = encode_access_instruction(instruction, subs, context_index) 576 output.append(encoded) 577 substituted.update(_substituted) 578 579 # Record temporary name usage. 580 581 for sub in substituted: 582 if self.temp_subs.has_key(sub): 583 self.record_temp(self.temp_subs[sub]) 584 585 del self.attrs[0] 586 return AttrResult(output, refs, location, context_identity) 587 588 def init_substitutions(self): 589 590 """ 591 Initialise substitutions, defining temporary variable mappings, some of 592 which are also used as substitutions, together with operation mappings 593 used as substitutions in instructions defined by the optimiser. 594 """ 595 596 self.temp_subs = { 597 598 # Substitutions used by instructions. 599 600 "<private_context>" : "__tmp_private_context", 601 "<accessor>" : "__tmp_value", 602 "<target_accessor>" : "__tmp_target_value", 603 604 # Mappings to be replaced by those given below. 605 606 "<context>" : "__tmp_contexts", 607 "<test_context_revert>" : "__tmp_contexts", 608 "<test_context_static>" : "__tmp_contexts", 609 "<set_context>" : "__tmp_contexts", 610 "<set_private_context>" : "__tmp_private_context", 611 "<set_accessor>" : "__tmp_value", 612 "<set_target_accessor>" : "__tmp_target_value", 613 } 614 615 self.op_subs = { 616 "<context>" : "__get_context", 617 "<test_context_revert>" : "__test_context_revert", 618 "<test_context_static>" : "__test_context_static", 619 "<set_context>" : "__set_context", 620 "<set_private_context>" : "__set_private_context", 621 "<set_accessor>" : "__set_accessor", 622 "<set_target_accessor>" : "__set_target_accessor", 623 } 624 625 def get_referenced_attributes(self, location): 626 627 """ 628 Convert 'location' to the form used by the deducer and retrieve any 629 identified attributes. 630 """ 631 632 access_location = self.deducer.const_accesses.get(location) 633 refs = [] 634 for attrtype, objpath, attr in self.deducer.referenced_attrs[access_location or location]: 635 refs.append(attr) 636 return refs 637 638 def get_referenced_attribute_invocations(self, location): 639 640 """ 641 Convert 'location' to the form used by the deducer and retrieve any 642 identified attribute invocation details. 643 """ 644 645 access_location = self.deducer.const_accesses.get(location) 646 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 647 648 def get_accessor_kinds(self, location): 649 650 "Return the accessor kinds for 'location'." 651 652 return self.deducer.accessor_kinds.get(location) 653 654 def get_access_location(self, name, attrnames=None): 655 656 """ 657 Using the current namespace, the given 'name', and the 'attrnames' 658 employed in an access, return the access location. 659 """ 660 661 path = self.get_path_for_access() 662 663 # Get the location used by the deducer and optimiser and find any 664 # recorded access. 665 666 attrnames = attrnames and ".".join(self.attrs) 667 access_number = self.get_access_number(path, name, attrnames) 668 self.update_access_number(path, name, attrnames) 669 return (path, name, attrnames, access_number) 670 671 def get_access_number(self, path, name, attrnames): 672 access = name, attrnames 673 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 674 return self.attr_accesses[path][access] 675 else: 676 return 0 677 678 def update_access_number(self, path, name, attrnames): 679 access = name, attrnames 680 if name: 681 init_item(self.attr_accesses, path, dict) 682 init_item(self.attr_accesses[path], access, lambda: 0) 683 self.attr_accesses[path][access] += 1 684 685 def get_accessor_location(self, name): 686 687 """ 688 Using the current namespace and the given 'name', return the accessor 689 location. 690 """ 691 692 path = self.get_path_for_access() 693 694 # Get the location used by the deducer and optimiser and find any 695 # recorded accessor. 696 697 access_number = self.get_accessor_number(path, name) 698 self.update_accessor_number(path, name) 699 return (path, name, None, access_number) 700 701 def get_accessor_number(self, path, name): 702 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 703 return self.attr_accessors[path][name] 704 else: 705 return 0 706 707 def update_accessor_number(self, path, name): 708 if name: 709 init_item(self.attr_accessors, path, dict) 710 init_item(self.attr_accessors[path], name, lambda: 0) 711 self.attr_accessors[path][name] += 1 712 713 def process_class_node(self, n): 714 715 "Process the given class node 'n'." 716 717 class_name = self.get_object_path(n.name) 718 719 # Where a class is set conditionally or where the name may refer to 720 # different values, assign the name. 721 722 ref = self.importer.identify(class_name) 723 724 if not ref.static(): 725 self.process_assignment_for_object(n.name, 726 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 727 728 self.enter_namespace(n.name) 729 730 if self.have_object(): 731 self.write_comment("Class: %s" % class_name) 732 733 self.initialise_inherited_members(class_name) 734 735 self.process_structure(n) 736 self.write_comment("End class: %s" % class_name) 737 738 self.exit_namespace() 739 740 def initialise_inherited_members(self, class_name): 741 742 "Initialise members of 'class_name' inherited from its ancestors." 