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, is_newer, \ 24 predefined_constants 25 from encoders import encode_access_instruction, encode_access_instruction_arg, \ 26 encode_function_pointer, encode_literal_constant, \ 27 encode_literal_instantiator, encode_instantiator_pointer, \ 28 encode_instructions, \ 29 encode_path, encode_symbol, encode_type_attribute, \ 30 is_type_attribute 31 from errors import InspectError, TranslateError 32 from os.path import exists, join 33 from os import makedirs 34 from referencing import Reference 35 from StringIO import StringIO 36 import compiler 37 import results 38 import sys 39 40 class Translator(CommonOutput): 41 42 "A program translator." 43 44 def __init__(self, importer, deducer, optimiser, output): 45 self.importer = importer 46 self.deducer = deducer 47 self.optimiser = optimiser 48 self.output = output 49 50 def to_output(self, debug=False, gc_sections=False): 51 52 "Write a program to the configured output directory." 53 54 # Make a directory for the final sources. 55 56 output = join(self.output, "src") 57 58 if not exists(output): 59 makedirs(output) 60 61 # Clean the output directory of irrelevant data. 62 63 self.check_output("debug=%r gc_sections=%r" % (debug, gc_sections)) 64 65 for module in self.importer.modules.values(): 66 output_filename = join(output, "%s.c" % module.name) 67 68 # Do not generate modules in the native package. They are provided 69 # by native functionality source files. 70 71 parts = module.name.split(".") 72 73 if parts[0] != "native" and is_newer(module.filename, output_filename): 74 tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser) 75 tm.translate(module.filename, output_filename) 76 77 # Classes representing intermediate translation results. 78 79 class TranslationResult: 80 81 "An abstract translation result mix-in." 82 83 pass 84 85 class ReturnRef(TranslationResult): 86 87 "Indicates usage of a return statement." 88 89 pass 90 91 class Expression(results.Result, TranslationResult): 92 93 "A general expression." 94 95 def __init__(self, s): 96 self.s = s 97 def __str__(self): 98 return self.s 99 def __repr__(self): 100 return "Expression(%r)" % self.s 101 102 class TrResolvedNameRef(results.ResolvedNameRef, TranslationResult): 103 104 "A reference to a name in the translation." 105 106 def __init__(self, name, ref, expr=None, is_global=False, parameter=None, location=None): 107 results.ResolvedNameRef.__init__(self, name, ref, expr, is_global) 108 self.parameter = parameter 109 self.location = location 110 111 def access_location(self): 112 return self.location 113 114 def __str__(self): 115 116 "Return an output representation of the referenced name." 117 118 # For sources, any identified static origin will be constant and thus 119 # usable directly. For targets, no constant should be assigned and thus 120 # the alias (or any plain name) will be used. 121 122 ref = self.static() 123 origin = ref and self.get_origin() 124 static_name = origin and encode_path(origin) 125 126 # Determine whether a qualified name is involved. 127 128 t = (not self.is_constant_alias() and self.get_name() or self.name).rsplit(".", 1) 129 parent = len(t) > 1 and t[0] or None 130 attrname = t[-1] and encode_path(t[-1]) 131 132 # Assignments. 133 134 if self.expr: 135 136 # Eliminate assignments between constants. 137 138 if ref and isinstance(self.expr, results.ResolvedNameRef) and self.expr.static(): 139 return "" 140 141 # Qualified names must be converted into parent-relative assignments. 142 143 elif parent: 144 return "__store_via_object(&%s, %s, %s)" % ( 145 encode_path(parent), encode_symbol("pos", attrname), self.expr) 146 147 # All other assignments involve the names as they were given. 148 149 else: 150 return "(%s%s) = %s" % (self.parameter and "*" or "", attrname, self.expr) 151 152 # Expressions. 153 154 elif static_name: 155 parent = ref.parent() 156 context = ref.has_kind("<function>") and encode_path(parent) or None 157 return "((__attr) {.value=&%s})" % static_name 158 159 # Qualified names must be converted into parent-relative accesses. 160 161 elif parent: 162 return "__load_via_object(&%s, %s)" % ( 163 encode_path(parent), encode_symbol("pos", attrname)) 164 165 # All other accesses involve the names as they were given. 166 167 else: 168 return "(%s%s)" % (self.parameter and "*" or "", attrname) 169 170 class TrConstantValueRef(results.ConstantValueRef, TranslationResult): 171 172 "A constant value reference in the translation." 173 174 def __str__(self): 175 return encode_literal_constant(self.number) 176 177 class TrLiteralSequenceRef(results.LiteralSequenceRef, TranslationResult): 178 179 "A reference representing a sequence of values." 180 181 def __str__(self): 182 return str(self.node) 183 184 class TrInstanceRef(results.InstanceRef, TranslationResult): 185 186 "A reference representing instantiation of a class." 187 188 def __init__(self, ref, expr): 189 190 """ 191 Initialise the reference with 'ref' indicating the nature of the 192 reference and 'expr' being an expression used to create the instance. 193 """ 194 195 results.InstanceRef.__init__(self, ref) 196 self.expr = expr 197 198 def __str__(self): 199 return self.expr 200 201 def __repr__(self): 202 return "TrResolvedInstanceRef(%r, %r)" % (self.ref, self.expr) 203 204 class AttrResult(Expression, TranslationResult, InstructionSequence): 205 206 "A translation result for an attribute access." 207 208 def __init__(self, instructions, refs, location, context_identity): 209 InstructionSequence.__init__(self, instructions) 210 self.refs = refs 211 self.location = location 212 self.context_identity = context_identity 213 214 def references(self): 215 return self.refs 216 217 def access_location(self): 218 return self.location 219 220 def context(self): 221 return self.context_identity 222 223 def get_origin(self): 224 return self.refs and len(self.refs) == 1 and first(self.refs).get_origin() 225 226 def has_kind(self, kinds): 227 if not self.refs: 228 return False 229 for ref in self.refs: 230 if ref.has_kind(kinds): 231 return True 232 return False 233 234 def __nonzero__(self): 235 return bool(self.instructions) 236 237 def __str__(self): 238 return encode_instructions(self.instructions) 239 240 def __repr__(self): 241 return "AttrResult(%r, %r, %r)" % (self.instructions, self.refs, self.location) 242 243 class InvocationResult(Expression, TranslationResult, InstructionSequence): 244 245 "A translation result for an invocation." 246 247 def __init__(self, instructions): 248 InstructionSequence.__init__(self, instructions) 249 250 def __str__(self): 251 return encode_instructions(self.instructions) 252 253 def __repr__(self): 254 return "InvocationResult(%r)" % self.instructions 255 256 class InstantiationResult(InvocationResult, TrInstanceRef): 257 258 "An instantiation result acting like an invocation result." 259 260 def __init__(self, ref, instructions): 261 results.InstanceRef.__init__(self, ref) 262 InvocationResult.__init__(self, instructions) 263 264 def __repr__(self): 265 return "InstantiationResult(%r, %r)" % (self.ref, self.instructions) 266 267 class PredefinedConstantRef(Expression, TranslationResult): 268 269 "A predefined constant reference." 270 271 def __init__(self, value, expr=None): 272 self.value = value 273 self.expr = expr 274 275 def __str__(self): 276 277 # Eliminate predefined constant assignments. 278 279 if self.expr: 280 return "" 281 282 # Generate the specific constants. 283 284 if self.value in ("False", "True"): 285 return encode_path("__builtins__.boolean.