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 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.process_structure(n) 758 759 self.exit_namespace() 760 761 def process_function_body_node(self, n): 762 763 """ 764 Process the given function, lambda, if expression or list comprehension 765 node 'n', generating the body. 766 """ 767 768 function_name = self.get_namespace_path() 769 self.start_function(function_name) 770 771 # Process the function body. 772 773 in_conditional = self.in_conditional 774 self.in_conditional = False 775 self.function_target = 0 776 777 # Process any guards defined for the parameters. 778 779 for name in self.importer.function_parameters.get(function_name): 780 self.generate_guard(name) 781 782 # Produce the body and any additional return statement. 783 784 expr = self.process_structure_node(n.code) or PredefinedConstantRef("None") 785 if not isinstance(expr, ReturnRef): 786 self.writestmt("return %s;" % expr) 787 788 self.in_conditional = in_conditional 789 790 self.end_function(function_name) 791 792 def generate_guard(self, name): 793 794 """ 795 Get the accessor details for 'name', found in the current namespace, and 796 generate any guards defined for it. 797 """ 798 799 # Obtain the location, keeping track of assignment versions. 800 801 location = self.get_accessor_location(name) 802 test = self.deducer.accessor_guard_tests.get(location) 803 804 # Generate any guard from the deduced information. 805 806 if test: 807 guard, guard_type = test 808 809 if guard == "specific": 810 ref = first(self.deducer.accessor_all_types[location]) 811 argstr = "&%s" % encode_path(ref.get_origin()) 812 elif guard == "common": 813 ref = first(self.deducer.accessor_all_general_types[location]) 814 typeattr = encode_type_attribute(ref.get_origin()) 815 argstr = "%s, %s" % (encode_symbol("pos", typeattr), encode_symbol("code", typeattr)) 816 else: 817 return 818 819 # Write a test that raises a TypeError upon failure. 820 821 self.writestmt("if (!__test_%s_%s(%s->value, %s)) __raise_type_error();" % ( 822 guard, guard_type, name, argstr)) 823 824 def process_function_node(self, n): 825 826 """ 827 Process the given function, lambda, if expression or list comprehension 828 node 'n', generating any initialisation statements. 829 """ 830 831 # Where a function is declared conditionally, use a separate name for 832 # the definition, and assign the definition to the stated name. 833 834 original_name = n.name 835 836 if self.in_conditional or self.in_function: 837 name = self.get_lambda_name() 838 else: 839 name = n.name 840 841 objpath = self.get_object_path(name) 842 843 # Obtain details of the defaults. 844 845 defaults = self.process_function_defaults(n, name, "&%s" % objpath) 846 if defaults: 847 for default in defaults: 848 self.writeline("%s;" % default) 849 850 # Where a function is set conditionally or where the name may refer to 851 # different values, assign the name. 852 853 ref = self.importer.identify(objpath) 854 855 if self.in_conditional or self.in_function: 856 self.process_assignment_for_function(original_name, compiler.ast.Name(name)) 857 elif not ref.static(): 858 self.process_assignment_for_function(original_name, 859 make_expression("((__attr) {0, &%s})" % encode_path(objpath))) 860 861 def process_function_defaults(self, n, name, instance_name): 862 863 """ 864 Process the given function or lambda node 'n', initialising defaults 865 that are dynamically set. The given 'name' indicates the name of the 866 function. The given 'instance_name' indicates the name of any separate 867 instance of the function created to hold the defaults. 868 869 Return a list of operations setting defaults on a function instance. 870 """ 871 872 function_name = self.get_object_path(name) 873 function_defaults = self.importer.function_defaults.get(function_name) 874 if not function_defaults: 875 return None 876 877 # Determine whether any unidentified defaults are involved. 878 879 need_defaults = [argname for argname, default in function_defaults if default.has_kind("<var>")] 880 if not need_defaults: 881 return None 882 883 # Where defaults are involved but cannot be identified, obtain a new 884 # instance of the lambda and populate the defaults. 