743 744 for name, path in self.importer.all_class_attrs[class_name].items(): 745 target = "%s.%s" % (class_name, name) 746 747 # Ignore attributes with definitions. 748 749 ref = self.importer.identify(target) 750 if ref: 751 continue 752 753 # Ignore special type attributes. 754 755 if is_type_attribute(name): 756 continue 757 758 # Reference inherited attributes. 759 760 ref = self.importer.identify(path) 761 if ref and not ref.static(): 762 parent, attrname = path.rsplit(".", 1) 763 764 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 765 encode_path(class_name), name, 766 encode_path(parent), attrname 767 )) 768 769 def process_from_node(self, n): 770 771 "Process the given node 'n', importing from another module." 772 773 path = self.get_namespace_path() 774 775 # Attempt to obtain the referenced objects. 776 777 for name, alias in n.names: 778 if name == "*": 779 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 780 781 # Obtain the path of the assigned name. 782 783 objpath = self.get_object_path(alias or name) 784 785 # Obtain the identity of the name. 786 787 ref = self.importer.identify(objpath) 788 789 # Where the name is not static, assign the value. 790 791 if ref and not ref.static() and ref.get_name(): 792 self.writestmt("%s;" % 793 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 794 expr=TrResolvedNameRef(name, ref))) 795 796 def process_function_body_node(self, n): 797 798 """ 799 Process the given function, lambda, if expression or list comprehension 800 node 'n', generating the body. 801 """ 802 803 function_name = self.get_namespace_path() 804 self.start_function(function_name) 805 806 # Process the function body. 807 808 in_conditional = self.in_conditional 809 self.in_conditional = False 810 self.function_target = 0 811 self.max_function_targets = 0 812 813 # Volatile locals for exception handling. 814 815 self.volatile_locals = set() 816 817 # Process any guards defined for the parameters. 818 819 for name in self.importer.function_parameters.get(function_name): 820 self.generate_guard(name) 821 822 # Produce the body and any additional return statement. 823 824 expr = self.process_structure_node(n.code) or \ 825 self.in_method() and \ 826 function_name.rsplit(".", 1)[-1] == "__init__" and \ 827 TrResolvedNameRef("self", self.importer.function_locals[function_name]["self"]) or \ 828 PredefinedConstantRef("None") 829 830 if not isinstance(expr, ReturnRef): 831 self.writestmt("return %s;" % expr) 832 833 self.in_conditional = in_conditional 834 835 self.end_function(function_name) 836 837 def generate_guard(self, name): 838 839 """ 840 Get the accessor details for 'name', found in the current namespace, and 841 generate any guards defined for it. 842 """ 843 844 # Obtain the location, keeping track of assignment versions. 845 846 location = self.get_accessor_location(name) 847 test = self.deducer.accessor_guard_tests.get(location) 848 849 # Generate any guard from the deduced information. 850 851 if test: 852 guard, guard_type = test 853 854 if guard == "specific": 855 ref = first(self.deducer.accessor_all_types[location]) 856 argstr = "&%s" % encode_path(ref.get_origin()) 857 elif guard == "common": 858 ref = first(self.deducer.accessor_all_general_types[location]) 859 argstr = encode_path(encode_type_attribute(ref.get_origin())) 860 else: 861 return 862 863 # Produce an appropriate access to an attribute's value. 864 865 name_to_value = "%s.value" % name 866 867 # Write a test that raises a TypeError upon failure. 868 869 self.writestmt("if (!__test_%s_%s(%s, %s)) __raise_type_error();" % ( 870 guard, guard_type, name_to_value, argstr)) 871 872 def process_function_node(self, n): 873 874 """ 875 Process the given function, lambda, if expression or list comprehension 876 node 'n', generating any initialisation statements. 877 """ 878 879 # Where a function is declared conditionally, use a separate name for 880 # the definition, and assign the definition to the stated name. 881 882 original_name = n.name 883 884 if self.in_conditional or self.in_function: 885 name = self.get_lambda_name() 886 else: 887 name = n.name 888 889 objpath = self.get_object_path(name) 890 891 # Obtain details of the defaults. 892 893 defaults = self.process_function_defaults(n, name, objpath) 894 if defaults: 895 for default in defaults: 896 self.writeline("%s;" % default) 897 898 # Where a function is set conditionally or where the name may refer to 899 # different values, assign the name. 900 901 ref = self.importer.identify(objpath) 902 903 if self.in_conditional or self.in_function: 904 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 905 elif not ref.static(): 906 context = self.is_method(objpath) 907 908 self.process_assignment_for_object(original_name, 909 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 910 911 def process_function_defaults(self, n, name, objpath, instance_name=None): 912 913 """ 914 Process the given function or lambda node 'n', initialising defaults 915 that are dynamically set. The given 'name' indicates the name of the 916 function. The given 'objpath' indicates the origin of the function. 