%s" % self.value) 286 elif self.value == "None": 287 return encode_path("__builtins__.none.%s" % self.value) 288 elif self.value == "NotImplemented": 289 return encode_path("__builtins__.notimplemented.%s" % self.value) 290 else: 291 return self.value 292 293 def __repr__(self): 294 return "PredefinedConstantRef(%r)" % self.value 295 296 class BooleanResult(Expression, TranslationResult): 297 298 "A expression producing a boolean result." 299 300 def __str__(self): 301 return "__builtins___bool_bool(%s)" % self.s 302 303 def __repr__(self): 304 return "BooleanResult(%r)" % self.s 305 306 def make_expression(expr): 307 308 "Make a new expression from the existing 'expr'." 309 310 if isinstance(expr, results.Result): 311 return expr 312 else: 313 return Expression(str(expr)) 314 315 316 317 # The actual translation process itself. 318 319 class TranslatedModule(CommonModule): 320 321 "A module translator." 322 323 def __init__(self, name, importer, deducer, optimiser): 324 CommonModule.__init__(self, name, importer) 325 self.deducer = deducer 326 self.optimiser = optimiser 327 328 # Output stream. 329 330 self.out_toplevel = self.out = None 331 self.indent = 0 332 self.tabstop = " " 333 334 # Recorded namespaces. 335 336 self.namespaces = [] 337 self.in_conditional = False 338 339 # Exception raising adjustments. 340 341 self.in_try_finally = False 342 self.in_try_except = False 343 344 # Attribute access and accessor counting. 345 346 self.attr_accesses = {} 347 self.attr_accessors = {} 348 349 # Special variable usage. 350 351 self.temp_usage = {} 352 353 # Initialise some data used for attribute access generation. 354 355 self.init_substitutions() 356 357 def __repr__(self): 358 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 359 360 def translate(self, filename, output_filename): 361 362 """ 363 Parse the file having the given 'filename', writing the translation to 364 the given 'output_filename'. 365 """ 366 367 self.parse_file(filename) 368 369 # Collect function namespaces for separate processing. 370 371 self.record_namespaces(self.astnode) 372 373 # Reset the lambda naming (in order to obtain the same names again) and 374 # translate the program. 375 376 self.reset_lambdas() 377 378 self.out_toplevel = self.out = open(output_filename, "w") 379 try: 380 self.start_output() 381 382 # Process namespaces, writing the translation. 383 384 for path, node in self.namespaces: 385 self.process_namespace(path, node) 386 387 # Process the module namespace including class namespaces. 388 389 self.process_namespace([], self.astnode) 390 391 finally: 392 self.out.close() 393 394 def have_object(self): 395 396 "Return whether a namespace is a recorded object." 397 398 return self.importer.objects.get(self.get_namespace_path()) 399 400 def get_builtin_class(self, name): 401 402 "Return a reference to the actual object providing 'name'." 403 404 return self.importer.get_object(get_builtin_class(name)) 405 406 def is_method(self, path): 407 408 "Return whether 'path' is a method." 409 410 class_name, method_name = path.rsplit(".", 1) 411 return self.importer.classes.has_key(class_name) and class_name or None 412 413 def in_method(self): 414 415 "Return whether the current namespace provides a method." 416 417 return self.in_function and self.is_method(self.get_namespace_path()) 418 419 # Namespace recording. 420 421 def record_namespaces(self, node): 422 423 "Process the program structure 'node', recording namespaces." 424 425 for n in node.getChildNodes(): 426 self.record_namespaces_in_node(n) 427 428 def record_namespaces_in_node(self, node): 429 430 "Process the program structure 'node', recording namespaces." 431 432 # Function namespaces within modules, classes and other functions. 433 # Functions appearing within conditional statements are given arbitrary 434 # names. 435 436 if isinstance(node, compiler.ast.Function): 437 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 438 439 elif isinstance(node, compiler.ast.Lambda): 440 self.record_function_node(node, self.get_lambda_name()) 441 442 # Classes are visited, but may be ignored if inside functions. 443 444 elif isinstance(node, compiler.ast.Class): 445 self.enter_namespace(node.name) 446 if self.have_object(): 447 self.record_namespaces(node) 448 self.exit_namespace() 449 450 # Conditional nodes are tracked so that function definitions may be 451 # handled. Since "for" loops are converted to "while" loops, they are 452 # included here. 453 454 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 455 in_conditional = self.in_conditional 456 self.in_conditional = True 457 self.record_namespaces(node) 458 self.in_conditional = in_conditional 459 460 # All other nodes are processed depth-first. 461 462 else: 463 self.record_namespaces(node) 464 465 def record_function_node(self, n, name): 466 467 """ 468 Record the given function, lambda, if expression or list comprehension 469 node 'n' with the given 'name'. 470 """ 471 472 self.in_function = True 473 self.enter_namespace(name) 474 475 if self.have_object(): 476 477 # Record the namespace path and the node itself. 478 479 self.namespaces.append((self.namespace_path[:], n)) 480 self.record_namespaces_in_node(n.code) 481 482 self.exit_namespace() 483 self.in_function = False 484 485 # Constant referencing. 486 487 def get_literal_instance(self, n, name=None): 488 489 """ 490 For node 'n', return a reference for the type of the given 'name', or if 491 'name' is not specified, deduce the type from the value. 492 """ 493 494 # Handle stray None constants (Sliceobj seems to produce them). 495 496 if name is None and n.value is None: 497 return self.process_name_node(compiler.ast.Name("None")) 498 499 if name in ("dict", "list", "tuple"): 500 ref = self.get_builtin_class(name) 501 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 502 else: 503 value, typename, encoding = self.get_constant_value(n.value, n.literals) 504 ref = self.get_builtin_class(typename) 505 value_type = ref.get_origin() 506 507 path = self.get_namespace_path() 508 509 # Obtain the local numbering of the constant and thus the 510 # locally-qualified name. 511 512 local_number = self.importer.all_constants[path][(value, value_type, encoding)] 513 constant_name = "$c%d" % local_number 514 objpath = self.get_object_path(constant_name) 515 516 # Obtain the unique identifier for the constant. 517 518 number = self.optimiser.constant_numbers[objpath] 519 return TrConstantValueRef(constant_name, ref.instance_of(), value, number) 520 521 # Namespace translation. 522 523 def process_namespace(self, path, node): 524 525 """ 526 Process the namespace for the given 'path' defined by the given 'node'. 527 """ 528 529 self.namespace_path = path 530 531 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 532 self.in_function = True 533 self.process_function_body_node(node) 534 else: 535 self.in_function = False 536 self.function_target = 0 537 self.start_module() 538 self.process_structure(node) 539 self.end_module() 540 541 def process_structure(self, node): 542 543 "Process the given 'node' or result." 544 545 # Handle processing requests on results. 546 547 if isinstance(node, results.Result): 548 return node 549 550 # Handle processing requests on nodes. 551 552 else: 553 l = CommonModule.process_structure(self, node) 554 555 # Return indications of return statement usage. 556 557 if l and isinstance(l[-1], ReturnRef): 558 return l[-1] 559 else: 560 return None 561 562 def process_structure_node(self, n): 563 564 "Process the individual node 'n'." 