885 886 defaults = [] 887 888 # Join the original defaults with the inspected defaults. 889 890 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 891 892 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 893 894 # Obtain any reference for the default. 895 896 if original: 897 argname, default = original 898 name_ref = self.process_structure_node(default) 899 elif inspected: 900 argname, default = inspected 901 name_ref = TrResolvedNameRef(argname, default) 902 else: 903 continue 904 905 if name_ref: 906 defaults.append("__SETDEFAULT(%s, %s, %s)" % (encode_path(instance_name), i, name_ref)) 907 908 return defaults 909 910 def process_if_node(self, n): 911 912 """ 913 Process the given "if" node 'n'. 914 """ 915 916 first = True 917 for test, body in n.tests: 918 test_ref = self.process_structure_node(test) 919 self.start_if(first, test_ref) 920 921 in_conditional = self.in_conditional 922 self.in_conditional = True 923 self.process_structure_node(body) 924 self.in_conditional = in_conditional 925 926 self.end_if() 927 first = False 928 929 if n.else_: 930 self.start_else() 931 self.process_structure_node(n.else_) 932 self.end_else() 933 934 def process_invocation_node(self, n): 935 936 "Process the given invocation node 'n'." 937 938 expr = self.process_structure_node(n.node) 939 objpath = expr.get_origin() 940 target = None 941 function = None 942 literal_instantiation = False 943 944 # Obtain details of the callable. 945 946 # Literals may be instantiated specially. 947 948 if expr.is_name() and expr.name.startswith("$L") and objpath: 949 literal_instantiation = True 950 parameters = None 951 target = encode_literal_instantiator(objpath) 952 953 # Identified targets employ function pointers directly. 954 955 elif objpath: 956 parameters = self.importer.function_parameters.get(objpath) 957 958 # Class invocation involves instantiators. 959 960 if expr.has_kind("<class>"): 961 target = encode_instantiator_pointer(objpath) 962 target_structure = encode_initialiser_pointer(objpath) 963 964 # Only plain functions and bound methods employ function pointers. 965 966 elif expr.has_kind("<function>"): 967 function = objpath 968 969 # Test for functions and methods. 970 971 accessor_kinds = expr.get_accessor_kinds() 972 973 if not self.is_method(objpath) or accessor_kinds and len(accessor_kinds) == 1 and first(accessor_kinds) == "<instance>": 974 target = encode_function_pointer(objpath) 975 target_structure = encode_path(objpath) 976 977 # Other targets are retrieved at run-time. 978 979 else: 980 parameters = None 981 982 # Arguments are presented in a temporary frame array with any context 983 # always being the first argument (although it may be set to null for 984 # invocations where it would be unused). 985 986 args = ["__CONTEXT_AS_VALUE(__tmp_targets[%d])" % self.function_target] 987 args += [None] * (not parameters and len(n.args) or parameters and len(parameters) or 0) 988 kwcodes = [] 989 kwargs = [] 990 991 # Any invocations in the arguments will store target details in a 992 # different location. 993 994 self.function_target += 1 995 996 for i, arg in enumerate(n.args): 997 argexpr = self.process_structure_node(arg) 998 999 # Store a keyword argument, either in the argument list or 1000 # in a separate keyword argument list for subsequent lookup. 1001 1002 if isinstance(arg, compiler.ast.Keyword): 1003 1004 # With knowledge of the target, store the keyword 1005 # argument directly. 1006 1007 if parameters: 1008 argnum = parameters.index(arg.name) 1009 args[argnum+1] = str(argexpr) 1010 1011 # Otherwise, store the details in a separate collection. 1012 1013 else: 1014 kwargs.append(str(argexpr)) 1015 kwcodes.append("{%s, %s}" % ( 1016 encode_symbol("ppos", arg.name), 1017 encode_symbol("pcode", arg.name))) 1018 1019 else: 1020 try: 1021 args[i+1] = str(argexpr) 1022 except IndexError: 1023 raise TranslateError("Too many arguments specified.", 1024 self.get_namespace_path(), n) 1025 1026 # Reference the current target again. 