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._visitBinaryBit 205 visitBitor = Helper._visitBinaryBit 206 visitBitxor = Helper._visitBinaryBit 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): 424 425 # Handle names referring to constants. 426 427 if self.importer.predefined_constants.has_key(node.name): 428 const = self.importer.get_predefined_constant(node.name) 429 self.new_op(LoadConst(const)) 430 431 # Handle all other names. 432 433 else: 434 self._visitName(node, self.name_load_instructions) 435 436 def visitSlice(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Slice") 437 438 def visitSubscript(self, node): 439 self.dispatch(node.expr) 440 self._startCallFunc() 441 self._generateAttr(node, "__getitem__", self.attribute_load_instructions) 442 temp_target, target, temp_context = self._generateCallFunc(node.subs, node) 443 self._doCallFunc(temp_target, target) 444 self._endCallFunc(temp_target, target, temp_context) 445 446 def visitTuple(self, node): 447 self._generateTuple(node) 448 449 # Definitions. 450 451 def visitAssign(self, node): 452 453 """ 454 Evaluate the expression from the given 'node' and assign it to the 455 associated recipients. 456 """ 457 458 self.dispatch(node.expr) 459 460 # Record the value and then dispatch to the assignment targets. 461 462 self.record_value(self.has_immediate_usage(node.nodes)) 463 464 for n in node.nodes: 465 self.dispatch(n) 466 467 self.discard_value() 468 469 def visitAssAttr(self, node): 470 471 "Assign the assignment expression to the recipient 'node'." 472 473 self._visitAttr(node, self.attribute_store_instructions) 474 self.set_source() 475 476 def visitAssList(self, node): 477 478 """ 479 Assign items from the assignment expression to each of the recipients 480 found within the given 'node'. 481 """ 482 483 for i, n in enumerate(node.nodes): 484 self._startCallFunc() 485 self.new_op(self.expr_temp[-1]) 486 self._generateAttr(node, "__getitem__", self.attribute_load_instructions) 487 temp_target, target, temp_context = self._generateCallFunc([compiler.ast.Const(i)], node) 488 self._doCallFunc(temp_target, target) 489 self._endCallFunc(temp_target, target, temp_context) 490 491 # Provide a different source value. 492 # NOTE: Permitting immediate usage given that neither name nor 493 # NOTE: attribute accesses should involve a function call 494 # NOTE: overwriting the above result. 495 496 self.record_value(self.is_immediate_user(n)) 497 self.dispatch(n) 498 self.discard_value() 499 500 def visitAssName(self, node): 501 502 "Assign the assignment expression to the recipient 'node'." 503 504 self._visitName(node, self.name_store_instructions) 505 self.set_source() 506 507 visitAssTuple = visitAssList 508 509 def visitAugAssign(self, node): 510 use_binary_block = self.new_block() 511 end_block = self.new_block() 512 513 # Evaluate the expression. 514 515 self.dispatch(node.expr) 516 temp2 = self.optimiser.optimise_temp_storage() 517 518 # Evaluate the target. 519 520 self.dispatch(node.node) 521 temp1 = self.optimiser.optimise_temp_storage() 522 523 # Find the augmented assignment method and attempt to use it. 524 525 aug_method, (left_method, right_method) = augassign_methods[node.op] 526 temp_out = self._generateOpMethod(node, temp1, temp2, aug_method, use_binary_block, use_binary_block, end_block) 527 self.discard_temp(temp_out) # NOTE: Will re-use the same storage. 528 529 # Where no such method exists, use the binary operator methods. 530 531 self.set_block(use_binary_block) 532 temp_out = self._generateBinary(node, temp1, temp2, left_method, right_method) 533 534 # Assign the result to the name. 535 536 self.set_block(end_block) 537 self.new_op(temp_out) 538 self.record_value(1) 539 540 if isinstance(node.node, compiler.ast.Name): 541 self.visitAssName(node.node) 542 elif isinstance(node.node, compiler.ast.Getattr): 543 self.visitAssAttr(node.node) 544 else: 545 raise TranslationNotImplementedError(self.module.full_name(), node, "AugAssign(Slice or Subscript)") 546 547 self.discard_value() 548 549 # Compilation duties... 