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, InstructionSequence, \ 23 first, get_builtin_class, init_item, predefined_constants 24 from encoders import encode_access_instruction, \ 25 encode_function_pointer, encode_literal_constant, \ 26 encode_literal_instantiator, encode_instantiator_pointer, \ 27 encode_instructions, \ 28 encode_path, encode_symbol, encode_type_attribute, \ 29 is_type_attribute 30 from errors import InspectError, TranslateError 31 from os.path import exists, join 32 from os import makedirs 33 from referencing import Reference 34 from StringIO import StringIO 35 import compiler 36 import results 37 import sys 38 39 class Translator(CommonOutput): 40 41 "A program translator." 42 43 def __init__(self, importer, deducer, optimiser, output): 44 self.importer = importer 45 self.deducer = deducer 46 self.optimiser = optimiser 47 self.output = output 48 self.modules = {} 49 50 def to_output(self): 51 output = join(self.output, "src") 52 53 if not exists(output): 54 makedirs(output) 55 56 self.check_output() 57 58 for module in self.importer.modules.values(): 59 parts = module.name.split(".") 60 if parts[0] != "native": 61 tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser) 62 tm.translate(module.filename, join(output, "%s.c" % module.name)) 63 self.modules[module.name] = tm 64 65 # Classes representing intermediate translation results. 66 67 class TranslationResult: 68 69 "An abstract translation result mix-in." 70 71 pass 72 73 class ReturnRef(TranslationResult): 74 75 "Indicates usage of a return statement." 76 77 pass 78 79 class Expression(results.Result, TranslationResult): 80 81 "A general expression." 82 83 def __init__(self, s): 84 self.s = s 85 def __str__(self): 86 return self.s 87 def __repr__(self): 88 return "Expression(%r)" % self.s 89 90 class TrResolvedNameRef(results.ResolvedNameRef, TranslationResult): 91 92 "A reference to a name in the translation." 93 94 def __init__(self, name, ref, expr=None, parameter=None, location=None): 95 results.ResolvedNameRef.__init__(self, name, ref, expr) 96 self.parameter = parameter 97 self.location = location 98 99 def access_location(self): 100 return self.location 101 102 def __str__(self): 103 104 "Return an output representation of the referenced name." 105 106 # For sources, any identified static origin will be constant and thus 107 # usable directly. For targets, no constant should be assigned and thus 108 # the alias (or any plain name) will be used. 109 110 ref = self.static() 111 origin = ref and self.get_origin() 112 static_name = origin and encode_path(origin) 113 114 # Determine whether a qualified name is involved. 115 116 t = (not self.is_constant_alias() and self.get_name() or self.name).rsplit(".", 1) 117 parent = len(t) > 1 and t[0] or None 118 attrname = t[-1] and encode_path(t[-1]) 119 120 # Assignments. 121 122 if self.expr: 123 124 # Eliminate assignments between constants. 125 126 if ref and isinstance(self.expr, results.ResolvedNameRef) and self.expr.static(): 127 return "" 128 129 # Qualified names must be converted into parent-relative assignments. 130 131 elif parent: 132 return "__store_via_object(&%s, %s, %s)" % ( 133 encode_path(parent), encode_symbol("pos", attrname), self.expr) 134 135 # All other assignments involve the names as they were given. 136 137 else: 138 return "(%s%s) = %s" % (self.parameter and "*" or "", attrname, self.expr) 139 140 # Expressions. 141 142 elif static_name: 143 parent = ref.parent() 144 context = ref.has_kind("<function>") and encode_path(parent) or None 145 return "((__attr) {.value=&%s})" % static_name 146 147 # Qualified names must be converted into parent-relative accesses. 148 149 elif parent: 150 return "__load_via_object(&%s, %s)" % ( 151 encode_path(parent), encode_symbol("pos", attrname)) 152 153 # All other accesses involve the names as they were given. 154 155 else: 156 return "(%s%s)" % (self.parameter and "*" or "", attrname) 157 158 class TrConstantValueRef(results.ConstantValueRef, TranslationResult): 159 160 "A constant value reference in the translation." 161 162 def __str__(self): 163 return encode_literal_constant(self.number) 164 165 class TrLiteralSequenceRef(results.LiteralSequenceRef, TranslationResult): 166 167 "A reference representing a sequence of values." 168 169 def __str__(self): 170 return str(self.node) 171 172 class TrInstanceRef(results.InstanceRef, TranslationResult): 173 174 "A reference representing instantiation of a class." 175 176 def __init__(self, ref, expr): 177 178 """ 179 Initialise the reference with 'ref' indicating the nature of the 180 reference and 'expr' being an expression used to create the instance. 181 """ 182 183 results.InstanceRef.__init__(self, ref) 184 self.expr = expr 185 186 def __str__(self): 187 return self.expr 188 189 def __repr__(self): 190 return "TrResolvedInstanceRef(%r, %r)" % (self.ref, self.expr) 191 192 class AttrResult(Expression, TranslationResult, InstructionSequence): 193 194 "A translation result for an attribute access." 195 196 def __init__(self, instructions, refs, location): 197 InstructionSequence.__init__(self, instructions) 198 self.refs = refs 199 self.location = location 200 201 def references(self): 202 return self.refs 203 204 def access_location(self): 205 return self.location 206 207 def get_origin(self): 208 return self.refs and len(self.refs) == 1 and first(self.refs).get_origin() 209 210 def has_kind(self, kinds): 211 if not self.refs: 212 return False 213 for ref in self.refs: 214 if ref.has_kind(kinds): 215 return True 216 return False 217 218 def __str__(self): 219 return encode_instructions(self.instructions) 220 221 def __repr__(self): 222 return "AttrResult(%r, %r, %r)" % (self.instructions, self.refs, self.location) 223 224 class InvocationResult(Expression, TranslationResult, InstructionSequence): 225 226 "A translation result for an invocation." 227 228 def __init__(self, instructions): 229 InstructionSequence.__init__(self, instructions) 230 231 def __str__(self): 232 return encode_instructions(self.instructions) 233 234 def __repr__(self): 235 return "InvocationResult(%r)" % self.instructions 236 237 class InstantiationResult(InvocationResult, TrInstanceRef): 238 239 "An instantiation result acting like an invocation result." 240 241 def __init__(self, ref, instructions): 242 results.InstanceRef.__init__(self, ref) 243 InvocationResult.__init__(self, instructions) 244 245 def __repr__(self): 246 return "InstantiationResult(%r, %r)" % (self.ref, self.instructions) 247 248 class PredefinedConstantRef(Expression, TranslationResult): 249 250 "A predefined constant reference." 251 252 def __init__(self, value, expr=None): 253 self.value = value 254 self.expr = expr 255 256 def __str__(self): 257 258 # Eliminate predefined constant assignments. 259 260 if self.expr: 261 return "" 262 263 # Generate the specific constants. 264 265 if self.value in ("False", "True"): 266 return encode_path("__builtins__.boolean.%s" % self.value) 267 elif self.value == "None": 268 return encode_path("__builtins__.none.%s" % self.value) 269 elif self.value == "NotImplemented": 270 return encode_path("__builtins__.notimplemented.