| 1 | # The MIT License (MIT) |
| 2 | # |
| 3 | # Copyright (c) 2023 Philippe Proulx <eeppeliteloop@gmail.com> |
| 4 | # |
| 5 | # Permission is hereby granted, free of charge, to any person obtaining |
| 6 | # a copy of this software and associated documentation files (the |
| 7 | # "Software"), to deal in the Software without restriction, including |
| 8 | # without limitation the rights to use, copy, modify, merge, publish, |
| 9 | # distribute, sublicense, and/or sell copies of the Software, and to |
| 10 | # permit persons to whom the Software is furnished to do so, subject to |
| 11 | # the following conditions: |
| 12 | # |
| 13 | # The above copyright notice and this permission notice shall be |
| 14 | # included in all copies or substantial portions of the Software. |
| 15 | # |
| 16 | # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 17 | # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 18 | # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 19 | # IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 20 | # CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 21 | # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 22 | # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 23 | |
| 24 | # This module is the portable Normand processor. It offers both the |
| 25 | # parse() function and the command-line tool (run the module itself) |
| 26 | # without external dependencies except a `typing` module for Python 3.4. |
| 27 | # |
| 28 | # Feel free to copy this module file to your own project to use Normand. |
| 29 | # |
| 30 | # Upstream repository: <https://github.com/efficios/normand>. |
| 31 | |
| 32 | __author__ = "Philippe Proulx" |
| 33 | __version__ = "0.23.0" |
| 34 | __all__ = [ |
| 35 | "__author__", |
| 36 | "__version__", |
| 37 | "ByteOrder", |
| 38 | "LabelsT", |
| 39 | "parse", |
| 40 | "ParseError", |
| 41 | "ParseErrorMessage", |
| 42 | "ParseResult", |
| 43 | "TextLocation", |
| 44 | "VariablesT", |
| 45 | ] |
| 46 | |
| 47 | import re |
| 48 | import abc |
| 49 | import ast |
| 50 | import bz2 |
| 51 | import sys |
| 52 | import copy |
| 53 | import enum |
| 54 | import gzip |
| 55 | import math |
| 56 | import base64 |
| 57 | import quopri |
| 58 | import struct |
| 59 | import typing |
| 60 | import functools |
| 61 | from typing import Any, Set, Dict, List, Union, Pattern, Callable, NoReturn, Optional |
| 62 | |
| 63 | |
| 64 | # Text location (line and column numbers). |
| 65 | class TextLocation: |
| 66 | @classmethod |
| 67 | def _create(cls, line_no: int, col_no: int): |
| 68 | self = cls.__new__(cls) |
| 69 | self._init(line_no, col_no) |
| 70 | return self |
| 71 | |
| 72 | def __init__(*args, **kwargs): # type: ignore |
| 73 | raise NotImplementedError |
| 74 | |
| 75 | def _init(self, line_no: int, col_no: int): |
| 76 | self._line_no = line_no |
| 77 | self._col_no = col_no |
| 78 | |
| 79 | # Line number. |
| 80 | @property |
| 81 | def line_no(self): |
| 82 | return self._line_no |
| 83 | |
| 84 | # Column number. |
| 85 | @property |
| 86 | def col_no(self): |
| 87 | return self._col_no |
| 88 | |
| 89 | def __repr__(self): |
| 90 | return "TextLocation({}, {})".format(self._line_no, self._col_no) |
| 91 | |
| 92 | |
| 93 | # Any item. |
| 94 | class _Item: |
| 95 | def __init__(self, text_loc: TextLocation): |
| 96 | self._text_loc = text_loc |
| 97 | |
| 98 | # Source text location. |
| 99 | @property |
| 100 | def text_loc(self): |
| 101 | return self._text_loc |
| 102 | |
| 103 | |
| 104 | # Scalar item. |
| 105 | class _ScalarItem(_Item): |
| 106 | # Returns the size, in bytes, of this item. |
| 107 | @property |
| 108 | @abc.abstractmethod |
| 109 | def size(self) -> int: |
| 110 | ... |
| 111 | |
| 112 | |
| 113 | # A repeatable item. |
| 114 | class _RepableItem: |
| 115 | pass |
| 116 | |
| 117 | |
| 118 | # Single byte. |
| 119 | class _Byte(_ScalarItem, _RepableItem): |
| 120 | def __init__(self, val: int, text_loc: TextLocation): |
| 121 | super().__init__(text_loc) |
| 122 | self._val = val |
| 123 | |
| 124 | # Byte value. |
| 125 | @property |
| 126 | def val(self): |
| 127 | return self._val |
| 128 | |
| 129 | @property |
| 130 | def size(self): |
| 131 | return 1 |
| 132 | |
| 133 | def __repr__(self): |
| 134 | return "_Byte({}, {})".format(hex(self._val), repr(self._text_loc)) |
| 135 | |
| 136 | |
| 137 | # Literal string. |
| 138 | class _LitStr(_ScalarItem, _RepableItem): |
| 139 | def __init__(self, data: bytes, text_loc: TextLocation): |
| 140 | super().__init__(text_loc) |
| 141 | self._data = data |
| 142 | |
| 143 | # Encoded bytes. |
| 144 | @property |
| 145 | def data(self): |
| 146 | return self._data |
| 147 | |
| 148 | @property |
| 149 | def size(self): |
| 150 | return len(self._data) |
| 151 | |
| 152 | def __repr__(self): |
| 153 | return "_LitStr({}, {})".format(repr(self._data), repr(self._text_loc)) |
| 154 | |
| 155 | |
| 156 | # Byte order. |
| 157 | @enum.unique |
| 158 | class ByteOrder(enum.Enum): |
| 159 | # Big endian. |
| 160 | BE = "be" |
| 161 | |
| 162 | # Little endian. |
| 163 | LE = "le" |
| 164 | |
| 165 | |
| 166 | # Byte order setting. |
| 167 | class _SetBo(_Item): |
| 168 | def __init__(self, bo: ByteOrder, text_loc: TextLocation): |
| 169 | super().__init__(text_loc) |
| 170 | self._bo = bo |
| 171 | |
| 172 | @property |
| 173 | def bo(self): |
| 174 | return self._bo |
| 175 | |
| 176 | def __repr__(self): |
| 177 | return "_SetBo({}, {})".format(repr(self._bo), repr(self._text_loc)) |
| 178 | |
| 179 | |
| 180 | # Label. |
| 181 | class _Label(_Item): |
| 182 | def __init__(self, name: str, text_loc: TextLocation): |
| 183 | super().__init__(text_loc) |
| 184 | self._name = name |
| 185 | |
| 186 | # Label name. |
| 187 | @property |
| 188 | def name(self): |
| 189 | return self._name |
| 190 | |
| 191 | def __repr__(self): |
| 192 | return "_Label({}, {})".format(repr(self._name), repr(self._text_loc)) |
| 193 | |
| 194 | |
| 195 | # Offset setting. |
| 196 | class _SetOffset(_Item): |
| 197 | def __init__(self, val: int, text_loc: TextLocation): |
| 198 | super().__init__(text_loc) |
| 199 | self._val = val |
| 200 | |
