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 if node.flags == "OP_DELETE": 505 raise TranslationNotImplementedError(self.module.full_name(), node, "AssName(OP_DELETE)") 506 507 self._visitName(node, self.name_store_instructions) 508 self.set_source() 509 510 # Add any attribute usage guards. 511 512 self._generateGuards(node) 513 514 visitAssTuple = visitAssList 515 516 def visitAugAssign(self, node): 517 use_binary_block = self.new_block() 518 end_block = self.new_block() 519 520 # Evaluate the expression. 521 522 self.dispatch(node.expr) 523 temp2 = self.optimiser.optimise_temp_storage() 524 525 # Evaluate the target. 526 527 self.dispatch(node.node) 528 temp1 = self.optimiser.optimise_temp_storage() 529 530 # Find the augmented assignment method and attempt to use it. 531 532 aug_method, (left_method, right_method) = augassign_methods[node.op] 533 temp_out = self._generateOpMethod(node, temp1, temp2, aug_method, use_binary_block, use_binary_block, end_block) 534 self.discard_temp(temp_out) # NOTE: Will re-use the same storage. 535 536 # Where no such method exists, use the binary operator methods. 537 538 self.set_block(use_binary_block) 539 temp_out = self._generateBinary(node, temp1, temp2, left_method, right_method) 540 541 # Assign the result to the name. 542 543 self.set_block(end_block) 544 self.new_op(temp_out) 545 self.record_value(1) 546 547 if isinstance(node.node, compiler.ast.Name): 548 self.visitAssName(node.node) 549 elif isinstance(node.node, compiler.ast.Getattr): 550 self.visitAssAttr(node.node) 551 else: 552 raise TranslationNotImplementedError(self.module.full_name(), node, "AugAssign(Slice or Subscript)") 553 554 self.discard_value() 555 556 # Compilation duties... 557 558 self.discard_temp(temp1) 559 self.discard_temp(temp2) 560 561 def visitClass(self, node): 562 if not node.unit.parent.has_key(node.unit.name): 563 return 564 565 # Store the name. 566 567 self.new_op(LoadClass(node.unit)) 568 self.record_value() 569 self._visitName(node, self.name_store_instructions) 570 self.set_source() 571 self.discard_value() 572 573 # Visit the code. 574 575 unit = self.unit 576 self.unit = node.unit 577 self.dispatch(node.code) 578 self.unit = unit 579 580 def visitDecorators(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Decorators") 581 582 def visitFrom(self, node): pass 583 584 def visitFunction(self, node): 585 if not node.unit.parent.has_key(node.unit.name): 586 return 587 588 # Only store the name when visiting this node from outside. 589 590 if self.unit is not node.unit: 591 self.new_op(LoadFunction(node.unit)) 592 self.record_value() 593 594 self._visitName(node, self.name_store_instructions) # AssName equivalent 595 self.set_source() 596 self.discard_value() 597 598 self._generateFunctionDefaults(node.unit) 599 600 # Visiting of the code occurs when get_code is invoked on this node. 601 602 else: 603 # Check frames using the function's details. 604 605 fn = node.unit 606 nparams = len(fn.positional_names) 607 ndefaults = len(fn.defaults) 608 609 fn.body_block = self.new_block() 610 611 # Check the number of parameters and defaults. 612 613 self.new_op(CheckFrame((nparams, ndefaults))) 614 if ndefaults > 0: 615 self.new_op(LoadFunction(fn)) 616 self.new_op(FillDefaults((nparams, ndefaults))) 617 618 # Produce the body. 619 620 self.set_block(fn.body_block) 621 622 extend = ExtendFrame() 623 self.new_op(extend) 624 625 # For functions with star parameters, make a special list for the 626 # extra arguments and re-map the parameter. 627 628 if fn.has_star: 629 self.new_op(CopyExtra(nparams)) 630 631 # Ensure that the star parameter has a slot in the frame. 632 633 self.new_op(CheckExtra(nparams)) 634 self.new_op(StoreTemp(nparams)) 635 636 # Add any attribute usage guards. 