917 The given 'instance_name' indicates the name of any separate instance 918 of the function created to hold the defaults. 919 920 Return a list of operations setting defaults on a function instance. 921 """ 922 923 function_name = self.get_object_path(name) 924 function_defaults = self.importer.function_defaults.get(function_name) 925 if not function_defaults: 926 return None 927 928 # Determine whether any unidentified defaults are involved. 929 930 for argname, default in function_defaults: 931 if not default.static(): 932 break 933 else: 934 return None 935 936 # Handle bound methods. 937 938 if not instance_name: 939 instance_name = "&%s" % encode_path(objpath) 940 941 # Where defaults are involved but cannot be identified, obtain a new 942 # instance of the lambda and populate the defaults. 943 944 defaults = [] 945 946 # Join the original defaults with the inspected defaults. 947 948 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 949 950 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 951 952 # Obtain any reference for the default. 953 954 if original: 955 argname, default = original 956 name_ref = self.process_structure_node(default) 957 elif inspected: 958 argname, default = inspected 959 name_ref = TrResolvedNameRef(argname, default) 960 else: 961 continue 962 963 # Generate default initialisers except when constants are employed. 964 # Constants should be used when populating the function structures. 965 966 if name_ref and not isinstance(name_ref, TrConstantValueRef): 967 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 968 969 return defaults 970 971 def process_if_node(self, n): 972 973 """ 974 Process the given "if" node 'n'. 975 """ 976 977 first = True 978 for test, body in n.tests: 979 test_ref = self.process_structure_node(test) 980 self.start_if(first, test_ref) 981 982 in_conditional = self.in_conditional 983 self.in_conditional = True 984 self.process_structure_node(body) 985 self.in_conditional = in_conditional 986 987 self.end_if() 988 first = False 989 990 if n.else_: 991 self.start_else() 992 self.process_structure_node(n.else_) 993 self.end_else() 994 995 print >>self.out 996 997 def process_invocation_node(self, n): 998 999 "Process the given invocation node 'n'." 1000 1001 # Any invocations in the expression will store target details in a 1002 # different location. 1003 1004 self.next_target() 1005 1006 in_argument_list = self.in_argument_list 1007 self.in_argument_list = False 1008 1009 # Process the expression. 1010 1011 expr = self.process_structure_node(n.node) 1012 1013 # Reference the current target again. 1014 1015 self.in_argument_list = in_argument_list 1016 self.function_target -= 1 1017 1018 # Obtain details of the invocation expression. 1019 1020 objpath = expr.get_origin() 1021 location = expr.access_location() 1022 1023 # Identified target details. 1024 1025 target = None 1026 target_structure = None 1027 1028 # Specific function target information. 1029 1030 function = None 1031 1032 # Instantiation involvement. 1033 1034 instantiation = False 1035 literal_instantiation = False 1036 1037 # Invocation requirements. 1038 1039 context_required = True 1040 have_access_context = isinstance(expr, AttrResult) 1041 context_identity = have_access_context and expr.context() 1042 parameters = None 1043 1044 # Obtain details of the callable and of its parameters. 1045 1046 # Literals may be instantiated specially. 1047 1048 if expr.is_name() and expr.name.startswith("$L") and objpath: 1049 instantiation = literal_instantiation = objpath 1050 target = encode_literal_instantiator(objpath) 1051 context_required = False 1052 1053 # Identified targets employ function pointers directly. 1054 1055 elif objpath: 1056 parameters = self.importer.function_parameters.get(objpath) 1057 1058 # Class invocation involves instantiators. 1059 1060 if expr.has_kind("<class>"): 1061 instantiation = objpath 1062 target = encode_instantiator_pointer(objpath) 1063 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1064 target_structure = "&%s" % encode_path(init_ref) 1065 context_required = False 1066 1067 # Only plain functions and bound methods employ function pointers. 1068 1069 elif expr.has_kind("<function>"): 1070 function = objpath 1071 1072 # Test for functions and methods. 1073 1074 context_required = self.is_method(objpath) 1075 accessor_kinds = self.get_accessor_kinds(location) 1076 instance_accessor = accessor_kinds and \ 1077 len(accessor_kinds) == 1 and \ 1078 first(accessor_kinds) == "<instance>" 1079 1080 # Only identify certain bound methods or functions. 1081 1082 if not context_required or instance_accessor: 1083 target = encode_function_pointer(objpath) 1084 1085 # Access bound method defaults even if it is not clear whether 1086 # the accessor is appropriate. 1087 1088 target_structure = "&%s" % encode_path(objpath) 1089 1090 # Other targets are retrieved at run-time. Some information about them 1091 # may be available and be used to provide warnings about argument 1092 # compatibility. 