565 566 # Plain statements emit their expressions. 567 568 if isinstance(n, compiler.ast.Discard): 569 expr = self.process_structure_node(n.expr) 570 self.statement(expr) 571 572 # Module import declarations. 573 574 elif isinstance(n, compiler.ast.From): 575 self.process_from_node(n) 576 577 # Nodes using operator module functions. 578 579 elif isinstance(n, compiler.ast.Operator): 580 return self.process_operator_node(n) 581 582 elif isinstance(n, compiler.ast.AugAssign): 583 self.process_augassign_node(n) 584 585 elif isinstance(n, compiler.ast.Compare): 586 return self.process_compare_node(n) 587 588 elif isinstance(n, compiler.ast.Slice): 589 return self.process_slice_node(n) 590 591 elif isinstance(n, compiler.ast.Sliceobj): 592 return self.process_sliceobj_node(n) 593 594 elif isinstance(n, compiler.ast.Subscript): 595 return self.process_subscript_node(n) 596 597 # Classes are visited, but may be ignored if inside functions. 598 599 elif isinstance(n, compiler.ast.Class): 600 self.process_class_node(n) 601 602 # Functions within namespaces have any dynamic defaults initialised. 603 604 elif isinstance(n, compiler.ast.Function): 605 self.process_function_node(n) 606 607 # Lambdas are replaced with references to separately-generated 608 # functions. 609 610 elif isinstance(n, compiler.ast.Lambda): 611 return self.process_lambda_node(n) 612 613 # Assignments. 614 615 elif isinstance(n, compiler.ast.Assign): 616 617 # Handle each assignment node. 618 619 for node in n.nodes: 620 self.process_assignment_node(node, n.expr) 621 622 # Accesses. 623 624 elif isinstance(n, compiler.ast.Getattr): 625 return self.process_attribute_access(n) 626 627 # Names. 628 629 elif isinstance(n, compiler.ast.Name): 630 return self.process_name_node(n) 631 632 # Loops and conditionals. 633 634 elif isinstance(n, compiler.ast.For): 635 self.process_for_node(n) 636 637 elif isinstance(n, compiler.ast.While): 638 self.process_while_node(n) 639 640 elif isinstance(n, compiler.ast.If): 641 self.process_if_node(n) 642 643 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 644 return self.process_logical_node(n) 645 646 elif isinstance(n, compiler.ast.Not): 647 return self.process_not_node(n) 648 649 # Exception control-flow tracking. 650 651 elif isinstance(n, compiler.ast.TryExcept): 652 self.process_try_node(n) 653 654 elif isinstance(n, compiler.ast.TryFinally): 655 self.process_try_finally_node(n) 656 657 # Control-flow modification statements. 658 659 elif isinstance(n, compiler.ast.Break): 660 self.writestmt("break;") 661 662 elif isinstance(n, compiler.ast.Continue): 663 self.writestmt("continue;") 664 665 elif isinstance(n, compiler.ast.Raise): 666 self.process_raise_node(n) 667 668 elif isinstance(n, compiler.ast.Return): 669 return self.process_return_node(n) 670 671 # Print statements. 672 673 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 674 self.statement(self.process_print_node(n)) 675 676 # Invocations. 677 678 elif isinstance(n, compiler.ast.CallFunc): 679 return self.process_invocation_node(n) 680 681 elif isinstance(n, compiler.ast.Keyword): 682 return self.process_structure_node(n.expr) 683 684 # Constant usage. 685 686 elif isinstance(n, compiler.ast.Const): 687 return self.get_literal_instance(n) 688 689 elif isinstance(n, compiler.ast.Dict): 690 return self.get_literal_instance(n, "dict") 691 692 elif isinstance(n, compiler.ast.List): 693 return self.get_literal_instance(n, "list") 694 695 elif isinstance(n, compiler.ast.Tuple): 696 return self.get_literal_instance(n, "tuple") 697 698 # All other nodes are processed depth-first. 699 700 else: 701 return self.process_structure(n) 702 703 def process_assignment_node(self, n, expr): 704 705 "Process the individual node 'n' to be assigned the contents of 'expr'." 706 707 # Names and attributes are assigned the entire expression. 708 709 if isinstance(n, compiler.ast.AssName): 710 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 711 self.statement(name_ref) 712 713 # Employ guards after assignments if required. 714 715 if expr and name_ref.is_name(): 716 self.generate_guard(name_ref.name) 717 718 elif isinstance(n, compiler.ast.AssAttr): 719 in_assignment = self.in_assignment 720 self.in_assignment = self.process_structure_node(expr) 721 self.statement(self.process_attribute_access(n)) 722 self.in_assignment = in_assignment 723 724 # Lists and tuples are matched against the expression and their 725 # items assigned to expression items. 726 727 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 728 self.process_assignment_node_items(n, expr) 729 730 # Slices and subscripts are permitted within assignment nodes. 731 732 elif isinstance(n, compiler.ast.Slice): 733 self.statement(self.process_slice_node(n, expr)) 734 735 elif isinstance(n, compiler.ast.Subscript): 736 self.statement(self.process_subscript_node(n, expr)) 737 738 def process_attribute_access(self, n): 739 740 "Process the given attribute access node 'n'." 741 742 # Obtain any completed chain and return the reference to it. 743 744 attr_expr = self.process_attribute_chain(n) 745 if self.have_access_expression(n): 746 return attr_expr 747 748 # Where the start of the chain of attributes has been reached, process 749 # the complete access. 750 751 name_ref = attr_expr and attr_expr.is_name() and attr_expr 752 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref) or None 753 754 location = self.get_access_location(name, self.attrs) 755 refs = self.get_referenced_attributes(location) 756 757 # Generate access instructions. 758 759 subs = { 760 "<expr>" : attr_expr, 761 "<name>" : "%s.value" % attr_expr, 762 "<assexpr>" : self.in_assignment, 763 } 764 765 subs.update(self.temp_subs) 766 subs.update(self.op_subs) 767 768 output = [] 769 substituted = set() 770 771 # The context set or retrieved will be that used by any enclosing 772 # invocation. 773 774 context_index = self.function_target - 1 775 context_identity = None 776 777 # Obtain encoded versions of each instruction, accumulating temporary 778 # variables. 779 780 for instruction in self.optimiser.access_instructions[location]: 781 782 # Intercept a special instruction identifying the context. 783 784 if instruction[0] == "<context_identity>": 785 context_identity, _substituted = encode_access_instruction_arg(instruction[1], subs, instruction[0], context_index) 786 continue 787 788 # Collect the encoded instruction, noting any temporary variables 789 # required by it. 790 791 encoded, _substituted = encode_access_instruction(instruction, subs, context_index) 792 output.append(encoded) 793 substituted.update(_substituted) 794 795 # Record temporary name usage. 796 797 for sub in substituted: 798 if self.temp_subs.has_key(sub): 799 self.record_temp(self.temp_subs[sub]) 800 801 del self.attrs[0] 802 return AttrResult(output, refs, location, context_identity) 803 804 def init_substitutions(self): 805 806 """ 807 Initialise substitutions, defining temporary variable mappings, some of 808 which are also used as substitutions, together with operation mappings 809 used as substitutions in instructions defined by the optimiser. 810 """ 811 812 self.temp_subs = { 813 814 # Substitutions used by instructions. 815 816 "<private_context>" : "__tmp_private_context", 817 "<accessor>" : "__tmp_value", 818 "<target_accessor>" : "__tmp_target_value", 819 820 # Mappings to be replaced by those given below. 