1 #!/usr/bin/env python 2 3 """ 4 Translate programs. 5 6 Copyright (C) 2015, 2016 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 * 23 from encoders import * 24 from os.path import exists, join 25 from os import makedirs 26 import compiler 27 import results 28 29 class Translator(CommonOutput): 30 31 "A program translator." 32 33 def __init__(self, importer, deducer, optimiser, output): 34 self.importer = importer 35 self.deducer = deducer 36 self.optimiser = optimiser 37 self.output = output 38 39 def to_output(self): 40 output = join(self.output, "src") 41 42 if not exists(output): 43 makedirs(output) 44 45 self.check_output() 46 47 for module in self.importer.modules.values(): 48 if module.name != "native": 49 tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser) 50 tm.translate(module.filename, join(output, "%s.c" % module.name)) 51 52 # Classes representing intermediate translation results. 53 54 class TranslationResult: 55 56 "An abstract translation result mix-in." 57 58 def get_accessor_kinds(self): 59 return None 60 61 class ReturnRef(TranslationResult): 62 63 "Indicates usage of a return statement." 64 65 pass 66 67 class Expression(results.Result, TranslationResult): 68 69 "A general expression." 70 71 def __init__(self, s): 72 self.s = s 73 def __str__(self): 74 return self.s 75 def __repr__(self): 76 return "Expression(%r)" % self.s 77 78 class TrResolvedNameRef(results.ResolvedNameRef, TranslationResult): 79 80 "A reference to a name in the translation." 81 82 def __init__(self, name, ref, expr=None, parameter=None): 83 results.ResolvedNameRef.__init__(self, name, ref, expr) 84 self.parameter = parameter 85 86 def __str__(self): 87 88 "Return an output representation of the referenced name." 89 90 # For sources, any identified static origin will be constant and thus 91 # usable directly. For targets, no constant should be assigned and thus 92 # the alias (or any plain name) will be used. 93 94 ref = self.static() 95 origin = ref and self.get_origin() 96 static_name = origin and encode_path(origin) 97 98 # Determine whether a qualified name is involved. 99 100 t = (self.get_name() or self.name).rsplit(".", 1) 101 parent = len(t) > 1 and t[0] or None 102 attrname = encode_path(t[-1]) 103 104 # Assignments. 105 106 if self.expr: 107 108 # Eliminate assignments between constants. 109 110 if ref and isinstance(self.expr, results.ResolvedNameRef) and self.expr.static(): 111 return "" 112 113 # Qualified names must be converted into parent-relative assignments. 114 115 elif parent: 116 return "__store_via_object(&%s, %s, %s)" % ( 117 encode_path(parent), encode_symbol("pos", attrname), self.expr) 118 119 # All other assignments involve the names as they were given. 120 121 else: 122 return "(%s%s) = %s" % (self.parameter and "*" or "", attrname, self.expr) 123 124 # Expressions. 125 126 elif static_name: 127 parent = ref.parent() 128 context = ref.has_kind("<function>") and encode_path(parent) or None 129 return "((__attr) {%s, &%s})" % (context and "&%s" % context or "0", static_name) 130 131 # Qualified names must be converted into parent-relative accesses. 132 133 elif parent: 134 return "__load_via_object(&%s, %s)" % ( 135 encode_path(parent), encode_symbol("pos", attrname)) 136 137 # All other accesses involve the names as they were given. 138 139 else: 140 return "(%s%s)" % (self.parameter and "*" or "", attrname) 141 142 class TrConstantValueRef(results.ConstantValueRef, TranslationResult): 143 144 "A constant value reference in the translation." 145 146 def __str__(self): 147 return encode_literal_constant(self.number) 148 149 class TrLiteralSequenceRef(results.LiteralSequenceRef, TranslationResult): 150 151 "A reference representing a sequence of values." 152 153 def __str__(self): 154 return str(self.node) 155 156 class AttrResult(Expression, TranslationResult): 157 158 "A translation result for an attribute access." 159 160 def __init__(self, s, refs, accessor_kinds): 161 Expression.__init__(self, s) 162 self.refs = refs 163 self.accessor_kinds = accessor_kinds 164 165 def get_origin(self): 166 return self.refs and len(self.refs) == 1 and first(self.refs).get_origin() 167 168 def has_kind(self, kinds): 169 if not self.refs: 170 return False 171 for ref in self.refs: 172 if ref.has_kind(kinds): 173 return True 174 return False 175 176 def get_accessor_kinds(self): 177 return self.accessor_kinds 178 179 def __repr__(self): 180 return "AttrResult(%r, %r)" % (self.s, self.get_origin()) 181 182 class PredefinedConstantRef(AttrResult): 183 184 "A predefined constant reference." 185 186 def __init__(self, value): 187 self.value = value 188 189 def __str__(self): 190 if self.value in ("False", "True"): 191 return encode_path("__builtins__.boolean.%s" % self.value) 192 elif self.value == "None": 193 return encode_path("__builtins__.none.%s" % self.value) 194 elif self.value == "NotImplemented": 195 return encode_path("__builtins__.notimplemented.%s" % self.value) 196 else: 197 return self.value 198 199 def __repr__(self): 200 return "PredefinedConstantRef(%r)" % self.value 201 202 class BooleanResult(Expression, TranslationResult): 203 204 "A expression producing a boolean result." 205 206 def __str__(self): 207 return "__builtins___bool_bool(%s)" % self.s 208 209 def __repr__(self): 210 return "BooleanResult(%r)" % self.s 211 212 def make_expression(expr): 213 214 "Make a new expression from the existing 'expr'." 215 216 if isinstance(expr, results.Result): 217 return expr 218 else: 219 return Expression(str(expr)) 220 221 # The actual translation process itself. 222 223 class TranslatedModule(CommonModule): 224 225 "A module translator." 226 227 def __init__(self, name, importer, deducer, optimiser): 228 CommonModule.__init__(self, name, importer) 229 self.deducer = deducer 230 self.optimiser = optimiser 231 232 # Output stream. 