1027 1028 self.function_target -= 1 1029 1030 # Defaults are added to the frame where arguments are missing. 1031 1032 if parameters: 1033 function_defaults = self.importer.function_defaults.get(objpath) 1034 if function_defaults: 1035 1036 # Visit each default and set any missing arguments. 1037 # Use the target structure to obtain defaults, as opposed to the 1038 # actual function involved. 1039 1040 for i, (argname, default) in enumerate(function_defaults): 1041 argnum = parameters.index(argname) 1042 if not args[argnum+1]: 1043 args[argnum+1] = "__GETDEFAULT(&%s, %d)" % (target_structure, i) 1044 1045 # Test for missing arguments. 1046 1047 if None in args: 1048 raise TranslateError("Not all arguments supplied.", 1049 self.get_namespace_path(), n) 1050 1051 # Encode the arguments. 1052 1053 argstr = "__ARGS(%s)" % ", ".join(args) 1054 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1055 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1056 1057 # Where literal instantiation is occurring, add an argument indicating 1058 # the number of values. 1059 1060 if literal_instantiation: 1061 argstr += ", %d" % (len(args) - 1) 1062 1063 # First, the invocation expression is presented. 1064 1065 stages = [] 1066 1067 # Without a known specific callable, the expression provides the target. 1068 1069 stages.append("__tmp_targets[%d] = %s" % (self.function_target, expr)) 1070 1071 # Any specific callable is then obtained. 1072 1073 if target: 1074 stages.append(target) 1075 elif function: 1076 stages.append("__load_via_object(__tmp_targets[%d].value, %s).fn" % ( 1077 self.function_target, encode_symbol("pos", "__fn__"))) 1078 1079 # With a known target, the function is obtained directly and called. 1080 1081 if target or function: 1082 output = "(\n%s\n)(%s)" % (",\n".join(stages), argstr) 1083 1084 # With unknown targets, the generic invocation function is applied to 1085 # the callable and argument collections. 1086 1087 else: 1088 output = "(%s, __invoke(\n__tmp_targets[%d],\n%d, %d, %s, %s,\n%d, %s\n))" % ( 1089 ",\n".join(stages), 1090 self.function_target, 1091 self.always_callable and 1 or 0, 1092 len(kwargs), kwcodestr, kwargstr, 1093 len(args), argstr) 1094 1095 return make_expression(output) 1096 1097 def always_callable(self, refs): 1098 1099 "Determine whether all 'refs' are callable." 1100 1101 for ref in refs: 1102 if not ref.static(): 1103 return False 1104 else: 1105 origin = ref.final() 1106 if not self.importer.get_attribute(origin, "__fn__"): 1107 return False 1108 return True 1109 1110 def need_default_arguments(self, objpath, nargs): 1111 1112 """ 1113 Return whether any default arguments are needed when invoking the object 1114 given by 'objpath'. 1115 """ 1116 1117 parameters = self.importer.function_parameters.get(objpath) 1118 return nargs < len(parameters) 1119 1120 def process_lambda_node(self, n): 1121 1122 "Process the given lambda node 'n'." 1123 1124 name = self.get_lambda_name() 1125 function_name = self.get_object_path(name) 1126 1127 defaults = self.process_function_defaults(n, name, "__tmp_value") 1128 1129 # Without defaults, produce an attribute referring to the function. 1130 1131 if not defaults: 1132 return make_expression("((__attr) {0, &%s})" % encode_path(function_name)) 1133 1134 # With defaults, copy the function structure and set the defaults on the 1135 # copy. 1136 1137 else: 1138 return make_expression("(__tmp_value = __COPY(&%s, sizeof(%s)), %s, (__attr) {0, __tmp_value})" % ( 1139 encode_path(function_name), 1140 encode_symbol("obj", function_name), 1141 ", ".join(defaults))) 1142 1143 def process_logical_node(self, n): 1144 1145 """ 1146 Process the given operator node 'n'. 1147 1148 Convert ... to ... 1149 1150 <a> and <b> 1151 (__tmp_result = <a>, !__BOOL(__tmp_result)) ? __tmp_result : <b> 1152 1153 <a> or <b> 1154 (__tmp_result = <a>, __BOOL(__tmp_result)) ? __tmp_result : <b> 1155 """ 1156 1157 if isinstance(n, compiler.ast.And): 1158 op = "!" 