821 822 "<context>" : "__tmp_contexts", 823 "<test_context_revert>" : "__tmp_contexts", 824 "<test_context_static>" : "__tmp_contexts", 825 "<set_context>" : "__tmp_contexts", 826 "<set_private_context>" : "__tmp_private_context", 827 "<set_accessor>" : "__tmp_value", 828 "<set_target_accessor>" : "__tmp_target_value", 829 } 830 831 self.op_subs = { 832 "<context>" : "__get_context", 833 "<test_context_revert>" : "__test_context_revert", 834 "<test_context_static>" : "__test_context_static", 835 "<set_context>" : "__set_context", 836 "<set_private_context>" : "__set_private_context", 837 "<set_accessor>" : "__set_accessor", 838 "<set_target_accessor>" : "__set_target_accessor", 839 } 840 841 def get_referenced_attributes(self, location): 842 843 """ 844 Convert 'location' to the form used by the deducer and retrieve any 845 identified attributes. 846 """ 847 848 access_location = self.deducer.const_accesses.get(location) 849 refs = [] 850 for attrtype, objpath, attr in self.deducer.referenced_attrs[access_location or location]: 851 refs.append(attr) 852 return refs 853 854 def get_referenced_attribute_invocations(self, location): 855 856 """ 857 Convert 'location' to the form used by the deducer and retrieve any 858 identified attribute invocation details. 859 """ 860 861 access_location = self.deducer.const_accesses.get(location) 862 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 863 864 def get_accessor_kinds(self, location): 865 866 "Return the accessor kinds for 'location'." 867 868 return self.optimiser.accessor_kinds.get(location) 869 870 def get_access_location(self, name, attrnames=None): 871 872 """ 873 Using the current namespace, the given 'name', and the 'attrnames' 874 employed in an access, return the access location. 875 """ 876 877 path = self.get_path_for_access() 878 879 # Get the location used by the deducer and optimiser and find any 880 # recorded access. 881 882 attrnames = attrnames and ".".join(self.attrs) 883 access_number = self.get_access_number(path, name, attrnames) 884 self.update_access_number(path, name, attrnames) 885 return (path, name, attrnames, access_number) 886 887 def get_access_number(self, path, name, attrnames): 888 access = name, attrnames 889 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 890 return self.attr_accesses[path][access] 891 else: 892 return 0 893 894 def update_access_number(self, path, name, attrnames): 895 access = name, attrnames 896 if name: 897 init_item(self.attr_accesses, path, dict) 898 init_item(self.attr_accesses[path], access, lambda: 0) 899 self.attr_accesses[path][access] += 1 900 901 def get_accessor_location(self, name): 902 903 """ 904 Using the current namespace and the given 'name', return the accessor 905 location. 906 """ 907 908 path = self.get_path_for_access() 909 910 # Get the location used by the deducer and optimiser and find any 911 # recorded accessor. 912 913 access_number = self.get_accessor_number(path, name) 914 self.update_accessor_number(path, name) 915 return (path, name, None, access_number) 916 917 def get_accessor_number(self, path, name): 918 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 919 return self.attr_accessors[path][name] 920 else: 921 return 0 922 923 def update_accessor_number(self, path, name): 924 if name: 925 init_item(self.attr_accessors, path, dict) 926 init_item(self.attr_accessors[path], name, lambda: 0) 927 self.attr_accessors[path][name] += 1 928 929 def process_class_node(self, n): 930 931 "Process the given class node 'n'." 932 933 class_name = self.get_object_path(n.name) 934 935 # Where a class is set conditionally or where the name may refer to 936 # different values, assign the name. 937 938 ref = self.importer.identify(class_name) 939 940 if not ref.static(): 941 self.process_assignment_for_object( 942 n.name, make_expression("((__attr) {.value=&%s})" % 943 encode_path(class_name))) 944 945 self.enter_namespace(n.name) 946 947 if self.have_object(): 948 self.write_comment("Class: %s" % class_name) 949 950 self.initialise_inherited_members(class_name) 951 952 self.process_structure(n) 953 self.write_comment("End class: %s" % class_name) 954 955 self.exit_namespace() 956 957 def initialise_inherited_members(self, class_name): 958 959 "Initialise members of 'class_name' inherited from its ancestors." 960 961 for name, path in self.importer.all_class_attrs[class_name].items(): 962 target = "%s.%s" % (class_name, name) 963 964 # Ignore attributes with definitions. 965 966 ref = self.importer.identify(target) 967 if ref: 968 continue 969 970 # Ignore special type attributes. 971 972 if is_type_attribute(name): 973 continue 974 975 # Reference inherited attributes. 976 977 ref = self.importer.identify(path) 978 if ref and not ref.static(): 979 parent, attrname = path.rsplit(".", 1) 980 981 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 982 encode_path(class_name), encode_symbol("pos", name), 983 encode_path(parent), encode_symbol("pos", attrname) 984 )) 985 986 def process_from_node(self, n): 987 988 "Process the given node 'n', importing from another module." 989 990 path = self.get_namespace_path() 991 992 # Attempt to obtain the referenced objects. 993 994 for name, alias in n.names: 995 if name == "*": 996 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 997 998 # Obtain the path of the assigned name. 999 1000 objpath = self.get_object_path(alias or name) 1001 1002 # Obtain the identity of the name. 1003 1004 ref = self.importer.identify(objpath) 1005 1006 # Where the name is not static, assign the value. 1007 1008 if ref and not ref.static() and ref.get_name(): 1009 self.writestmt("%s;" % 1010 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 1011 expr=TrResolvedNameRef(name, ref))) 1012 1013 def process_function_body_node(self, n): 1014 1015 """ 1016 Process the given function, lambda, if expression or list comprehension 1017 node 'n', generating the body. 1018 """ 1019 1020 function_name = self.get_namespace_path() 1021 self.start_function(function_name) 1022 1023 # Process the function body. 1024 1025 in_conditional = self.in_conditional 1026 self.in_conditional = False 1027 self.function_target = 0 1028 1029 # Process any guards defined for the parameters. 1030 1031 for name in self.importer.function_parameters.get(function_name): 1032 self.generate_guard(name) 1033 1034 # Produce the body and any additional return statement. 1035 1036 expr = self.process_structure_node(n.code) or PredefinedConstantRef("None") 1037 if not isinstance(expr, ReturnRef): 1038 self.writestmt("return %s;" % expr) 1039 1040 self.in_conditional = in_conditional 1041 1042 self.end_function(function_name) 1043 1044 def generate_guard(self, name): 1045 1046 """ 1047 Get the accessor details for 'name', found in the current namespace, and 1048 generate any guards defined for it. 1049 """ 1050 1051 # Obtain the location, keeping track of assignment versions. 1052 1053 location = self.get_accessor_location(name) 1054 test = self.deducer.accessor_guard_tests.get(location) 1055 1056 # Generate any guard from the deduced information. 1057 1058 if test: 1059 guard, guard_type = test 1060 1061 if guard == "specific": 1062 ref = first(self.deducer.accessor_all_types[location]) 1063 argstr = "&%s" % encode_path(ref.get_origin()) 1064 elif guard == "common": 1065 ref = first(self.deducer.accessor_all_general_types[location]) 1066 typeattr = encode_type_attribute(ref.get_origin()) 1067 argstr = "%s, %s" % (encode_symbol("pos", typeattr), encode_symbol("code", typeattr)) 1068 else: 1069 return 1070 1071 # Produce an appropriate access to an attribute's value. 