1 #!/usr/bin/env python 2 3 """ 4 Translate the AST of a Python program into a more interpretable representation. 5 6 Copyright (C) 2007, 2008, 2009 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 micropython.opt import Optimiser 23 from micropython.common import * 24 from micropython.data import * 25 from micropython.rsvp import * 26 from micropython.trans import Helper 27 import compiler.ast 28 from compiler.visitor import ASTVisitor 29 30 # Program visitors. 31 32 class Translation(ASTVisitor, Helper): 33 34 "A translated module." 35 36 # Attribute access instructions, for use with the appropriate handlers. 37 38 attribute_load_instructions = ( 39 LoadAddress, LoadAddressContext, LoadAddressContextCond, 40 LoadAttr, LoadAttrIndex, LoadAttrIndexContextCond 41 ) 42 attribute_store_instructions = ( 43 None, None, None, 44 StoreAttr, StoreAttrIndex, None 45 ) 46 47 # Name access instructions, for use with the appropriate handlers. 48 49 name_load_instructions = (LoadName, LoadAddress, None) 50 name_store_instructions = (StoreName, StoreAddress, StoreAddressContext) 51 52 def __init__(self, module, program): 53 54 """ 55 Initialise the translation with an inspected 'module' and the 'program' 56 container. 57 """ 58 59 ASTVisitor.__init__(self) 60 self.visitor = self 61 self.module = module 62 63 # Global program dependencies. 64 65 self.program = program 66 self.objtable = self.program.get_object_table() 67 self.paramtable = self.program.get_parameter_table() 68 self.importer = self.program.get_importer() 69 self.builtins = self.importer.modules.get("__builtins__") 70 71 # Optimisation. 72 73 self.optimiser = Optimiser(self, program.optimisations) 74 75 # The current unit being translated. 76 77 self.unit = None 78 79 # The temporary storage used by the current assignment expression. 80 81 self.expr_temp = [] 82 83 # Wiring within the code. 84 85 self.labels = {} 86 self.label_number = 0 87 self.loop_blocks = [] 88 self.exception_blocks = [] 89 self.in_exception_handler = 0 90 91 self.reset() 92 93 def __repr__(self): 94 return "Translation(%r)" % self.module 95 96 def reset(self): 97 98 "Reset the state of the translator." 99 100 # The code itself. This is limited to the code for a particular block 101 # being processed. 102 103 self.blocks = [] 104 105 # Information about temporary values. 106 107 self.temp_positions = set() 108 self.max_temp_position = -1 109 110 # Information about instructions which construct frames. 111 112 self.frame_makers = [] 113 114 # Optimiser state must be reset for each unit. 115 116 self.optimiser.reset() 117 118 def get_module_code(self): 119 120 """ 121 Return the top-level module code. 122 """ 123 124 self.unit = self.module 125 self.reset() 126 127 block = self.new_block() 128 self.set_block(block) 129 130 if self.module.module is not None: 131 self.dispatch(self.module.module) 132 133 # Finish off the translated program if appropriate. 134 135 if self.module.name == "__main__": 136 self.new_op(Return()) 137 138 self.unit.temp_usage = self.max_temp_position + 1 139 self.unit.blocks = self.blocks 140 return self.blocks 141 142 def get_code(self, unit): 143 144 "Return the code for the given 'unit'." 145 146 self.unit = unit 147 self.reset() 148 149 block = self.new_block() 150 self.set_block(block) 151 152 if unit.astnode is not None: 153 self.dispatch(unit.astnode) 154 155 self.unit.temp_usage = self.max_temp_position + 2 # include space for instantiators to expand backwards 156 self.unit.blocks = self.blocks 157 return self.blocks 158 159 def get_instantiator_code(self, cls): 160 161 "Return the code for the given class 'cls'." 162 163 self.unit = cls.get_instantiator() 164 self.reset() 165 166 block = self.new_block() 167 self.set_block(block) 168 169 init_method = cls.get_init_method() 170 171 # Make an object and store it in the unused first slot. 172 173 self.make_instance(cls, len(cls.instance_attributes())) 174 self.new_op(StoreTemp(0)) 175 176 # Invoke the appropriate initialiser. 