550 551 self.discard_temp(temp1) 552 self.discard_temp(temp2) 553 554 def visitClass(self, node): 555 if not node.unit.parent.has_key(node.unit.name): 556 return 557 558 # Store the name. 559 560 self.new_op(LoadClass(node.unit)) 561 self.record_value() 562 self._visitName(node, self.name_store_instructions) 563 self.set_source() 564 self.discard_value() 565 566 # Visit the code. 567 568 unit = self.unit 569 self.unit = node.unit 570 self.dispatch(node.code) 571 self.unit = unit 572 573 def visitDecorators(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Decorators") 574 575 def visitFrom(self, node): pass 576 577 def visitFunction(self, node): 578 if not node.unit.parent.has_key(node.unit.name): 579 return 580 581 # Only store the name when visiting this node from outside. 582 583 if self.unit is not node.unit: 584 self.new_op(LoadFunction(node.unit)) 585 self.record_value() 586 587 self._visitName(node, self.name_store_instructions) # AssName equivalent 588 self.set_source() 589 self.discard_value() 590 591 self._generateFunctionDefaults(node.unit) 592 593 # Visiting of the code occurs when get_code is invoked on this node. 594 595 else: 596 # Check frames using the function's details. 597 598 fn = node.unit 599 nparams = len(fn.positional_names) 600 ndefaults = len(fn.defaults) 601 602 fn.body_block = self.new_block() 603 604 # Check the number of parameters and defaults. 605 606 self.new_op(CheckFrame((nparams, ndefaults))) 607 if ndefaults > 0: 608 self.new_op(LoadFunction(fn)) 609 self.new_op(FillDefaults((nparams, ndefaults))) 610 611 # Produce the body. 612 613 self.set_block(fn.body_block) 614 615 extend = ExtendFrame() 616 self.new_op(extend) 617 618 # For functions with star parameters, make a special list for the 619 # extra arguments and re-map the parameter. 620 621 if fn.has_star: 622 self.new_op(CopyExtra(nparams)) 623 624 # Ensure that the star parameter has a slot in the frame. 625 626 self.new_op(CheckExtra(nparams)) 627 self.new_op(StoreTemp(nparams)) 628 629 self.dispatch(node.code) 630 631 if not isinstance(self.last_op(), Return): 632 self.dispatch(compiler.ast.Name("None")) 633 self.new_op(StoreResult()) 634 self.new_op(Return()) 635 636 # Make sure that enough frame space is reserved from the start. 637 638 self.set_frame_usage(node, extend) 639 640 def visitGlobal(self, node): pass 641 642 def visitImport(self, node): pass 643 644 def visitKeyword(self, node): pass 645 646 def visitLambda(self, node): 647 648 """ 649 Lambda functions can be represented as globally defined functions 650 provided they do not define any default parameter values, since these 651 may defined in a non-global scope. 652 653 Where defaults are defined, an object must be created and its content 654 defined: the callable member of the object's structure must be set to 655 the lambda function definition; each default must be attached to the 656 object as an attribute, as is the case with normal functions and 657 methods. 658 """ 659 660 # Produce the reference to this function when visiting this node from 661 # outside. 662 663 if self.unit is not node.unit: 664 fn = node.unit 665 ndefaults = len(fn.defaults) 666 temp = self._generateFunctionDefaults(fn) 667 668 if ndefaults > 0: 669 self.new_op(LoadConst(fn)) 670 else: 671 self.new_op(LoadFunction(fn)) 672 673 # Populate the new object required for the function. 674 675 if temp is not None: 676 self.new_op(LoadCallable()) 677 self.new_op(temp) 678 self.new_op(StoreCallable()) 679 680 self.new_op(temp) 681 #self.discard_temp(temp) 682 683 # Visiting of the code occurs when get_code is invoked on this node. 684 685 else: 686 # Check frames using the function's details. 687 688 fn = node.unit 689 nparams = len(fn.positional_names) 690 ndefaults = len(fn.defaults) 691 692 fn.body_block = self.new_block() 693 694 # Check the number of parameters and defaults. 695 696 self.new_op(CheckFrame((nparams, ndefaults))) 697 if ndefaults > 0: 698 self.new_op(LoadTemp(0)) # context provides storage 699 self.new_op(FillDefaults((nparams, ndefaults))) 700 701 # Produce the body. 702 703 self.set_block(fn.body_block) 704 705 extend = ExtendFrame() 706 self.new_op(extend) 707 708 self.dispatch(node.code) 709 710 self.new_op(StoreResult()) 711 self.new_op(Return()) 712 713 # Make sure that enough frame space is reserved from the start. 714 715 self.set_frame_usage(node, extend) 716 717 def visitModule(self, node): 718 extend = ExtendFrame() 719 self.new_op(extend) 720 self.dispatch(node.node) 721 self.set_frame_usage(node, extend) 722 723 # Statements. 