1093 1094 elif self.importer.give_warning("args"): 1095 unsuitable = self.get_referenced_attribute_invocations(location) 1096 1097 if unsuitable: 1098 for ref in unsuitable: 1099 _objpath = ref.get_origin() 1100 num_parameters = len(self.importer.function_parameters[_objpath]) 1101 print >>sys.stderr, \ 1102 "In %s, at line %d, inappropriate number of " \ 1103 "arguments given. Need %d arguments to call %s." % ( 1104 self.get_namespace_path(), n.lineno, num_parameters, 1105 _objpath) 1106 1107 # Determine any readily-accessible target identity. 1108 1109 target_identity = target or expr.is_name() and str(expr) or None 1110 target_var = target_identity or "__tmp_targets[%d]" % self.function_target 1111 1112 if not target_identity: 1113 self.record_temp("__tmp_targets") 1114 1115 if context_identity and context_identity.startswith("__tmp_contexts"): 1116 self.record_temp("__tmp_contexts") 1117 1118 # Arguments are presented in a temporary frame array with any context 1119 # always being the first argument. Where it would be unused, it may be 1120 # set to null. 1121 1122 if context_required: 1123 if have_access_context: 1124 args = ["__ATTRVALUE(%s)" % context_identity] 1125 else: 1126 args = ["__CONTEXT_AS_VALUE(%s)" % target_var] 1127 else: 1128 args = ["__NULL"] 1129 1130 # Complete the array with null values, permitting tests for a complete 1131 # set of arguments. 1132 1133 args += [None] * (parameters is None and len(n.args) or parameters is not None and len(parameters) or 0) 1134 kwcodes = [] 1135 kwargs = [] 1136 1137 # Any invocations in the arguments will store target details in a 1138 # different location. 1139 1140 function_target = self.function_target 1141 1142 if not target_identity: 1143 self.next_target() 1144 1145 in_argument_list = self.in_argument_list 1146 self.in_argument_list = True 1147 1148 for i, arg in enumerate(n.args): 1149 argexpr = self.process_structure_node(arg) 1150 1151 # Store a keyword argument, either in the argument list or 1152 # in a separate keyword argument list for subsequent lookup. 1153 1154 if isinstance(arg, compiler.ast.Keyword): 1155 1156 # With knowledge of the target, store the keyword 1157 # argument directly. 1158 1159 if parameters: 1160 try: 1161 argnum = parameters.index(arg.name) 1162 except ValueError: 1163 raise TranslateError("Argument %s is not recognised." % arg.name, 1164 self.get_namespace_path(), n) 1165 args[argnum+1] = str(argexpr) 1166 1167 # Otherwise, store the details in a separate collection. 1168 1169 else: 1170 kwargs.append(str(argexpr)) 1171 kwcodes.append("{%s, %s}" % ( 1172 encode_ppos(arg.name), encode_pcode(arg.name))) 1173 1174 # Store non-keyword arguments in the argument list, rejecting 1175 # superfluous arguments. 1176 1177 else: 1178 try: 1179 args[i+1] = str(argexpr) 1180 except IndexError: 1181 raise TranslateError("Too many arguments specified.", 1182 self.get_namespace_path(), n) 1183 1184 # Reference the current target again. 1185 1186 self.in_argument_list = in_argument_list 1187 1188 if not self.in_argument_list: 1189 self.function_target = function_target 1190 1191 # Defaults are added to the frame where arguments are missing. 1192 1193 if parameters: 1194 function_defaults = self.importer.function_defaults.get(objpath) 1195 if function_defaults: 1196 1197 # Visit each default and set any missing arguments. 1198 # Use the target structure to obtain defaults, as opposed to the 1199 # actual function involved. 1200 1201 for i, (argname, default) in enumerate(function_defaults): 1202 argnum = parameters.index(argname) 1203 if not args[argnum+1]: 1204 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1205 1206 # Test for missing arguments. 1207 1208 if None in args: 1209 raise TranslateError("Not all arguments supplied.", 1210 self.get_namespace_path(), n) 1211 1212 # Encode the arguments. 1213 1214 # Where literal instantiation is occurring, add an argument indicating 1215 # the number of values. The context is excluded. 1216 1217 if literal_instantiation: 1218 argstr = "__ARGS(%s), %d" % (", ".join(args[1:]), len(args) - 1) 1219 else: 1220 argstr = ", ".join(args) 1221 1222 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1223 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1224 1225 # First, the invocation expression is presented. 1226 1227 stages = [] 1228 1229 # Without a known specific callable, the expression provides the target. 1230 1231 if not target or context_required: 1232 if target: 1233 if expr: 1234 stages.append(str(expr)) 1235 elif not target_identity: 1236 stages.append("%s = %s" % (target_var, expr)) 1237 1238 # Any specific callable is then obtained. 1239 1240 if target: 1241 stages.append(target) 1242 1243 # Methods accessed via unidentified accessors are obtained. 