| 201 | # Offset value (bytes). |
| 202 | @property |
| 203 | def val(self): |
| 204 | return self._val |
| 205 | |
| 206 | def __repr__(self): |
| 207 | return "_SetOffset({}, {})".format(repr(self._val), repr(self._text_loc)) |
| 208 | |
| 209 | |
| 210 | # Offset alignment. |
| 211 | class _AlignOffset(_Item): |
| 212 | def __init__(self, val: int, pad_val: int, text_loc: TextLocation): |
| 213 | super().__init__(text_loc) |
| 214 | self._val = val |
| 215 | self._pad_val = pad_val |
| 216 | |
| 217 | # Alignment value (bits). |
| 218 | @property |
| 219 | def val(self): |
| 220 | return self._val |
| 221 | |
| 222 | # Padding byte value. |
| 223 | @property |
| 224 | def pad_val(self): |
| 225 | return self._pad_val |
| 226 | |
| 227 | def __repr__(self): |
| 228 | return "_AlignOffset({}, {}, {})".format( |
| 229 | repr(self._val), repr(self._pad_val), repr(self._text_loc) |
| 230 | ) |
| 231 | |
| 232 | |
| 233 | # Mixin of containing an AST expression and its string. |
| 234 | class _ExprMixin: |
| 235 | def __init__(self, expr_str: str, expr: ast.Expression): |
| 236 | self._expr_str = expr_str |
| 237 | self._expr = expr |
| 238 | |
| 239 | # Expression string. |
| 240 | @property |
| 241 | def expr_str(self): |
| 242 | return self._expr_str |
| 243 | |
| 244 | # Expression node to evaluate. |
| 245 | @property |
| 246 | def expr(self): |
| 247 | return self._expr |
| 248 | |
| 249 | |
| 250 | # Fill until some offset. |
| 251 | class _FillUntil(_Item, _ExprMixin): |
| 252 | def __init__( |
| 253 | self, expr_str: str, expr: ast.Expression, pad_val: int, text_loc: TextLocation |
| 254 | ): |
| 255 | super().__init__(text_loc) |
| 256 | _ExprMixin.__init__(self, expr_str, expr) |
| 257 | self._pad_val = pad_val |
| 258 | |
| 259 | # Padding byte value. |
| 260 | @property |
| 261 | def pad_val(self): |
| 262 | return self._pad_val |
| 263 | |
| 264 | def __repr__(self): |
| 265 | return "_FillUntil({}, {}, {}, {})".format( |
| 266 | repr(self._expr_str), |
| 267 | repr(self._expr), |
| 268 | repr(self._pad_val), |
| 269 | repr(self._text_loc), |
| 270 | ) |
| 271 | |
| 272 | |
| 273 | # Variable assignment. |
| 274 | class _VarAssign(_Item, _ExprMixin): |
| 275 | def __init__( |
| 276 | self, name: str, expr_str: str, expr: ast.Expression, text_loc: TextLocation |
| 277 | ): |
| 278 | super().__init__(text_loc) |
| 279 | _ExprMixin.__init__(self, expr_str, expr) |
| 280 | self._name = name |
| 281 | |
| 282 | # Name. |
| 283 | @property |
| 284 | def name(self): |
| 285 | return self._name |
| 286 | |
| 287 | def __repr__(self): |
| 288 | return "_VarAssign({}, {}, {}, {})".format( |
| 289 | repr(self._name), |
| 290 | repr(self._expr_str), |
| 291 | repr(self._expr), |
| 292 | repr(self._text_loc), |
| 293 | ) |
| 294 | |
| 295 | |
| 296 | # Fixed-length number, possibly needing more than one byte. |
| 297 | class _FlNum(_ScalarItem, _RepableItem, _ExprMixin): |
| 298 | def __init__( |
| 299 | self, |
| 300 | expr_str: str, |
| 301 | expr: ast.Expression, |
| 302 | len: int, |
| 303 | bo: Optional[ByteOrder], |
| 304 | text_loc: TextLocation, |
| 305 | ): |
| 306 | super().__init__(text_loc) |
| 307 | _ExprMixin.__init__(self, expr_str, expr) |
| 308 | self._len = len |
| 309 | self._bo = bo |
| 310 | |
| 311 | # Length (bits). |
| 312 | @property |
| 313 | def len(self): |
| 314 | return self._len |
| 315 | |
| 316 | # Byte order override. |
| 317 | @property |
| 318 | def bo(self): |
| 319 | return self._bo |
| 320 | |
| 321 | @property |
| 322 | def size(self): |
| 323 | return self._len // 8 |
| 324 | |
| 325 | def __repr__(self): |
| 326 | return "_FlNum({}, {}, {}, {}, {})".format( |
| 327 | repr(self._expr_str), |
| 328 | repr(self._expr), |
| 329 | repr(self._len), |
| 330 | repr(self._bo), |
| 331 | repr(self._text_loc), |
| 332 | ) |
| 333 | |
| 334 | |
| 335 | # LEB128 integer. |
| 336 | class _Leb128Int(_Item, _RepableItem, _ExprMixin): |
| 337 | def __init__(self, expr_str: str, expr: ast.Expression, text_loc: TextLocation): |
| 338 | super().__init__(text_loc) |
| 339 | _ExprMixin.__init__(self, expr_str, expr) |
| 340 | |
| 341 | def __repr__(self): |
| 342 | return "{}({}, {}, {})".format( |
| 343 | self.__class__.__name__, |
| 344 | repr(self._expr_str), |
| 345 | repr(self._expr), |
| 346 | repr(self._text_loc), |
| 347 | ) |
| 348 | |
| 349 | |
| 350 | # Unsigned LEB128 integer. |
| 351 | class _ULeb128Int(_Leb128Int, _RepableItem, _ExprMixin): |
| 352 | pass |
| 353 | |
| 354 | |
| 355 | # Signed LEB128 integer. |
| 356 | class _SLeb128Int(_Leb128Int, _RepableItem, _ExprMixin): |
| 357 | pass |
| 358 | |
| 359 | |
| 360 | # String. |
| 361 | class _Str(_Item, _RepableItem, _ExprMixin): |
| 362 | def __init__( |
| 363 | self, expr_str: str, expr: ast.Expression, codec: str, text_loc: TextLocation |
| 364 | ): |
| 365 | super().__init__(text_loc) |
| 366 | _ExprMixin.__init__(self, expr_str, expr) |
| 367 | self._codec = codec |
| 368 | |
| 369 | # Codec name. |
| 370 | @property |
| 371 | def codec(self): |
| 372 | return self._codec |
| 373 | |
| 374 | def __repr__(self): |
| 375 | return "_Str({}, {}, {}, {})".format( |
| 376 | repr(self._expr_str), |
| 377 | repr(self._expr), |
| 378 | repr(self._codec), |
| 379 | repr(self._text_loc), |
| 380 | ) |
| 381 | |
| 382 | |
| 383 | # Group of items. |
| 384 | class _Group(_Item, _RepableItem): |
| 385 | def __init__(self, items: List[_Item], text_loc: TextLocation): |
| 386 | super().__init__(text_loc) |
| 387 | self._items = items |
| 388 | |
| 389 | # Contained items. |
| 390 | @property |
| 391 | def items(self): |
| 392 | return self._items |
| 393 | |
| 394 | def __repr__(self): |
| 395 | return "_Group({}, {})".format(repr(self._items), repr(self._text_loc)) |
| 396 | |
| 397 | |
| 398 | # Repetition item. |
| 399 | class _Rep(_Group, _ExprMixin): |
| 400 | def __init__( |
| 401 | self, |
| 402 | items: List[_Item], |
| 403 | expr_str: str, |
| 404 | expr: ast.Expression, |
| 405 | text_loc: TextLocation, |
| 406 | ): |
| 407 | super().__init__(items, text_loc) |
| 408 | _ExprMixin.__init__(self, expr_str, expr) |
| 409 | |
| 410 | def __repr__(self): |