%s" % self.value) 271 else: 272 return self.value 273 274 def __repr__(self): 275 return "PredefinedConstantRef(%r)" % self.value 276 277 class BooleanResult(Expression, TranslationResult): 278 279 "A expression producing a boolean result." 280 281 def __str__(self): 282 return "__builtins___bool_bool(%s)" % self.s 283 284 def __repr__(self): 285 return "BooleanResult(%r)" % self.s 286 287 def make_expression(expr): 288 289 "Make a new expression from the existing 'expr'." 290 291 if isinstance(expr, results.Result): 292 return expr 293 else: 294 return Expression(str(expr)) 295 296 297 298 # The actual translation process itself. 299 300 class TranslatedModule(CommonModule): 301 302 "A module translator." 303 304 def __init__(self, name, importer, deducer, optimiser): 305 CommonModule.__init__(self, name, importer) 306 self.deducer = deducer 307 self.optimiser = optimiser 308 309 # Output stream. 310 311 self.out_toplevel = self.out = None 312 self.indent = 0 313 self.tabstop = " " 314 315 # Recorded namespaces. 316 317 self.namespaces = [] 318 self.in_conditional = False 319 320 # Exception raising adjustments. 321 322 self.in_try_finally = False 323 self.in_try_except = False 324 325 # Attribute access and accessor counting. 326 327 self.attr_accesses = {} 328 self.attr_accessors = {} 329 330 # Special variable usage. 331 332 self.temp_usage = {} 333 334 def __repr__(self): 335 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 336 337 def translate(self, filename, output_filename): 338 339 """ 340 Parse the file having the given 'filename', writing the translation to 341 the given 'output_filename'. 342 """ 343 344 self.parse_file(filename) 345 346 # Collect function namespaces for separate processing. 347 348 self.record_namespaces(self.astnode) 349 350 # Reset the lambda naming (in order to obtain the same names again) and 351 # translate the program. 352 353 self.reset_lambdas() 354 355 self.out_toplevel = self.out = open(output_filename, "w") 356 try: 357 self.start_output() 358 359 # Process namespaces, writing the translation. 360 361 for path, node in self.namespaces: 362 self.process_namespace(path, node) 363 364 # Process the module namespace including class namespaces. 365 366 self.process_namespace([], self.astnode) 367 368 finally: 369 self.out.close() 370 371 def have_object(self): 372 373 "Return whether a namespace is a recorded object." 374 375 return self.importer.objects.get(self.get_namespace_path()) 376 377 def get_builtin_class(self, name): 378 379 "Return a reference to the actual object providing 'name'." 380 381 return self.importer.get_object(get_builtin_class(name)) 382 383 def is_method(self, path): 384 385 "Return whether 'path' is a method." 386 387 class_name, method_name = path.rsplit(".", 1) 388 return self.importer.classes.has_key(class_name) and class_name or None 389 390 def in_method(self): 391 392 "Return whether the current namespace provides a method." 393 394 return self.in_function and self.is_method(self.get_namespace_path()) 395 396 # Namespace recording. 397 398 def record_namespaces(self, node): 399 400 "Process the program structure 'node', recording namespaces." 401 402 for n in node.getChildNodes(): 403 self.record_namespaces_in_node(n) 404 405 def record_namespaces_in_node(self, node): 406 407 "Process the program structure 'node', recording namespaces." 408 409 # Function namespaces within modules, classes and other functions. 410 # Functions appearing within conditional statements are given arbitrary 411 # names. 412 413 if isinstance(node, compiler.ast.Function): 414 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 415 416 elif isinstance(node, compiler.ast.Lambda): 417 self.record_function_node(node, self.get_lambda_name()) 418 419 # Classes are visited, but may be ignored if inside functions. 420 421 elif isinstance(node, compiler.ast.Class): 422 self.enter_namespace(node.name) 423 if self.have_object(): 424 self.record_namespaces(node) 425 self.exit_namespace() 426 427 # Conditional nodes are tracked so that function definitions may be 428 # handled. Since "for" loops are converted to "while" loops, they are 429 # included here. 430 431 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 432 in_conditional = self.in_conditional 433 self.in_conditional = True 434 self.record_namespaces(node) 435 self.in_conditional = in_conditional 436 437 # All other nodes are processed depth-first. 438 439 else: 440 self.record_namespaces(node) 441 442 def record_function_node(self, n, name): 443 444 """ 445 Record the given function, lambda, if expression or list comprehension 446 node 'n' with the given 'name'. 447 """ 448 449 self.in_function = True 450 self.enter_namespace(name) 451 452 if self.have_object(): 453 454 # Record the namespace path and the node itself. 455 456 self.namespaces.append((self.namespace_path[:], n)) 457 self.record_namespaces_in_node(n.code) 458 459 self.exit_namespace() 460 self.in_function = False 461 462 # Constant referencing. 463 464 def get_literal_instance(self, n, name=None): 465 466 """ 467 For node 'n', return a reference for the type of the given 'name', or if 468 'name' is not specified, deduce the type from the value. 469 """ 470 471 # Handle stray None constants (Sliceobj seems to produce them). 472 473 if name is None and n.value is None: 474 return self.process_name_node(compiler.ast.Name("None")) 475 476 if name in ("dict", "list", "tuple"): 477 ref = self.get_builtin_class(name) 478 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 479 else: 480 value, typename, encoding = self.get_constant_value(n.value, n.literals) 481 ref = self.get_builtin_class(typename) 482 value_type = ref.get_origin() 483 484 path = self.get_namespace_path() 485 486 # Obtain the local numbering of the constant and thus the 487 # locally-qualified name. 488 489 local_number = self.importer.all_constants[path][(value, value_type, encoding)] 490 constant_name = "$c%d" % local_number 491 objpath = self.get_object_path(constant_name) 492 493 # Obtain the unique identifier for the constant. 494 495 number = self.optimiser.constant_numbers[objpath] 496 return TrConstantValueRef(constant_name, ref.instance_of(), value, number) 497 498 # Namespace translation. 499 500 def process_namespace(self, path, node): 501 502 """ 503 Process the namespace for the given 'path' defined by the given 'node'. 504 """ 505 506 self.namespace_path = path 507 508 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 509 self.in_function = True 510 self.process_function_body_node(node) 511 else: 512 self.in_function = False 513 self.function_target = 0 514 self.start_module() 515 self.process_structure(node) 516 self.end_module() 517 518 def process_structure(self, node): 519 520 "Process the given 'node' or result." 521 522 # Handle processing requests on results. 523 524 if isinstance(node, results.Result): 525 return node 526 527 # Handle processing requests on nodes. 528 529 else: 530 l = CommonModule.process_structure(self, node) 531 532 # Return indications of return statement usage. 