724 725 def visitStmt(self, node): 726 727 "Process the collection of statements provided by 'node'." 728 729 for n in node.nodes: 730 731 # Process the statement. 732 733 self.dispatch(n) 734 735 # Discard temporary storage. 736 737 if self.temp_positions: 738 #print "Had temp", self.temp_positions 739 self.temp_positions = set() 740 741 # Prevent incorrect optimisation by resetting the optimiser after 742 # each statement. 743 744 self.optimiser.reset() 745 746 def visitAssert(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Assert") 747 748 def visitBreak(self, node): 749 next_block, exit_block = self.get_loop_blocks() 750 self.new_op(Jump(exit_block)) 751 752 def visitContinue(self, node): 753 next_block, exit_block = self.get_loop_blocks() 754 self.new_op(Jump(next_block)) 755 756 def visitDiscard(self, node): 757 self.dispatch(node.expr) 758 self.optimiser.optimise_unused_results() 759 760 def visitFor(self, node): 761 next_handler_block = self.new_block() 762 end_handler_block = self.new_block() 763 exit_block = self.new_block() 764 next_block = self.new_block() 765 else_block = self.new_block() 766 767 # Get the "list" to be iterated over, obtain its iterator. 768 769 self._startCallFunc() 770 self.dispatch(node.list) 771 self._generateAttr(node, "__iter__", self.attribute_load_instructions) 772 temp_target, target, temp_context = self._generateCallFunc([], node) 773 self._doCallFunc(temp_target, target) 774 self._endCallFunc(temp_target, target, temp_context) 775 776 # Use a long-lasting temporary storage slot, since any result from the 777 # __iter__ method will not remain around for long. 778 779 temp_iterator = self.get_temp() 780 781 # In the loop... 782 783 self.set_block(next_block) 784 785 # Handle exceptions when calling "next"... 786 787 self.new_op(PushHandler(next_handler_block)) 788 789 # Use the iterator to get the next value. 790 791 self._startCallFunc() 792 self.new_op(temp_iterator) 793 self._generateAttr(node, "next", self.attribute_load_instructions) 794 temp_target, target, temp_context = self._generateCallFunc([], node) 795 self._doCallFunc(temp_target, target) 796 self._endCallFunc(temp_target, target, temp_context) 797 798 # Record the value to be assigned. 799 800 self.record_value() 801 802 # Skip the handler where the call was successful. 803 804 self.new_op(PopHandler()) 805 self.new_op(Jump(end_handler_block)) 806 807 # Enter the exception handler. 808 809 self.set_block(next_handler_block) 810 self.new_op(PopHandler()) 811 812 # Test for StopIteration. 813 814 self.load_builtin("StopIteration", node) 815 self.new_op(CheckException()) 816 if node.else_ is not None: 817 self.new_op(JumpIfTrue(else_block)) 818 else: 819 self.new_op(JumpIfTrue(exit_block)) 820 821 # Re-raise the exception otherwise. 822 823 self.new_op(RaiseException()) 824 825 # After the handler, clear the exception. 826 827 self.set_block(end_handler_block) 828 829 # Assign to the target. 830 831 self.dispatch(node.assign) 832 self.discard_value() 833 834 # Process the body with the current next and exit points. 835 836 self.add_loop_blocks(next_block, exit_block) 837 self.dispatch(node.body) 838 self.drop_loop_blocks() 839 840 # Repeat the loop. 841 842 self.new_op(Jump(next_block)) 843 844 # Produce the "else" section. 845 846 if node.else_ is not None: 847 self.set_block(else_block) 848 self.new_op(ClearException()) 849 self.dispatch(node.else_) 850 851 # After the loop... 852 853 self.set_block(exit_block) 854 855 else: 856 # After the loop... 857 858 self.set_block(exit_block) 859 self.new_op(ClearException()) 860 861 # Compilation duties... 