| 411 | return "_Rep({}, {}, {}, {})".format( |
| 412 | repr(self._items), |
| 413 | repr(self._expr_str), |
| 414 | repr(self._expr), |
| 415 | repr(self._text_loc), |
| 416 | ) |
| 417 | |
| 418 | |
| 419 | # Conditional item. |
| 420 | class _Cond(_Item, _ExprMixin): |
| 421 | def __init__( |
| 422 | self, |
| 423 | true_item: _Group, |
| 424 | false_item: _Group, |
| 425 | expr_str: str, |
| 426 | expr: ast.Expression, |
| 427 | text_loc: TextLocation, |
| 428 | ): |
| 429 | super().__init__(text_loc) |
| 430 | _ExprMixin.__init__(self, expr_str, expr) |
| 431 | self._true_item = true_item |
| 432 | self._false_item = false_item |
| 433 | |
| 434 | # Item when condition is true. |
| 435 | @property |
| 436 | def true_item(self): |
| 437 | return self._true_item |
| 438 | |
| 439 | # Item when condition is false. |
| 440 | @property |
| 441 | def false_item(self): |
| 442 | return self._false_item |
| 443 | |
| 444 | def __repr__(self): |
| 445 | return "_Cond({}, {}, {}, {}, {})".format( |
| 446 | repr(self._true_item), |
| 447 | repr(self._false_item), |
| 448 | repr(self._expr_str), |
| 449 | repr(self._expr), |
| 450 | repr(self._text_loc), |
| 451 | ) |
| 452 | |
| 453 | |
| 454 | # Transformation. |
| 455 | class _Trans(_Group, _RepableItem): |
| 456 | def __init__( |
| 457 | self, |
| 458 | items: List[_Item], |
| 459 | name: str, |
| 460 | func: Callable[[Union[bytes, bytearray]], bytes], |
| 461 | text_loc: TextLocation, |
| 462 | ): |
| 463 | super().__init__(items, text_loc) |
| 464 | self._name = name |
| 465 | self._func = func |
| 466 | |
| 467 | @property |
| 468 | def name(self): |
| 469 | return self._name |
| 470 | |
| 471 | # Transforms the data `data`. |
| 472 | def trans(self, data: Union[bytes, bytearray]): |
| 473 | return self._func(data) |
| 474 | |
| 475 | def __repr__(self): |
| 476 | return "_Trans({}, {}, {}, {})".format( |
| 477 | repr(self._items), |
| 478 | repr(self._name), |
| 479 | repr(self._func), |
| 480 | repr(self._text_loc), |
| 481 | ) |
| 482 | |
| 483 | |
| 484 | # Macro definition item. |
| 485 | class _MacroDef(_Group): |
| 486 | def __init__( |
| 487 | self, |
| 488 | name: str, |
| 489 | param_names: List[str], |
| 490 | items: List[_Item], |
| 491 | text_loc: TextLocation, |
| 492 | ): |
| 493 | super().__init__(items, text_loc) |
| 494 | self._name = name |
| 495 | self._param_names = param_names |
| 496 | |
| 497 | # Name. |
| 498 | @property |
| 499 | def name(self): |
| 500 | return self._name |
| 501 | |
| 502 | # Parameters. |
| 503 | @property |
| 504 | def param_names(self): |
| 505 | return self._param_names |
| 506 | |
| 507 | def __repr__(self): |
| 508 | return "_MacroDef({}, {}, {}, {})".format( |
| 509 | repr(self._name), |
| 510 | repr(self._param_names), |
| 511 | repr(self._items), |
| 512 | repr(self._text_loc), |
| 513 | ) |
| 514 | |
| 515 | |
| 516 | # Macro expansion parameter. |
| 517 | class _MacroExpParam: |
| 518 | def __init__(self, expr_str: str, expr: ast.Expression, text_loc: TextLocation): |
| 519 | self._expr_str = expr_str |
| 520 | self._expr = expr |
| 521 | self._text_loc = text_loc |
| 522 | |
| 523 | # Expression string. |
| 524 | @property |
| 525 | def expr_str(self): |
| 526 | return self._expr_str |
| 527 | |
| 528 | # Expression. |
| 529 | @property |
| 530 | def expr(self): |
| 531 | return self._expr |
| 532 | |
| 533 | # Source text location. |
| 534 | @property |
| 535 | def text_loc(self): |
| 536 | return self._text_loc |
| 537 | |
| 538 | def __repr__(self): |
| 539 | return "_MacroExpParam({}, {}, {})".format( |
| 540 | repr(self._expr_str), repr(self._expr), repr(self._text_loc) |
| 541 | ) |
| 542 | |
| 543 | |
| 544 | # Macro expansion item. |
| 545 | class _MacroExp(_Item, _RepableItem): |
| 546 | def __init__( |
| 547 | self, |
| 548 | name: str, |
| 549 | params: List[_MacroExpParam], |
| 550 | text_loc: TextLocation, |
| 551 | ): |
| 552 | super().__init__(text_loc) |
| 553 | self._name = name |
| 554 | self._params = params |
| 555 | |
| 556 | # Name. |
| 557 | @property |
| 558 | def name(self): |
| 559 | return self._name |
| 560 | |
| 561 | # Parameters. |
| 562 | @property |
| 563 | def params(self): |
| 564 | return self._params |
| 565 | |
| 566 | def __repr__(self): |
| 567 | return "_MacroExp({}, {}, {})".format( |
| 568 | repr(self._name), |
| 569 | repr(self._params), |
| 570 | repr(self._text_loc), |
| 571 | ) |
| 572 | |
| 573 | |
| 574 | # A parsing error message: a string and a text location. |
| 575 | class ParseErrorMessage: |
| 576 | @classmethod |
| 577 | def _create(cls, text: str, text_loc: TextLocation): |
| 578 | self = cls.__new__(cls) |
| 579 | self._init(text, text_loc) |
| 580 | return self |
| 581 | |
| 582 | def __init__(self, *args, **kwargs): # type: ignore |
| 583 | raise NotImplementedError |
| 584 | |
| 585 | def _init(self, text: str, text_loc: TextLocation): |
| 586 | self._text = text |
| 587 | self._text_loc = text_loc |
| 588 | |
| 589 | # Message text. |
| 590 | @property |
| 591 | def text(self): |
| 592 | return self._text |
| 593 | |
| 594 | # Source text location. |
| 595 | @property |
| 596 | def text_location(self): |
| 597 | return self._text_loc |
| 598 | |
| 599 | |
| 600 | # A parsing error containing one or more messages (`ParseErrorMessage`). |
| 601 | class ParseError(RuntimeError): |
| 602 | @classmethod |
| 603 | def _create(cls, msg: str, text_loc: TextLocation): |
| 604 | self = cls.__new__(cls) |
| 605 | self._init(msg, text_loc) |
| 606 | return self |
| 607 | |
| 608 | def __init__(self, *args, **kwargs): # type: ignore |
| 609 | raise NotImplementedError |
| 610 | |
| 611 | def _init(self, msg: str, text_loc: TextLocation): |
| 612 | super().__init__(msg) |
| 613 | self._msgs = [] # type: List[ParseErrorMessage] |
| 614 | self._add_msg(msg, text_loc) |
| 615 | |
| 616 | def _add_msg(self, msg: str, text_loc: TextLocation): |
| 617 | self._msgs.append( |
| 618 | ParseErrorMessage._create( # pyright: ignore[reportPrivateUsage] |
| 619 | msg, text_loc |
| 620 | ) |
| 621 | ) |
| 622 | |
| 623 | # Parsing error messages. |
| 624 | # |
| 625 | # The first message is the most specific one. |
| 626 | @property |