177 178 self.new_op(LoadFunction(init_method)) 179 self.new_op(LoadCallable()) 180 self.new_op(JumpInFrame()) 181 182 # Store the object as the result. 183 184 self.new_op(LoadTemp(0)) # load the context from the locals 185 self.new_op(StoreResult()) 186 self.new_op(Return()) 187 188 self.unit.blocks = self.blocks 189 return self.blocks 190 191 # Visitor methods. 192 193 def default(self, node, *args): 194 raise TranslateError(self.module.full_name(), node, "Node class %r is not supported." % node.__class__) 195 196 def dispatch(self, node, *args): 197 return ASTVisitor.dispatch(self, node, *args) 198 199 # Concrete visitor methods. 200 201 # Binary operators. 202 203 visitAdd = Helper._visitBinary 204 visitBitand = Helper._visitBinary 205 visitBitor = Helper._visitBinary 206 visitBitxor = Helper._visitBinary 207 visitDiv = Helper._visitBinary 208 visitFloorDiv = Helper._visitBinary 209 visitLeftShift = Helper._visitBinary 210 visitMod = Helper._visitBinary 211 visitMul = Helper._visitBinary 212 visitPower = Helper._visitBinary 213 visitRightShift = Helper._visitBinary 214 visitSub = Helper._visitBinary 215 216 # Unary operators. 217 218 visitInvert = Helper._visitUnary 219 visitUnaryAdd = Helper._visitUnary 220 visitUnarySub = Helper._visitUnary 221 222 # Logical operators. 223 224 def visitAnd(self, node): 225 end_block = self.new_block() 226 temp_pos = self.reserve_temp() 227 temp = LoadTemp(temp_pos) 228 229 for n in node.nodes[:-1]: 230 self.dispatch(n) 231 self.new_op(StoreTemp(temp_pos)) 232 233 self._generateTestBoolean(n, temp) 234 self.new_op(JumpIfFalse(end_block)) 235 236 self.dispatch(node.nodes[-1]) 237 self.new_op(StoreTemp(temp_pos)) 238 239 self.set_block(end_block) 240 241 self.new_op(temp) 242 self.discard_temp(temp) 243 244 def visitNot(self, node): 245 self.dispatch(node.expr) 246 247 temp = self.optimiser.optimise_temp_storage() 248 self._generateTestBoolean(node.expr, temp) 249 self.discard_temp(temp) 250 251 self.new_op(InvertBoolean()) 252 self._generateLoadBoolean(node) 253 254 def visitOr(self, node): 255 end_block = self.new_block() 256 temp_pos = self.reserve_temp() 257 temp = LoadTemp(temp_pos) 258 259 for n in node.nodes[:-1]: 260 self.dispatch(n) 261 self.new_op(StoreTemp(temp_pos)) 262 263 self._generateTestBoolean(n, temp) 264 self.new_op(JumpIfTrue(end_block)) 265 266 self.dispatch(node.nodes[-1]) 267 self.new_op(StoreTemp(temp_pos)) 268 269 self.set_block(end_block) 270 271 self.new_op(temp) 272 self.discard_temp(temp) 273 274 # Comparisons. 275 276 def visitCompare(self, node): 277 278 """ 279 _t1 = node.expr 280 _t1 op1 _t2 and _t2 op2 _t3 and ... 281 """ 282 283 end_block = self.new_block() 284 285 self.dispatch(node.expr) 286 temp2 = self.optimiser.optimise_temp_storage() 287 288 # NOTE: Replicated by some code in micropython.inspect.visitCompare. 289 290 last_op = node.ops[-1] 291 292 for op in node.ops: 293 op_name, next_node = op 294 methods = comparison_methods[op_name] 295 296 # Propagate the arguments as we traverse the construct. 297 298 temp1 = temp2 299 self.dispatch(next_node) 300 temp2 = self.optimiser.optimise_temp_storage() 301 302 # Use the appropriate mechanism, setting the boolean status for the 303 # comparison. 304 305 if methods is not None: 306 left_method, right_method = methods 307 308 # Generate method call using evaluated argument and next node. 309 310 temp_result = self._generateBinary(node, temp1, temp2, left_method, right_method) 311 self.new_op(temp_result) 312 self._generateTestBoolean(node, temp_result) 313 self.discard_temp(temp_result) 314 315 else: 316 # Deal with the special operators. 