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(&%s, %s).fn" % ( 1077 encode_path(function), 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_object_path(n.name) 1194 1195 # Get the static identity of the name. 1196 1197 ref = self.importer.identify(path) 1198 if ref and not ref.get_name(): 1199 ref = ref.alias(path) 1200 1201 # Obtain any resolved names for non-assignment names. 1202 1203 if not expr and not ref and self.in_function: 1204 locals = self.importer.function_locals.get(self.get_namespace_path()) 1205 ref = locals and locals.get(n.name) 1206 1207 # Determine whether the name refers to a parameter. The generation of 1208 # parameter references is different from other names. 1209 1210 parameters = self.importer.function_parameters.get(self.get_namespace_path()) 1211 parameter = n.name == "self" and self.in_method() or \ 1212 parameters and n.name in parameters 1213 1214 # Qualified names are used for resolved static references or for 1215 # static namespace members. The reference should be configured to return 1216 # such names. 1217 1218 return TrResolvedNameRef(n.name, ref, expr=expr, parameter=parameter) 1219 1220 def process_not_node(self, n): 1221 1222 "Process the given operator node 'n'." 1223 1224 return make_expression("(__BOOL(%s) ? %s : %s)" % 1225 (self.process_structure_node(n.expr), PredefinedConstantRef("False"), 1226 PredefinedConstantRef("True"))) 1227 1228 def process_raise_node(self, n): 1229 1230 "Process the given raise node 'n'." 1231 1232 # NOTE: Determine which raise statement variants should be permitted. 1233 1234 if n.expr1: 1235 self.writestmt("__Raise(%s);" % self.process_structure_node(n.expr1)) 1236 else: 1237 self.writestmt("__Complete;") 1238 1239 def process_return_node(self, n): 1240 1241 "Process the given return node 'n'." 1242 1243 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1244 if self.in_try_finally or self.in_try_except: 1245 self.writestmt("__Return(%s);" % expr) 1246 else: 1247 self.writestmt("return %s;" % expr) 1248 1249 return ReturnRef() 1250 1251 def process_try_node(self, n): 1252 1253 """ 1254 Process the given "try...except" node 'n'. 1255 """ 1256 1257 in_try_except = self.in_try_except 1258 self.in_try_except = True 1259 1260 # Use macros to implement exception handling. 1261 1262 self.writestmt("__Try") 1263 self.writeline("{") 1264 self.indent += 1 1265 self.process_structure_node(n.body) 1266 1267 # Put the else statement in another try block that handles any raised 1268 # exceptions and converts them to exceptions that will not be handled by 1269 # the main handling block. 1270 1271 if n.else_: 1272 self.writestmt("__Try") 1273 self.writeline("{") 1274 self.indent += 1 1275 self.process_structure_node(n.else_) 1276 self.indent -= 1 1277 self.writeline("}") 1278 self.writeline("__Catch (__tmp_exc)") 1279 self.writeline("{") 1280 self.indent += 1 1281 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1282 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1283 self.indent -= 1 1284 self.writeline("}") 1285 1286 # Complete the try block and enter the finally block, if appropriate. 1287 1288 if self.in_try_finally: 1289 self.writestmt("__Complete;") 1290 1291 self.indent -= 1 1292 self.writeline("}") 1293 1294 self.in_try_except = in_try_except 1295 1296 # Handlers are tests within a common handler block. 1297 1298 self.writeline("__Catch (__tmp_exc)") 1299 self.writeline("{") 1300 self.indent += 1 1301 1302 # Introduce an if statement to handle the completion of a try block. 1303 1304 self.process_try_completion() 1305 1306 # Handle exceptions in else blocks converted to __RaiseElse, converting 1307 # them back to normal exceptions. 1308 1309 if n.else_: 1310 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1311 1312 # Exception handling. 