233 234 self.out = None 235 self.indent = 0 236 self.tabstop = " " 237 238 # Recorded namespaces. 239 240 self.namespaces = [] 241 self.in_conditional = False 242 243 # Exception raising adjustments. 244 245 self.in_try_finally = False 246 self.in_try_except = False 247 248 # Attribute access and accessor counting. 249 250 self.attr_accesses = {} 251 self.attr_accessors = {} 252 253 def __repr__(self): 254 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 255 256 def translate(self, filename, output_filename): 257 258 """ 259 Parse the file having the given 'filename', writing the translation to 260 the given 'output_filename'. 261 """ 262 263 self.parse_file(filename) 264 265 # Collect function namespaces for separate processing. 266 267 self.record_namespaces(self.astnode) 268 269 # Reset the lambda naming (in order to obtain the same names again) and 270 # translate the program. 271 272 self.reset_lambdas() 273 274 self.out = open(output_filename, "w") 275 try: 276 self.start_output() 277 278 # Process namespaces, writing the translation. 279 280 for path, node in self.namespaces: 281 self.process_namespace(path, node) 282 283 # Process the module namespace including class namespaces. 284 285 self.process_namespace([], self.astnode) 286 287 finally: 288 self.out.close() 289 290 def have_object(self): 291 292 "Return whether a namespace is a recorded object." 293 294 return self.importer.objects.get(self.get_namespace_path()) 295 296 def get_builtin_class(self, name): 297 298 "Return a reference to the actual object providing 'name'." 299 300 # NOTE: This makes assumptions about the __builtins__ structure. 301 302 return self.importer.get_object("__builtins__.%s.%s" % (name, name)) 303 304 def is_method(self, path): 305 306 "Return whether 'path' is a method." 307 308 class_name, method_name = path.rsplit(".", 1) 309 return self.importer.classes.has_key(class_name) and class_name or None 310 311 def in_method(self): 312 313 "Return whether the current namespace provides a method." 314 315 return self.in_function and self.is_method(self.get_namespace_path()) 316 317 # Namespace recording. 318 319 def record_namespaces(self, node): 320 321 "Process the program structure 'node', recording namespaces." 322 323 for n in node.getChildNodes(): 324 self.record_namespaces_in_node(n) 325 326 def record_namespaces_in_node(self, node): 327 328 "Process the program structure 'node', recording namespaces." 329 330 # Function namespaces within modules, classes and other functions. 331 # Functions appearing within conditional statements are given arbitrary 332 # names. 333 334 if isinstance(node, compiler.ast.Function): 335 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 336 337 elif isinstance(node, compiler.ast.Lambda): 338 self.record_function_node(node, self.get_lambda_name()) 339 340 # Classes are visited, but may be ignored if inside functions. 341 342 elif isinstance(node, compiler.ast.Class): 343 self.enter_namespace(node.name) 344 if self.have_object(): 345 self.record_namespaces(node) 346 self.exit_namespace() 347 348 # Conditional nodes are tracked so that function definitions may be 349 # handled. Since "for" loops are converted to "while" loops, they are 350 # included here. 351 352 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 353 in_conditional = self.in_conditional 354 self.in_conditional = True 355 self.record_namespaces(node) 356 self.in_conditional = in_conditional 357 358 # All other nodes are processed depth-first. 359 360 else: 361 self.record_namespaces(node) 362 363 def record_function_node(self, n, name): 364 365 """ 366 Record the given function, lambda, if expression or list comprehension 367 node 'n' with the given 'name'. 368 """ 369 370 self.in_function = True 371 self.enter_namespace(name) 372 373 if self.have_object(): 374 375 # Record the namespace path and the node itself. 376 377 self.namespaces.append((self.namespace_path[:], n)) 378 self.record_namespaces_in_node(n.code) 379 380 self.exit_namespace() 381 self.in_function = False 382 383 # Constant referencing. 384 385 def get_literal_instance(self, n, name): 386 387 """ 388 For node 'n', return a reference for the type of the given 'name'. 389 """ 390 391 ref = self.get_builtin_class(name) 392 393 if name in ("dict", "list", "tuple"): 394 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 395 else: 396 path = self.get_namespace_path() 397 local_number = self.importer.all_constants[path][n.value] 398 constant_name = "$c%d" % local_number 399 objpath = self.get_object_path(constant_name) 400 number = self.optimiser.constant_numbers[objpath] 401 return TrConstantValueRef(constant_name, ref.instance_of(), n.value, number) 402 403 # Namespace translation. 404 405 def process_namespace(self, path, node): 406 407 """ 408 Process the namespace for the given 'path' defined by the given 'node'. 409 """ 410 411 self.namespace_path = path 412 413 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 414 self.in_function = True 415 self.process_function_body_node(node) 416 else: 417 self.in_function = False 418 self.function_target = 0 419 self.start_module() 420 self.process_structure(node) 421 self.end_module() 422 423 def process_structure(self, node): 424 425 "Process the given 'node' or result." 426 427 # Handle processing requests on results. 428 429 if isinstance(node, results.Result): 430 return node 431 432 # Handle processing requests on nodes. 433 434 else: 435 l = CommonModule.process_structure(self, node) 436 437 # Return indications of return statement usage. 438 439 if l and isinstance(l[-1], ReturnRef): 440 return l[-1] 441 else: 442 return None 443 444 def process_structure_node(self, n): 445 446 "Process the individual node 'n'." 447 448 # Plain statements emit their expressions. 