1072 1073 parameters = self.importer.function_parameters.get(self.get_namespace_path()) 1074 if parameters and name in parameters: 1075 name_to_value = "%s->value" % name 1076 else: 1077 name_to_value = "%s.value" % name 1078 1079 # Write a test that raises a TypeError upon failure. 1080 1081 self.writestmt("if (!__test_%s_%s(%s, %s)) __raise_type_error();" % ( 1082 guard, guard_type, name_to_value, argstr)) 1083 1084 def process_function_node(self, n): 1085 1086 """ 1087 Process the given function, lambda, if expression or list comprehension 1088 node 'n', generating any initialisation statements. 1089 """ 1090 1091 # Where a function is declared conditionally, use a separate name for 1092 # the definition, and assign the definition to the stated name. 1093 1094 original_name = n.name 1095 1096 if self.in_conditional or self.in_function: 1097 name = self.get_lambda_name() 1098 else: 1099 name = n.name 1100 1101 objpath = self.get_object_path(name) 1102 1103 # Obtain details of the defaults. 1104 1105 defaults = self.process_function_defaults(n, name, objpath) 1106 if defaults: 1107 for default in defaults: 1108 self.writeline("%s;" % default) 1109 1110 # Where a function is set conditionally or where the name may refer to 1111 # different values, assign the name. 1112 1113 ref = self.importer.identify(objpath) 1114 1115 if self.in_conditional or self.in_function: 1116 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 1117 elif not ref.static(): 1118 context = self.is_method(objpath) 1119 1120 self.process_assignment_for_object(original_name, 1121 make_expression("((__attr) {.value=&%s})" % encode_path(objpath))) 1122 1123 def process_function_defaults(self, n, name, objpath, instance_name=None): 1124 1125 """ 1126 Process the given function or lambda node 'n', initialising defaults 1127 that are dynamically set. The given 'name' indicates the name of the 1128 function. The given 'objpath' indicates the origin of the function. 1129 The given 'instance_name' indicates the name of any separate instance 1130 of the function created to hold the defaults. 1131 1132 Return a list of operations setting defaults on a function instance. 1133 """ 1134 1135 function_name = self.get_object_path(name) 1136 function_defaults = self.importer.function_defaults.get(function_name) 1137 if not function_defaults: 1138 return None 1139 1140 # Determine whether any unidentified defaults are involved. 1141 1142 for argname, default in function_defaults: 1143 if not default.static(): 1144 break 1145 else: 1146 return None 1147 1148 # Handle bound methods. 1149 1150 if not instance_name: 1151 instance_name = "&%s" % encode_path(objpath) 1152 1153 # Where defaults are involved but cannot be identified, obtain a new 1154 # instance of the lambda and populate the defaults. 1155 1156 defaults = [] 1157 1158 # Join the original defaults with the inspected defaults. 1159 1160 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 1161 1162 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 1163 1164 # Obtain any reference for the default. 1165 1166 if original: 1167 argname, default = original 1168 name_ref = self.process_structure_node(default) 1169 elif inspected: 1170 argname, default = inspected 1171 name_ref = TrResolvedNameRef(argname, default) 1172 else: 1173 continue 1174 1175 # Generate default initialisers except when constants are employed. 1176 # Constants should be used when populating the function structures. 1177 1178 if name_ref and not isinstance(name_ref, TrConstantValueRef): 1179 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 1180 1181 return defaults 1182 1183 def process_if_node(self, n): 1184 1185 """ 1186 Process the given "if" node 'n'. 1187 """ 1188 1189 first = True 1190 for test, body in n.tests: 1191 test_ref = self.process_structure_node(test) 1192 self.start_if(first, test_ref) 1193 1194 in_conditional = self.in_conditional 1195 self.in_conditional = True 1196 self.process_structure_node(body) 1197 self.in_conditional = in_conditional 1198 1199 self.end_if() 1200 first = False 1201 1202 if n.else_: 1203 self.start_else() 1204 self.process_structure_node(n.else_) 1205 self.end_else() 1206 1207 def process_invocation_node(self, n): 1208 1209 "Process the given invocation node 'n'." 1210 1211 # Any invocations in the expression will store target details in a 1212 # different location. 1213 1214 self.function_target += 1 1215 1216 # Process the expression. 1217 1218 expr = self.process_structure_node(n.node) 1219 1220 # Reference the current target again. 1221 1222 self.function_target -= 1 1223 1224 # Obtain details of the invocation expression. 1225 1226 objpath = expr.get_origin() 1227 location = expr.access_location() 1228 1229 # Identified target details. 1230 1231 target = None 1232 target_structure = None 1233 1234 # Specific function target information. 1235 1236 function = None 1237 1238 # Instantiation involvement. 1239 1240 instantiation = False 1241 literal_instantiation = False 1242 1243 # Invocation requirements. 1244 1245 context_required = True 1246 have_access_context = isinstance(expr, AttrResult) 1247 context_identity = have_access_context and expr.context() 1248 parameters = None 1249 1250 # Obtain details of the callable and of its parameters. 1251 1252 # Literals may be instantiated specially. 1253 1254 if expr.is_name() and expr.name.startswith("$L") and objpath: 1255 instantiation = literal_instantiation = objpath 1256 target = encode_literal_instantiator(objpath) 1257 context_required = False 1258 1259 # Identified targets employ function pointers directly. 1260 1261 elif objpath: 1262 parameters = self.importer.function_parameters.get(objpath) 1263 1264 # Class invocation involves instantiators. 1265 1266 if expr.has_kind("<class>"): 1267 instantiation = objpath 1268 target = encode_instantiator_pointer(objpath) 1269 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1270 target_structure = "&%s" % encode_path(init_ref) 1271 context_required = False 1272 1273 # Only plain functions and bound methods employ function pointers. 1274 1275 elif expr.has_kind("<function>"): 1276 function = objpath 1277 1278 # Test for functions and methods. 1279 1280 context_required = self.is_method(objpath) 1281 accessor_kinds = self.get_accessor_kinds(location) 1282 instance_accessor = accessor_kinds and \ 1283 len(accessor_kinds) == 1 and \ 1284 first(accessor_kinds) == "<instance>" 1285 1286 # Only identify certain bound methods or functions. 1287 1288 if not context_required or instance_accessor: 1289 target = encode_function_pointer(objpath) 1290 1291 # Access bound method defaults even if it is not clear whether 1292 # the accessor is appropriate. 1293 1294 target_structure = "&%s" % encode_path(objpath) 1295 1296 # Other targets are retrieved at run-time. Some information about them 1297 # may be available and be used to provide warnings about argument 1298 # compatibility. 1299 1300 elif self.importer.give_warning("args"): 1301 unsuitable = self.get_referenced_attribute_invocations(location) 1302 1303 if unsuitable: 1304 for ref in unsuitable: 1305 _objpath = ref.get_origin() 1306 num_parameters = len(self.importer.function_parameters[_objpath]) 1307 print >>sys.stderr, \ 1308 "In %s, at line %d, inappropriate number of " \ 1309 "arguments given. Need %d arguments to call %s." % ( 1310 self.get_namespace_path(), n.lineno, num_parameters, 1311 _objpath) 1312 1313 # Arguments are presented in a temporary frame array with any context 1314 # always being the first argument. Where it would be unused, it may be 1315 # set to null. 1316 1317 if context_required: 1318 if have_access_context: 1319 if context_identity.startswith("__tmp_contexts"): 1320 self.record_temp("__tmp_contexts") 1321 args = ["(__attr) {.value=%s}" % context_identity] 1322 else: 1323 self.record_temp("__tmp_targets") 1324 args = ["__CONTEXT_AS_VALUE(__tmp_targets[%d])" % self.function_target] 1325 else: 1326 args = ["__NULL"] 1327 1328 # Complete the array with null values, permitting tests for a complete 1329 # set of arguments. 