862 863 self.discard_temp(temp_iterator) 864 865 def visitIf(self, node): 866 first = 1 867 next_block = None 868 exit_block = self.new_block() 869 870 clauses = node.tests + [(None, node.else_)] 871 872 for clause in clauses: 873 test, body = clause 874 if body is None: 875 break 876 877 if not first: 878 self.new_op(Jump(exit_block)) # finish last body 879 self.set_block(next_block) # start next test 880 next_block = None 881 882 if test is not None: 883 self.dispatch(test) 884 885 temp = self.optimiser.optimise_temp_storage() 886 self._generateTestBoolean(node, temp) 887 888 next_block = self.new_block() 889 self.new_op(JumpIfFalse(next_block)) 890 891 self.dispatch(body) 892 first = 0 893 894 if next_block is not None: 895 self.set_block(next_block) 896 897 self.set_block(exit_block) 898 899 def visitPass(self, node): pass 900 901 def visitPrint(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Print") 902 903 def visitPrintnl(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Printnl") 904 905 def visitRaise(self, node): 906 # NOTE: expr1 only => instance provided 907 self.dispatch(node.expr1) 908 909 if node.expr2 is not None: 910 temp = self.optimiser.optimise_temp_storage() 911 912 self.dispatch(node.expr2) 913 temp_arg = self.optimiser.optimise_temp_storage() 914 915 self._startCallFunc() 916 self.new_op(temp_arg) 917 self.new_op(StoreFrame(0)) 918 self._endCallFuncArgs(1) 919 self._doCallFunc(temp) 920 self._endCallFunc(temp) 921 922 self.discard_temp(temp_arg) 923 924 self.new_op(StoreException()) 925 self.new_op(RaiseException()) 926 927 def visitReturn(self, node): 928 if node.value is not None: 929 self.dispatch(node.value) 930 else: 931 self.dispatch(compiler.ast.Name("None")) 932 933 self.new_op(StoreResult()) 934 935 if self.in_exception_handler: 936 self.new_op(ClearException()) 937 938 self.new_op(Return()) 939 940 def visitTryExcept(self, node): 941 exit_block = self.new_block() 942 else_block = self.new_block() 943 handler_block = self.new_block() 944 945 self.add_exception_blocks(handler_block, exit_block) 946 947 # Try... 948 # Produce the code, then jump to the exit. 949 950 self.new_op(PushHandler(handler_block)) 951 self.dispatch(node.body) 952 self.new_op(PopHandler()) 953 954 if node.else_ is not None: 955 self.new_op(Jump(else_block)) 956 else: 957 self.new_op(Jump(exit_block)) 958 959 # Start of handlers. 960 961 self.set_block(handler_block) 962 self.new_op(PopHandler()) 963 964 for name, assignment, handler in node.handlers: 965 next_block = self.new_block() 966 967 # Test the given exception against the current exception. 968 969 if name is not None: 970 self.dispatch(name) 971 972 self.new_op(CheckException()) 973 self.new_op(JumpIfFalse(next_block)) 974 975 # Handle assignment to exception variable. 976 977 if assignment is not None: 978 self.new_op(LoadException()) 979 980 # Record the value to be assigned. 981 982 self.record_value() 983 self.dispatch(assignment) 984 self.discard_value() 985 986 # Produce the handler code, then jump to the exit. 987 988 self.in_exception_handler = 1 989 self.dispatch(handler) 990 self.in_exception_handler = 0 991 992 self.new_op(Jump(exit_block)) 993 994 self.set_block(next_block) 995 996 # Unhandled exceptions. 997 998 self.new_op(RaiseException()) 999 1000 # Optional else clause. 1001 1002 if node.else_ is not None: 1003 self.set_block(else_block) 1004 self.dispatch(node.else_) 1005 1006 # Clear the exception. 1007 1008 self.set_block(exit_block) 1009 self.new_op(ClearException()) 1010 self.drop_exception_blocks() 1011 1012 def visitTryFinally(self, node): 1013 1014 """ 1015 Add finally handler, potentially as an exception handler. 1016 Generate body, potentially changing return statements so that they do 1017 not return immediately. 1018 Generate handler, removing the handler from the active handler list, 1019 adding instructions which raise active exceptions. 1020 """ 1021 1022 raise TranslationNotImplementedError(self.module.full_name(), node, "TryFinally") 1023 1024 def visitWhile(self, node): 1025 exit_block = self.new_block() 1026 next_block = self.new_block() 1027 else_block = self.new_block() 1028 1029 self.set_block(next_block) 1030 self.dispatch(node.test) 1031 if node.else_ is not None: 1032 self.new_op(JumpIfFalse(else_block)) 1033 else: 1034 self.new_op(JumpIfFalse(exit_block)) 1035 1036 self.add_loop_blocks(next_block, exit_block) 1037 1038 self.dispatch(node.body) 1039 self.new_op(Jump(next_block)) 1040 1041 if node.else_ is not None: 1042 self.set_block(else_block) 1043 1044 self.dispatch(node.else_) 1045 1046 self.set_block(exit_block) 1047 1048 self.drop_loop_blocks() 1049 1050 def visitWith(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "With") 1051 1052 def visitYield(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Yield") 1053 1054 # 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