449 450 if isinstance(n, compiler.ast.Discard): 451 expr = self.process_structure_node(n.expr) 452 self.statement(expr) 453 454 # Nodes using operator module functions. 455 456 elif isinstance(n, compiler.ast.Operator): 457 return self.process_operator_node(n) 458 459 elif isinstance(n, compiler.ast.AugAssign): 460 self.process_augassign_node(n) 461 462 elif isinstance(n, compiler.ast.Compare): 463 return self.process_compare_node(n) 464 465 elif isinstance(n, compiler.ast.Slice): 466 return self.process_slice_node(n) 467 468 elif isinstance(n, compiler.ast.Sliceobj): 469 return self.process_sliceobj_node(n) 470 471 elif isinstance(n, compiler.ast.Subscript): 472 return self.process_subscript_node(n) 473 474 # Classes are visited, but may be ignored if inside functions. 475 476 elif isinstance(n, compiler.ast.Class): 477 self.process_class_node(n) 478 479 # Functions within namespaces have any dynamic defaults initialised. 480 481 elif isinstance(n, compiler.ast.Function): 482 self.process_function_node(n) 483 484 # Lambdas are replaced with references to separately-generated 485 # functions. 486 487 elif isinstance(n, compiler.ast.Lambda): 488 return self.process_lambda_node(n) 489 490 # Assignments. 491 492 elif isinstance(n, compiler.ast.Assign): 493 494 # Handle each assignment node. 495 496 for node in n.nodes: 497 self.process_assignment_node(node, n.expr) 498 499 # Accesses. 500 501 elif isinstance(n, compiler.ast.Getattr): 502 return self.process_attribute_access(n) 503 504 # Names. 505 506 elif isinstance(n, compiler.ast.Name): 507 return self.process_name_node(n) 508 509 # Loops and conditionals. 510 511 elif isinstance(n, compiler.ast.For): 512 self.process_for_node(n) 513 514 elif isinstance(n, compiler.ast.While): 515 self.process_while_node(n) 516 517 elif isinstance(n, compiler.ast.If): 518 self.process_if_node(n) 519 520 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 521 return self.process_logical_node(n) 522 523 elif isinstance(n, compiler.ast.Not): 524 return self.process_not_node(n) 525 526 # Exception control-flow tracking. 527 528 elif isinstance(n, compiler.ast.TryExcept): 529 self.process_try_node(n) 530 531 elif isinstance(n, compiler.ast.TryFinally): 532 self.process_try_finally_node(n) 533 534 # Control-flow modification statements. 535 536 elif isinstance(n, compiler.ast.Break): 537 self.writestmt("break;") 538 539 elif isinstance(n, compiler.ast.Continue): 540 self.writestmt("continue;") 541 542 elif isinstance(n, compiler.ast.Raise): 543 self.process_raise_node(n) 544 545 elif isinstance(n, compiler.ast.Return): 546 return self.process_return_node(n) 547 548 # Print statements. 549 550 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 551 self.statement(self.process_print_node(n)) 552 553 # Invocations. 554 555 elif isinstance(n, compiler.ast.CallFunc): 556 return self.process_invocation_node(n) 557 558 elif isinstance(n, compiler.ast.Keyword): 559 return self.process_structure_node(n.expr) 560 561 # Constant usage. 562 563 elif isinstance(n, compiler.ast.Const): 564 return self.get_literal_instance(n, n.value.__class__.__name__) 565 566 elif isinstance(n, compiler.ast.Dict): 567 return self.get_literal_instance(n, "dict") 568 569 elif isinstance(n, compiler.ast.List): 570 return self.get_literal_instance(n, "list") 571 572 elif isinstance(n, compiler.ast.Tuple): 573 return self.get_literal_instance(n, "tuple") 574 575 # All other nodes are processed depth-first. 576 577 else: 578 return self.process_structure(n) 579 580 def process_assignment_node(self, n, expr): 581 582 "Process the individual node 'n' to be assigned the contents of 'expr'." 583 584 # Names and attributes are assigned the entire expression. 585 586 if isinstance(n, compiler.ast.AssName): 587 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 588 self.statement(name_ref) 589 590 # Employ guards after assignments if required. 591 592 if expr and name_ref.is_name(): 593 self.generate_guard(name_ref.name) 594 595 elif isinstance(n, compiler.ast.AssAttr): 596 in_assignment = self.in_assignment 597 self.in_assignment = self.process_structure_node(expr) 598 self.statement(self.process_attribute_access(n)) 599 self.in_assignment = in_assignment 600 601 # Lists and tuples are matched against the expression and their 602 # items assigned to expression items. 603 604 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 605 self.process_assignment_node_items(n, expr) 606 607 # Slices and subscripts are permitted within assignment nodes. 608 609 elif isinstance(n, compiler.ast.Slice): 610 self.statement(self.process_slice_node(n, expr)) 611 612 elif isinstance(n, compiler.ast.Subscript): 613 self.statement(self.process_subscript_node(n, expr)) 614 615 def process_attribute_access(self, n): 616 617 """ 618 Process the given attribute access node 'n'. 619 620 Where a name is provided, a single access should be recorded 621 involving potentially many attributes, thus providing a path to an 622 object. The remaining attributes are then accessed dynamically. 623 The remaining accesses could be deduced and computed, but they would 624 also need to be tested. 625 626 Where no name is provided, potentially many accesses should be 627 recorded, one per attribute name. These could be used to provide 628 computed accesses, but the accessors would need to be tested in each 629 case. 630 """ 631 632 # Obtain any completed chain and return the reference to it. 633 634 attr_expr = self.process_attribute_chain(n) 635 if self.have_access_expression(n): 636 return attr_expr 637 638 # Where the start of the chain of attributes has been reached, process 639 # the complete access. 