1330 1331 args += [None] * (not parameters and len(n.args) or parameters and len(parameters) or 0) 1332 kwcodes = [] 1333 kwargs = [] 1334 1335 # Any invocations in the arguments will store target details in a 1336 # different location. 1337 1338 self.function_target += 1 1339 1340 for i, arg in enumerate(n.args): 1341 argexpr = self.process_structure_node(arg) 1342 1343 # Store a keyword argument, either in the argument list or 1344 # in a separate keyword argument list for subsequent lookup. 1345 1346 if isinstance(arg, compiler.ast.Keyword): 1347 1348 # With knowledge of the target, store the keyword 1349 # argument directly. 1350 1351 if parameters: 1352 try: 1353 argnum = parameters.index(arg.name) 1354 except ValueError: 1355 raise TranslateError("Argument %s is not recognised." % arg.name, 1356 self.get_namespace_path(), n) 1357 args[argnum+1] = str(argexpr) 1358 1359 # Otherwise, store the details in a separate collection. 1360 1361 else: 1362 kwargs.append(str(argexpr)) 1363 kwcodes.append("{%s, %s}" % ( 1364 encode_symbol("ppos", arg.name), 1365 encode_symbol("pcode", arg.name))) 1366 1367 # Store non-keyword arguments in the argument list, rejecting 1368 # superfluous arguments. 1369 1370 else: 1371 try: 1372 args[i+1] = str(argexpr) 1373 except IndexError: 1374 raise TranslateError("Too many arguments specified.", 1375 self.get_namespace_path(), n) 1376 1377 # Reference the current target again. 1378 1379 self.function_target -= 1 1380 1381 # Defaults are added to the frame where arguments are missing. 1382 1383 if parameters: 1384 function_defaults = self.importer.function_defaults.get(objpath) 1385 if function_defaults: 1386 1387 # Visit each default and set any missing arguments. 1388 # Use the target structure to obtain defaults, as opposed to the 1389 # actual function involved. 1390 1391 for i, (argname, default) in enumerate(function_defaults): 1392 argnum = parameters.index(argname) 1393 if not args[argnum+1]: 1394 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1395 1396 # Test for missing arguments. 1397 1398 if None in args: 1399 raise TranslateError("Not all arguments supplied.", 1400 self.get_namespace_path(), n) 1401 1402 # Encode the arguments. 1403 1404 argstr = "__ARGS(%s)" % ", ".join(args) 1405 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1406 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1407 1408 # Where literal instantiation is occurring, add an argument indicating 1409 # the number of values. 1410 1411 if literal_instantiation: 1412 argstr += ", %d" % (len(args) - 1) 1413 1414 # First, the invocation expression is presented. 1415 1416 stages = [] 1417 1418 # Without a known specific callable, the expression provides the target. 1419 1420 if not target or context_required: 1421 if target: 1422 if expr: 1423 stages.append(str(expr)) 1424 else: 1425 self.record_temp("__tmp_targets") 1426 stages.append("__tmp_targets[%d] = %s" % (self.function_target, expr)) 1427 1428 # Any specific callable is then obtained. 1429 1430 if target: 1431 stages.append(target) 1432 1433 # Methods accessed via unidentified accessors are obtained. 1434 1435 elif function: 1436 self.record_temp("__tmp_targets") 1437 1438 if context_required: 1439 if have_access_context: 1440 if context_identity.startswith("__tmp_contexts"): 1441 self.record_temp("__tmp_contexts") 1442 stages.append("__get_function(%s, __tmp_targets[%d])" % ( 1443 context_identity, self.function_target)) 1444 else: 1445 stages.append("__get_function(__CONTEXT_AS_VALUE(__tmp_targets[%d]).value, __tmp_targets[%d])" % ( 1446 self.function_target, self.function_target)) 1447 else: 1448 stages.append("__load_via_object(__tmp_targets[%d].value, %s).fn" % ( 1449 self.function_target, encode_symbol("pos", "__fn__"))) 1450 1451 # With a known target, the function is obtained directly and called. 1452 # By putting the invocation at the end of the final element in the 1453 # instruction sequence (the stages), the result becomes the result of 1454 # the sequence. Moreover, the parameters become part of the sequence 1455 # and thereby participate in a guaranteed evaluation order. 1456 1457 if target or function: 1458 stages[-1] += "(%s)" % argstr 1459 if instantiation: 1460 return InstantiationResult(instantiation, stages) 1461 else: 1462 return InvocationResult(stages) 1463 1464 # With unknown targets, the generic invocation function is applied to 1465 # the callable and argument collections. 1466 1467 else: 1468 self.record_temp("__tmp_targets") 1469 stages.append("__invoke(\n__tmp_targets[%d],\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1470 self.function_target, 1471 self.always_callable and 1 or 0, 1472 len(kwargs), kwcodestr, kwargstr, 1473 len(args), argstr)) 1474 return InvocationResult(stages) 1475 1476 def always_callable(self, refs): 1477 1478 "Determine whether all 'refs' are callable." 1479 1480 for ref in refs: 1481 if not ref.static(): 1482 return False 1483 else: 1484 origin = ref.final() 1485 if not self.importer.get_attribute(origin, "__fn__"): 1486 return False 1487 return True 1488 1489 def need_default_arguments(self, objpath, nargs): 1490 1491 """ 1492 Return whether any default arguments are needed when invoking the object 1493 given by 'objpath'. 1494 """ 1495 1496 parameters = self.importer.function_parameters.get(objpath) 1497 return nargs < len(parameters) 1498 1499 def process_lambda_node(self, n): 1500 1501 "Process the given lambda node 'n'." 1502 1503 name = self.get_lambda_name() 1504 function_name = self.get_object_path(name) 1505 1506 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1507 1508 # Without defaults, produce an attribute referring to the function. 1509 1510 if not defaults: 1511 return make_expression("((__attr) {.value=&%s})" % encode_path(function_name)) 1512 1513 # With defaults, copy the function structure and set the defaults on the 1514 # copy. 1515 1516 else: 1517 self.record_temp("__tmp_value") 1518 return make_expression("(__tmp_value = __COPY(&%s, sizeof(%s)), %s, (__attr) {.value=__tmp_value})" % ( 1519 encode_path(function_name), 1520 encode_symbol("obj", function_name), 1521 ", ".join(defaults))) 1522 1523 def process_logical_node(self, n): 1524 1525 """ 1526 Process the given operator node 'n'. 1527 1528 Convert ... to ... 1529 1530 <a> and <b> 1531 (__tmp_result = <a>, !__BOOL(__tmp_result)) ? __tmp_result : <b> 1532 1533 <a> or <b> 1534 (__tmp_result = <a>, __BOOL(__tmp_result)) ? __tmp_result : <b> 1535 """ 1536 1537 self.record_temp("__tmp_result") 1538 1539 if isinstance(n, compiler.ast.And): 1540 op = "!" 1541 else: 1542 op = "" 1543 1544 results = [] 1545 1546 for node in n.nodes[:-1]: 1547 expr = self.process_structure_node(node) 1548 results.append("(__tmp_result = %s, %s__BOOL(__tmp_result)) ? __tmp_result : " % (expr, op)) 1549 1550 expr = self.process_structure_node(n.nodes[-1]) 1551 results.append(str(expr)) 1552 1553 return make_expression("(%s)" % "".join(results)) 1554 1555 def process_name_node(self, n, expr=None): 1556 1557 "Process the given name node 'n' with the optional assignment 'expr'." 1558 1559 # Determine whether the name refers to a static external entity. 