533 534 if l and isinstance(l[-1], ReturnRef): 535 return l[-1] 536 else: 537 return None 538 539 def process_structure_node(self, n): 540 541 "Process the individual node 'n'." 542 543 # Plain statements emit their expressions. 544 545 if isinstance(n, compiler.ast.Discard): 546 expr = self.process_structure_node(n.expr) 547 self.statement(expr) 548 549 # Module import declarations. 550 551 elif isinstance(n, compiler.ast.From): 552 self.process_from_node(n) 553 554 # Nodes using operator module functions. 555 556 elif isinstance(n, compiler.ast.Operator): 557 return self.process_operator_node(n) 558 559 elif isinstance(n, compiler.ast.AugAssign): 560 self.process_augassign_node(n) 561 562 elif isinstance(n, compiler.ast.Compare): 563 return self.process_compare_node(n) 564 565 elif isinstance(n, compiler.ast.Slice): 566 return self.process_slice_node(n) 567 568 elif isinstance(n, compiler.ast.Sliceobj): 569 return self.process_sliceobj_node(n) 570 571 elif isinstance(n, compiler.ast.Subscript): 572 return self.process_subscript_node(n) 573 574 # Classes are visited, but may be ignored if inside functions. 575 576 elif isinstance(n, compiler.ast.Class): 577 self.process_class_node(n) 578 579 # Functions within namespaces have any dynamic defaults initialised. 580 581 elif isinstance(n, compiler.ast.Function): 582 self.process_function_node(n) 583 584 # Lambdas are replaced with references to separately-generated 585 # functions. 586 587 elif isinstance(n, compiler.ast.Lambda): 588 return self.process_lambda_node(n) 589 590 # Assignments. 591 592 elif isinstance(n, compiler.ast.Assign): 593 594 # Handle each assignment node. 595 596 for node in n.nodes: 597 self.process_assignment_node(node, n.expr) 598 599 # Accesses. 600 601 elif isinstance(n, compiler.ast.Getattr): 602 return self.process_attribute_access(n) 603 604 # Names. 605 606 elif isinstance(n, compiler.ast.Name): 607 return self.process_name_node(n) 608 609 # Loops and conditionals. 610 611 elif isinstance(n, compiler.ast.For): 612 self.process_for_node(n) 613 614 elif isinstance(n, compiler.ast.While): 615 self.process_while_node(n) 616 617 elif isinstance(n, compiler.ast.If): 618 self.process_if_node(n) 619 620 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 621 return self.process_logical_node(n) 622 623 elif isinstance(n, compiler.ast.Not): 624 return self.process_not_node(n) 625 626 # Exception control-flow tracking. 627 628 elif isinstance(n, compiler.ast.TryExcept): 629 self.process_try_node(n) 630 631 elif isinstance(n, compiler.ast.TryFinally): 632 self.process_try_finally_node(n) 633 634 # Control-flow modification statements. 635 636 elif isinstance(n, compiler.ast.Break): 637 self.writestmt("break;") 638 639 elif isinstance(n, compiler.ast.Continue): 640 self.writestmt("continue;") 641 642 elif isinstance(n, compiler.ast.Raise): 643 self.process_raise_node(n) 644 645 elif isinstance(n, compiler.ast.Return): 646 return self.process_return_node(n) 647 648 # Print statements. 649 650 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 651 self.statement(self.process_print_node(n)) 652 653 # Invocations. 654 655 elif isinstance(n, compiler.ast.CallFunc): 656 return self.process_invocation_node(n) 657 658 elif isinstance(n, compiler.ast.Keyword): 659 return self.process_structure_node(n.expr) 660 661 # Constant usage. 662 663 elif isinstance(n, compiler.ast.Const): 664 return self.get_literal_instance(n) 665 666 elif isinstance(n, compiler.ast.Dict): 667 return self.get_literal_instance(n, "dict") 668 669 elif isinstance(n, compiler.ast.List): 670 return self.get_literal_instance(n, "list") 671 672 elif isinstance(n, compiler.ast.Tuple): 673 return self.get_literal_instance(n, "tuple") 674 675 # All other nodes are processed depth-first. 676 677 else: 678 return self.process_structure(n) 679 680 def process_assignment_node(self, n, expr): 681 682 "Process the individual node 'n' to be assigned the contents of 'expr'." 683 684 # Names and attributes are assigned the entire expression. 685 686 if isinstance(n, compiler.ast.AssName): 687 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 688 self.statement(name_ref) 689 690 # Employ guards after assignments if required. 691 692 if expr and name_ref.is_name(): 693 self.generate_guard(name_ref.name) 694 695 elif isinstance(n, compiler.ast.AssAttr): 696 in_assignment = self.in_assignment 697 self.in_assignment = self.process_structure_node(expr) 698 self.statement(self.process_attribute_access(n)) 699 self.in_assignment = in_assignment 700 701 # Lists and tuples are matched against the expression and their 702 # items assigned to expression items. 703 704 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 705 self.process_assignment_node_items(n, expr) 706 707 # Slices and subscripts are permitted within assignment nodes. 708 709 elif isinstance(n, compiler.ast.Slice): 710 self.statement(self.process_slice_node(n, expr)) 711 712 elif isinstance(n, compiler.ast.Subscript): 713 self.statement(self.process_subscript_node(n, expr)) 714 715 def process_attribute_access(self, n): 716 717 "Process the given attribute access node 'n'." 718 719 # Obtain any completed chain and return the reference to it. 720 721 attr_expr = self.process_attribute_chain(n) 722 if self.have_access_expression(n): 723 return attr_expr 724 725 # Where the start of the chain of attributes has been reached, process 726 # the complete access. 727 728 name_ref = attr_expr and attr_expr.is_name() and attr_expr 729 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref and name_ref.final()) or None 730 731 location = self.get_access_location(name, self.attrs) 732 refs = self.get_referenced_attributes(location) 733 734 # Generate access instructions. 735 736 subs = { 737 "<expr>" : attr_expr, 738 "<assexpr>" : self.in_assignment, 739 } 740 741 temp_subs = { 742 "<context>" : "__tmp_context", 743 "<set_context>" : "__tmp_context", 744 "<accessor>" : "__tmp_value", 745 "<target_accessor>" : "__tmp_target_value", 746 "<set_accessor>" : "__tmp_value", 747 "<set_target_accessor>" : "__tmp_target_value", 748 } 749 750 op_subs = { 751 "<set_context>" : "__set_context", 752 "<set_accessor>" : "__set_accessor", 753 "<set_target_accessor>" : "__set_target_accessor", 754 } 755 756 subs.update(temp_subs) 757 subs.update(op_subs) 758 759 output = [] 760 substituted = set() 761 762 # Obtain encoded versions of each instruction, accumulating temporary 763 # variables. 764 765 for instruction in self.optimiser.access_instructions[location]: 766 encoded, _substituted = encode_access_instruction(instruction, subs) 767 output.append(encoded) 768 substituted.update(_substituted) 769 770 # Record temporary name usage. 771 772 for sub in substituted: 773 if temp_subs.has_key(sub): 774 self.record_temp(temp_subs[sub]) 775 776 del self.attrs[0] 777 return AttrResult(output, refs, location) 778 779 def get_referenced_attributes(self, location): 780 781 """ 782 Convert 'location' to the form used by the deducer and retrieve any 783 identified attributes. 