| 627 | def messages(self): |
| 628 | return self._msgs |
| 629 | |
| 630 | |
| 631 | # Raises a parsing error, forwarding the parameters to the constructor. |
| 632 | def _raise_error(msg: str, text_loc: TextLocation) -> NoReturn: |
| 633 | raise ParseError._create(msg, text_loc) # pyright: ignore[reportPrivateUsage] |
| 634 | |
| 635 | |
| 636 | # Adds a message to the parsing error `exc`. |
| 637 | def _add_error_msg(exc: ParseError, msg: str, text_loc: TextLocation): |
| 638 | exc._add_msg(msg, text_loc) # pyright: ignore[reportPrivateUsage] |
| 639 | |
| 640 | |
| 641 | # Appends a message to the parsing error `exc` and reraises it. |
| 642 | def _augment_error(exc: ParseError, msg: str, text_loc: TextLocation) -> NoReturn: |
| 643 | _add_error_msg(exc, msg, text_loc) |
| 644 | raise exc |
| 645 | |
| 646 | |
| 647 | # Returns a normalized version (so as to be parseable by int()) of |
| 648 | # the constant integer string `s`, possibly negative, dealing with |
| 649 | # any radix suffix. |
| 650 | def _norm_const_int(s: str): |
| 651 | neg = "" |
| 652 | pos = s |
| 653 | |
| 654 | if s.startswith("-"): |
| 655 | neg = "-" |
| 656 | pos = s[1:] |
| 657 | |
| 658 | for r in "xXoObB": |
| 659 | if pos.startswith("0" + r): |
| 660 | # Already correct |
| 661 | return s |
| 662 | |
| 663 | # Try suffix |
| 664 | asm_suf_base = { |
| 665 | "h": "x", |
| 666 | "H": "x", |
| 667 | "q": "o", |
| 668 | "Q": "o", |
| 669 | "o": "o", |
| 670 | "O": "o", |
| 671 | "b": "b", |
| 672 | "B": "B", |
| 673 | } |
| 674 | |
| 675 | for suf in asm_suf_base: |
| 676 | if pos[-1] == suf: |
| 677 | s = "{}0{}{}".format(neg, asm_suf_base[suf], pos.rstrip(suf)) |
| 678 | |
| 679 | return s |
| 680 | |
| 681 | |
| 682 | # Encodes the string `s` using the codec `codec`, raising `ParseError` |
| 683 | # with `text_loc` on encoding error. |
| 684 | def _encode_str(s: str, codec: str, text_loc: TextLocation): |
| 685 | try: |
| 686 | return s.encode(codec) |
| 687 | except UnicodeEncodeError: |
| 688 | _raise_error( |
| 689 | "Cannot encode `{}` with the `{}` encoding".format(s, codec), text_loc |
| 690 | ) |
| 691 | |
| 692 | |
| 693 | # Variables dictionary type (for type hints). |
| 694 | VariablesT = Dict[str, Union[int, float, str]] |
| 695 | |
| 696 | |
| 697 | # Labels dictionary type (for type hints). |
| 698 | LabelsT = Dict[str, int] |
| 699 | |
| 700 | |
| 701 | # Common patterns. |
| 702 | _py_name_pat = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*") |
| 703 | _pos_const_int_pat = re.compile( |
| 704 | r"(?:0[Xx][A-Fa-f0-9]+|0[Oo][0-7]+|0[Bb][01]+|[A-Fa-f0-9]+[hH]|[0-7]+[qQoO]|[01]+[bB]|\d+)\b" |
| 705 | ) |
| 706 | _const_int_pat = re.compile(r"(?P<neg>-)?(?:{})".format(_pos_const_int_pat.pattern)) |
| 707 | _const_float_pat = re.compile( |
| 708 | r"[-+]?(?:(?:\d*\.\d+)|(?:\d+\.))(?:[Ee][+-]?\d+)?(?=\W|)" |
| 709 | ) |
| 710 | |
| 711 | |
| 712 | # Macro definition dictionary. |
| 713 | _MacroDefsT = Dict[str, _MacroDef] |
| 714 | |
| 715 | |
| 716 | # Normand parser. |
| 717 | # |
| 718 | # The constructor accepts a Normand input. After building, use the `res` |
| 719 | # property to get the resulting main group. |
| 720 | class _Parser: |
| 721 | # Builds a parser to parse the Normand input `normand`, parsing |
| 722 | # immediately. |
| 723 | def __init__(self, normand: str, variables: VariablesT, labels: LabelsT): |
| 724 | self._normand = normand |
| 725 | self._at = 0 |
| 726 | self._line_no = 1 |
| 727 | self._col_no = 1 |
| 728 | self._label_names = set(labels.keys()) |
| 729 | self._var_names = set(variables.keys()) |
| 730 | self._macro_defs = {} # type: _MacroDefsT |
| 731 | self._base_item_parse_funcs = [ |
| 732 | self._try_parse_byte, |
| 733 | self._try_parse_str, |
| 734 | self._try_parse_val, |
| 735 | self._try_parse_var_assign, |
| 736 | self._try_parse_set_bo, |
| 737 | self._try_parse_label_or_set_offset, |
| 738 | self._try_parse_align_offset, |
| 739 | self._try_parse_fill_until, |
| 740 | self._try_parse_group, |
| 741 | self._try_parse_rep_block, |
| 742 | self._try_parse_cond_block, |
| 743 | self._try_parse_macro_exp, |
| 744 | self._try_parse_trans_block, |
| 745 | ] |
| 746 | self._parse() |
| 747 | |
| 748 | # Result (main group). |
| 749 | @property |
| 750 | def res(self): |
| 751 | return self._res |
| 752 | |
| 753 | # Macro definitions. |
| 754 | @property |
| 755 | def macro_defs(self): |
| 756 | return self._macro_defs |
| 757 | |
| 758 | # Current text location. |
| 759 | @property |
| 760 | def _text_loc(self): |
| 761 | return TextLocation._create( # pyright: ignore[reportPrivateUsage] |
| 762 | self._line_no, self._col_no |
| 763 | ) |
| 764 | |
| 765 | # Returns `True` if this parser is done parsing. |
| 766 | def _is_done(self): |
| 767 | return self._at == len(self._normand) |
| 768 | |
| 769 | # Returns `True` if this parser isn't done parsing. |
| 770 | def _isnt_done(self): |
| 771 | return not self._is_done() |
| 772 | |
| 773 | # Raises a parse error, creating it using the message `msg` and the |
| 774 | # current text location. |
| 775 | def _raise_error(self, msg: str) -> NoReturn: |
| 776 | _raise_error(msg, self._text_loc) |
| 777 | |
| 778 | # Tries to make the pattern `pat` match the current substring, |
| 779 | # returning the match object and updating `self._at`, |
| 780 | # `self._line_no`, and `self._col_no` on success. |
| 781 | def _try_parse_pat(self, pat: Pattern[str]): |
| 782 | m = pat.match(self._normand, self._at) |
| 783 | |
| 784 | if m is None: |
| 785 | return |
| 786 | |
| 787 | # Skip matched string |
| 788 | self._at += len(m.group(0)) |
| 789 | |
| 790 | # Update line number |
| 791 | self._line_no += m.group(0).count("\n") |
| 792 | |
| 793 | # Update column number |
| 794 | for i in reversed(range(self._at)): |
| 795 | if self._normand[i] == "\n" or i == 0: |
| 796 | if i == 0: |
| 797 | self._col_no = self._at + 1 |
| 798 | else: |
| 799 | self._col_no = self._at - i |
| 800 | |
| 801 | break |
| 802 | |
| 803 | # Return match object |
| 804 | return m |
| 805 | |
| 806 | # Expects the pattern `pat` to match the current substring, |
| 807 | # returning the match object and updating `self._at`, |