1560 1561 if n.name in predefined_constants: 1562 return PredefinedConstantRef(n.name, expr) 1563 1564 # Convert literal references, operator function names, and print 1565 # function names to references. 1566 1567 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1568 n.name.startswith("$print"): 1569 1570 ref, paths = self.importer.get_module(self.name).special[n.name] 1571 return TrResolvedNameRef(n.name, ref) 1572 1573 # Temporary names are output program locals. 1574 1575 elif n.name.startswith("$t"): 1576 return TrResolvedNameRef(n.name, Reference("<var>"), expr=expr) 1577 1578 # Get the appropriate name for the name reference, using the same method 1579 # as in the inspector. 1580 1581 path = self.get_namespace_path() 1582 objpath = self.get_object_path(n.name) 1583 1584 # Determine any assigned globals. 1585 1586 globals = self.importer.get_module(self.name).scope_globals.get(path) 1587 1588 # Explicitly declared globals. 1589 1590 if globals and n.name in globals: 1591 objpath = self.get_global_path(n.name) 1592 is_global = True 1593 1594 # Implicitly referenced globals in functions. 1595 1596 elif self.in_function: 1597 is_global = n.name not in self.importer.function_locals[path] 1598 1599 # Implicitly referenced globals elsewhere. 1600 1601 else: 1602 namespace = self.importer.identify(path) 1603 is_global = not self.importer.get_attributes(namespace, n.name) 1604 1605 # Get the static identity of the name. 1606 1607 ref = self.importer.identify(objpath) 1608 if ref and not ref.get_name(): 1609 ref = ref.alias(objpath) 1610 1611 # Obtain any resolved names for non-assignment names. 1612 1613 if not expr and not ref and self.in_function: 1614 locals = self.importer.function_locals.get(path) 1615 ref = locals and locals.get(n.name) 1616 1617 # Determine whether the name refers to a parameter. The generation of 1618 # parameter references is different from other names. 1619 1620 parameters = self.importer.function_parameters.get(path) 1621 parameter = n.name == "self" and self.in_method() or \ 1622 parameters and n.name in parameters 1623 1624 # Find any invocation details. 1625 1626 location = self.get_access_location(n.name) 1627 1628 # Qualified names are used for resolved static references or for 1629 # static namespace members. The reference should be configured to return 1630 # such names. 1631 1632 return TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, parameter=parameter, location=location) 1633 1634 def process_not_node(self, n): 1635 1636 "Process the given operator node 'n'." 1637 1638 return make_expression("(__BOOL(%s) ? %s : %s)" % 1639 (self.process_structure_node(n.expr), PredefinedConstantRef("False"), 1640 PredefinedConstantRef("True"))) 1641 1642 def process_raise_node(self, n): 1643 1644 "Process the given raise node 'n'." 1645 1646 # NOTE: Determine which raise statement variants should be permitted. 1647 1648 if n.expr1: 1649 1650 # Names with accompanying arguments are treated like invocations. 1651 1652 if n.expr2: 1653 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1654 exc = self.process_structure_node(call) 1655 self.writestmt("__Raise(%s);" % exc) 1656 1657 # Raise instances, testing the kind at run-time if necessary and 1658 # instantiating any non-instance. 1659 1660 else: 1661 exc = self.process_structure_node(n.expr1) 1662 1663 if isinstance(exc, TrInstanceRef): 1664 self.writestmt("__Raise(%s);" % exc) 1665 else: 1666 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1667 else: 1668 self.writestmt("__Throw(__tmp_exc);") 1669 1670 def process_return_node(self, n): 1671 1672 "Process the given return node 'n'." 1673 1674 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1675 if self.in_try_finally or self.in_try_except: 1676 self.writestmt("__Return(%s);" % expr) 1677 else: 1678 self.writestmt("return %s;" % expr) 1679 1680 return ReturnRef() 1681 1682 def process_try_node(self, n): 1683 1684 """ 1685 Process the given "try...except" node 'n'. 1686 """ 1687 1688 in_try_except = self.in_try_except 1689 self.in_try_except = True 1690 1691 # Use macros to implement exception handling. 1692 1693 self.writestmt("__Try") 1694 self.writeline("{") 1695 self.indent += 1 1696 self.process_structure_node(n.body) 1697 1698 # Put the else statement in another try block that handles any raised 1699 # exceptions and converts them to exceptions that will not be handled by 1700 # the main handling block. 1701 1702 if n.else_: 1703 self.writestmt("__Try") 1704 self.writeline("{") 1705 self.indent += 1 1706 self.process_structure_node(n.else_) 1707 self.indent -= 1 1708 self.writeline("}") 1709 self.writeline("__Catch (__tmp_exc)") 1710 self.writeline("{") 1711 self.indent += 1 1712 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1713 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1714 self.indent -= 1 1715 self.writeline("}") 1716 1717 # Complete the try block and enter the finally block, if appropriate. 1718 1719 if self.in_try_finally: 1720 self.writestmt("__Complete;") 1721 1722 self.indent -= 1 1723 self.writeline("}") 1724 1725 self.in_try_except = in_try_except 1726 1727 # Handlers are tests within a common handler block. 1728 1729 self.writeline("__Catch (__tmp_exc)") 1730 self.writeline("{") 1731 self.indent += 1 1732 1733 # Introduce an if statement to handle the completion of a try block. 1734 1735 self.process_try_completion() 1736 1737 # Handle exceptions in else blocks converted to __RaiseElse, converting 1738 # them back to normal exceptions. 1739 1740 if n.else_: 1741 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1742 1743 # Exception handling. 1744 1745 for name, var, handler in n.handlers: 1746 1747 # Test for specific exceptions. 1748 1749 if name is not None: 1750 name_ref = self.process_structure_node(name) 1751 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1752 else: 1753 self.writeline("else if (1)") 1754 1755 self.writeline("{") 1756 self.indent += 1 1757 1758 # Establish the local for the handler. 1759 1760 if var is not None: 1761 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1762 1763 if handler is not None: 1764 self.process_structure_node(handler) 1765 1766 self.indent -= 1 1767 self.writeline("}") 1768 1769 # Re-raise unhandled exceptions. 1770 1771 self.writeline("else __Throw(__tmp_exc);") 1772 1773 # End the handler block. 1774 1775 self.indent -= 1 1776 self.writeline("}") 1777 1778 def process_try_finally_node(self, n): 1779 1780 """ 1781 Process the given "try...finally" node 'n'. 1782 """ 1783 1784 in_try_finally = self.in_try_finally 1785 self.in_try_finally = True 1786 1787 # Use macros to implement exception handling. 1788 1789 self.writestmt("__Try") 1790 self.writeline("{") 1791 self.indent += 1 1792 self.process_structure_node(n.body) 1793 self.indent -= 1 1794 self.writeline("}") 1795 1796 self.in_try_finally = in_try_finally 1797 1798 # Finally clauses handle special exceptions. 1799 1800 self.writeline("__Catch (__tmp_exc)") 1801 self.writeline("{") 1802 self.indent += 1 1803 self.process_structure_node(n.final) 1804 1805 # Introduce an if statement to handle the completion of a try block. 1806 1807 self.process_try_completion() 1808 self.writeline("else __Throw(__tmp_exc);") 1809 1810 self.indent -= 1 1811 self.writeline("}") 1812 1813 def process_try_completion(self): 1814 1815 "Generate a test for the completion of a try block." 1816 1817 self.writestmt("if (__tmp_exc.completing)") 1818 self.writeline("{") 1819 self.indent += 1 1820 1821 # Do not return anything at the module level. 