784 """ 785 786 access_location = self.deducer.const_accesses.get(location) 787 refs = [] 788 for attrtype, objpath, attr in self.deducer.referenced_attrs[access_location or location]: 789 refs.append(attr) 790 return refs 791 792 def get_referenced_attribute_invocations(self, location): 793 794 """ 795 Convert 'location' to the form used by the deducer and retrieve any 796 identified attribute invocation details. 797 """ 798 799 access_location = self.deducer.const_accesses.get(location) 800 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 801 802 def get_accessor_kinds(self, location): 803 804 "Return the accessor kinds for 'location'." 805 806 return self.optimiser.accessor_kinds.get(location) 807 808 def get_access_location(self, name, attrnames=None): 809 810 """ 811 Using the current namespace, the given 'name', and the 'attrnames' 812 employed in an access, return the access location. 813 """ 814 815 path = self.get_path_for_access() 816 817 # Get the location used by the deducer and optimiser and find any 818 # recorded access. 819 820 attrnames = attrnames and ".".join(self.attrs) 821 access_number = self.get_access_number(path, name, attrnames) 822 self.update_access_number(path, name, attrnames) 823 return (path, name, attrnames, access_number) 824 825 def get_access_number(self, path, name, attrnames): 826 access = name, attrnames 827 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 828 return self.attr_accesses[path][access] 829 else: 830 return 0 831 832 def update_access_number(self, path, name, attrnames): 833 access = name, attrnames 834 if name: 835 init_item(self.attr_accesses, path, dict) 836 init_item(self.attr_accesses[path], access, lambda: 0) 837 self.attr_accesses[path][access] += 1 838 839 def get_accessor_location(self, name): 840 841 """ 842 Using the current namespace and the given 'name', return the accessor 843 location. 844 """ 845 846 path = self.get_path_for_access() 847 848 # Get the location used by the deducer and optimiser and find any 849 # recorded accessor. 850 851 access_number = self.get_accessor_number(path, name) 852 self.update_accessor_number(path, name) 853 return (path, name, None, access_number) 854 855 def get_accessor_number(self, path, name): 856 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 857 return self.attr_accessors[path][name] 858 else: 859 return 0 860 861 def update_accessor_number(self, path, name): 862 if name: 863 init_item(self.attr_accessors, path, dict) 864 init_item(self.attr_accessors[path], name, lambda: 0) 865 self.attr_accessors[path][name] += 1 866 867 def process_class_node(self, n): 868 869 "Process the given class node 'n'." 870 871 class_name = self.get_object_path(n.name) 872 873 # Where a class is set conditionally or where the name may refer to 874 # different values, assign the name. 875 876 ref = self.importer.identify(class_name) 877 878 if not ref.static(): 879 self.process_assignment_for_object( 880 n.name, make_expression("((__attr) {.value=&%s})" % 881 encode_path(class_name))) 882 883 self.enter_namespace(n.name) 884 885 if self.have_object(): 886 self.write_comment("Class: %s" % class_name) 887 888 self.initialise_inherited_members(class_name) 889 890 self.process_structure(n) 891 self.write_comment("End class: %s" % class_name) 892 893 self.exit_namespace() 894 895 def initialise_inherited_members(self, class_name): 896 897 "Initialise members of 'class_name' inherited from its ancestors." 898 899 for name, path in self.importer.all_class_attrs[class_name].items(): 900 target = "%s.%s" % (class_name, name) 901 902 # Ignore attributes with definitions. 903 904 ref = self.importer.identify(target) 905 if ref: 906 continue 907 908 # Ignore special type attributes. 909 910 if is_type_attribute(name): 911 continue 912 913 # Reference inherited attributes. 914 915 ref = self.importer.identify(path) 916 if ref and not ref.static(): 917 parent, attrname = path.rsplit(".", 1) 918 919 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 920 encode_path(class_name), encode_symbol("pos", name), 921 encode_path(parent), encode_symbol("pos", attrname) 922 )) 923 924 def process_from_node(self, n): 925 926 "Process the given node 'n', importing from another module." 927 928 path = self.get_namespace_path() 929 930 # Attempt to obtain the referenced objects. 931 932 for name, alias in n.names: 933 if name == "*": 934 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 935 936 # Obtain the path of the assigned name. 937 938 objpath = self.get_object_path(alias or name) 939 940 # Obtain the identity of the name. 941 942 ref = self.importer.identify(objpath) 943 944 # Where the name is not static, assign the value. 945 946 if ref and not ref.static() and ref.get_name(): 947 self.writestmt("%s;" % 948 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 949 expr=TrResolvedNameRef(name, ref))) 950 951 def process_function_body_node(self, n): 952 953 """ 954 Process the given function, lambda, if expression or list comprehension 955 node 'n', generating the body. 956 """ 957 958 function_name = self.get_namespace_path() 959 self.start_function(function_name) 960 961 # Process the function body. 962 963 in_conditional = self.in_conditional 964 self.in_conditional = False 965 self.function_target = 0 966 967 # Process any guards defined for the parameters. 968 969 for name in self.importer.function_parameters.get(function_name): 970 self.generate_guard(name) 971 972 # Produce the body and any additional return statement. 973 974 expr = self.process_structure_node(n.code) or PredefinedConstantRef("None") 975 if not isinstance(expr, ReturnRef): 976 self.writestmt("return %s;" % expr) 977 978 self.in_conditional = in_conditional 979 980 self.end_function(function_name) 981 982 def generate_guard(self, name): 983 984 """ 985 Get the accessor details for 'name', found in the current namespace, and 986 generate any guards defined for it. 987 """ 988 989 # Obtain the location, keeping track of assignment versions. 990 991 location = self.get_accessor_location(name) 992 test = self.deducer.accessor_guard_tests.get(location) 993 994 # Generate any guard from the deduced information. 995 996 if test: 997 guard, guard_type = test 998 999 if guard == "specific": 1000 ref = first(self.deducer.accessor_all_types[location]) 1001 argstr = "&%s" % encode_path(ref.get_origin()) 1002 elif guard == "common": 1003 ref = first(self.deducer.accessor_all_general_types[location]) 1004 typeattr = encode_type_attribute(ref.get_origin()) 1005 argstr = "%s, %s" % (encode_symbol("pos", typeattr), encode_symbol("code", typeattr)) 1006 else: 1007 return 1008 1009 # Produce an appropriate access to an attribute's value. 1010 1011 parameters = self.importer.function_parameters.get(self.get_namespace_path()) 1012 if parameters and name in parameters: 1013 name_to_value = "%s->value" % name 1014 else: 1015 name_to_value = "%s.value" % name 1016 1017 # Write a test that raises a TypeError upon failure. 1018 1019 self.writestmt("if (!__test_%s_%s(%s, %s)) __raise_type_error();" % ( 1020 guard, guard_type, name_to_value, argstr)) 1021 1022 def process_function_node(self, n): 1023 1024 """ 1025 Process the given function, lambda, if expression or list comprehension 1026 node 'n', generating any initialisation statements. 