1244 1245 elif function: 1246 if context_required: 1247 if have_access_context: 1248 stages.append("__get_function(%s, %s)" % ( 1249 context_identity, target_var)) 1250 else: 1251 stages.append("__get_function(__CONTEXT_AS_VALUE(%s).value, %s)" % ( 1252 target_var, target_var)) 1253 else: 1254 stages.append("__load_via_object(%s.value, __fn__).fn" % target_var) 1255 1256 # With a known target, the function is obtained directly and called. 1257 # By putting the invocation at the end of the final element in the 1258 # instruction sequence (the stages), the result becomes the result of 1259 # the sequence. Moreover, the parameters become part of the sequence 1260 # and thereby participate in a guaranteed evaluation order. 1261 1262 if target or function: 1263 stages[-1] += "(%s)" % argstr 1264 if instantiation: 1265 return InstantiationResult(instantiation, stages) 1266 else: 1267 return InvocationResult(stages) 1268 1269 # With unknown targets, the generic invocation function is applied to 1270 # the callable and argument collections. 1271 1272 else: 1273 stages.append("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1274 target_var, 1275 self.always_callable and 1 or 0, 1276 len(kwargs), kwcodestr, kwargstr, 1277 len(args), "__ARGS(%s)" % argstr)) 1278 return InvocationResult(stages) 1279 1280 def next_target(self): 1281 1282 "Allocate the next function target storage." 1283 1284 self.function_target += 1 1285 self.max_function_targets = max(self.function_target, self.max_function_targets) 1286 1287 def always_callable(self, refs): 1288 1289 "Determine whether all 'refs' are callable." 1290 1291 for ref in refs: 1292 if not ref.static(): 1293 return False 1294 else: 1295 origin = ref.final() 1296 if not self.importer.get_attribute(origin, "__fn__"): 1297 return False 1298 return True 1299 1300 def need_default_arguments(self, objpath, nargs): 1301 1302 """ 1303 Return whether any default arguments are needed when invoking the object 1304 given by 'objpath'. 1305 """ 1306 1307 parameters = self.importer.function_parameters.get(objpath) 1308 return nargs < len(parameters) 1309 1310 def process_lambda_node(self, n): 1311 1312 "Process the given lambda node 'n'." 1313 1314 name = self.get_lambda_name() 1315 function_name = self.get_object_path(name) 1316 1317 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1318 1319 # Without defaults, produce an attribute referring to the function. 1320 1321 if not defaults: 1322 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1323 1324 # With defaults, copy the function structure and set the defaults on the 1325 # copy. 1326 1327 else: 1328 self.record_temp("__tmp_value") 1329 return make_expression("(__tmp_value = __COPY(&%s, sizeof(%s)), %s, __ATTRVALUE(__tmp_value))" % ( 1330 encode_path(function_name), 1331 encode_symbol("obj", function_name), 1332 ", ".join(defaults))) 1333 1334 def process_logical_node(self, n): 1335 1336 "Process the given operator node 'n'." 1337 1338 self.record_temp("__tmp_result") 1339 1340 conjunction = isinstance(n, compiler.ast.And) 1341 results = [] 1342 1343 for node in n.nodes: 1344 results.append(self.process_structure_node(node)) 1345 1346 return LogicalOperationResult(results, conjunction) 1347 1348 def process_name_node(self, n, expr=None): 1349 1350 "Process the given name node 'n' with the optional assignment 'expr'." 1351 1352 # Determine whether the name refers to a static external entity. 1353 1354 if n.name in predefined_constants: 1355 return PredefinedConstantRef(n.name, expr) 1356 1357 # Convert literal references, operator function names, and print 1358 # function names to references. 1359 1360 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1361 n.name.startswith("$print"): 1362 1363 ref, paths = self.importer.get_module(self.name).special[n.name] 1364 return TrResolvedNameRef(n.name, ref) 1365 1366 # Temporary names are output program locals. 1367 1368 elif n.name.startswith("$t"): 1369 return TrResolvedNameRef(n.name, Reference("<var>"), expr=expr) 1370 1371 # Get the appropriate name for the name reference, using the same method 1372 # as in the inspector. 1373 1374 path = self.get_namespace_path() 1375 objpath = self.get_object_path(n.name) 1376 1377 # Determine any assigned globals. 1378 1379 globals = self.importer.get_module(self.name).scope_globals.get(path) 1380 1381 # Explicitly declared globals. 1382 1383 if globals and n.name in globals: 1384 objpath = self.get_global_path(n.name) 1385 is_global = True 1386 1387 # Implicitly referenced globals in functions. 1388 1389 elif self.in_function: 1390 is_global = n.name not in self.importer.function_locals[path] 1391 1392 # Implicitly referenced globals elsewhere. 1393 1394 else: 1395 namespace = self.importer.identify(path) 1396 is_global = not self.importer.get_attributes(namespace, n.name) 1397 1398 # Get the static identity of the name. 1399 1400 ref = self.importer.identify(objpath) 1401 if ref and not ref.get_name(): 1402 ref = ref.alias(objpath) 1403 1404 # Obtain any resolved names for non-assignment names. 1405 1406 if not expr and not ref and self.in_function: 1407 locals = self.importer.function_locals.get(path) 1408 ref = locals and locals.get(n.name) 1409 1410 # Determine whether the name refers to a parameter. The generation of 1411 # parameter references is different from other names. 