| 808 | # `self._line_no`, and `self._col_no` on success, or raising a parse |
| 809 | # error with the message `error_msg` on error. |
| 810 | def _expect_pat(self, pat: Pattern[str], error_msg: str): |
| 811 | # Match |
| 812 | m = self._try_parse_pat(pat) |
| 813 | |
| 814 | if m is None: |
| 815 | # No match: error |
| 816 | self._raise_error(error_msg) |
| 817 | |
| 818 | # Return match object |
| 819 | return m |
| 820 | |
| 821 | # Patterns for _skip_*() |
| 822 | _comment_pat = re.compile(r"#[^#]*?(?:$|#)", re.M) |
| 823 | _ws_or_comments_pat = re.compile(r"(?:\s|{})*".format(_comment_pat.pattern), re.M) |
| 824 | _ws_or_syms_or_comments_pat = re.compile( |
| 825 | r"(?:[\s/\\?&:;.,_=|-]|{})*".format(_comment_pat.pattern), re.M |
| 826 | ) |
| 827 | |
| 828 | # Skips as many whitespaces and comments as possible, but not |
| 829 | # insignificant symbol characters. |
| 830 | def _skip_ws_and_comments(self): |
| 831 | self._try_parse_pat(self._ws_or_comments_pat) |
| 832 | |
| 833 | # Skips as many whitespaces, insignificant symbol characters, and |
| 834 | # comments as possible. |
| 835 | def _skip_ws_and_comments_and_syms(self): |
| 836 | self._try_parse_pat(self._ws_or_syms_or_comments_pat) |
| 837 | |
| 838 | # Pattern for _try_parse_hex_byte() |
| 839 | _nibble_pat = re.compile(r"[A-Fa-f0-9]") |
| 840 | |
| 841 | # Tries to parse a hexadecimal byte, returning a byte item on |
| 842 | # success. |
| 843 | def _try_parse_hex_byte(self): |
| 844 | begin_text_loc = self._text_loc |
| 845 | |
| 846 | # Match initial nibble |
| 847 | m_high = self._try_parse_pat(self._nibble_pat) |
| 848 | |
| 849 | if m_high is None: |
| 850 | # No match |
| 851 | return |
| 852 | |
| 853 | # Expect another nibble |
| 854 | self._skip_ws_and_comments_and_syms() |
| 855 | m_low = self._expect_pat( |
| 856 | self._nibble_pat, "Expecting another hexadecimal nibble" |
| 857 | ) |
| 858 | |
| 859 | # Return item |
| 860 | return _Byte(int(m_high.group(0) + m_low.group(0), 16), begin_text_loc) |
| 861 | |
| 862 | # Patterns for _try_parse_bin_byte() |
| 863 | _bin_byte_bit_pat = re.compile(r"[01]") |
| 864 | _bin_byte_prefix_pat = re.compile(r"%+") |
| 865 | |
| 866 | # Tries to parse a binary byte, returning a byte item on success. |
| 867 | def _try_parse_bin_byte(self): |
| 868 | begin_text_loc = self._text_loc |
| 869 | |
| 870 | # Match prefix |
| 871 | m = self._try_parse_pat(self._bin_byte_prefix_pat) |
| 872 | |
| 873 | if m is None: |
| 874 | # No match |
| 875 | return |
| 876 | |
| 877 | # Expect as many bytes as there are `%` prefixes |
| 878 | items = [] # type: List[_Item] |
| 879 | |
| 880 | for _ in range(len(m.group(0))): |
| 881 | self._skip_ws_and_comments_and_syms() |
| 882 | byte_text_loc = self._text_loc |
| 883 | bits = [] # type: List[str] |
| 884 | |
| 885 | # Expect eight bits |
| 886 | for _ in range(8): |
| 887 | self._skip_ws_and_comments_and_syms() |
| 888 | m = self._expect_pat( |
| 889 | self._bin_byte_bit_pat, "Expecting a bit (`0` or `1`)" |
| 890 | ) |
| 891 | bits.append(m.group(0)) |
| 892 | |
| 893 | items.append(_Byte(int("".join(bits), 2), byte_text_loc)) |
| 894 | |
| 895 | # Return item |
| 896 | if len(items) == 1: |
| 897 | return items[0] |
| 898 | |
| 899 | # As group |
| 900 | return _Group(items, begin_text_loc) |
| 901 | |
| 902 | # Patterns for _try_parse_dec_byte() |
| 903 | _dec_byte_prefix_pat = re.compile(r"\$") |
| 904 | _dec_byte_val_pat = re.compile(r"(?P<neg>-?)(?P<val>\d+)") |
| 905 | |
| 906 | # Tries to parse a decimal byte, returning a byte item on success. |
| 907 | def _try_parse_dec_byte(self): |
| 908 | begin_text_loc = self._text_loc |
| 909 | |
| 910 | # Match prefix |
| 911 | if self._try_parse_pat(self._dec_byte_prefix_pat) is None: |
| 912 | # No match |
| 913 | return |
| 914 | |
| 915 | # Expect the value |
| 916 | self._skip_ws_and_comments() |
| 917 | m = self._expect_pat(self._dec_byte_val_pat, "Expecting a decimal constant") |
| 918 | |
| 919 | # Compute value |
| 920 | val = int(m.group("val")) * (-1 if m.group("neg") == "-" else 1) |
| 921 | |
| 922 | # Validate |
| 923 | if val < -128 or val > 255: |
| 924 | _raise_error("Invalid decimal byte value {}".format(val), begin_text_loc) |
| 925 | |
| 926 | # Two's complement |
| 927 | val %= 256 |
| 928 | |
| 929 | # Return item |
| 930 | return _Byte(val, begin_text_loc) |
| 931 | |
| 932 | # Tries to parse a byte, returning a byte item on success. |
| 933 | def _try_parse_byte(self): |
| 934 | # Hexadecimal |
| 935 | item = self._try_parse_hex_byte() |
| 936 | |
| 937 | if item is not None: |
| 938 | return item |
| 939 | |
| 940 | # Binary |
| 941 | item = self._try_parse_bin_byte() |
| 942 | |
| 943 | if item is not None: |
| 944 | return item |
| 945 | |
| 946 | # Decimal |
| 947 | item = self._try_parse_dec_byte() |
| 948 | |
| 949 | if item is not None: |
| 950 | return item |
| 951 | |
| 952 | # Strings corresponding to escape sequence characters |
| 953 | _lit_str_escape_seq_strs = { |
| 954 | "0": "\0", |
| 955 | "a": "\a", |
| 956 | "b": "\b", |
| 957 | "e": "\x1b", |
| 958 | "f": "\f", |
| 959 | "n": "\n", |
| 960 | "r": "\r", |
| 961 | "t": "\t", |
| 962 | "v": "\v", |
| 963 | "\\": "\\", |
| 964 | '"': '"', |
| 965 | } |
| 966 | |
| 967 | # Patterns for _try_parse_lit_str() |
| 968 | _lit_str_prefix_suffix_pat = re.compile(r'"') |
| 969 | _lit_str_contents_pat = re.compile(r'(?:(?:\\.)|[^"])*') |
| 970 | |
| 971 | # Parses a literal string between double quotes (without an encoding |
| 972 | # prefix) and returns the resulting string. |
| 973 | def _try_parse_lit_str(self, with_prefix: bool): |
| 974 | # Match prefix if needed |
| 975 | if with_prefix: |
| 976 | if self._try_parse_pat(self._lit_str_prefix_suffix_pat) is None: |
| 977 | # No match |
| 978 | return |
| 979 | |
| 980 | # Expect literal string |
| 981 | m = self._expect_pat(self._lit_str_contents_pat, "Expecting a literal string") |
| 982 | |
| 983 | # Expect end of string |
| 984 | self._expect_pat( |
| 985 | self._lit_str_prefix_suffix_pat, 'Expecting `"` (end of literal string)' |
| 986 | ) |
| 987 | |
| 988 | # Replace escape sequences |