1159 else: 1160 op = "" 1161 1162 results = [] 1163 1164 for node in n.nodes[:-1]: 1165 expr = self.process_structure_node(node) 1166 results.append("(__tmp_result = %s, %s__BOOL(__tmp_result)) ? __tmp_result : " % (expr, op)) 1167 1168 expr = self.process_structure_node(n.nodes[-1]) 1169 results.append(str(expr)) 1170 1171 return make_expression("(%s)" % "".join(results)) 1172 1173 def process_name_node(self, n, expr=None): 1174 1175 "Process the given name node 'n' with the optional assignment 'expr'." 1176 1177 # Determine whether the name refers to a static external entity. 1178 1179 if n.name in predefined_constants: 1180 return PredefinedConstantRef(n.name) 1181 1182 # Convert literal references, operator function names, and print 1183 # function names to references. 1184 1185 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1186 n.name.startswith("$print"): 1187 ref = self.importer.get_module(self.name).special.get(n.name) 1188 return TrResolvedNameRef(n.name, ref) 1189 1190 # Get the appropriate name for the name reference, using the same method 1191 # as in the inspector. 1192 1193 path = self.get_namespace_path() 1194 objpath = self.get_object_path(n.name) 1195 1196 # Determine any assigned globals. 1197 1198 globals = self.importer.get_module(self.name).scope_globals.get(path) 1199 if globals and n.name in globals: 1200 objpath = self.get_global_path(n.name) 1201 1202 # Get the static identity of the name. 1203 1204 ref = self.importer.identify(objpath) 1205 if ref and not ref.get_name(): 1206 ref = ref.alias(objpath) 1207 1208 # Obtain any resolved names for non-assignment names. 1209 1210 if not expr and not ref and self.in_function: 1211 locals = self.importer.function_locals.get(path) 1212 ref = locals and locals.get(n.name) 1213 1214 # Determine whether the name refers to a parameter. The generation of 1215 # parameter references is different from other names. 1216 1217 parameters = self.importer.function_parameters.get(path) 1218 parameter = n.name == "self" and self.in_method() or \ 1219 parameters and n.name in parameters 1220 1221 # Qualified names are used for resolved static references or for 1222 # static namespace members. The reference should be configured to return 1223 # such names. 1224 1225 return TrResolvedNameRef(n.name, ref, expr=expr, parameter=parameter) 1226 1227 def process_not_node(self, n): 1228 1229 "Process the given operator node 'n'." 1230 1231 return make_expression("(__BOOL(%s) ? %s : %s)" % 1232 (self.process_structure_node(n.expr), PredefinedConstantRef("False"), 1233 PredefinedConstantRef("True"))) 1234 1235 def process_raise_node(self, n): 1236 1237 "Process the given raise node 'n'." 1238 1239 # NOTE: Determine which raise statement variants should be permitted. 1240 1241 if n.expr1: 1242 self.writestmt("__Raise(%s);" % self.process_structure_node(n.expr1)) 1243 else: 1244 self.writestmt("__Complete;") 1245 1246 def process_return_node(self, n): 1247 1248 "Process the given return node 'n'." 1249 1250 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1251 if self.in_try_finally or self.in_try_except: 1252 self.writestmt("__Return(%s);" % expr) 1253 else: 1254 self.writestmt("return %s;" % expr) 1255 1256 return ReturnRef() 1257 1258 def process_try_node(self, n): 1259 1260 """ 1261 Process the given "try...except" node 'n'. 1262 """ 1263 1264 in_try_except = self.in_try_except 1265 self.in_try_except = True 1266 1267 # Use macros to implement exception handling. 1268 1269 self.writestmt("__Try") 1270 self.writeline("{") 1271 self.indent += 1 1272 self.process_structure_node(n.body) 1273 1274 # Put the else statement in another try block that handles any raised 1275 # exceptions and converts them to exceptions that will not be handled by 1276 # the main handling block. 1277 1278 if n.else_: 1279 self.writestmt("__Try") 1280 self.writeline("{") 1281 self.indent += 1 1282 self.process_structure_node(n.else_) 1283 self.indent -= 1 1284 self.writeline("}") 1285 self.writeline("__Catch (__tmp_exc)") 1286 self.writeline("{") 1287 self.indent += 1 1288 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1289 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1290 self.indent -= 1 1291 self.writeline("}") 1292 1293 # Complete the try block and enter the finally block, if appropriate. 