640 641 name_ref = attr_expr and attr_expr.is_name() and attr_expr 642 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref and name_ref.final()) or None 643 644 location = self.get_access_location(name) 645 refs = self.get_referenced_attributes(location) 646 647 # Generate access instructions. 648 649 subs = { 650 "<expr>" : str(attr_expr), 651 "<assexpr>" : str(self.in_assignment), 652 "<context>" : "__tmp_context", 653 "<accessor>" : "__tmp_value", 654 } 655 656 output = [] 657 658 for instruction in self.optimiser.access_instructions[location]: 659 output.append(encode_access_instruction(instruction, subs)) 660 661 if len(output) == 1: 662 out = output[0] 663 else: 664 out = "(\n%s\n)" % ",\n".join(output) 665 666 del self.attrs[0] 667 return AttrResult(out, refs, self.get_accessor_kinds(location)) 668 669 def get_referenced_attributes(self, location): 670 671 """ 672 Convert 'location' to the form used by the deducer and retrieve any 673 identified attribute. 674 """ 675 676 access_location = self.deducer.const_accesses.get(location) 677 refs = [] 678 for attrtype, objpath, attr in self.deducer.referenced_attrs[access_location or location]: 679 refs.append(attr) 680 return refs 681 682 def get_accessor_kinds(self, location): 683 684 "Return the accessor kinds for 'location'." 685 686 return self.optimiser.accessor_kinds[location] 687 688 def get_access_location(self, name): 689 690 """ 691 Using the current namespace and the given 'name', return the access 692 location. 693 """ 694 695 path = self.get_path_for_access() 696 697 # Get the location used by the deducer and optimiser and find any 698 # recorded access. 699 700 attrnames = ".".join(self.attrs) 701 access_number = self.get_access_number(path, name, attrnames) 702 self.update_access_number(path, name, attrnames) 703 return (path, name, attrnames, access_number) 704 705 def get_access_number(self, path, name, attrnames): 706 access = name, attrnames 707 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 708 return self.attr_accesses[path][access] 709 else: 710 return 0 711 712 def update_access_number(self, path, name, attrnames): 713 access = name, attrnames 714 if name: 715 init_item(self.attr_accesses, path, dict) 716 init_item(self.attr_accesses[path], access, lambda: 0) 717 self.attr_accesses[path][access] += 1 718 719 def get_accessor_location(self, name): 720 721 """ 722 Using the current namespace and the given 'name', return the accessor 723 location. 724 """ 725 726 path = self.get_path_for_access() 727 728 # Get the location used by the deducer and optimiser and find any 729 # recorded accessor. 730 731 access_number = self.get_accessor_number(path, name) 732 self.update_accessor_number(path, name) 733 return (path, name, None, access_number) 734 735 def get_accessor_number(self, path, name): 736 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 737 return self.attr_accessors[path][name] 738 else: 739 return 0 740 741 def update_accessor_number(self, path, name): 742 if name: 743 init_item(self.attr_accessors, path, dict) 744 init_item(self.attr_accessors[path], name, lambda: 0) 745 self.attr_accessors[path][name] += 1 746 747 def process_class_node(self, n): 748 749 "Process the given class node 'n'." 750 751 self.enter_namespace(n.name) 752 753 if self.have_object(): 754 class_name = self.get_namespace_path() 755 self.write_comment("Class: %s" % class_name) 756 757 self.initialise_inherited_members(class_name) 758 759 self.process_structure(n) 760 self.write_comment("End class: %s" % class_name) 761 762 self.exit_namespace() 763 764 def initialise_inherited_members(self, class_name): 765 766 "Initialise members of 'class_name' inherited from its ancestors." 767 768 for name, path in self.importer.all_class_attrs[class_name].items(): 769 target = "%s.%s" % (class_name, name) 770 771 # Ignore attributes with definitions. 772 773 ref = self.importer.identify(target) 774 if ref: 775 continue 776 777 # Reference inherited attributes. 778 779 ref = self.importer.identify(path) 780 if ref and not ref.static(): 781 parent, attrname = path.rsplit(".", 1) 782 783 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 784 encode_path(class_name), encode_symbol("pos", name), 785 encode_path(parent), encode_symbol("pos", attrname) 786 )) 787 788 def process_function_body_node(self, n): 789 790 """ 791 Process the given function, lambda, if expression or list comprehension 792 node 'n', generating the body. 793 """ 794 795 function_name = self.get_namespace_path() 796 self.start_function(function_name) 797 798 # Process the function body. 799 800 in_conditional = self.in_conditional 801 self.in_conditional = False 802 self.function_target = 0 803 804 # Process any guards defined for the parameters. 805 806 for name in self.importer.function_parameters.get(function_name): 807 self.generate_guard(name) 808 809 # Produce the body and any additional return statement. 810 811 expr = self.process_structure_node(n.code) or PredefinedConstantRef("None") 812 if not isinstance(expr, ReturnRef): 813 self.writestmt("return %s;" % expr) 814 815 self.in_conditional = in_conditional 816 817 self.end_function(function_name) 818 819 def generate_guard(self, name): 820 821 """ 822 Get the accessor details for 'name', found in the current namespace, and 823 generate any guards defined for it. 824 """ 825 826 # Obtain the location, keeping track of assignment versions. 827 828 location = self.get_accessor_location(name) 829 test = self.deducer.accessor_guard_tests.get(location) 830 831 # Generate any guard from the deduced information. 832 833 if test: 834 guard, guard_type = test 835 836 if guard == "specific": 837 ref = first(self.deducer.accessor_all_types[location]) 838 argstr = "&%s" % encode_path(ref.get_origin()) 839 elif guard == "common": 840 ref = first(self.deducer.accessor_all_general_types[location]) 841 typeattr = encode_type_attribute(ref.get_origin()) 842 argstr = "%s, %s" % (encode_symbol("pos", typeattr), encode_symbol("code", typeattr)) 843 else: 844 return 845 846 # Produce an appropriate access to an attribute's value. 