1027 """ 1028 1029 # Where a function is declared conditionally, use a separate name for 1030 # the definition, and assign the definition to the stated name. 1031 1032 original_name = n.name 1033 1034 if self.in_conditional or self.in_function: 1035 name = self.get_lambda_name() 1036 else: 1037 name = n.name 1038 1039 objpath = self.get_object_path(name) 1040 1041 # Obtain details of the defaults. 1042 1043 defaults = self.process_function_defaults(n, name, objpath) 1044 if defaults: 1045 for default in defaults: 1046 self.writeline("%s;" % default) 1047 1048 # Where a function is set conditionally or where the name may refer to 1049 # different values, assign the name. 1050 1051 ref = self.importer.identify(objpath) 1052 1053 if self.in_conditional or self.in_function: 1054 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 1055 elif not ref.static(): 1056 context = self.is_method(objpath) 1057 1058 self.process_assignment_for_object(original_name, 1059 make_expression("((__attr) {.value=&%s})" % encode_path(objpath))) 1060 1061 def process_function_defaults(self, n, name, objpath, instance_name=None): 1062 1063 """ 1064 Process the given function or lambda node 'n', initialising defaults 1065 that are dynamically set. The given 'name' indicates the name of the 1066 function. The given 'objpath' indicates the origin of the function. 1067 The given 'instance_name' indicates the name of any separate instance 1068 of the function created to hold the defaults. 1069 1070 Return a list of operations setting defaults on a function instance. 1071 """ 1072 1073 function_name = self.get_object_path(name) 1074 function_defaults = self.importer.function_defaults.get(function_name) 1075 if not function_defaults: 1076 return None 1077 1078 # Determine whether any unidentified defaults are involved. 1079 1080 for argname, default in function_defaults: 1081 if not default.static(): 1082 break 1083 else: 1084 return None 1085 1086 # Handle bound methods. 1087 1088 if not instance_name: 1089 instance_name = "&%s" % encode_path(objpath) 1090 1091 # Where defaults are involved but cannot be identified, obtain a new 1092 # instance of the lambda and populate the defaults. 1093 1094 defaults = [] 1095 1096 # Join the original defaults with the inspected defaults. 1097 1098 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 1099 1100 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 1101 1102 # Obtain any reference for the default. 1103 1104 if original: 1105 argname, default = original 1106 name_ref = self.process_structure_node(default) 1107 elif inspected: 1108 argname, default = inspected 1109 name_ref = TrResolvedNameRef(argname, default) 1110 else: 1111 continue 1112 1113 # Generate default initialisers except when constants are employed. 1114 # Constants should be used when populating the function structures. 1115 1116 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1117 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1118 1119 return defaults 1120 1121 def process_if_node(self, n): 1122 1123 """ 1124 Process the given "if" node 'n'. 1125 """ 1126 1127 first = True 1128 for test, body in n.tests: 1129 test_ref = self.process_structure_node(test) 1130 self.start_if(first, test_ref) 1131 1132 in_conditional = self.in_conditional 1133 self.in_conditional = True 1134 self.process_structure_node(body) 1135 self.in_conditional = in_conditional 1136 1137 self.end_if() 1138 first = False 1139 1140 if n.else_: 1141 self.start_else() 1142 self.process_structure_node(n.else_) 1143 self.end_else() 1144 1145 def process_invocation_node(self, n): 1146 1147 "Process the given invocation node 'n'." 1148 1149 expr = self.process_structure_node(n.node) 1150 objpath = expr.get_origin() 1151 location = expr.access_location() 1152 1153 # Identified target details. 1154 1155 target = None 1156 target_structure = None 1157 1158 # Specific function target information. 1159 1160 function = None 1161 1162 # Instantiation involvement. 1163 1164 instantiation = False 1165 literal_instantiation = False 1166 1167 # Invocation requirements. 1168 1169 context_required = True 1170 have_access_context = isinstance(expr, AttrResult) 1171 parameters = None 1172 1173 # Obtain details of the callable and of its parameters. 1174 1175 # Literals may be instantiated specially. 1176 1177 if expr.is_name() and expr.name.startswith("$L") and objpath: 1178 instantiation = literal_instantiation = objpath 1179 target = encode_literal_instantiator(objpath) 1180 context_required = False 1181 1182 # Identified targets employ function pointers directly. 1183 1184 elif objpath: 1185 parameters = self.importer.function_parameters.get(objpath) 1186 1187 # Class invocation involves instantiators. 1188 1189 if expr.has_kind("<class>"): 1190 instantiation = objpath 1191 target = encode_instantiator_pointer(objpath) 1192 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1193 target_structure = "&%s" % encode_path(init_ref) 1194 context_required = False 1195 1196 # Only plain functions and bound methods employ function pointers. 1197 1198 elif expr.has_kind("<function>"): 1199 function = objpath 1200 1201 # Test for functions and methods. 1202 1203 context_required = self.is_method(objpath) 1204 accessor_kinds = self.get_accessor_kinds(location) 1205 instance_accessor = accessor_kinds and \ 1206 len(accessor_kinds) == 1 and \ 1207 first(accessor_kinds) == "<instance>" 1208 1209 # Only identify certain bound methods or functions. 1210 1211 if not context_required or instance_accessor: 1212 target = encode_function_pointer(objpath) 1213 1214 # Access bound method defaults even if it is not clear whether 1215 # the accessor is appropriate. 1216 1217 target_structure = "&%s" % encode_path(objpath) 1218 1219 # Other targets are retrieved at run-time. Some information about them 1220 # may be available and be used to provide warnings about argument 1221 # compatibility. 1222 1223 elif self.importer.give_warning("args"): 1224 unsuitable = self.get_referenced_attribute_invocations(location) 1225 1226 if unsuitable: 1227 for ref in unsuitable: 1228 _objpath = ref.get_origin() 1229 num_parameters = len(self.importer.function_parameters[_objpath]) 1230 print >>sys.stderr, \ 1231 "In %s, at line %d, inappropriate number of " \ 1232 "arguments given. Need %d arguments to call %s." % ( 1233 self.get_namespace_path(), n.lineno, num_parameters, 1234 _objpath) 1235 1236 # Arguments are presented in a temporary frame array with any context 1237 # always being the first argument. Where it would be unused, it may be 1238 # set to null. 1239 1240 if context_required: 1241 if have_access_context: 1242 args = ["(__attr) {.value=__tmp_context}"] 1243 else: 1244 self.record_temp("__tmp_targets") 1245 args = ["__CONTEXT_AS_VALUE(__tmp_targets[%d])" % self.function_target] 1246 else: 1247 args = ["__NULL"] 1248 1249 # Complete the array with null values, permitting tests for a complete 1250 # set of arguments. 