317 318 if op_name.startswith("is"): 319 self.new_op(temp1) 320 self.record_value() 321 self.new_op(temp2) 322 self.new_op(TestIdentity()) 323 self.set_source() 324 self.discard_value() 325 326 elif op_name.endswith("in"): 327 self.new_op(temp2) 328 329 # Get method on temp2. 330 331 self._generateAttr(node, "__contains__", self.attribute_load_instructions) 332 temp_method = self.optimiser.optimise_temp_storage() 333 334 # Add arguments. 335 # NOTE: No support for defaults. 336 337 self._startCallFunc() 338 self.new_op(temp2) 339 self.new_op(StoreFrame(0)) 340 self.new_op(temp1) 341 self.new_op(StoreFrame(1)) 342 self._endCallFuncArgs(2) 343 self._doCallFunc(temp_method) 344 self._endCallFunc(temp_method) 345 346 temp_result = self.get_temp() 347 self._generateTestBoolean(node, temp_result) 348 self.discard_temp(temp_result) 349 350 if op_name.find("not") != -1: 351 self.new_op(InvertBoolean()) 352 353 # Test the result and jump to the end block if false. 354 355 if op is not last_op: 356 self.new_op(JumpIfFalse(end_block)) 357 358 # Compilation duties... 359 360 self.discard_temp(temp1) 361 362 self.discard_temp(temp2) 363 364 # With the status set above, produce a boolean result. 365 366 self.set_block(end_block) 367 368 # Yield the appropriate value. 369 370 self._generateLoadBoolean(node) 371 372 # Expressions. 373 374 def visitBackquote(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Backquote") 375 376 def visitCallFunc(self, node): 377 378 """ 379 Evaluate positional arguments, evaluate and store keyword arguments in 380 the correct location, then invoke the function. 381 """ 382 383 # Mark the frame, evaluate the target, generate the call. 384 385 self._startCallFunc() 386 self.dispatch(node.node) 387 temp_target, target, temp_context = self._generateCallFunc(node.args, node) 388 self._doCallFunc(temp_target, target) 389 self._endCallFunc(temp_target, target, temp_context) 390 391 def visitConst(self, node): 392 const = self.importer.get_constant(node.value) 393 self.new_op(LoadConst(const)) 394 395 def visitDict(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Dict") 396 397 def visitEllipsis(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Ellipsis") 398 399 def visitExec(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Exec") 400 401 def visitExpression(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Expression") 402 403 def visitGenExpr(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExpr") 404 405 def visitGenExprFor(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExprFor") 406 407 def visitGenExprIf(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExprIf") 408 409 def visitGenExprInner(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "GenExprInner") 410 411 def visitGetattr(self, node): 412 self._visitAttr(node, self.attribute_load_instructions) 413 414 def visitList(self, node): 415 self._generateList(node) 416 417 def visitListComp(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "ListComp") 418 419 def visitListCompFor(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "ListCompFor") 420 421 def visitListCompIf(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "ListCompIf") 422 423 def visitName(self, node): 424 if self.importer.predefined_constants.has_key(node.name): 425 const = self.importer.get_predefined_constant(node.name) 426 self.new_op(LoadConst(const)) 427 else: 428 self._visitName(node, self.name_load_instructions) 429 430 def visitSlice(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Slice") 431 432 def visitSubscript(self, node): 433 self.dispatch(node.expr) 434 self._startCallFunc() 435 self._generateAttr(node, "__getitem__", self.attribute_load_instructions) 436 temp_target, target, temp_context = self._generateCallFunc(node.subs, node) 437 self._doCallFunc(temp_target, target) 438 self._endCallFunc(temp_target, target, temp_context) 439 440 def visitTuple(self, node): 441 self._generateTuple(node) 442 443 # Definitions. 