1294 1295 if self.in_try_finally: 1296 self.writestmt("__Complete;") 1297 1298 self.indent -= 1 1299 self.writeline("}") 1300 1301 self.in_try_except = in_try_except 1302 1303 # Handlers are tests within a common handler block. 1304 1305 self.writeline("__Catch (__tmp_exc)") 1306 self.writeline("{") 1307 self.indent += 1 1308 1309 # Introduce an if statement to handle the completion of a try block. 1310 1311 self.process_try_completion() 1312 1313 # Handle exceptions in else blocks converted to __RaiseElse, converting 1314 # them back to normal exceptions. 1315 1316 if n.else_: 1317 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1318 1319 # Exception handling. 1320 1321 for name, var, handler in n.handlers: 1322 1323 # Test for specific exceptions. 1324 1325 if name is not None: 1326 name_ref = self.process_structure_node(name) 1327 self.writeline("else if (__BOOL(__fn_native__isinstance((__attr[]) {{0, 0}, __tmp_exc.arg, %s})))" % name_ref) 1328 else: 1329 self.writeline("else if (1)") 1330 1331 self.writeline("{") 1332 self.indent += 1 1333 1334 # Establish the local for the handler. 1335 1336 if var is not None: 1337 var_ref = self.process_name_node(var, make_expression("__tmp_exc")) 1338 1339 if handler is not None: 1340 self.process_structure_node(handler) 1341 1342 self.indent -= 1 1343 self.writeline("}") 1344 1345 # Re-raise unhandled exceptions. 1346 1347 self.writeline("else __Throw(__tmp_exc);") 1348 1349 # End the handler block. 1350 1351 self.indent -= 1 1352 self.writeline("}") 1353 1354 def process_try_finally_node(self, n): 1355 1356 """ 1357 Process the given "try...finally" node 'n'. 1358 """ 1359 1360 in_try_finally = self.in_try_finally 1361 self.in_try_finally = True 1362 1363 # Use macros to implement exception handling. 1364 1365 self.writestmt("__Try") 1366 self.writeline("{") 1367 self.indent += 1 1368 self.process_structure_node(n.body) 1369 self.indent -= 1 1370 self.writeline("}") 1371 1372 self.in_try_finally = in_try_finally 1373 1374 # Finally clauses handle special exceptions. 1375 1376 self.writeline("__Catch (__tmp_exc)") 1377 self.writeline("{") 1378 self.indent += 1 1379 self.process_structure_node(n.final) 1380 1381 # Introduce an if statement to handle the completion of a try block. 1382 1383 self.process_try_completion() 1384 self.writeline("else __Throw(__tmp_exc);") 1385 1386 self.indent -= 1 1387 self.writeline("}") 1388 1389 def process_try_completion(self): 1390 1391 "Generate a test for the completion of a try block." 1392 1393 self.writestmt("if (__tmp_exc.completing)") 1394 self.writeline("{") 1395 self.indent += 1 1396 1397 # Only use the normal return statement if no surrounding try blocks 1398 # apply. 1399 1400 if not self.in_try_finally and not self.in_try_except: 1401 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1402 else: 1403 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1404 1405 self.indent -= 1 1406 self.writeline("}") 1407 1408 def process_while_node(self, n): 1409 1410 "Process the given while node 'n'." 1411 1412 self.writeline("while (1)") 1413 self.writeline("{") 1414 self.indent += 1 1415 test = self.process_structure_node(n.test) 1416 1417 # Emit the loop termination condition unless "while <true value>" is 1418 # indicated. 1419 1420 if not (isinstance(test, PredefinedConstantRef) and test.value): 1421 1422 # NOTE: This needs to evaluate whether the operand is true or false 1423 # NOTE: according to Python rules. 1424 1425 self.writeline("if (!__BOOL(%s))" % test) 1426 self.writeline("{") 1427 self.indent += 1 1428 if n.else_: 1429 self.process_structure_node(n.else_) 1430 self.writestmt("break;") 1431 self.indent -= 1 1432 self.writeline("}") 1433 1434 in_conditional = self.in_conditional 1435 self.in_conditional = True 1436 self.process_structure_node(n.body) 1437 self.in_conditional = in_conditional 1438 1439 self.indent -= 1 1440 self.writeline("}") 1441 1442 # Output generation. 