1822 1823 if self.get_namespace_path() != self.name: 1824 1825 # Only use the normal return statement if no surrounding try blocks 1826 # apply. 1827 1828 if not self.in_try_finally and not self.in_try_except: 1829 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1830 else: 1831 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1832 1833 self.indent -= 1 1834 self.writeline("}") 1835 1836 def process_while_node(self, n): 1837 1838 "Process the given while node 'n'." 1839 1840 self.writeline("while (1)") 1841 self.writeline("{") 1842 self.indent += 1 1843 test = self.process_structure_node(n.test) 1844 1845 # Emit the loop termination condition unless "while <true value>" is 1846 # indicated. 1847 1848 if not (isinstance(test, PredefinedConstantRef) and test.value): 1849 1850 # NOTE: This needs to evaluate whether the operand is true or false 1851 # NOTE: according to Python rules. 1852 1853 self.writeline("if (!__BOOL(%s))" % test) 1854 self.writeline("{") 1855 self.indent += 1 1856 if n.else_: 1857 self.process_structure_node(n.else_) 1858 self.writestmt("break;") 1859 self.indent -= 1 1860 self.writeline("}") 1861 1862 in_conditional = self.in_conditional 1863 self.in_conditional = True 1864 self.process_structure_node(n.body) 1865 self.in_conditional = in_conditional 1866 1867 self.indent -= 1 1868 self.writeline("}") 1869 1870 # Special variable usage. 1871 1872 def record_temp(self, name): 1873 1874 """ 1875 Record the use of the temporary 'name' in the current namespace. At the 1876 class or module level, the temporary name is associated with the module, 1877 since the variable will then be allocated in the module's own main 1878 program. 1879 """ 1880 1881 if self.in_function: 1882 path = self.get_namespace_path() 1883 else: 1884 path = self.name 1885 1886 init_item(self.temp_usage, path, set) 1887 self.temp_usage[path].add(name) 1888 1889 def uses_temp(self, path, name): 1890 1891 """ 1892 Return whether the given namespace 'path' employs a temporary variable 1893 with the given 'name'. Note that 'path' should only be a module or a 1894 function or method, not a class. 1895 """ 1896 1897 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1898 1899 # Output generation. 1900 1901 def start_output(self): 1902 1903 "Write the declarations at the top of each source file." 1904 1905 print >>self.out, """\ 1906 #include "types.h" 1907 #include "exceptions.h" 1908 #include "ops.h" 1909 #include "progconsts.h" 1910 #include "progops.h" 1911 #include "progtypes.h" 1912 #include "main.h" 1913 """ 1914 1915 def start_unit(self): 1916 1917 "Record output within a generated function for later use." 1918 1919 self.out = StringIO() 1920 1921 def end_unit(self, name): 1922 1923 "Add declarations and generated code." 1924 1925 # Restore the output stream. 1926 1927 out = self.out 1928 self.out = self.out_toplevel 1929 1930 self.write_temporaries(name) 1931 out.seek(0) 1932 self.out.write(out.read()) 1933 1934 self.indent -= 1 1935 print >>self.out, "}" 1936 1937 def start_module(self): 1938 1939 "Write the start of each module's main function." 1940 1941 print >>self.out, "void __main_%s()" % encode_path(self.name) 1942 print >>self.out, "{" 1943 self.indent += 1 1944 1945 # Define temporary variables, excluded from the module structure itself. 1946 1947 tempnames = [] 1948 1949 for n in self.importer.all_module_attrs[self.name]: 1950 if n.startswith("$t"): 1951 tempnames.append(encode_path(n)) 1952 1953 if tempnames: 1954 tempnames.sort() 1955 self.writeline("__attr %s;" % ", ".join(tempnames)) 1956 1957 self.start_unit() 1958 1959 def end_module(self): 1960 1961 "End each module by closing its main function." 1962 1963 self.end_unit(self.name) 1964 1965 def start_function(self, name): 1966 1967 "Start the function having the given 'name'." 1968 1969 print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name) 1970 print >>self.out, "{" 1971 self.indent += 1 1972 1973 # Obtain local names from parameters. 1974 1975 parameters = self.importer.function_parameters[name] 1976 locals = self.importer.function_locals[name].keys() 1977 names = [] 1978 1979 for n in locals: 1980 1981 # Filter out special names and parameters. Note that self is a local 1982 # regardless of whether it originally appeared in the parameters or 1983 # not. 1984 1985 if n.startswith("$l") or n in parameters or n == "self": 1986 continue 1987 names.append(encode_path(n)) 1988 1989 # Emit required local names. 1990 1991 if names: 1992 names.sort() 1993 self.writeline("__attr %s;" % ", ".join(names)) 1994 1995 self.write_parameters(name) 1996 self.start_unit() 1997 1998 def end_function(self, name): 1999 2000 "End the function having the given 'name'." 2001 2002 self.end_unit(name) 2003 print >>self.out 2004 2005 def write_temporaries(self, name): 2006 2007 "Write temporary storage employed by 'name'." 2008 2009 # Provide space for the given number of targets. 2010 2011 targets = self.importer.function_targets.get(name) 2012 2013 if self.uses_temp(name, "__tmp_targets"): 2014 self.writeline("__attr __tmp_targets[%d];" % targets) 2015 if self.uses_temp(name, "__tmp_contexts"): 2016 self.writeline("__ref __tmp_contexts[%d];" % targets) 2017 2018 # Add temporary variable usage details. 2019 2020 if self.uses_temp(name, "__tmp_private_context"): 2021 self.writeline("__ref __tmp_private_context;") 2022 if self.uses_temp(name, "__tmp_value"): 2023 self.writeline("__ref __tmp_value;") 2024 if self.uses_temp(name, "__tmp_target_value"): 2025 self.writeline("__ref __tmp_target_value;") 2026 if self.uses_temp(name, "__tmp_result"): 2027 self.writeline("__attr __tmp_result;") 2028 2029 module = self.importer.get_module(self.name) 2030 2031 if name in module.exception_namespaces: 2032 self.writeline("__exc __tmp_exc;") 2033 2034 def write_parameters(self, name): 2035 2036 """ 2037 For the function having the given 'name', write definitions of 2038 parameters found in the arguments array. 2039 """ 2040 2041 parameters = self.importer.function_parameters[name] 2042 2043 # Generate any self reference. 2044 2045 if self.is_method(name): 2046 self.writeline("__attr * const self = &__args[0];") 2047 2048 # Generate aliases for the parameters. 2049 2050 for i, parameter in enumerate(parameters): 2051 self.writeline("__attr * const %s = &__args[%d];" % (encode_path(parameter), i+1)) 2052 2053 def start_if(self, first, test_ref): 2054 self.writestmt("%sif (__BOOL(%s))" % (not first and "else " or "", test_ref)) 2055 self.writeline("{") 2056 self.indent += 1 2057 2058 def end_if(self): 2059 self.indent -= 1 2060 self.writeline("}") 2061 2062 def start_else(self): 2063 self.writeline("else") 2064 self.writeline("{") 2065 self.indent += 1 2066 2067 def end_else(self): 2068 self.indent -= 1 2069 self.writeline("}") 2070 2071 def statement(self, expr): 2072 s = str(expr) 2073 if s: 2074 self.writestmt("%s;" % s) 2075 2076 def statements(self, results): 2077 for result in results: 2078 self.statement(result) 2079 2080 def writeline(self, s): 2081 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2082 2083 def writestmt(self, s): 2084 print >>self.out 2085 self.writeline(s) 2086 2087 def write_comment(self, s): 2088 self.writestmt("/* %s */" % s) 2089 2090 def pad(self, extra=0): 2091 return (self.indent + extra) * self.tabstop 2092 2093 def indenttext(self, s, levels): 2094 lines = s.split("\n") 2095 out = [lines[0]] 2096 for line in lines[1:]: 2097 out.append(levels * self.tabstop + line) 2098 if line.endswith("("): 2099 levels += 1 2100 elif line.startswith(")"): 2101 levels -= 1 2102 return "\n".join(out) 2103 2104 # vim: tabstop=4 expandtab shiftwidth=4