1251 1252 args += [None] * (not parameters and len(n.args) or parameters and len(parameters) or 0) 1253 kwcodes = [] 1254 kwargs = [] 1255 1256 # Any invocations in the arguments will store target details in a 1257 # different location. 1258 1259 self.function_target += 1 1260 1261 for i, arg in enumerate(n.args): 1262 argexpr = self.process_structure_node(arg) 1263 1264 # Store a keyword argument, either in the argument list or 1265 # in a separate keyword argument list for subsequent lookup. 1266 1267 if isinstance(arg, compiler.ast.Keyword): 1268 1269 # With knowledge of the target, store the keyword 1270 # argument directly. 1271 1272 if parameters: 1273 try: 1274 argnum = parameters.index(arg.name) 1275 except ValueError: 1276 raise TranslateError("Argument %s is not recognised." % arg.name, 1277 self.get_namespace_path(), n) 1278 args[argnum+1] = str(argexpr) 1279 1280 # Otherwise, store the details in a separate collection. 1281 1282 else: 1283 kwargs.append(str(argexpr)) 1284 kwcodes.append("{%s, %s}" % ( 1285 encode_symbol("ppos", arg.name), 1286 encode_symbol("pcode", arg.name))) 1287 1288 # Store non-keyword arguments in the argument list, rejecting 1289 # superfluous arguments. 1290 1291 else: 1292 try: 1293 args[i+1] = str(argexpr) 1294 except IndexError: 1295 raise TranslateError("Too many arguments specified.", 1296 self.get_namespace_path(), n) 1297 1298 # Reference the current target again. 1299 1300 self.function_target -= 1 1301 1302 # Defaults are added to the frame where arguments are missing. 1303 1304 if parameters: 1305 function_defaults = self.importer.function_defaults.get(objpath) 1306 if function_defaults: 1307 1308 # Visit each default and set any missing arguments. 1309 # Use the target structure to obtain defaults, as opposed to the 1310 # actual function involved. 1311 1312 for i, (argname, default) in enumerate(function_defaults): 1313 argnum = parameters.index(argname) 1314 if not args[argnum+1]: 1315 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1316 1317 # Test for missing arguments. 1318 1319 if None in args: 1320 raise TranslateError("Not all arguments supplied.", 1321 self.get_namespace_path(), n) 1322 1323 # Encode the arguments. 1324 1325 argstr = "__ARGS(%s)" % ", ".join(args) 1326 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1327 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1328 1329 # Where literal instantiation is occurring, add an argument indicating 1330 # the number of values. 1331 1332 if literal_instantiation: 1333 argstr += ", %d" % (len(args) - 1) 1334 1335 # First, the invocation expression is presented. 1336 1337 stages = [] 1338 1339 # Without a known specific callable, the expression provides the target. 1340 1341 if not target or context_required: 1342 self.record_temp("__tmp_targets") 1343 stages.append("__tmp_targets[%d] = %s" % (self.function_target, expr)) 1344 1345 # Any specific callable is then obtained. 1346 1347 if target: 1348 stages.append(target) 1349 1350 # Methods accessed via unidentified accessors are obtained. 1351 1352 elif function: 1353 self.record_temp("__tmp_targets") 1354 1355 if context_required: 1356 if have_access_context: 1357 stages.append("__get_function(__tmp_context, __tmp_targets[%d])" % ( 1358 self.function_target)) 1359 else: 1360 stages.append("__get_function(__CONTEXT_AS_VALUE(__tmp_targets[%d]).value, __tmp_targets[%d])" % ( 1361 self.function_target, self.function_target)) 1362 else: 1363 stages.append("__load_via_object(__tmp_targets[%d].value, %s).fn" % ( 1364 self.function_target, encode_symbol("pos", "__fn__"))) 1365 1366 # With a known target, the function is obtained directly and called. 1367 # By putting the invocation at the end of the final element in the 1368 # instruction sequence (the stages), the result becomes the result of 1369 # the sequence. Moreover, the parameters become part of the sequence 1370 # and thereby participate in a guaranteed evaluation order. 1371 1372 if target or function: 1373 stages[-1] += "(%s)" % argstr 1374 if instantiation: 1375 return InstantiationResult(instantiation, stages) 1376 else: 1377 return InvocationResult(stages) 1378 1379 # With unknown targets, the generic invocation function is applied to 1380 # the callable and argument collections. 1381 1382 else: 1383 self.record_temp("__tmp_targets") 1384 stages.append("__invoke(\n__tmp_targets[%d],\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1385 self.function_target, 1386 self.always_callable and 1 or 0, 1387 len(kwargs), kwcodestr, kwargstr, 1388 len(args), argstr)) 1389 return InvocationResult(stages) 1390 1391 def always_callable(self, refs): 1392 1393 "Determine whether all 'refs' are callable." 1394 1395 for ref in refs: 1396 if not ref.static(): 1397 return False 1398 else: 1399 origin = ref.final() 1400 if not self.importer.get_attribute(origin, "__fn__"): 1401 return False 1402 return True 1403 1404 def need_default_arguments(self, objpath, nargs): 1405 1406 """ 1407 Return whether any default arguments are needed when invoking the object 1408 given by 'objpath'. 1409 """ 1410 1411 parameters = self.importer.function_parameters.get(objpath) 1412 return nargs < len(parameters) 1413 1414 def process_lambda_node(self, n): 1415 1416 "Process the given lambda node 'n'." 1417 1418 name = self.get_lambda_name() 1419 function_name = self.get_object_path(name) 1420 1421 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1422 1423 # Without defaults, produce an attribute referring to the function. 1424 1425 if not defaults: 1426 return make_expression("((__attr) {.value=&%s})" % encode_path(function_name)) 1427 1428 # With defaults, copy the function structure and set the defaults on the 1429 # copy. 1430 1431 else: 1432 self.record_temp("__tmp_value") 1433 return make_expression("(__tmp_value = __COPY(&%s, sizeof(%s)), %s, (__attr) {.value=__tmp_value})" % ( 1434 encode_path(function_name), 1435 encode_symbol("obj", function_name), 1436 ", ".join(defaults))) 1437 1438 def process_logical_node(self, n): 1439 1440 """ 1441 Process the given operator node 'n'. 1442 1443 Convert ... to ... 1444 1445 <a> and <b> 1446 (__tmp_result = <a>, !__BOOL(__tmp_result)) ? __tmp_result : <b> 1447 1448 <a> or <b> 1449 (__tmp_result = <a>, __BOOL(__tmp_result)) ? __tmp_result : <b> 1450 """ 1451 1452 self.record_temp("__tmp_result") 1453 1454 if isinstance(n, compiler.ast.And): 1455 op = "!" 1456 else: 1457 op = "" 1458 1459 results = [] 1460 1461 for node in n.nodes[:-1]: 1462 expr = self.process_structure_node(node) 1463 results.append("(__tmp_result = %s, %s__BOOL(__tmp_result)) ? __tmp_result : " % (expr, op)) 1464 1465 expr = self.process_structure_node(n.nodes[-1]) 1466 results.append(str(expr)) 1467 1468 return make_expression("(%s)" % "".join(results)) 1469 1470 def process_name_node(self, n, expr=None): 1471 1472 "Process the given name node 'n' with the optional assignment 'expr'." 1473 1474 # Determine whether the name refers to a static external entity. 1475 1476 if n.name in predefined_constants: 1477 return PredefinedConstantRef(n.name, expr) 1478 1479 # Convert literal references, operator function names, and print 1480 # function names to references. 