847 848 parameters = self.importer.function_parameters.get(self.get_namespace_path()) 849 if parameters and name in parameters: 850 name_to_value = "%s->value" % name 851 else: 852 name_to_value = "%s.value" % name 853 854 # Write a test that raises a TypeError upon failure. 855 856 self.writestmt("if (!__test_%s_%s(%s, %s)) __raise_type_error();" % ( 857 guard, guard_type, name_to_value, argstr)) 858 859 def process_function_node(self, n): 860 861 """ 862 Process the given function, lambda, if expression or list comprehension 863 node 'n', generating any initialisation statements. 864 """ 865 866 # Where a function is declared conditionally, use a separate name for 867 # the definition, and assign the definition to the stated name. 868 869 original_name = n.name 870 871 if self.in_conditional or self.in_function: 872 name = self.get_lambda_name() 873 else: 874 name = n.name 875 876 objpath = self.get_object_path(name) 877 878 # Obtain details of the defaults. 879 880 defaults = self.process_function_defaults(n, name, "&%s" % objpath) 881 if defaults: 882 for default in defaults: 883 self.writeline("%s;" % default) 884 885 # Where a function is set conditionally or where the name may refer to 886 # different values, assign the name. 887 888 ref = self.importer.identify(objpath) 889 890 if self.in_conditional or self.in_function: 891 self.process_assignment_for_function(original_name, compiler.ast.Name(name)) 892 elif not ref.static(): 893 context = self.is_method(objpath) 894 895 self.process_assignment_for_function(original_name, 896 make_expression("((__attr) {%s, &%s})" % ( 897 context and "&%s" % encode_path(context) or "0", 898 encode_path(objpath)))) 899 900 def process_function_defaults(self, n, name, instance_name): 901 902 """ 903 Process the given function or lambda node 'n', initialising defaults 904 that are dynamically set. The given 'name' indicates the name of the 905 function. The given 'instance_name' indicates the name of any separate 906 instance of the function created to hold the defaults. 907 908 Return a list of operations setting defaults on a function instance. 909 """ 910 911 function_name = self.get_object_path(name) 912 function_defaults = self.importer.function_defaults.get(function_name) 913 if not function_defaults: 914 return None 915 916 # Determine whether any unidentified defaults are involved. 917 918 need_defaults = [argname for argname, default in function_defaults if default.has_kind("<var>")] 919 if not need_defaults: 920 return None 921 922 # Where defaults are involved but cannot be identified, obtain a new 923 # instance of the lambda and populate the defaults. 924 925 defaults = [] 926 927 # Join the original defaults with the inspected defaults. 928 929 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 930 931 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 932 933 # Obtain any reference for the default. 934 935 if original: 936 argname, default = original 937 name_ref = self.process_structure_node(default) 938 elif inspected: 939 argname, default = inspected 940 name_ref = TrResolvedNameRef(argname, default) 941 else: 942 continue 943 944 if name_ref: 945 defaults.append("__SETDEFAULT(%s, %s, %s)" % (encode_path(instance_name), i, name_ref)) 946 947 return defaults 948 949 def process_if_node(self, n): 950 951 """ 952 Process the given "if" node 'n'. 953 """ 954 955 first = True 956 for test, body in n.tests: 957 test_ref = self.process_structure_node(test) 958 self.start_if(first, test_ref) 959 960 in_conditional = self.in_conditional 961 self.in_conditional = True 962 self.process_structure_node(body) 963 self.in_conditional = in_conditional 964 965 self.end_if() 966 first = False 967 968 if n.else_: 969 self.start_else() 970 self.process_structure_node(n.else_) 971 self.end_else() 972 973 def process_invocation_node(self, n): 974 975 "Process the given invocation node 'n'." 976 977 expr = self.process_structure_node(n.node) 978 objpath = expr.get_origin() 979 target = None 980 function = None 981 literal_instantiation = False 982 983 # Obtain details of the callable. 984 985 # Literals may be instantiated specially. 986 987 if expr.is_name() and expr.name.startswith("$L") and objpath: 988 literal_instantiation = True 989 parameters = None 990 target = encode_literal_instantiator(objpath) 991 992 # Identified targets employ function pointers directly. 993 994 elif objpath: 995 parameters = self.importer.function_parameters.get(objpath) 996 997 # Class invocation involves instantiators. 998 999 if expr.has_kind("<class>"): 1000 target = encode_instantiator_pointer(objpath) 1001 target_structure = encode_initialiser_pointer(objpath) 1002 1003 # Only plain functions and bound methods employ function pointers. 1004 1005 elif expr.has_kind("<function>"): 1006 function = objpath 1007 1008 # Test for functions and methods. 1009 1010 accessor_kinds = expr.get_accessor_kinds() 1011 1012 if not self.is_method(objpath) or accessor_kinds and len(accessor_kinds) == 1 and first(accessor_kinds) == "<instance>": 1013 target = encode_function_pointer(objpath) 1014 target_structure = encode_path(objpath) 1015 1016 # Other targets are retrieved at run-time. 1017 1018 else: 1019 parameters = None 1020 1021 # Arguments are presented in a temporary frame array with any context 1022 # always being the first argument (although it may be set to null for 1023 # invocations where it would be unused). 1024 1025 args = ["__CONTEXT_AS_VALUE(__tmp_targets[%d])" % self.function_target] 1026 args += [None] * (not parameters and len(n.args) or parameters and len(parameters) or 0) 1027 kwcodes = [] 1028 kwargs = [] 1029 1030 # Any invocations in the arguments will store target details in a 1031 # different location. 