637 638 if self.optimiser.should_optimise_accesses_by_attribute_usage() and hasattr(node, "_attrnames"): 639 self._generateGuards(node) 640 641 # Visit the actual code. 642 643 self.dispatch(node.code) 644 645 # Add a return statement where one is not already produced. 646 647 if not isinstance(self.last_op(), Return): 648 self.dispatch(compiler.ast.Name("None")) 649 self.new_op(StoreResult()) 650 self.new_op(Return()) 651 652 # Make sure that enough frame space is reserved from the start. 653 654 self.set_frame_usage(node, extend) 655 656 def visitGlobal(self, node): pass 657 658 def visitImport(self, node): pass 659 660 def visitKeyword(self, node): pass 661 662 def visitLambda(self, node): 663 664 """ 665 Lambda functions can be represented as globally defined functions 666 provided they do not define any default parameter values, since these 667 may defined in a non-global scope. 668 669 Where defaults are defined, an object must be created and its content 670 defined: the callable member of the object's structure must be set to 671 the lambda function definition; each default must be attached to the 672 object as an attribute, as is the case with normal functions and 673 methods. 674 """ 675 676 # Produce the reference to this function when visiting this node from 677 # outside. 678 679 if self.unit is not node.unit: 680 fn = node.unit 681 ndefaults = len(fn.defaults) 682 temp = self._generateFunctionDefaults(fn) 683 684 if ndefaults > 0: 685 self.new_op(LoadConst(fn)) 686 else: 687 self.new_op(LoadFunction(fn)) 688 689 # Populate the new object required for the function. 690 691 if temp is not None: 692 self.new_op(LoadCallable()) 693 self.new_op(temp) 694 self.new_op(StoreCallable()) 695 696 self.new_op(temp) 697 #self.discard_temp(temp) 698 699 # Visiting of the code occurs when get_code is invoked on this node. 700 701 else: 702 # Check frames using the function's details. 703 704 fn = node.unit 705 nparams = len(fn.positional_names) 706 ndefaults = len(fn.defaults) 707 708 fn.body_block = self.new_block() 709 710 # Check the number of parameters and defaults. 711 712 self.new_op(CheckFrame((nparams, ndefaults))) 713 if ndefaults > 0: 714 self.new_op(LoadTemp(0)) # context provides storage 715 self.new_op(FillDefaults((nparams, ndefaults))) 716 717 # Produce the body. 718 719 self.set_block(fn.body_block) 720 721 extend = ExtendFrame() 722 self.new_op(extend) 723 724 self.dispatch(node.code) 725 726 self.new_op(StoreResult()) 727 self.new_op(Return()) 728 729 # Make sure that enough frame space is reserved from the start. 730 731 self.set_frame_usage(node, extend) 732 733 def visitModule(self, node): 734 extend = ExtendFrame() 735 self.new_op(extend) 736 self.dispatch(node.node) 737 self.set_frame_usage(node, extend) 738 739 # Statements. 740 741 def visitStmt(self, node): 742 743 "Process the collection of statements provided by 'node'." 744 745 for n in node.nodes: 746 747 # Process the statement. 748 749 self.dispatch(n) 750 751 # Discard temporary storage. 752 753 if self.temp_positions: 754 #print "Had temp", self.temp_positions 755 self.temp_positions = set() 756 757 # Prevent incorrect optimisation by resetting the optimiser after 758 # each statement. 759 760 self.optimiser.reset() 761 762 def visitAssert(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Assert") 763 764 def visitBreak(self, node): 765 next_block, exit_block = self.get_loop_blocks() 766 self.new_op(Jump(exit_block)) 767 768 def visitContinue(self, node): 769 next_block, exit_block = self.get_loop_blocks() 770 self.new_op(Jump(next_block)) 771 772 def visitDiscard(self, node): 773 self.dispatch(node.expr) 774 self.optimiser.optimise_unused_results() 775 776 def visitFor(self, node): 777 next_handler_block = self.new_block() 778 end_handler_block = self.new_block() 779 exit_block = self.new_block() 780 next_block = self.new_block() 781 else_block = self.new_block() 782 783 # Get the "list" to be iterated over, obtain its iterator. 