1481 1482 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1483 n.name.startswith("$print"): 1484 1485 ref, paths = self.importer.get_module(self.name).special[n.name] 1486 return TrResolvedNameRef(n.name, ref) 1487 1488 # Temporary names are output program locals. 1489 1490 elif n.name.startswith("$t"): 1491 return TrResolvedNameRef(n.name, Reference("<var>"), expr=expr) 1492 1493 # Get the appropriate name for the name reference, using the same method 1494 # as in the inspector. 1495 1496 path = self.get_namespace_path() 1497 objpath = self.get_object_path(n.name) 1498 1499 # Determine any assigned globals. 1500 1501 globals = self.importer.get_module(self.name).scope_globals.get(path) 1502 if globals and n.name in globals: 1503 objpath = self.get_global_path(n.name) 1504 1505 # Get the static identity of the name. 1506 1507 ref = self.importer.identify(objpath) 1508 if ref and not ref.get_name(): 1509 ref = ref.alias(objpath) 1510 1511 # Obtain any resolved names for non-assignment names. 1512 1513 if not expr and not ref and self.in_function: 1514 locals = self.importer.function_locals.get(path) 1515 ref = locals and locals.get(n.name) 1516 1517 # Determine whether the name refers to a parameter. The generation of 1518 # parameter references is different from other names. 1519 1520 parameters = self.importer.function_parameters.get(path) 1521 parameter = n.name == "self" and self.in_method() or \ 1522 parameters and n.name in parameters 1523 1524 # Find any invocation details. 1525 1526 location = self.get_access_location(n.name) 1527 1528 # Qualified names are used for resolved static references or for 1529 # static namespace members. The reference should be configured to return 1530 # such names. 1531 1532 return TrResolvedNameRef(n.name, ref, expr=expr, parameter=parameter, location=location) 1533 1534 def process_not_node(self, n): 1535 1536 "Process the given operator node 'n'." 1537 1538 return make_expression("(__BOOL(%s) ? %s : %s)" % 1539 (self.process_structure_node(n.expr), PredefinedConstantRef("False"), 1540 PredefinedConstantRef("True"))) 1541 1542 def process_raise_node(self, n): 1543 1544 "Process the given raise node 'n'." 1545 1546 # NOTE: Determine which raise statement variants should be permitted. 1547 1548 if n.expr1: 1549 1550 # Names with accompanying arguments are treated like invocations. 1551 1552 if n.expr2: 1553 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1554 exc = self.process_structure_node(call) 1555 self.writestmt("__Raise(%s);" % exc) 1556 1557 # Raise instances, testing the kind at run-time if necessary and 1558 # instantiating any non-instance. 1559 1560 else: 1561 exc = self.process_structure_node(n.expr1) 1562 1563 if isinstance(exc, TrInstanceRef): 1564 self.writestmt("__Raise(%s);" % exc) 1565 else: 1566 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1567 else: 1568 self.writestmt("__Throw(__tmp_exc);") 1569 1570 def process_return_node(self, n): 1571 1572 "Process the given return node 'n'." 1573 1574 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1575 if self.in_try_finally or self.in_try_except: 1576 self.writestmt("__Return(%s);" % expr) 1577 else: 1578 self.writestmt("return %s;" % expr) 1579 1580 return ReturnRef() 1581 1582 def process_try_node(self, n): 1583 1584 """ 1585 Process the given "try...except" node 'n'. 1586 """ 1587 1588 in_try_except = self.in_try_except 1589 self.in_try_except = 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 1598 # Put the else statement in another try block that handles any raised 1599 # exceptions and converts them to exceptions that will not be handled by 1600 # the main handling block. 1601 1602 if n.else_: 1603 self.writestmt("__Try") 1604 self.writeline("{") 1605 self.indent += 1 1606 self.process_structure_node(n.else_) 1607 self.indent -= 1 1608 self.writeline("}") 1609 self.writeline("__Catch (__tmp_exc)") 1610 self.writeline("{") 1611 self.indent += 1 1612 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1613 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1614 self.indent -= 1 1615 self.writeline("}") 1616 1617 # Complete the try block and enter the finally block, if appropriate. 1618 1619 if self.in_try_finally: 1620 self.writestmt("__Complete;") 1621 1622 self.indent -= 1 1623 self.writeline("}") 1624 1625 self.in_try_except = in_try_except 1626 1627 # Handlers are tests within a common handler block. 1628 1629 self.writeline("__Catch (__tmp_exc)") 1630 self.writeline("{") 1631 self.indent += 1 1632 1633 # Introduce an if statement to handle the completion of a try block. 1634 1635 self.process_try_completion() 1636 1637 # Handle exceptions in else blocks converted to __RaiseElse, converting 1638 # them back to normal exceptions. 1639 1640 if n.else_: 1641 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1642 1643 # Exception handling. 1644 1645 for name, var, handler in n.handlers: 1646 1647 # Test for specific exceptions. 1648 1649 if name is not None: 1650 name_ref = self.process_structure_node(name) 1651 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1652 else: 1653 self.writeline("else if (1)") 1654 1655 self.writeline("{") 1656 self.indent += 1 1657 1658 # Establish the local for the handler. 1659 1660 if var is not None: 1661 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1662 1663 if handler is not None: 1664 self.process_structure_node(handler) 1665 1666 self.indent -= 1 1667 self.writeline("}") 1668 1669 # Re-raise unhandled exceptions. 1670 1671 self.writeline("else __Throw(__tmp_exc);") 1672 1673 # End the handler block. 1674 1675 self.indent -= 1 1676 self.writeline("}") 1677 1678 def process_try_finally_node(self, n): 1679 1680 """ 1681 Process the given "try...finally" node 'n'. 1682 """ 1683 1684 in_try_finally = self.in_try_finally 1685 self.in_try_finally = True 1686 1687 # Use macros to implement exception handling. 1688 1689 self.writestmt("__Try") 1690 self.writeline("{") 1691 self.indent += 1 1692 self.process_structure_node(n.body) 1693 self.indent -= 1 1694 self.writeline("}") 1695 1696 self.in_try_finally = in_try_finally 1697 1698 # Finally clauses handle special exceptions. 1699 1700 self.writeline("__Catch (__tmp_exc)") 1701 self.writeline("{") 1702 self.indent += 1 1703 self.process_structure_node(n.final) 1704 1705 # Introduce an if statement to handle the completion of a try block. 1706 1707 self.process_try_completion() 1708 self.writeline("else __Throw(__tmp_exc);") 1709 1710 self.indent -= 1 1711 self.writeline("}") 1712 1713 def process_try_completion(self): 1714 1715 "Generate a test for the completion of a try block." 1716 1717 self.writestmt("if (__tmp_exc.completing)") 1718 self.writeline("{") 1719 self.indent += 1 1720 1721 # Do not return anything at the module level. 1722 1723 if self.get_namespace_path() != self.name: 1724 1725 # Only use the normal return statement if no surrounding try blocks 1726 # apply. 1727 1728 if not self.in_try_finally and not self.in_try_except: 1729 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1730 else: 1731 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1732 1733 self.indent -= 1 1734 self.writeline("}") 1735 1736 def process_while_node(self, n): 1737 1738 "Process the given while node 'n'." 