1032 1033 self.function_target += 1 1034 1035 for i, arg in enumerate(n.args): 1036 argexpr = self.process_structure_node(arg) 1037 1038 # Store a keyword argument, either in the argument list or 1039 # in a separate keyword argument list for subsequent lookup. 1040 1041 if isinstance(arg, compiler.ast.Keyword): 1042 1043 # With knowledge of the target, store the keyword 1044 # argument directly. 1045 1046 if parameters: 1047 argnum = parameters.index(arg.name) 1048 args[argnum+1] = str(argexpr) 1049 1050 # Otherwise, store the details in a separate collection. 1051 1052 else: 1053 kwargs.append(str(argexpr)) 1054 kwcodes.append("{%s, %s}" % ( 1055 encode_symbol("ppos", arg.name), 1056 encode_symbol("pcode", arg.name))) 1057 1058 else: 1059 try: 1060 args[i+1] = str(argexpr) 1061 except IndexError: 1062 raise TranslateError("Too many arguments specified.", 1063 self.get_namespace_path(), n) 1064 1065 # Reference the current target again. 1066 1067 self.function_target -= 1 1068 1069 # Defaults are added to the frame where arguments are missing. 1070 1071 if parameters: 1072 function_defaults = self.importer.function_defaults.get(objpath) 1073 if function_defaults: 1074 1075 # Visit each default and set any missing arguments. 1076 # Use the target structure to obtain defaults, as opposed to the 1077 # actual function involved. 1078 1079 for i, (argname, default) in enumerate(function_defaults): 1080 argnum = parameters.index(argname) 1081 if not args[argnum+1]: 1082 args[argnum+1] = "__GETDEFAULT(&%s, %d)" % (target_structure, i) 1083 1084 # Test for missing arguments. 1085 1086 if None in args: 1087 raise TranslateError("Not all arguments supplied.", 1088 self.get_namespace_path(), n) 1089 1090 # Encode the arguments. 1091 1092 argstr = "__ARGS(%s)" % ", ".join(args) 1093 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1094 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1095 1096 # Where literal instantiation is occurring, add an argument indicating 1097 # the number of values. 1098 1099 if literal_instantiation: 1100 argstr += ", %d" % (len(args) - 1) 1101 1102 # First, the invocation expression is presented. 1103 1104 stages = [] 1105 1106 # Without a known specific callable, the expression provides the target. 1107 1108 stages.append("__tmp_targets[%d] = %s" % (self.function_target, expr)) 1109 1110 # Any specific callable is then obtained. 1111 1112 if target: 1113 stages.append(target) 1114 elif function: 1115 stages.append("__load_via_object(__tmp_targets[%d].value, %s).fn" % ( 1116 self.function_target, encode_symbol("pos", "__fn__"))) 1117 1118 # With a known target, the function is obtained directly and called. 1119 1120 if target or function: 1121 output = "(\n%s\n)(%s)" % (",\n".join(stages), argstr) 1122 1123 # With unknown targets, the generic invocation function is applied to 1124 # the callable and argument collections. 1125 1126 else: 1127 output = "(%s, __invoke(\n__tmp_targets[%d],\n%d, %d, %s, %s,\n%d, %s\n))" % ( 1128 ",\n".join(stages), 1129 self.function_target, 1130 self.always_callable and 1 or 0, 1131 len(kwargs), kwcodestr, kwargstr, 1132 len(args), argstr) 1133 1134 return make_expression(output) 1135 1136 def always_callable(self, refs): 1137 1138 "Determine whether all 'refs' are callable." 1139 1140 for ref in refs: 1141 if not ref.static(): 1142 return False 1143 else: 1144 origin = ref.final() 1145 if not self.importer.get_attribute(origin, "__fn__"): 1146 return False 1147 return True 1148 1149 def need_default_arguments(self, objpath, nargs): 1150 1151 """ 1152 Return whether any default arguments are needed when invoking the object 1153 given by 'objpath'. 1154 """ 1155 1156 parameters = self.importer.function_parameters.get(objpath) 1157 return nargs < len(parameters) 1158 1159 def process_lambda_node(self, n): 1160 1161 "Process the given lambda node 'n'." 1162 1163 name = self.get_lambda_name() 1164 function_name = self.get_object_path(name) 1165 1166 defaults = self.process_function_defaults(n, name, "__tmp_value") 1167 1168 # Without defaults, produce an attribute referring to the function. 1169 1170 if not defaults: 1171 return make_expression("((__attr) {0, &%s})" % encode_path(function_name)) 1172 1173 # With defaults, copy the function structure and set the defaults on the 1174 # copy. 1175 1176 else: 1177 return make_expression("(__tmp_value = __COPY(&%s, sizeof(%s)), %s, (__attr) {0, __tmp_value})" % ( 1178 encode_path(function_name), 1179 encode_symbol("obj", function_name), 1180 ", ".join(defaults))) 1181 1182 def process_logical_node(self, n): 1183 1184 """ 1185 Process the given operator node 'n'. 1186 1187 Convert ... to ... 1188 1189 <a> and <b> 1190 (__tmp_result = <a>, !__BOOL(__tmp_result)) ? __tmp_result : <b> 1191 1192 <a> or <b> 1193 (__tmp_result = <a>, __BOOL(__tmp_result)) ? __tmp_result : <b> 1194 """ 1195 1196 if isinstance(n, compiler.ast.And): 1197 op = "!" 1198 else: 1199 op = "" 1200 1201 results = [] 1202 1203 for node in n.nodes[:-1]: 1204 expr = self.process_structure_node(node) 1205 results.append("(__tmp_result = %s, %s__BOOL(__tmp_result)) ? __tmp_result : " % (expr, op)) 1206 1207 expr = self.process_structure_node(n.nodes[-1]) 1208 results.append(str(expr)) 1209 1210 return make_expression("(%s)" % "".join(results)) 1211 1212 def process_name_node(self, n, expr=None): 1213 1214 "Process the given name node 'n' with the optional assignment 'expr'." 1215 1216 # Determine whether the name refers to a static external entity. 1217 1218 if n.name in predefined_constants: 1219 return PredefinedConstantRef(n.name) 1220 1221 # Convert literal references, operator function names, and print 1222 # function names to references. 