444 445 def visitAssign(self, node): 446 447 """ 448 Evaluate the expression from the given 'node' and assign it to the 449 associated recipients. 450 """ 451 452 self.dispatch(node.expr) 453 454 # Record the value and then dispatch to the assignment targets. 455 456 self.record_value(self.has_immediate_usage(node.nodes)) 457 458 for n in node.nodes: 459 self.dispatch(n) 460 461 self.discard_value() 462 463 def visitAssAttr(self, node): 464 465 "Assign the assignment expression to the recipient 'node'." 466 467 self._visitAttr(node, self.attribute_store_instructions) 468 self.set_source() 469 470 def visitAssList(self, node): 471 472 """ 473 Assign items from the assignment expression to each of the recipients 474 found within the given 'node'. 475 """ 476 477 for i, n in enumerate(node.nodes): 478 self._startCallFunc() 479 self.new_op(self.expr_temp[-1]) 480 self._generateAttr(node, "__getitem__", self.attribute_load_instructions) 481 temp_target, target, temp_context = self._generateCallFunc([compiler.ast.Const(i)], node) 482 self._doCallFunc(temp_target, target) 483 self._endCallFunc(temp_target, target, temp_context) 484 485 # Provide a different source value. 486 # NOTE: Permitting immediate usage given that neither name nor 487 # NOTE: attribute accesses should involve a function call 488 # NOTE: overwriting the above result. 489 490 self.record_value(self.is_immediate_user(n)) 491 self.dispatch(n) 492 self.discard_value() 493 494 def visitAssName(self, node): 495 496 "Assign the assignment expression to the recipient 'node'." 497 498 self._visitName(node, self.name_store_instructions) 499 self.set_source() 500 501 visitAssTuple = visitAssList 502 503 def visitAugAssign(self, node): 504 use_binary_block = self.new_block() 505 end_block = self.new_block() 506 507 # Evaluate the expression. 508 509 self.dispatch(node.expr) 510 temp2 = self.optimiser.optimise_temp_storage() 511 512 # Evaluate the target. 513 514 self.dispatch(node.node) 515 temp1 = self.optimiser.optimise_temp_storage() 516 517 # Find the augmented assignment method and attempt to use it. 518 519 aug_method, (left_method, right_method) = augassign_methods[node.op] 520 temp_out = self._generateOpMethod(node, temp1, temp2, aug_method, use_binary_block, use_binary_block, end_block) 521 self.discard_temp(temp_out) # NOTE: Will re-use the same storage. 522 523 # Where no such method exists, use the binary operator methods. 524 525 self.set_block(use_binary_block) 526 temp_out = self._generateBinary(node, temp1, temp2, left_method, right_method) 527 528 # Assign the result to the name. 529 530 self.set_block(end_block) 531 self.new_op(temp_out) 532 self.record_value(1) 533 534 if isinstance(node.node, compiler.ast.Name): 535 self.visitAssName(node.node) 536 elif isinstance(node.node, compiler.ast.Getattr): 537 self.visitAssAttr(node.node) 538 else: 539 raise TranslationNotImplementedError(self.module.full_name(), node, "AugAssign(Slice or Subscript)") 540 541 self.discard_value() 542 543 # Compilation duties... 544 545 self.discard_temp(temp1) 546 self.discard_temp(temp2) 547 548 def visitClass(self, node): 549 if not node.unit.parent.has_key(node.unit.name): 550 return 551 552 # Store the name. 553 554 self.new_op(LoadClass(node.unit)) 555 self.record_value() 556 self._visitName(node, self.name_store_instructions) 557 self.set_source() 558 self.discard_value() 559 560 # Visit the code. 561 562 unit = self.unit 563 self.unit = node.unit 564 self.dispatch(node.code) 565 self.unit = unit 566 567 def visitDecorators(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Decorators") 568 569 def visitFrom(self, node): pass 570 571 def visitFunction(self, node): 572 if not node.unit.parent.has_key(node.unit.name): 573 return 574 575 # Only store the name when visiting this node from outside. 