1739 1740 self.writeline("while (1)") 1741 self.writeline("{") 1742 self.indent += 1 1743 test = self.process_structure_node(n.test) 1744 1745 # Emit the loop termination condition unless "while <true value>" is 1746 # indicated. 1747 1748 if not (isinstance(test, PredefinedConstantRef) and test.value): 1749 1750 # NOTE: This needs to evaluate whether the operand is true or false 1751 # NOTE: according to Python rules. 1752 1753 self.writeline("if (!__BOOL(%s))" % test) 1754 self.writeline("{") 1755 self.indent += 1 1756 if n.else_: 1757 self.process_structure_node(n.else_) 1758 self.writestmt("break;") 1759 self.indent -= 1 1760 self.writeline("}") 1761 1762 in_conditional = self.in_conditional 1763 self.in_conditional = True 1764 self.process_structure_node(n.body) 1765 self.in_conditional = in_conditional 1766 1767 self.indent -= 1 1768 self.writeline("}") 1769 1770 # Special variable usage. 1771 1772 def record_temp(self, name): 1773 1774 """ 1775 Record the use of the temporary 'name' in the current namespace. At the 1776 class or module level, the temporary name is associated with the module, 1777 since the variable will then be allocated in the module's own main 1778 program. 1779 """ 1780 1781 if self.in_function: 1782 path = self.get_namespace_path() 1783 else: 1784 path = self.name 1785 1786 init_item(self.temp_usage, path, set) 1787 self.temp_usage[path].add(name) 1788 1789 def uses_temp(self, path, name): 1790 1791 """ 1792 Return whether the given namespace 'path' employs a temporary variable 1793 with the given 'name'. Note that 'path' should only be a module or a 1794 function or method, not a class. 1795 """ 1796 1797 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1798 1799 # Output generation. 1800 1801 def start_output(self): 1802 1803 "Write the declarations at the top of each source file." 1804 1805 print >>self.out, """\ 1806 #include "types.h" 1807 #include "exceptions.h" 1808 #include "ops.h" 1809 #include "progconsts.h" 1810 #include "progops.h" 1811 #include "progtypes.h" 1812 #include "main.h" 1813 """ 1814 1815 def start_unit(self): 1816 1817 "Record output within a generated function for later use." 1818 1819 self.out = StringIO() 1820 1821 def end_unit(self, name): 1822 1823 "Add declarations and generated code." 1824 1825 # Restore the output stream. 1826 1827 out = self.out 1828 self.out = self.out_toplevel 1829 1830 self.write_temporaries(name) 1831 out.seek(0) 1832 self.out.write(out.read()) 1833 1834 self.indent -= 1 1835 print >>self.out, "}" 1836 1837 def start_module(self): 1838 1839 "Write the start of each module's main function." 1840 1841 print >>self.out, "void __main_%s()" % encode_path(self.name) 1842 print >>self.out, "{" 1843 self.indent += 1 1844 1845 # Define temporary variables, excluded from the module structure itself. 1846 1847 tempnames = [] 1848 1849 for n in self.importer.all_module_attrs[self.name]: 1850 if n.startswith("$t"): 1851 tempnames.append(encode_path(n)) 1852 1853 if tempnames: 1854 tempnames.sort() 1855 self.writeline("__attr %s;" % ", ".join(tempnames)) 1856 1857 self.start_unit() 1858 1859 def end_module(self): 1860 1861 "End each module by closing its main function." 1862 1863 self.end_unit(self.name) 1864 1865 def start_function(self, name): 1866 1867 "Start the function having the given 'name'." 1868 1869 print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name) 1870 print >>self.out, "{" 1871 self.indent += 1 1872 1873 # Obtain local names from parameters. 1874 1875 parameters = self.importer.function_parameters[name] 1876 locals = self.importer.function_locals[name].keys() 1877 names = [] 1878 1879 for n in locals: 1880 1881 # Filter out special names and parameters. Note that self is a local 1882 # regardless of whether it originally appeared in the parameters or 1883 # not. 1884 1885 if n.startswith("$l") or n in parameters or n == "self": 1886 continue 1887 names.append(encode_path(n)) 1888 1889 # Emit required local names. 1890 1891 if names: 1892 names.sort() 1893 self.writeline("__attr %s;" % ", ".join(names)) 1894 1895 self.write_parameters(name) 1896 self.start_unit() 1897 1898 def end_function(self, name): 1899 1900 "End the function having the given 'name'." 1901 1902 self.end_unit(name) 1903 print >>self.out 1904 1905 def write_temporaries(self, name): 1906 1907 "Write temporary storage employed by 'name'." 1908 1909 # Provide space for the given number of targets. 1910 1911 if self.uses_temp(name, "__tmp_targets"): 1912 targets = self.importer.function_targets.get(name) 1913 self.writeline("__attr __tmp_targets[%d];" % targets) 1914 1915 # Add temporary variable usage details. 1916 1917 if self.uses_temp(name, "__tmp_context"): 1918 self.writeline("__ref __tmp_context;") 1919 if self.uses_temp(name, "__tmp_value"): 1920 self.writeline("__ref __tmp_value;") 1921 if self.uses_temp(name, "__tmp_target_value"): 1922 self.writeline("__ref __tmp_target_value;") 1923 if self.uses_temp(name, "__tmp_result"): 1924 self.writeline("__attr __tmp_result;") 1925 1926 module = self.importer.get_module(self.name) 1927 1928 if name in module.exception_namespaces: 1929 self.writeline("__exc __tmp_exc;") 1930 1931 def write_parameters(self, name): 1932 1933 """ 1934 For the function having the given 'name', write definitions of 1935 parameters found in the arguments array. 1936 """ 1937 1938 parameters = self.importer.function_parameters[name] 1939 1940 # Generate any self reference. 1941 1942 if self.is_method(name): 1943 self.writeline("__attr * const self = &__args[0];") 1944 1945 # Generate aliases for the parameters. 1946 1947 for i, parameter in enumerate(parameters): 1948 self.writeline("__attr * const %s = &__args[%d];" % (encode_path(parameter), i+1)) 1949 1950 def start_if(self, first, test_ref): 1951 self.writestmt("%sif (__BOOL(%s))" % (not first and "else " or "", test_ref)) 1952 self.writeline("{") 1953 self.indent += 1 1954 1955 def end_if(self): 1956 self.indent -= 1 1957 self.writeline("}") 1958 1959 def start_else(self): 1960 self.writeline("else") 1961 self.writeline("{") 1962 self.indent += 1 1963 1964 def end_else(self): 1965 self.indent -= 1 1966 self.writeline("}") 1967 1968 def statement(self, expr): 1969 s = str(expr) 1970 if s: 1971 self.writestmt("%s;" % s) 1972 1973 def statements(self, results): 1974 for result in results: 1975 self.statement(result) 1976 1977 def writeline(self, s): 1978 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 1979 1980 def writestmt(self, s): 1981 print >>self.out 1982 self.writeline(s) 1983 1984 def write_comment(self, s): 1985 self.writestmt("/* %s */" % s) 1986 1987 def pad(self, extra=0): 1988 return (self.indent + extra) * self.tabstop 1989 1990 def indenttext(self, s, levels): 1991 lines = s.split("\n") 1992 out = [lines[0]] 1993 for line in lines[1:]: 1994 out.append(levels * self.tabstop + line) 1995 if line.endswith("("): 1996 levels += 1 1997 elif line.startswith(")"): 1998 levels -= 1 1999 return "\n".join(out) 2000 2001 # vim: tabstop=4 expandtab shiftwidth=4