| 989 | val = m.group(0) |
| 990 | |
| 991 | for ec in '0abefnrtv"\\': |
| 992 | val = val.replace(r"\{}".format(ec), self._lit_str_escape_seq_strs[ec]) |
| 993 | |
| 994 | # Return string |
| 995 | return val |
| 996 | |
| 997 | # Patterns for _try_parse_utf_str_encoding() |
| 998 | _str_encoding_utf_prefix_pat = re.compile(r"u") |
| 999 | _str_encoding_utf_pat = re.compile(r"(?:8|(?:(?:16|32)(?:[bl]e)))\b") |
| 1000 | |
| 1001 | # Tries to parse a UTF encoding specification, returning the Python |
| 1002 | # codec name on success. |
| 1003 | def _try_parse_utf_str_encoding(self): |
| 1004 | # Match prefix |
| 1005 | if self._try_parse_pat(self._str_encoding_utf_prefix_pat) is None: |
| 1006 | # No match |
| 1007 | return |
| 1008 | |
| 1009 | # Expect UTF specification |
| 1010 | m = self._expect_pat( |
| 1011 | self._str_encoding_utf_pat, |
| 1012 | "Expecting `8`, `16be`, `16le`, `32be` or `32le`", |
| 1013 | ) |
| 1014 | |
| 1015 | # Convert to codec name |
| 1016 | return { |
| 1017 | "8": "utf_8", |
| 1018 | "16be": "utf_16_be", |
| 1019 | "16le": "utf_16_le", |
| 1020 | "32be": "utf_32_be", |
| 1021 | "32le": "utf_32_le", |
| 1022 | }[m.group(0)] |
| 1023 | |
| 1024 | # Patterns for _try_parse_str_encoding() |
| 1025 | _str_encoding_gen_prefix_pat = re.compile(r"s") |
| 1026 | _str_encoding_colon_pat = re.compile(r":") |
| 1027 | _str_encoding_non_utf_pat = re.compile(r"latin(?:[1-9]|10)\b") |
| 1028 | |
| 1029 | # Tries to parse a string encoding specification, returning the |
| 1030 | # Python codec name on success. |
| 1031 | # |
| 1032 | # Requires the general prefix (`s:`) if `req_gen_prefix` is `True`. |
| 1033 | def _try_parse_str_encoding(self, req_gen_prefix: bool = False): |
| 1034 | # General prefix? |
| 1035 | if self._try_parse_pat(self._str_encoding_gen_prefix_pat) is not None: |
| 1036 | # Expect `:` |
| 1037 | self._skip_ws_and_comments() |
| 1038 | self._expect_pat(self._str_encoding_colon_pat, "Expecting `:`") |
| 1039 | |
| 1040 | # Expect encoding specification |
| 1041 | self._skip_ws_and_comments() |
| 1042 | |
| 1043 | # UTF? |
| 1044 | codec = self._try_parse_utf_str_encoding() |
| 1045 | |
| 1046 | if codec is not None: |
| 1047 | return codec |
| 1048 | |
| 1049 | # Expect Latin |
| 1050 | m = self._expect_pat( |
| 1051 | self._str_encoding_non_utf_pat, |
| 1052 | "Expecting `u8`, `u16be`, `u16le`, `u32be`, `u32le`, or `latin1` to `latin10`", |
| 1053 | ) |
| 1054 | return m.group(0) |
| 1055 | |
| 1056 | # UTF? |
| 1057 | if not req_gen_prefix: |
| 1058 | return self._try_parse_utf_str_encoding() |
| 1059 | |
| 1060 | # Patterns for _try_parse_str() |
| 1061 | _lit_str_prefix_pat = re.compile(r'"') |
| 1062 | _str_prefix_pat = re.compile(r'"|\{') |
| 1063 | _str_expr_pat = re.compile(r"[^}]+") |
| 1064 | _str_expr_suffix_pat = re.compile(r"\}") |
| 1065 | |
| 1066 | # Tries to parse a string, returning a literal string or string item |
| 1067 | # on success. |
| 1068 | def _try_parse_str(self): |
| 1069 | begin_text_loc = self._text_loc |
| 1070 | |
| 1071 | # Encoding |
| 1072 | codec = self._try_parse_str_encoding() |
| 1073 | |
| 1074 | # Match prefix (expect if there's an encoding specification) |
| 1075 | self._skip_ws_and_comments() |
| 1076 | |
| 1077 | if codec is None: |
| 1078 | # No encoding: only a literal string (UTF-8) is legal |
| 1079 | m_prefix = self._try_parse_pat(self._lit_str_prefix_pat) |
| 1080 | |
| 1081 | if m_prefix is None: |
| 1082 | return |
| 1083 | else: |
| 1084 | # Encoding present: expect a string prefix |
| 1085 | m_prefix = self._expect_pat(self._str_prefix_pat, 'Expecting `"` or `{`') |
| 1086 | |
| 1087 | # Literal string or expression? |
| 1088 | prefix = m_prefix.group(0) |
| 1089 | |
| 1090 | if prefix == '"': |
| 1091 | # Expect literal string |
| 1092 | str_text_loc = self._text_loc |
| 1093 | val = self._try_parse_lit_str(False) |
| 1094 | |
| 1095 | if val is None: |
| 1096 | self._raise_error("Expecting a literal string") |
| 1097 | |
| 1098 | # Encode string |
| 1099 | data = _encode_str(val, "utf_8" if codec is None else codec, str_text_loc) |
| 1100 | |
| 1101 | # Return item |
| 1102 | return _LitStr(data, begin_text_loc) |
| 1103 | else: |
| 1104 | # Expect expression |
| 1105 | self._skip_ws_and_comments() |
| 1106 | expr_text_loc = self._text_loc |
| 1107 | m = self._expect_pat(self._str_expr_pat, "Expecting an expression") |
| 1108 | |
| 1109 | # Expect `}` |
| 1110 | self._expect_pat(self._str_expr_suffix_pat, "Expecting `}`") |
| 1111 | |
| 1112 | # Create an expression node from the expression string |
| 1113 | expr_str, expr = self._ast_expr_from_str(m.group(0), expr_text_loc) |
| 1114 | |
| 1115 | # Return item |
| 1116 | assert codec is not None |
| 1117 | return _Str(expr_str, expr, codec, begin_text_loc) |
| 1118 | |
| 1119 | # Common right parenthesis pattern |
| 1120 | _right_paren_pat = re.compile(r"\)") |
| 1121 | |
| 1122 | # Patterns for _try_parse_group() |
| 1123 | _group_prefix_pat = re.compile(r"\(|!g(?:roup)?\b") |
| 1124 | |
| 1125 | # Tries to parse a group, returning a group item on success. |
| 1126 | def _try_parse_group(self): |
| 1127 | begin_text_loc = self._text_loc |
| 1128 | |
| 1129 | # Match prefix |
| 1130 | m_open = self._try_parse_pat(self._group_prefix_pat) |
| 1131 | |
| 1132 | if m_open is None: |
| 1133 | # No match |
| 1134 | return |
| 1135 | |
| 1136 | # Parse items |
| 1137 | items = self._parse_items() |
| 1138 | |
| 1139 | # Expect end of group |
| 1140 | self._skip_ws_and_comments_and_syms() |
| 1141 | |
| 1142 | if m_open.group(0) == "(": |
| 1143 | pat = self._right_paren_pat |
| 1144 | exp = ")" |
| 1145 | else: |
| 1146 | pat = self._block_end_pat |
| 1147 | exp = "!end" |
| 1148 | |
| 1149 | self._expect_pat(pat, "Expecting an item or `{}` (end of group)".format(exp)) |
| 1150 | |
| 1151 | # Return item |
| 1152 | return _Group(items, begin_text_loc) |
| 1153 | |
| 1154 | # Returns a stripped expression string and an AST expression node |
| 1155 | # from the expression string `expr_str` at text location `text_loc`. |
| 1156 | def _ast_expr_from_str(self, expr_str: str, text_loc: TextLocation): |