1412 1413 parameters = self.importer.function_parameters.get(path) 1414 parameter = n.name == "self" and self.in_method() or \ 1415 parameters and n.name in parameters 1416 1417 # Find any invocation details. 1418 1419 name = self.get_name_for_tracking(n.name, is_global=is_global) 1420 location = self.get_access_location(name) 1421 1422 # Mark any local assignments as volatile in exception blocks. 1423 1424 if expr and self.in_function and not is_global and self.in_try_except: 1425 self.make_volatile(n.name) 1426 1427 # Qualified names are used for resolved static references or for 1428 # static namespace members. The reference should be configured to return 1429 # such names. 1430 1431 return TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, location=location) 1432 1433 def make_volatile(self, name): 1434 1435 "Record 'name' as volatile in the current namespace." 1436 1437 self.volatile_locals.add(name) 1438 1439 def process_not_node(self, n): 1440 1441 "Process the given operator node 'n'." 1442 1443 return self.make_negation(self.process_structure_node(n.expr)) 1444 1445 def process_raise_node(self, n): 1446 1447 "Process the given raise node 'n'." 1448 1449 # NOTE: Determine which raise statement variants should be permitted. 1450 1451 if n.expr1: 1452 1453 # Names with accompanying arguments are treated like invocations. 1454 1455 if n.expr2: 1456 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1457 exc = self.process_structure_node(call) 1458 self.writestmt("__Raise(%s);" % exc) 1459 1460 # Raise instances, testing the kind at run-time if necessary and 1461 # instantiating any non-instance. 1462 1463 else: 1464 exc = self.process_structure_node(n.expr1) 1465 1466 if isinstance(exc, TrInstanceRef): 1467 self.writestmt("__Raise(%s);" % exc) 1468 else: 1469 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1470 else: 1471 self.writestmt("__Throw(__tmp_exc);") 1472 1473 def process_return_node(self, n): 1474 1475 "Process the given return node 'n'." 1476 1477 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1478 if self.in_try_finally or self.in_try_except: 1479 self.writestmt("__Return(%s);" % expr) 1480 else: 1481 self.writestmt("return %s;" % expr) 1482 1483 return ReturnRef() 1484 1485 def process_try_node(self, n): 1486 1487 """ 1488 Process the given "try...except" node 'n'. 1489 """ 1490 1491 in_try_except = self.in_try_except 1492 self.in_try_except = True 1493 1494 # Use macros to implement exception handling. 1495 1496 self.writestmt("__Try") 1497 self.writeline("{") 1498 self.indent += 1 1499 self.process_structure_node(n.body) 1500 1501 # Put the else statement in another try block that handles any raised 1502 # exceptions and converts them to exceptions that will not be handled by 1503 # the main handling block. 1504 1505 if n.else_: 1506 self.writestmt("__Try") 1507 self.writeline("{") 1508 self.indent += 1 1509 self.process_structure_node(n.else_) 1510 self.indent -= 1 1511 self.writeline("}") 1512 self.writeline("__Catch (__tmp_exc)") 1513 self.writeline("{") 1514 self.indent += 1 1515 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1516 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1517 self.indent -= 1 1518 self.writeline("}") 1519 1520 # Complete the try block and enter the finally block, if appropriate. 1521 1522 if self.in_try_finally: 1523 self.writestmt("__Complete;") 1524 1525 self.indent -= 1 1526 self.writeline("}") 1527 1528 self.in_try_except = in_try_except 1529 1530 # Handlers are tests within a common handler block. 1531 1532 self.writeline("__Catch (__tmp_exc)") 1533 self.writeline("{") 1534 self.indent += 1 1535 1536 # Introduce an if statement to handle the completion of a try block. 1537 1538 self.process_try_completion() 1539 1540 # Handle exceptions in else blocks converted to __RaiseElse, converting 1541 # them back to normal exceptions. 1542 1543 if n.else_: 1544 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1545 1546 # Exception handling. 1547 1548 for name, var, handler in n.handlers: 1549 1550 # Test for specific exceptions. 1551 1552 if name is not None: 1553 name_ref = self.process_structure_node(name) 1554 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1555 else: 1556 self.writeline("else if (1)") 1557 1558 self.writeline("{") 1559 self.indent += 1 1560 1561 # Establish the local for the handler. 1562 1563 if var is not None: 1564 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1565 1566 if handler is not None: 1567 self.process_structure_node(handler) 1568 1569 self.indent -= 1 1570 self.writeline("}") 1571 1572 # Re-raise unhandled exceptions. 1573 1574 self.writeline("else __Throw(__tmp_exc);") 1575 1576 # End the handler block. 1577 1578 self.indent -= 1 1579 self.writeline("}") 1580 print >>self.out 1581 1582 def process_try_finally_node(self, n): 1583 1584 """ 1585 Process the given "try...finally" node 'n'. 1586 """ 1587 1588 in_try_finally = self.in_try_finally 1589 self.in_try_finally = True 1590 1591 # Use macros to implement exception handling. 