576 577 if self.unit is not node.unit: 578 self.new_op(LoadFunction(node.unit)) 579 self.record_value() 580 581 self._visitName(node, self.name_store_instructions) # AssName equivalent 582 self.set_source() 583 self.discard_value() 584 585 self._generateFunctionDefaults(node.unit) 586 587 # Visiting of the code occurs when get_code is invoked on this node. 588 589 else: 590 # Check frames using the function's details. 591 592 fn = node.unit 593 nparams = len(fn.positional_names) 594 ndefaults = len(fn.defaults) 595 596 fn.body_block = self.new_block() 597 598 # Check the number of parameters and defaults. 599 600 self.new_op(CheckFrame((nparams, ndefaults, fn.has_star))) 601 if ndefaults > 0: 602 self.new_op(LoadFunction(fn)) 603 self.new_op(FillDefaults((nparams, ndefaults))) 604 605 # Produce the body. 606 607 self.set_block(fn.body_block) 608 609 extend = ExtendFrame() 610 self.new_op(extend) 611 612 self.dispatch(node.code) 613 614 if not isinstance(self.last_op(), Return): 615 self.dispatch(compiler.ast.Name("None")) 616 self.new_op(StoreResult()) 617 self.new_op(Return()) 618 619 # Make sure that enough frame space is reserved from the start. 620 621 self.set_frame_usage(node, extend) 622 623 def visitGlobal(self, node): pass 624 625 def visitImport(self, node): pass 626 627 def visitKeyword(self, node): pass 628 629 def visitLambda(self, node): 630 631 """ 632 Lambda functions can be represented as globally defined functions 633 provided they do not define any default parameter values, since these 634 may defined in a non-global scope. 635 636 Where defaults are defined, an object must be created and its content 637 defined: the callable member of the object's structure must be set to 638 the lambda function definition; each default must be attached to the 639 object as an attribute, as is the case with normal functions and 640 methods. 641 """ 642 643 # Produce the reference to this function when visiting this node from 644 # outside. 645 646 if self.unit is not node.unit: 647 fn = node.unit 648 ndefaults = len(fn.defaults) 649 temp = self._generateFunctionDefaults(fn) 650 651 if ndefaults > 0: 652 self.new_op(LoadConst(fn)) 653 else: 654 self.new_op(LoadFunction(fn)) 655 656 # Populate the new object required for the function. 657 658 if temp is not None: 659 self.new_op(LoadCallable()) 660 self.new_op(temp) 661 self.new_op(StoreCallable()) 662 663 self.new_op(temp) 664 #self.discard_temp(temp) 665 666 # Visiting of the code occurs when get_code is invoked on this node. 667 668 else: 669 # Check frames using the function's details. 670 671 fn = node.unit 672 nparams = len(fn.positional_names) 673 ndefaults = len(fn.defaults) 674 675 fn.body_block = self.new_block() 676 677 # Check the number of parameters and defaults. 678 679 self.new_op(CheckFrame((nparams, ndefaults, fn.has_star))) 680 if ndefaults > 0: 681 self.new_op(LoadTemp(0)) # context provides storage 682 self.new_op(FillDefaults((nparams, ndefaults))) 683 684 # Produce the body. 685 686 self.set_block(fn.body_block) 687 688 extend = ExtendFrame() 689 self.new_op(extend) 690 691 self.dispatch(node.code) 692 693 self.new_op(StoreResult()) 694 self.new_op(Return()) 695 696 # Make sure that enough frame space is reserved from the start. 697 698 self.set_frame_usage(node, extend) 699 700 def visitModule(self, node): 701 extend = ExtendFrame() 702 self.new_op(extend) 703 self.dispatch(node.node) 704 self.set_frame_usage(node, extend) 705 706 # Statements. 707 708 def visitStmt(self, node): 709 710 "Process the collection of statements provided by 'node'." 711 712 for n in node.nodes: 713 714 # Process the statement. 715 716 self.dispatch(n) 717 718 # Discard temporary storage. 719 720 if self.temp_positions: 721 #print "Had temp", self.temp_positions 722 self.temp_positions = set() 723 724 # Prevent incorrect optimisation by resetting the optimiser after 725 # each statement. 