| 1157 | # Create an expression node from the expression string |
| 1158 | expr_str = expr_str.strip().replace("\n", " ") |
| 1159 | |
| 1160 | try: |
| 1161 | expr = ast.parse(expr_str, mode="eval") |
| 1162 | except SyntaxError: |
| 1163 | _raise_error( |
| 1164 | "Invalid expression `{}`: invalid syntax".format(expr_str), |
| 1165 | text_loc, |
| 1166 | ) |
| 1167 | |
| 1168 | return expr_str, expr |
| 1169 | |
| 1170 | # Returns a `ByteOrder` value from the _valid_ byte order string |
| 1171 | # `bo_str`. |
| 1172 | @staticmethod |
| 1173 | def _bo_from_str(bo_str: str): |
| 1174 | return { |
| 1175 | "be": ByteOrder.BE, |
| 1176 | "le": ByteOrder.LE, |
| 1177 | }[bo_str] |
| 1178 | |
| 1179 | # Patterns for _try_parse_val() |
| 1180 | _val_prefix_pat = re.compile(r"\[") |
| 1181 | _val_expr_pat = re.compile(r"([^\]:]+):") |
| 1182 | _fl_num_len_fmt_pat = re.compile(r"(?P<len>8|16|24|32|40|48|56|64)(?P<bo>[bl]e)?") |
| 1183 | _leb128_int_fmt_pat = re.compile(r"(u|s)leb128") |
| 1184 | _val_suffix_pat = re.compile(r"]") |
| 1185 | |
| 1186 | # Tries to parse a value (number or string) and format (fixed length |
| 1187 | # in bits and optional byte order override, `uleb128`, `sleb128`, or |
| 1188 | # `s:` followed with an encoding name), returning an item on |
| 1189 | # success. |
| 1190 | def _try_parse_val(self): |
| 1191 | # Match prefix |
| 1192 | if self._try_parse_pat(self._val_prefix_pat) is None: |
| 1193 | # No match |
| 1194 | return |
| 1195 | |
| 1196 | # Expect expression and `:` |
| 1197 | self._skip_ws_and_comments() |
| 1198 | expr_text_loc = self._text_loc |
| 1199 | m = self._expect_pat(self._val_expr_pat, "Expecting an expression") |
| 1200 | |
| 1201 | # Create an expression node from the expression string |
| 1202 | expr_str, expr = self._ast_expr_from_str(m.group(1), expr_text_loc) |
| 1203 | |
| 1204 | # Fixed length? |
| 1205 | self._skip_ws_and_comments() |
| 1206 | m_fmt = self._try_parse_pat(self._fl_num_len_fmt_pat) |
| 1207 | |
| 1208 | if m_fmt is not None: |
| 1209 | # Byte order override |
| 1210 | if m_fmt.group("bo") is None: |
| 1211 | bo = None |
| 1212 | else: |
| 1213 | bo = self._bo_from_str(m_fmt.group("bo")) |
| 1214 | |
| 1215 | # Create fixed-length number item |
| 1216 | item = _FlNum( |
| 1217 | expr_str, |
| 1218 | expr, |
| 1219 | int(m_fmt.group("len")), |
| 1220 | bo, |
| 1221 | expr_text_loc, |
| 1222 | ) |
| 1223 | else: |
| 1224 | # LEB128? |
| 1225 | m_fmt = self._try_parse_pat(self._leb128_int_fmt_pat) |
| 1226 | |
| 1227 | if m_fmt is not None: |
| 1228 | # Create LEB128 integer item |
| 1229 | cls = _ULeb128Int if m_fmt.group(1) == "u" else _SLeb128Int |
| 1230 | item = cls(expr_str, expr, expr_text_loc) |
| 1231 | else: |
| 1232 | # String encoding? |
| 1233 | codec = self._try_parse_str_encoding(True) |
| 1234 | |
| 1235 | if codec is not None: |
| 1236 | # Create string item |
| 1237 | item = _Str(expr_str, expr, codec, expr_text_loc) |
| 1238 | else: |
| 1239 | # At this point it's invalid |
| 1240 | self._raise_error( |
| 1241 | "Expecting a fixed length (multiple of eight bits and optional `be` or `le`), `uleb128`, `sleb128`, or `s:` followed with a valid encoding (`u8`, `u16be`, `u16le`, `u32be`, `u32le`, or `latin1` to `latin10`)" |
| 1242 | ) |
| 1243 | |
| 1244 | # Expect `]` |
| 1245 | self._skip_ws_and_comments() |
| 1246 | m = self._expect_pat(self._val_suffix_pat, "Expecting `]`") |
| 1247 | |
| 1248 | # Return item |
| 1249 | return item |
| 1250 | |
| 1251 | # Patterns for _try_parse_var_assign() |
| 1252 | _var_assign_prefix_pat = re.compile(r"\{") |
| 1253 | _var_assign_equal_pat = re.compile(r"=") |
| 1254 | _var_assign_expr_pat = re.compile(r"[^}]+") |
| 1255 | _var_assign_suffix_pat = re.compile(r"\}") |
| 1256 | |
| 1257 | # Tries to parse a variable assignment, returning a variable |
| 1258 | # assignment item on success. |
| 1259 | def _try_parse_var_assign(self): |
| 1260 | # Match prefix |
| 1261 | if self._try_parse_pat(self._var_assign_prefix_pat) is None: |
| 1262 | # No match |
| 1263 | return |
| 1264 | |
| 1265 | # Expect a name |
| 1266 | self._skip_ws_and_comments() |
| 1267 | name_text_loc = self._text_loc |
| 1268 | m = self._expect_pat(_py_name_pat, "Expecting a valid Python name") |
| 1269 | name = m.group(0) |
| 1270 | |
| 1271 | # Expect `=` |
| 1272 | self._skip_ws_and_comments() |
| 1273 | self._expect_pat(self._var_assign_equal_pat, "Expecting `=`") |
| 1274 | |
| 1275 | # Expect expression |
| 1276 | self._skip_ws_and_comments() |
| 1277 | expr_text_loc = self._text_loc |
| 1278 | m_expr = self._expect_pat(self._var_assign_expr_pat, "Expecting an expression") |
| 1279 | |
| 1280 | # Expect `}` |
| 1281 | self._skip_ws_and_comments() |
| 1282 | self._expect_pat(self._var_assign_suffix_pat, "Expecting `}`") |
| 1283 | |
| 1284 | # Validate name |
| 1285 | if name == _icitte_name: |
| 1286 | _raise_error( |
| 1287 | "`{}` is a reserved variable name".format(_icitte_name), name_text_loc |
| 1288 | ) |
| 1289 | |
| 1290 | if name in self._label_names: |
| 1291 | _raise_error("Existing label named `{}`".format(name), name_text_loc) |
| 1292 | |
| 1293 | # Create an expression node from the expression string |
| 1294 | expr_str, expr = self._ast_expr_from_str(m_expr.group(0), expr_text_loc) |
| 1295 | |
| 1296 | # Add to known variable names |
| 1297 | self._var_names.add(name) |
| 1298 | |
| 1299 | # Return item |
| 1300 | return _VarAssign( |
| 1301 | name, |
| 1302 | expr_str, |
| 1303 | expr, |
| 1304 | name_text_loc, |
| 1305 | ) |
| 1306 | |
| 1307 | # Pattern for _try_parse_set_bo() |
| 1308 | _set_bo_pat = re.compile(r"!([bl]e)\b") |
| 1309 | |
| 1310 | # Tries to parse a byte order setting, returning a byte order |
| 1311 | # setting item on success. |
| 1312 | def _try_parse_set_bo(self): |
| 1313 | begin_text_loc = self._text_loc |
| 1314 | |
| 1315 | # Match |
| 1316 | m = self._try_parse_pat(self._set_bo_pat) |
| 1317 | |
| 1318 | if m is None: |
| 1319 | # No match |
| 1320 | return |
| 1321 | |
| 1322 | # Return corresponding item |
| 1323 | if m.group(1) == "be": |
| 1324 | bo = ByteOrder.BE |
| 1325 | else: |
| 1326 | assert m.group(1) == "le" |