1223 1224 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1225 n.name.startswith("$print"): 1226 ref = self.importer.get_module(self.name).special.get(n.name) 1227 return TrResolvedNameRef(n.name, ref) 1228 1229 # Get the appropriate name for the name reference, using the same method 1230 # as in the inspector. 1231 1232 path = self.get_namespace_path() 1233 objpath = self.get_object_path(n.name) 1234 1235 # Determine any assigned globals. 1236 1237 globals = self.importer.get_module(self.name).scope_globals.get(path) 1238 if globals and n.name in globals: 1239 objpath = self.get_global_path(n.name) 1240 1241 # Get the static identity of the name. 1242 1243 ref = self.importer.identify(objpath) 1244 if ref and not ref.get_name(): 1245 ref = ref.alias(objpath) 1246 1247 # Obtain any resolved names for non-assignment names. 1248 1249 if not expr and not ref and self.in_function: 1250 locals = self.importer.function_locals.get(path) 1251 ref = locals and locals.get(n.name) 1252 1253 # Determine whether the name refers to a parameter. The generation of 1254 # parameter references is different from other names. 1255 1256 parameters = self.importer.function_parameters.get(path) 1257 parameter = n.name == "self" and self.in_method() or \ 1258 parameters and n.name in parameters 1259 1260 # Qualified names are used for resolved static references or for 1261 # static namespace members. The reference should be configured to return 1262 # such names. 1263 1264 return TrResolvedNameRef(n.name, ref, expr=expr, parameter=parameter) 1265 1266 def process_not_node(self, n): 1267 1268 "Process the given operator node 'n'." 1269 1270 return make_expression("(__BOOL(%s) ? %s : %s)" % 1271 (self.process_structure_node(n.expr), PredefinedConstantRef("False"), 1272 PredefinedConstantRef("True"))) 1273 1274 def process_raise_node(self, n): 1275 1276 "Process the given raise node 'n'." 1277 1278 # NOTE: Determine which raise statement variants should be permitted. 1279 1280 if n.expr1: 1281 self.writestmt("__Raise(%s);" % self.process_structure_node(n.expr1)) 1282 else: 1283 self.writestmt("__Complete;") 1284 1285 def process_return_node(self, n): 1286 1287 "Process the given return node 'n'." 1288 1289 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1290 if self.in_try_finally or self.in_try_except: 1291 self.writestmt("__Return(%s);" % expr) 1292 else: 1293 self.writestmt("return %s;" % expr) 1294 1295 return ReturnRef() 1296 1297 def process_try_node(self, n): 1298 1299 """ 1300 Process the given "try...except" node 'n'. 1301 """ 1302 1303 in_try_except = self.in_try_except 1304 self.in_try_except = True 1305 1306 # Use macros to implement exception handling. 1307 1308 self.writestmt("__Try") 1309 self.writeline("{") 1310 self.indent += 1 1311 self.process_structure_node(n.body) 1312 1313 # Put the else statement in another try block that handles any raised 1314 # exceptions and converts them to exceptions that will not be handled by 1315 # the main handling block. 1316 1317 if n.else_: 1318 self.writestmt("__Try") 1319 self.writeline("{") 1320 self.indent += 1 1321 self.process_structure_node(n.else_) 1322 self.indent -= 1 1323 self.writeline("}") 1324 self.writeline("__Catch (__tmp_exc)") 1325 self.writeline("{") 1326 self.indent += 1 1327 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1328 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1329 self.indent -= 1 1330 self.writeline("}") 1331 1332 # Complete the try block and enter the finally block, if appropriate. 1333 1334 if self.in_try_finally: 1335 self.writestmt("__Complete;") 1336 1337 self.indent -= 1 1338 self.writeline("}") 1339 1340 self.in_try_except = in_try_except 1341 1342 # Handlers are tests within a common handler block. 1343 1344 self.writeline("__Catch (__tmp_exc)") 1345 self.writeline("{") 1346 self.indent += 1 1347 1348 # Introduce an if statement to handle the completion of a try block. 1349 1350 self.process_try_completion() 1351 1352 # Handle exceptions in else blocks converted to __RaiseElse, converting 1353 # them back to normal exceptions. 1354 1355 if n.else_: 1356 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1357 1358 # Exception handling. 1359 1360 for name, var, handler in n.handlers: 1361 1362 # Test for specific exceptions. 1363 1364 if name is not None: 1365 name_ref = self.process_structure_node(name) 1366 self.writeline("else if (__BOOL(__fn_native__isinstance((__attr[]) {{0, 0}, __tmp_exc.arg, %s})))" % name_ref) 1367 else: 1368 self.writeline("else if (1)") 1369 1370 self.writeline("{") 1371 self.indent += 1 1372 1373 # Establish the local for the handler. 1374 1375 if var is not None: 1376 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1377 1378 if handler is not None: 1379 self.process_structure_node(handler) 1380 1381 self.indent -= 1 1382 self.writeline("}") 1383 1384 # Re-raise unhandled exceptions. 1385 1386 self.writeline("else __Throw(__tmp_exc);") 1387 1388 # End the handler block. 1389 1390 self.indent -= 1 1391 self.writeline("}") 1392 1393 def process_try_finally_node(self, n): 1394 1395 """ 1396 Process the given "try...finally" node 'n'. 1397 """ 1398 1399 in_try_finally = self.in_try_finally 1400 self.in_try_finally = True 1401 1402 # Use macros to implement exception handling. 1403 1404 self.writestmt("__Try") 1405 self.writeline("{") 1406 self.indent += 1 1407 self.process_structure_node(n.body) 1408 self.indent -= 1 1409 self.writeline("}") 1410 1411 self.in_try_finally = in_try_finally 1412 1413 # Finally clauses handle special exceptions. 1414 1415 self.writeline("__Catch (__tmp_exc)") 1416 self.writeline("{") 1417 self.indent += 1 1418 self.process_structure_node(n.final) 1419 1420 # Introduce an if statement to handle the completion of a try block. 