726 727 self.optimiser.reset() 728 729 def visitAssert(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Assert") 730 731 def visitBreak(self, node): 732 next_block, exit_block = self.get_loop_blocks() 733 self.new_op(Jump(exit_block)) 734 735 def visitContinue(self, node): 736 next_block, exit_block = self.get_loop_blocks() 737 self.new_op(Jump(next_block)) 738 739 def visitDiscard(self, node): 740 self.dispatch(node.expr) 741 self.optimiser.optimise_unused_results() 742 743 def visitFor(self, node): 744 next_handler_block = self.new_block() 745 end_handler_block = self.new_block() 746 exit_block = self.new_block() 747 next_block = self.new_block() 748 else_block = self.new_block() 749 750 # Get the "list" to be iterated over, obtain its iterator. 751 752 self._startCallFunc() 753 self.dispatch(node.list) 754 self._generateAttr(node, "__iter__", self.attribute_load_instructions) 755 temp_target, target, temp_context = self._generateCallFunc([], node) 756 self._doCallFunc(temp_target, target) 757 self._endCallFunc(temp_target, target, temp_context) 758 759 # Use a long-lasting temporary storage slot, since any result from the 760 # __iter__ method will not remain around for long. 761 762 temp_iterator = self.get_temp() 763 764 # In the loop... 765 766 self.set_block(next_block) 767 768 # Handle exceptions when calling "next"... 769 770 self.new_op(PushHandler(next_handler_block)) 771 772 # Use the iterator to get the next value. 773 774 self._startCallFunc() 775 self.new_op(temp_iterator) 776 self._generateAttr(node, "next", self.attribute_load_instructions) 777 temp_target, target, temp_context = self._generateCallFunc([], node) 778 self._doCallFunc(temp_target, target) 779 self._endCallFunc(temp_target, target, temp_context) 780 781 # Record the value to be assigned. 782 783 self.record_value() 784 785 # Skip the handler where the call was successful. 786 787 self.new_op(PopHandler()) 788 self.new_op(Jump(end_handler_block)) 789 790 # Enter the exception handler. 791 792 self.set_block(next_handler_block) 793 self.new_op(PopHandler()) 794 795 # Test for StopIteration. 796 797 self.load_builtin("StopIteration", node) 798 self.new_op(CheckException()) 799 if node.else_ is not None: 800 self.new_op(JumpIfTrue(else_block)) 801 else: 802 self.new_op(JumpIfTrue(exit_block)) 803 804 # Re-raise the exception otherwise. 805 806 self.new_op(RaiseException()) 807 808 # After the handler, clear the exception. 809 810 self.set_block(end_handler_block) 811 812 # Assign to the target. 813 814 self.dispatch(node.assign) 815 self.discard_value() 816 817 # Process the body with the current next and exit points. 818 819 self.add_loop_blocks(next_block, exit_block) 820 self.dispatch(node.body) 821 self.drop_loop_blocks() 822 823 # Repeat the loop. 824 825 self.new_op(Jump(next_block)) 826 827 # Produce the "else" section. 828 829 if node.else_ is not None: 830 self.set_block(else_block) 831 self.new_op(ClearException()) 832 self.dispatch(node.else_) 833 834 # After the loop... 835 836 self.set_block(exit_block) 837 838 else: 839 # After the loop... 840 841 self.set_block(exit_block) 842 self.new_op(ClearException()) 843 844 # Compilation duties... 845 846 self.discard_temp(temp_iterator) 847 848 def visitIf(self, node): 849 first = 1 850 next_block = None 851 exit_block = self.new_block() 852 853 clauses = node.tests + [(None, node.else_)] 854 855 for clause in clauses: 856 test, body = clause 857 if body is None: 858 break 859 860 if not first: 861 self.new_op(Jump(exit_block)) # finish last body 862 self.set_block(next_block) # start next test 863 next_block = None 864 865 if test is not None: 866 self.dispatch(test) 867 868 temp = self.optimiser.optimise_temp_storage() 869 self._generateTestBoolean(node, temp) 870 871 next_block = self.new_block() 872 self.new_op(JumpIfFalse(next_block)) 