1313 1314 for name, var, handler in n.handlers: 1315 1316 # Test for specific exceptions. 1317 1318 if name is not None: 1319 name_ref = self.process_structure_node(name) 1320 self.writeline("else if (__BOOL(__fn_native__isinstance((__attr[]) {{0, 0}, __tmp_exc.arg, %s})))" % name_ref) 1321 else: 1322 self.writeline("else if (1)") 1323 1324 self.writeline("{") 1325 self.indent += 1 1326 1327 # Establish the local for the handler. 1328 1329 if var is not None: 1330 var_ref = self.process_name_node(var, make_expression("__tmp_exc")) 1331 1332 if handler is not None: 1333 self.process_structure_node(handler) 1334 1335 self.indent -= 1 1336 self.writeline("}") 1337 1338 # Re-raise unhandled exceptions. 1339 1340 self.writeline("else __Throw(__tmp_exc);") 1341 1342 # End the handler block. 1343 1344 self.indent -= 1 1345 self.writeline("}") 1346 1347 def process_try_finally_node(self, n): 1348 1349 """ 1350 Process the given "try...finally" node 'n'. 1351 """ 1352 1353 in_try_finally = self.in_try_finally 1354 self.in_try_finally = True 1355 1356 # Use macros to implement exception handling. 1357 1358 self.writestmt("__Try") 1359 self.writeline("{") 1360 self.indent += 1 1361 self.process_structure_node(n.body) 1362 self.indent -= 1 1363 self.writeline("}") 1364 1365 self.in_try_finally = in_try_finally 1366 1367 # Finally clauses handle special exceptions. 1368 1369 self.writeline("__Catch (__tmp_exc)") 1370 self.writeline("{") 1371 self.indent += 1 1372 self.process_structure_node(n.final) 1373 1374 # Introduce an if statement to handle the completion of a try block. 1375 1376 self.process_try_completion() 1377 self.writeline("else __Throw(__tmp_exc);") 1378 1379 self.indent -= 1 1380 self.writeline("}") 1381 1382 def process_try_completion(self): 1383 1384 "Generate a test for the completion of a try block." 1385 1386 self.writestmt("if (__tmp_exc.completing)") 1387 self.writeline("{") 1388 self.indent += 1 1389 1390 # Only use the normal return statement if no surrounding try blocks 1391 # apply. 1392 1393 if not self.in_try_finally and not self.in_try_except: 1394 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1395 else: 1396 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1397 1398 self.indent -= 1 1399 self.writeline("}") 1400 1401 def process_while_node(self, n): 1402 1403 "Process the given while node 'n'." 1404 1405 self.writeline("while (1)") 1406 self.writeline("{") 1407 self.indent += 1 1408 test = self.process_structure_node(n.test) 1409 1410 # Emit the loop termination condition unless "while <true value>" is 1411 # indicated. 1412 1413 if not (isinstance(test, PredefinedConstantRef) and test.value): 1414 1415 # NOTE: This needs to evaluate whether the operand is true or false 1416 # NOTE: according to Python rules. 1417 1418 self.writeline("if (!__BOOL(%s))" % test) 1419 self.writeline("{") 1420 self.indent += 1 1421 if n.else_: 1422 self.process_structure_node(n.else_) 1423 self.writestmt("break;") 1424 self.indent -= 1 1425 self.writeline("}") 1426 1427 in_conditional = self.in_conditional 1428 self.in_conditional = True 1429 self.process_structure_node(n.body) 1430 self.in_conditional = in_conditional 1431 1432 self.indent -= 1 1433 self.writeline("}") 1434 1435 # Output generation. 1436 1437 def start_output(self): 1438 1439 "Write the declarations at the top of each source file." 1440 1441 print >>self.out, """\ 1442 #include "types.h" 1443 #include "exceptions.h" 1444 #include "ops.h" 1445 #include "progconsts.h" 1446 #include "progops.h" 1447 #include "progtypes.h" 1448 #include "main.h" 1449 """ 1450 1451 def start_module(self): 1452 1453 "Write the start of each module's main function." 