1592 1593 self.writestmt("__Try") 1594 self.writeline("{") 1595 self.indent += 1 1596 self.process_structure_node(n.body) 1597 self.indent -= 1 1598 self.writeline("}") 1599 1600 self.in_try_finally = in_try_finally 1601 1602 # Finally clauses handle special exceptions. 1603 1604 self.writeline("__Catch (__tmp_exc)") 1605 self.writeline("{") 1606 self.indent += 1 1607 self.process_structure_node(n.final) 1608 1609 # Introduce an if statement to handle the completion of a try block. 1610 1611 self.process_try_completion() 1612 self.writeline("else __Throw(__tmp_exc);") 1613 1614 self.indent -= 1 1615 self.writeline("}") 1616 print >>self.out 1617 1618 def process_try_completion(self): 1619 1620 "Generate a test for the completion of a try block." 1621 1622 self.writestmt("if (__tmp_exc.completing)") 1623 self.writeline("{") 1624 self.indent += 1 1625 1626 # Do not return anything at the module level. 1627 1628 if self.get_namespace_path() != self.name: 1629 1630 # Only use the normal return statement if no surrounding try blocks 1631 # apply. 1632 1633 if not self.in_try_finally and not self.in_try_except: 1634 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1635 else: 1636 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1637 1638 self.indent -= 1 1639 self.writeline("}") 1640 1641 def process_while_node(self, n): 1642 1643 "Process the given while node 'n'." 1644 1645 self.writeline("while (1)") 1646 self.writeline("{") 1647 self.indent += 1 1648 test = self.process_structure_node(n.test) 1649 1650 # Emit the loop termination condition unless "while <true value>" is 1651 # indicated. 1652 1653 if not (isinstance(test, PredefinedConstantRef) and test.value): 1654 1655 # Emit a negated test of the continuation condition. 1656 1657 self.start_if(True, self.make_negation(test)) 1658 if n.else_: 1659 self.process_structure_node(n.else_) 1660 self.writestmt("break;") 1661 self.end_if() 1662 1663 in_conditional = self.in_conditional 1664 self.in_conditional = True 1665 self.process_structure_node(n.body) 1666 self.in_conditional = in_conditional 1667 1668 self.indent -= 1 1669 self.writeline("}") 1670 print >>self.out 1671 1672 # Special variable usage. 1673 1674 def get_temp_path(self): 1675 1676 """ 1677 Return the appropriate namespace path for temporary names in the current 1678 namespace. 1679 """ 1680 1681 if self.in_function: 1682 return self.get_namespace_path() 1683 else: 1684 return self.name 1685 1686 def record_temp(self, name): 1687 1688 """ 1689 Record the use of the temporary 'name' in the current namespace. At the 1690 class or module level, the temporary name is associated with the module, 1691 since the variable will then be allocated in the module's own main 1692 program. 1693 """ 1694 1695 path = self.get_temp_path() 1696 1697 init_item(self.temp_usage, path, list) 1698 self.temp_usage[path].append(name) 1699 1700 def remove_temps(self, names): 1701 1702 """ 1703 Remove 'names' from temporary storage allocations, each instance 1704 removing each request for storage. 1705 """ 1706 1707 path = self.get_temp_path() 1708 1709 for name in names: 1710 if self.uses_temp(path, name): 1711 self.temp_usage[path].remove(name) 1712 1713 def uses_temp(self, path, name): 1714 1715 """ 1716 Return whether the given namespace 'path' employs a temporary variable 1717 with the given 'name'. Note that 'path' should only be a module or a 1718 function or method, not a class. 1719 """ 1720 1721 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1722 1723 def make_negation(self, expr): 1724 1725 "Return a negated form of 'expr'." 1726 1727 result = NegationResult(expr) 1728 1729 # Negation discards the temporary results of its operand. 1730 1731 temps = expr.discards_temporary() 1732 if temps: 1733 self.remove_temps(temps) 1734 1735 return result 1736 1737 # Output generation. 1738 1739 def start_output(self): 1740 1741 "Write the declarations at the top of each source file." 1742 1743 print >>self.out, """\ 1744 #include "types.h" 1745 #include "exceptions.h" 1746 #include "ops.h" 1747 #include "progconsts.h" 1748 #include "progops.h" 1749 #include "progtypes.h" 1750 #include "main.h" 1751 """ 1752 1753 def start_unit(self): 1754 1755 "Record output within a generated function for later use." 1756 1757 self.out = StringIO() 1758 1759 def end_unit(self): 1760 1761 "Restore the output stream." 1762 1763 out = self.out 1764 self.out = self.out_toplevel 1765 return out 1766 1767 def flush_unit(self, name, out): 1768 1769 "Add declarations and generated code." 1770 1771 self.write_temporaries(name) 1772 print >>self.out 1773 out.seek(0) 1774 self.out.write(out.read()) 1775 1776 def start_module(self): 1777 1778 "Write the start of each module's main function." 1779 1780 print >>self.out, "void __main_%s()" % encode_path(self.name) 1781 print >>self.out, "{" 1782 self.indent += 1 1783 1784 # Define temporary variables, excluded from the module structure itself. 