873 874 self.dispatch(body) 875 first = 0 876 877 if next_block is not None: 878 self.set_block(next_block) 879 880 self.set_block(exit_block) 881 882 def visitPass(self, node): pass 883 884 def visitPrint(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Print") 885 886 def visitPrintnl(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Printnl") 887 888 def visitRaise(self, node): 889 # NOTE: expr1 only => instance provided 890 self.dispatch(node.expr1) 891 892 if node.expr2 is not None: 893 temp = self.optimiser.optimise_temp_storage() 894 895 self.dispatch(node.expr2) 896 temp_arg = self.optimiser.optimise_temp_storage() 897 898 self._startCallFunc() 899 self.new_op(temp_arg) 900 self.new_op(StoreFrame(0)) 901 self._endCallFuncArgs(1) 902 self._doCallFunc(temp) 903 self._endCallFunc(temp) 904 905 self.discard_temp(temp_arg) 906 907 self.new_op(StoreException()) 908 self.new_op(RaiseException()) 909 910 def visitReturn(self, node): 911 if node.value is not None: 912 self.dispatch(node.value) 913 else: 914 self.dispatch(compiler.ast.Name("None")) 915 916 self.new_op(StoreResult()) 917 918 if self.in_exception_handler: 919 self.new_op(ClearException()) 920 921 self.new_op(Return()) 922 923 def visitTryExcept(self, node): 924 exit_block = self.new_block() 925 else_block = self.new_block() 926 handler_block = self.new_block() 927 928 self.add_exception_blocks(handler_block, exit_block) 929 930 # Try... 931 # Produce the code, then jump to the exit. 932 933 self.new_op(PushHandler(handler_block)) 934 self.dispatch(node.body) 935 self.new_op(PopHandler()) 936 937 if node.else_ is not None: 938 self.new_op(Jump(else_block)) 939 else: 940 self.new_op(Jump(exit_block)) 941 942 # Start of handlers. 943 944 self.set_block(handler_block) 945 self.new_op(PopHandler()) 946 947 for name, assignment, handler in node.handlers: 948 next_block = self.new_block() 949 950 # Test the given exception against the current exception. 951 952 if name is not None: 953 self.dispatch(name) 954 955 self.new_op(CheckException()) 956 self.new_op(JumpIfFalse(next_block)) 957 958 # Handle assignment to exception variable. 959 960 if assignment is not None: 961 self.new_op(LoadException()) 962 963 # Record the value to be assigned. 964 965 self.record_value() 966 self.dispatch(assignment) 967 self.discard_value() 968 969 # Produce the handler code, then jump to the exit. 970 971 self.in_exception_handler = 1 972 self.dispatch(handler) 973 self.in_exception_handler = 0 974 975 self.new_op(Jump(exit_block)) 976 977 self.set_block(next_block) 978 979 # Unhandled exceptions. 980 981 self.new_op(RaiseException()) 982 983 # Optional else clause. 984 985 if node.else_ is not None: 986 self.set_block(else_block) 987 self.dispatch(node.else_) 988 989 # Clear the exception. 990 991 self.set_block(exit_block) 992 self.new_op(ClearException()) 993 self.drop_exception_blocks() 994 995 def visitTryFinally(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "TryFinally") 996 997 def visitWhile(self, node): 998 exit_block = self.new_block() 999 next_block = self.new_block() 1000 else_block = self.new_block() 1001 1002 self.set_block(next_block) 1003 self.dispatch(node.test) 1004 if node.else_ is not None: 1005 self.new_op(JumpIfFalse(else_block)) 1006 else: 1007 self.new_op(JumpIfFalse(exit_block)) 1008 1009 self.add_loop_blocks(next_block, exit_block) 1010 1011 self.dispatch(node.body) 1012 self.new_op(Jump(next_block)) 1013 1014 if node.else_ is not None: 1015 self.set_block(else_block) 1016 1017 self.dispatch(node.else_) 1018 1019 self.set_block(exit_block) 1020 1021 self.drop_loop_blocks() 1022 1023 def visitWith(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "With") 1024 1025 def visitYield(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Yield") 1026 1027 # 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