1454 1455 print >>self.out, "void __main_%s()" % encode_path(self.name) 1456 print >>self.out, "{" 1457 self.indent += 1 1458 self.write_temporaries(self.importer.function_targets.get(self.name)) 1459 1460 def end_module(self): 1461 1462 "End each module by closing its main function." 1463 1464 self.indent -= 1 1465 print >>self.out, "}" 1466 1467 def start_function(self, name): 1468 1469 "Start the function having the given 'name'." 1470 1471 print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name) 1472 print >>self.out, "{" 1473 self.indent += 1 1474 self.write_temporaries(self.importer.function_targets.get(name)) 1475 1476 # Obtain local names from parameters. 1477 1478 parameters = self.importer.function_parameters[name] 1479 locals = self.importer.function_locals[name].keys() 1480 names = [] 1481 1482 for n in locals: 1483 1484 # Filter out special names and parameters. Note that self is a local 1485 # regardless of whether it originally appeared in the parameters or 1486 # not. 1487 1488 if n.startswith("$l") or n in parameters or n == "self": 1489 continue 1490 names.append(encode_path(n)) 1491 1492 # Emit required local names. 1493 1494 if names: 1495 names.sort() 1496 self.writeline("__attr %s;" % ", ".join(names)) 1497 1498 self.write_parameters(name) 1499 1500 def end_function(self, name): 1501 1502 "End the function having the given 'name'." 1503 1504 self.indent -= 1 1505 print >>self.out, "}" 1506 print >>self.out 1507 1508 def write_temporaries(self, targets): 1509 1510 """ 1511 Write temporary storage employed by functions, providing space for the 1512 given number of 'targets'. 1513 """ 1514 1515 targets = targets is not None and "__tmp_targets[%d], " % targets or "" 1516 1517 self.writeline("__ref __tmp_context, __tmp_value;") 1518 self.writeline("__attr %s__tmp_result;" % targets) 1519 self.writeline("__exc __tmp_exc;") 1520 1521 def write_parameters(self, name): 1522 1523 """ 1524 For the function having the given 'name', write definitions of 1525 parameters found in the arguments array. 1526 """ 1527 1528 parameters = self.importer.function_parameters[name] 1529 1530 # Generate any self reference. 1531 1532 if self.is_method(name): 1533 self.writeline("__attr * const self = &__args[0];") 1534 1535 # Generate aliases for the parameters. 1536 1537 for i, parameter in enumerate(parameters): 1538 self.writeline("__attr * const %s = &__args[%d];" % (encode_path(parameter), i+1)) 1539 1540 def start_if(self, first, test_ref): 1541 self.writestmt("%sif (__BOOL(%s))" % (not first and "else " or "", test_ref)) 1542 self.writeline("{") 1543 self.indent += 1 1544 1545 def end_if(self): 1546 self.indent -= 1 1547 self.writeline("}") 1548 1549 def start_else(self): 1550 self.writeline("else") 1551 self.writeline("{") 1552 self.indent += 1 1553 1554 def end_else(self): 1555 self.indent -= 1 1556 self.writeline("}") 1557 1558 def statement(self, expr): 1559 # NOTE: Should never be None. 1560 if not expr: 1561 self.writestmt("...;") 1562 s = str(expr) 1563 if s: 1564 self.writestmt("%s;" % s) 1565 1566 def statements(self, results): 1567 for result in results: 1568 self.statement(result) 1569 1570 def writeline(self, s): 1571 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 1572 1573 def writestmt(self, s): 1574 print >>self.out 1575 self.writeline(s) 1576 1577 def write_comment(self, s): 1578 self.writestmt("/* %s */" % s) 1579 1580 def pad(self, extra=0): 1581 return (self.indent + extra) * self.tabstop 1582 1583 def indenttext(self, s, levels): 1584 lines = s.split("\n") 1585 out = [lines[0]] 1586 for line in lines[1:]: 1587 out.append(levels * self.tabstop + line) 1588 if line.endswith("("): 1589 levels += 1 1590 elif line.startswith(")"): 1591 levels -= 1 1592 return "\n".join(out) 1593 1594 # vim: tabstop=4 expandtab shiftwidth=4