1443 1444 def start_output(self): 1445 1446 "Write the declarations at the top of each source file." 1447 1448 print >>self.out, """\ 1449 #include "types.h" 1450 #include "exceptions.h" 1451 #include "ops.h" 1452 #include "progconsts.h" 1453 #include "progops.h" 1454 #include "progtypes.h" 1455 #include "main.h" 1456 """ 1457 1458 def start_module(self): 1459 1460 "Write the start of each module's main function." 1461 1462 print >>self.out, "void __main_%s()" % encode_path(self.name) 1463 print >>self.out, "{" 1464 self.indent += 1 1465 self.write_temporaries(self.importer.function_targets.get(self.name)) 1466 1467 def end_module(self): 1468 1469 "End each module by closing its main function." 1470 1471 self.indent -= 1 1472 print >>self.out, "}" 1473 1474 def start_function(self, name): 1475 1476 "Start the function having the given 'name'." 1477 1478 print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name) 1479 print >>self.out, "{" 1480 self.indent += 1 1481 self.write_temporaries(self.importer.function_targets.get(name)) 1482 1483 # Obtain local names from parameters. 1484 1485 parameters = self.importer.function_parameters[name] 1486 locals = self.importer.function_locals[name].keys() 1487 names = [] 1488 1489 for n in locals: 1490 1491 # Filter out special names and parameters. Note that self is a local 1492 # regardless of whether it originally appeared in the parameters or 1493 # not. 1494 1495 if n.startswith("$l") or n in parameters or n == "self": 1496 continue 1497 names.append(encode_path(n)) 1498 1499 # Emit required local names. 1500 1501 if names: 1502 names.sort() 1503 self.writeline("__attr %s;" % ", ".join(names)) 1504 1505 self.write_parameters(name) 1506 1507 def end_function(self, name): 1508 1509 "End the function having the given 'name'." 1510 1511 self.indent -= 1 1512 print >>self.out, "}" 1513 print >>self.out 1514 1515 def write_temporaries(self, targets): 1516 1517 """ 1518 Write temporary storage employed by functions, providing space for the 1519 given number of 'targets'. 1520 """ 1521 1522 targets = targets is not None and "__tmp_targets[%d], " % targets or "" 1523 1524 self.writeline("__ref __tmp_context, __tmp_value;") 1525 self.writeline("__attr %s__tmp_result;" % targets) 1526 self.writeline("__exc __tmp_exc;") 1527 1528 def write_parameters(self, name): 1529 1530 """ 1531 For the function having the given 'name', write definitions of 1532 parameters found in the arguments array. 1533 """ 1534 1535 parameters = self.importer.function_parameters[name] 1536 1537 # Generate any self reference. 1538 1539 if self.is_method(name): 1540 self.writeline("__attr * const self = &__args[0];") 1541 1542 # Generate aliases for the parameters. 1543 1544 for i, parameter in enumerate(parameters): 1545 self.writeline("__attr * const %s = &__args[%d];" % (encode_path(parameter), i+1)) 1546 1547 def start_if(self, first, test_ref): 1548 self.writestmt("%sif (__BOOL(%s))" % (not first and "else " or "", test_ref)) 1549 self.writeline("{") 1550 self.indent += 1 1551 1552 def end_if(self): 1553 self.indent -= 1 1554 self.writeline("}") 1555 1556 def start_else(self): 1557 self.writeline("else") 1558 self.writeline("{") 1559 self.indent += 1 1560 1561 def end_else(self): 1562 self.indent -= 1 1563 self.writeline("}") 1564 1565 def statement(self, expr): 1566 # NOTE: Should never be None. 1567 if not expr: 1568 self.writestmt("...;") 1569 s = str(expr) 1570 if s: 1571 self.writestmt("%s;" % s) 1572 1573 def statements(self, results): 1574 for result in results: 1575 self.statement(result) 1576 1577 def writeline(self, s): 1578 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 1579 1580 def writestmt(self, s): 1581 print >>self.out 1582 self.writeline(s) 1583 1584 def write_comment(self, s): 1585 self.writestmt("/* %s */" % s) 1586 1587 def pad(self, extra=0): 1588 return (self.indent + extra) * self.tabstop 1589 1590 def indenttext(self, s, levels): 1591 lines = s.split("\n") 1592 out = [lines[0]] 1593 for line in lines[1:]: 1594 out.append(levels * self.tabstop + line) 1595 if line.endswith("("): 1596 levels += 1 1597 elif line.startswith(")"): 1598 levels -= 1 1599 return "\n".join(out) 1600 1601 # vim: tabstop=4 expandtab shiftwidth=4