784 785 self._startCallFunc() 786 self.dispatch(node.list) 787 self._generateAttr(node, "__iter__", self.attribute_load_instructions) 788 temp_target, target, temp_context = self._generateCallFunc([], node) 789 self._doCallFunc(temp_target, target) 790 self._endCallFunc(temp_target, target, temp_context) 791 792 # Use a long-lasting temporary storage slot, since any result from the 793 # __iter__ method will not remain around for long. 794 795 temp_iterator = self.get_temp() 796 797 # In the loop... 798 799 self.set_block(next_block) 800 801 # Handle exceptions when calling "next"... 802 803 self.new_op(PushHandler(next_handler_block)) 804 805 # Use the iterator to get the next value. 806 807 self._startCallFunc() 808 self.new_op(temp_iterator) 809 self._generateAttr(node, "next", self.attribute_load_instructions) 810 temp_target, target, temp_context = self._generateCallFunc([], node) 811 self._doCallFunc(temp_target, target) 812 self._endCallFunc(temp_target, target, temp_context) 813 814 # Record the value to be assigned. 815 816 self.record_value() 817 818 # Skip the handler where the call was successful. 819 820 self.new_op(PopHandler()) 821 self.new_op(Jump(end_handler_block)) 822 823 # Enter the exception handler. 824 825 self.set_block(next_handler_block) 826 self.new_op(PopHandler()) 827 828 # Test for StopIteration. 829 830 self.load_builtin("StopIteration", node) 831 self.new_op(CheckException()) 832 if node.else_ is not None: 833 self.new_op(JumpIfTrue(else_block)) 834 else: 835 self.new_op(JumpIfTrue(exit_block)) 836 837 # Re-raise the exception otherwise. 838 839 self.new_op(RaiseException()) 840 841 # After the handler, clear the exception. 842 843 self.set_block(end_handler_block) 844 845 # Assign to the target. 846 847 self.dispatch(node.assign) 848 self.discard_value() 849 850 # Process the body with the current next and exit points. 851 852 self.add_loop_blocks(next_block, exit_block) 853 self.dispatch(node.body) 854 self.drop_loop_blocks() 855 856 # Repeat the loop. 857 858 self.new_op(Jump(next_block)) 859 860 # Produce the "else" section. 861 862 if node.else_ is not None: 863 self.set_block(else_block) 864 self.new_op(ClearException()) 865 self.dispatch(node.else_) 866 867 # After the loop... 868 869 self.set_block(exit_block) 870 871 else: 872 # After the loop... 873 874 self.set_block(exit_block) 875 self.new_op(ClearException()) 876 877 # Compilation duties... 878 879 self.discard_temp(temp_iterator) 880 881 def visitIf(self, node): 882 first = 1 883 next_block = None 884 exit_block = self.new_block() 885 886 clauses = node.tests + [(None, node.else_)] 887 888 for clause in clauses: 889 test, body = clause 890 if body is None: 891 break 892 893 if not first: 894 self.new_op(Jump(exit_block)) # finish last body 895 self.set_block(next_block) # start next test 896 next_block = None 897 898 if test is not None: 899 self.dispatch(test) 900 901 temp = self.optimiser.optimise_temp_storage() 902 self._generateTestBoolean(node, temp) 903 904 next_block = self.new_block() 905 self.new_op(JumpIfFalse(next_block)) 906 907 self.dispatch(body) 908 first = 0 909 910 if next_block is not None: 911 self.set_block(next_block) 912 913 self.set_block(exit_block) 914 915 def visitPass(self, node): pass 916 917 def visitPrint(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Print") 918 919 def visitPrintnl(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Printnl") 920 921 def visitRaise(self, node): 922 # NOTE: expr1 only => instance provided 923 self.dispatch(node.expr1) 924 925 