1785 1786 tempnames = [] 1787 1788 for n in self.importer.all_module_attrs[self.name]: 1789 if n.startswith("$t"): 1790 tempnames.append(encode_path(n)) 1791 1792 if tempnames: 1793 tempnames.sort() 1794 self.writeline("__attr %s;" % ", ".join(tempnames)) 1795 1796 self.start_unit() 1797 1798 def end_module(self): 1799 1800 "End each module by closing its main function." 1801 1802 out = self.end_unit() 1803 self.flush_unit(self.name, out) 1804 1805 self.indent -= 1 1806 print >>self.out, "}" 1807 1808 def start_function(self, name): 1809 1810 "Start the function having the given 'name'." 1811 1812 self.indent += 1 1813 1814 self.start_unit() 1815 1816 def end_function(self, name): 1817 1818 "End the function having the given 'name'." 1819 1820 out = self.end_unit() 1821 1822 # Write the signature at the top indentation level. 1823 1824 self.indent -= 1 1825 self.write_parameters(name) 1826 print >>self.out, "{" 1827 1828 # Obtain local names from parameters. 1829 1830 parameters = self.importer.function_parameters[name] 1831 locals = self.importer.function_locals[name].keys() 1832 names = [] 1833 volatile_names = [] 1834 1835 for n in locals: 1836 1837 # Filter out special names and parameters. Note that self is a local 1838 # regardless of whether it originally appeared in the parameters or 1839 # not. 1840 1841 if n.startswith("$l") or n in parameters or n == "self": 1842 continue 1843 if n in self.volatile_locals: 1844 volatile_names.append(encode_path(n)) 1845 else: 1846 names.append(encode_path(n)) 1847 1848 # Emit required local names at the function indentation level. 1849 1850 self.indent += 1 1851 1852 if names: 1853 names.sort() 1854 self.writeline("__attr %s;" % ", ".join(names)) 1855 1856 if volatile_names: 1857 volatile_names.sort() 1858 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 1859 1860 self.flush_unit(name, out) 1861 1862 self.indent -= 1 1863 print >>self.out, "}" 1864 print >>self.out 1865 1866 def write_parameters(self, name): 1867 1868 """ 1869 For the function having the given 'name', write definitions of 1870 parameters found in the arguments array. 1871 """ 1872 1873 # Generate any self reference. 1874 1875 l = [] 1876 1877 if self.is_method(name): 1878 l.append("__attr self") 1879 else: 1880 l.append("__attr __self") 1881 1882 # Generate aliases for the parameters. 1883 1884 for parameter in self.importer.function_parameters[name]: 1885 l.append("%s__attr %s" % ( 1886 parameter in self.volatile_locals and "volatile " or "", 1887 encode_path(parameter))) 1888 1889 self.writeline("__attr %s(%s)" % ( 1890 encode_function_pointer(name), ", ".join(l))) 1891 1892 def write_temporaries(self, name): 1893 1894 "Write temporary storage employed by 'name'." 1895 1896 # Provide space for the given number of targets. 1897 1898 targets = self.max_function_targets 1899 1900 if self.uses_temp(name, "__tmp_targets"): 1901 self.writeline("__attr __tmp_targets[%d];" % targets) 1902 if self.uses_temp(name, "__tmp_contexts"): 1903 self.writeline("__ref __tmp_contexts[%d];" % targets) 1904 1905 # Add temporary variable usage details. 1906 1907 if self.uses_temp(name, "__tmp_private_context"): 1908 self.writeline("__ref __tmp_private_context;") 1909 if self.uses_temp(name, "__tmp_value"): 1910 self.writeline("__ref __tmp_value;") 1911 if self.uses_temp(name, "__tmp_target_value"): 1912 self.writeline("__ref __tmp_target_value;") 1913 if self.uses_temp(name, "__tmp_result"): 1914 self.writeline("__attr __tmp_result;") 1915 1916 module = self.importer.get_module(self.name) 1917 1918 if name in module.exception_namespaces: 1919 self.writeline("__exc __tmp_exc;") 1920 1921 def start_if(self, first, test_ref): 1922 statement = "%sif" % (not first and "else " or "") 1923 1924 # Consume logical results directly. 1925 1926 if isinstance(test_ref, LogicalResult): 1927 self.writeline("%s %s" % (statement, test_ref.apply_test())) 1928 temps = test_ref.discards_temporary() 1929 if temps: 1930 self.remove_temps(temps) 1931 else: 1932 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 1933 1934 self.writeline("{") 1935 self.indent += 1 1936 1937 def end_if(self): 1938 self.indent -= 1 1939 self.writeline("}") 1940 1941 def start_else(self): 1942 self.writeline("else") 1943 self.writeline("{") 1944 self.indent += 1 1945 1946 def end_else(self): 1947 self.indent -= 1 1948 self.writeline("}") 1949 1950 def statement(self, expr): 1951 s = str(expr) 1952 if s: 1953 self.writestmt("%s;" % s) 1954 1955 def statements(self, results): 1956 for result in results: 1957 self.statement(result) 1958 1959 def writeline(self, s): 1960 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 1961 1962 def writestmt(self, s): 1963 self.writeline(s) 1964 1965 def write_comment(self, s): 1966 self.writestmt("/* %s */" % s) 1967 1968 def pad(self, extra=0): 1969 return (self.indent + extra) * self.tabstop 1970 1971 def indenttext(self, s, levels): 1972 lines = s.split("\n") 1973 out = [lines[0]] 1974 for line in lines[1:]: 1975 out.append(levels * self.tabstop + line) 1976 if line.endswith("("): 1977 levels += 1 1978 elif line.startswith(")"): 1979 levels -= 1 1980 return "\n".join(out) 1981 1982 # vim: tabstop=4 expandtab shiftwidth=4