1421 1422 self.process_try_completion() 1423 self.writeline("else __Throw(__tmp_exc);") 1424 1425 self.indent -= 1 1426 self.writeline("}") 1427 1428 def process_try_completion(self): 1429 1430 "Generate a test for the completion of a try block." 1431 1432 self.writestmt("if (__tmp_exc.completing)") 1433 self.writeline("{") 1434 self.indent += 1 1435 1436 # Only use the normal return statement if no surrounding try blocks 1437 # apply. 1438 1439 if not self.in_try_finally and not self.in_try_except: 1440 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1441 else: 1442 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1443 1444 self.indent -= 1 1445 self.writeline("}") 1446 1447 def process_while_node(self, n): 1448 1449 "Process the given while node 'n'." 1450 1451 self.writeline("while (1)") 1452 self.writeline("{") 1453 self.indent += 1 1454 test = self.process_structure_node(n.test) 1455 1456 # Emit the loop termination condition unless "while <true value>" is 1457 # indicated. 1458 1459 if not (isinstance(test, PredefinedConstantRef) and test.value): 1460 1461 # NOTE: This needs to evaluate whether the operand is true or false 1462 # NOTE: according to Python rules. 1463 1464 self.writeline("if (!__BOOL(%s))" % test) 1465 self.writeline("{") 1466 self.indent += 1 1467 if n.else_: 1468 self.process_structure_node(n.else_) 1469 self.writestmt("break;") 1470 self.indent -= 1 1471 self.writeline("}") 1472 1473 in_conditional = self.in_conditional 1474 self.in_conditional = True 1475 self.process_structure_node(n.body) 1476 self.in_conditional = in_conditional 1477 1478 self.indent -= 1 1479 self.writeline("}") 1480 1481 # Output generation. 1482 1483 def start_output(self): 1484 1485 "Write the declarations at the top of each source file." 1486 1487 print >>self.out, """\ 1488 #include "types.h" 1489 #include "exceptions.h" 1490 #include "ops.h" 1491 #include "progconsts.h" 1492 #include "progops.h" 1493 #include "progtypes.h" 1494 #include "main.h" 1495 """ 1496 1497 def start_module(self): 1498 1499 "Write the start of each module's main function." 1500 1501 print >>self.out, "void __main_%s()" % encode_path(self.name) 1502 print >>self.out, "{" 1503 self.indent += 1 1504 self.write_temporaries(self.importer.function_targets.get(self.name)) 1505 1506 def end_module(self): 1507 1508 "End each module by closing its main function." 1509 1510 self.indent -= 1 1511 print >>self.out, "}" 1512 1513 def start_function(self, name): 1514 1515 "Start the function having the given 'name'." 1516 1517 print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name) 1518 print >>self.out, "{" 1519 self.indent += 1 1520 self.write_temporaries(self.importer.function_targets.get(name)) 1521 1522 # Obtain local names from parameters. 1523 1524 parameters = self.importer.function_parameters[name] 1525 locals = self.importer.function_locals[name].keys() 1526 names = [] 1527 1528 for n in locals: 1529 1530 # Filter out special names and parameters. Note that self is a local 1531 # regardless of whether it originally appeared in the parameters or 1532 # not. 1533 1534 if n.startswith("$l") or n in parameters or n == "self": 1535 continue 1536 names.append(encode_path(n)) 1537 1538 # Emit required local names. 1539 1540 if names: 1541 names.sort() 1542 self.writeline("__attr %s;" % ", ".join(names)) 1543 1544 self.write_parameters(name) 1545 1546 def end_function(self, name): 1547 1548 "End the function having the given 'name'." 1549 1550 self.indent -= 1 1551 print >>self.out, "}" 1552 print >>self.out 1553 1554 def write_temporaries(self, targets): 1555 1556 """ 1557 Write temporary storage employed by functions, providing space for the 1558 given number of 'targets'. 1559 """ 1560 1561 targets = targets is not None and "__tmp_targets[%d], " % targets or "" 1562 1563 self.writeline("__ref __tmp_context, __tmp_value;") 1564 self.writeline("__attr %s__tmp_result;" % targets) 1565 self.writeline("__exc __tmp_exc;") 1566 1567 def write_parameters(self, name): 1568 1569 """ 1570 For the function having the given 'name', write definitions of 1571 parameters found in the arguments array. 1572 """ 1573 1574 parameters = self.importer.function_parameters[name] 1575 1576 # Generate any self reference. 1577 1578 if self.is_method(name): 1579 self.writeline("__attr * const self = &__args[0];") 1580 1581 # Generate aliases for the parameters. 1582 1583 for i, parameter in enumerate(parameters): 1584 self.writeline("__attr * const %s = &__args[%d];" % (encode_path(parameter), i+1)) 1585 1586 def start_if(self, first, test_ref): 1587 self.writestmt("%sif (__BOOL(%s))" % (not first and "else " or "", test_ref)) 1588 self.writeline("{") 1589 self.indent += 1 1590 1591 def end_if(self): 1592 self.indent -= 1 1593 self.writeline("}") 1594 1595 def start_else(self): 1596 self.writeline("else") 1597 self.writeline("{") 1598 self.indent += 1 1599 1600 def end_else(self): 1601 self.indent -= 1 1602 self.writeline("}") 1603 1604 def statement(self, expr): 1605 # NOTE: Should never be None. 1606 if not expr: 1607 self.writestmt("...;") 1608 s = str(expr) 1609 if s: 1610 self.writestmt("%s;" % s) 1611 1612 def statements(self, results): 1613 for result in results: 1614 self.statement(result) 1615 1616 def writeline(self, s): 1617 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 1618 1619 def writestmt(self, s): 1620 print >>self.out 1621 self.writeline(s) 1622 1623 def write_comment(self, s): 1624 self.writestmt("/* %s */" % s) 1625 1626 def pad(self, extra=0): 1627 return (self.indent + extra) * self.tabstop 1628 1629 def indenttext(self, s, levels): 1630 lines = s.split("\n") 1631 out = [lines[0]] 1632 for line in lines[1:]: 1633 out.append(levels * self.tabstop + line) 1634 if line.endswith("("): 1635 levels += 1 1636 elif line.startswith(")"): 1637 levels -= 1 1638 return "\n".join(out) 1639 1640 # vim: tabstop=4 expandtab shiftwidth=4