if node.expr2 is not None: 926 temp = self.optimiser.optimise_temp_storage() 927 928 self.dispatch(node.expr2) 929 temp_arg = self.optimiser.optimise_temp_storage() 930 931 self._startCallFunc() 932 self.new_op(temp_arg) 933 self.new_op(StoreFrame(0)) 934 self._endCallFuncArgs(1) 935 self._doCallFunc(temp) 936 self._endCallFunc(temp) 937 938 self.discard_temp(temp_arg) 939 940 self.new_op(StoreException()) 941 self.new_op(RaiseException()) 942 943 def visitReturn(self, node): 944 if node.value is not None: 945 self.dispatch(node.value) 946 else: 947 self.dispatch(compiler.ast.Name("None")) 948 949 self.new_op(StoreResult()) 950 951 if self.in_exception_handler: 952 self.new_op(ClearException()) 953 954 self.new_op(Return()) 955 956 def visitTryExcept(self, node): 957 exit_block = self.new_block() 958 else_block = self.new_block() 959 handler_block = self.new_block() 960 961 self.add_exception_blocks(handler_block, exit_block) 962 963 # Try... 964 # Produce the code, then jump to the exit. 965 966 self.new_op(PushHandler(handler_block)) 967 self.dispatch(node.body) 968 self.new_op(PopHandler()) 969 970 if node.else_ is not None: 971 self.new_op(Jump(else_block)) 972 else: 973 self.new_op(Jump(exit_block)) 974 975 # Start of handlers. 976 977 self.set_block(handler_block) 978 self.new_op(PopHandler()) 979 980 for name, assignment, handler in node.handlers: 981 next_block = self.new_block() 982 983 # Test the given exception against the current exception. 984 985 if name is not None: 986 self.dispatch(name) 987 988 self.new_op(CheckException()) 989 self.new_op(JumpIfFalse(next_block)) 990 991 # Handle assignment to exception variable. 992 993 if assignment is not None: 994 self.new_op(LoadException()) 995 996 # Record the value to be assigned. 997 998 self.record_value() 999 self.dispatch(assignment) 1000 self.discard_value() 1001 1002 # Produce the handler code, then jump to the exit. 1003 1004 self.in_exception_handler = 1 1005 self.dispatch(handler) 1006 self.in_exception_handler = 0 1007 1008 self.new_op(Jump(exit_block)) 1009 1010 self.set_block(next_block) 1011 1012 # Unhandled exceptions. 1013 1014 self.new_op(RaiseException()) 1015 1016 # Optional else clause. 1017 1018 if node.else_ is not None: 1019 self.set_block(else_block) 1020 self.dispatch(node.else_) 1021 1022 # Clear the exception. 1023 1024 self.set_block(exit_block) 1025 self.new_op(ClearException()) 1026 self.drop_exception_blocks() 1027 1028 def visitTryFinally(self, node): 1029 1030 """ 1031 Add finally handler, potentially as an exception handler. 1032 Generate body, potentially changing return statements so that they do 1033 not return immediately. 1034 Generate handler, removing the handler from the active handler list, 1035 adding instructions which raise active exceptions. 1036 """ 1037 1038 raise TranslationNotImplementedError(self.module.full_name(), node, "TryFinally") 1039 1040 def visitWhile(self, node): 1041 exit_block = self.new_block() 1042 next_block = self.new_block() 1043 else_block = self.new_block() 1044 1045 self.set_block(next_block) 1046 self.dispatch(node.test) 1047 if node.else_ is not None: 1048 self.new_op(JumpIfFalse(else_block)) 1049 else: 1050 self.new_op(JumpIfFalse(exit_block)) 1051 1052 self.add_loop_blocks(next_block, exit_block) 1053 1054 self.dispatch(node.body) 1055 self.new_op(Jump(next_block)) 1056 1057 if node.else_ is not None: 1058 self.set_block(else_block) 1059 1060 self.dispatch(node.else_) 1061 1062 self.set_block(exit_block) 1063 1064 self.drop_loop_blocks() 1065 1066 def visitWith(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "With") 1067 1068 def visitYield(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "Yield") 1069 1070 # 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