| 1327 | bo = ByteOrder.LE |
| 1328 | |
| 1329 | return _SetBo(bo, begin_text_loc) |
| 1330 | |
| 1331 | # Tries to parse an offset setting value (after the initial `<`), |
| 1332 | # returning an offset item on success. |
| 1333 | def _try_parse_set_offset_val(self): |
| 1334 | begin_text_loc = self._text_loc |
| 1335 | |
| 1336 | # Match |
| 1337 | m = self._try_parse_pat(_pos_const_int_pat) |
| 1338 | |
| 1339 | if m is None: |
| 1340 | # No match |
| 1341 | return |
| 1342 | |
| 1343 | # Return item |
| 1344 | return _SetOffset(int(_norm_const_int(m.group(0)), 0), begin_text_loc) |
| 1345 | |
| 1346 | # Tries to parse a label name (after the initial `<`), returning a |
| 1347 | # label item on success. |
| 1348 | def _try_parse_label_name(self): |
| 1349 | begin_text_loc = self._text_loc |
| 1350 | |
| 1351 | # Match |
| 1352 | m = self._try_parse_pat(_py_name_pat) |
| 1353 | |
| 1354 | if m is None: |
| 1355 | # No match |
| 1356 | return |
| 1357 | |
| 1358 | # Validate |
| 1359 | name = m.group(0) |
| 1360 | |
| 1361 | if name == _icitte_name: |
| 1362 | _raise_error( |
| 1363 | "`{}` is a reserved label name".format(_icitte_name), begin_text_loc |
| 1364 | ) |
| 1365 | |
| 1366 | if name in self._label_names: |
| 1367 | _raise_error("Duplicate label name `{}`".format(name), begin_text_loc) |
| 1368 | |
| 1369 | if name in self._var_names: |
| 1370 | _raise_error("Existing variable named `{}`".format(name), begin_text_loc) |
| 1371 | |
| 1372 | # Add to known label names |
| 1373 | self._label_names.add(name) |
| 1374 | |
| 1375 | # Return item |
| 1376 | return _Label(name, begin_text_loc) |
| 1377 | |
| 1378 | # Patterns for _try_parse_label_or_set_offset() |
| 1379 | _label_set_offset_prefix_pat = re.compile(r"<") |
| 1380 | _label_set_offset_suffix_pat = re.compile(r">") |
| 1381 | |
| 1382 | # Tries to parse a label or an offset setting, returning an item on |
| 1383 | # success. |
| 1384 | def _try_parse_label_or_set_offset(self): |
| 1385 | # Match prefix |
| 1386 | if self._try_parse_pat(self._label_set_offset_prefix_pat) is None: |
| 1387 | # No match |
| 1388 | return |
| 1389 | |
| 1390 | # Offset setting item? |
| 1391 | self._skip_ws_and_comments() |
| 1392 | item = self._try_parse_set_offset_val() |
| 1393 | |
| 1394 | if item is None: |
| 1395 | # Label item? |
| 1396 | item = self._try_parse_label_name() |
| 1397 | |
| 1398 | if item is None: |
| 1399 | # At this point it's invalid |
| 1400 | self._raise_error("Expecting a label name or an offset setting value") |
| 1401 | |
| 1402 | # Expect suffix |
| 1403 | self._skip_ws_and_comments() |
| 1404 | self._expect_pat(self._label_set_offset_suffix_pat, "Expecting `>`") |
| 1405 | return item |
| 1406 | |
| 1407 | # Pattern for _parse_pad_val() |
| 1408 | _pad_val_prefix_pat = re.compile(r"~") |
| 1409 | |
| 1410 | # Tries to parse a padding value, returning the padding value, or 0 |
| 1411 | # if none. |
| 1412 | def _parse_pad_val(self): |
| 1413 | # Padding value? |
| 1414 | self._skip_ws_and_comments() |
| 1415 | pad_val = 0 |
| 1416 | |
| 1417 | if self._try_parse_pat(self._pad_val_prefix_pat) is not None: |
| 1418 | self._skip_ws_and_comments() |
| 1419 | pad_val_text_loc = self._text_loc |
| 1420 | m = self._expect_pat( |
| 1421 | _pos_const_int_pat, |
| 1422 | "Expecting a positive constant integer (byte value)", |
| 1423 | ) |
| 1424 | |
| 1425 | # Validate |
| 1426 | pad_val = int(_norm_const_int(m.group(0)), 0) |
| 1427 | |
| 1428 | if pad_val > 255: |
| 1429 | _raise_error( |
| 1430 | "Invalid padding byte value {}".format(pad_val), |
| 1431 | pad_val_text_loc, |
| 1432 | ) |
| 1433 | |
| 1434 | return pad_val |
| 1435 | |
| 1436 | # Patterns for _try_parse_align_offset() |
| 1437 | _align_offset_prefix_pat = re.compile(r"@") |
| 1438 | _align_offset_val_pat = re.compile(r"\d+") |
| 1439 | |
| 1440 | # Tries to parse an offset alignment, returning an offset alignment |
| 1441 | # item on success. |
| 1442 | def _try_parse_align_offset(self): |
| 1443 | begin_text_loc = self._text_loc |
| 1444 | |
| 1445 | # Match prefix |
| 1446 | if self._try_parse_pat(self._align_offset_prefix_pat) is None: |
| 1447 | # No match |
| 1448 | return |
| 1449 | |
| 1450 | # Expect an alignment |
| 1451 | self._skip_ws_and_comments() |
| 1452 | align_text_loc = self._text_loc |
| 1453 | m = self._expect_pat( |
| 1454 | self._align_offset_val_pat, |
| 1455 | "Expecting an alignment (positive multiple of eight bits)", |
| 1456 | ) |
| 1457 | |
| 1458 | # Validate alignment |
| 1459 | val = int(m.group(0)) |
| 1460 | |
| 1461 | if val <= 0 or (val % 8) != 0: |
| 1462 | _raise_error( |
| 1463 | "Invalid alignment value {} (not a positive multiple of eight)".format( |
| 1464 | val |
| 1465 | ), |
| 1466 | align_text_loc, |
| 1467 | ) |
| 1468 | |
| 1469 | # Padding value |
| 1470 | pad_val = self._parse_pad_val() |
| 1471 | |
| 1472 | # Return item |
| 1473 | return _AlignOffset(val, pad_val, begin_text_loc) |
| 1474 | |
| 1475 | # Patterns for _expect_expr() |
| 1476 | _inner_expr_prefix_pat = re.compile(r"\{") |
| 1477 | _inner_expr_pat = re.compile(r"[^}]+") |
| 1478 | _inner_expr_suffix_pat = re.compile(r"\}") |
| 1479 | |
| 1480 | # Parses an expression outside a `{`/`}` context. |
| 1481 | # |
| 1482 | # This function accepts: |
| 1483 | # |
| 1484 | # • A Python expression within `{` and `}`. |
| 1485 | # |
| 1486 | # • A Python name. |
| 1487 | # |
| 1488 | # • If `accept_const_int` is `True`: a constant integer, which may |
| 1489 | # be negative if `allow_neg_int` is `True`. |
| 1490 | # |
| 1491 | # • If `accept_float` is `True`: a constant floating point number. |
| 1492 | # |
| 1493 | # Returns the stripped expression string and AST expression. |
| 1494 | def _expect_expr( |
| 1495 | self, |
| 1496 | accept_const_int: bool = False, |
| 1497 | allow_neg_int: bool = False, |
| 1498 | accept_const_float: bool = False, |
| 1499 | accept_lit_str: bool = False, |
| 1500 | ): |
| 1501 | begin_text_loc = self._text_loc |
| 1502 | |
| 1503 | # Constant floating point number? |
| 1504 | if accept_const_float: |
| 1505 | m = self._try_parse_pat(_const_float_pat) |
| 1506 | |
| 1507 | if m is not None: |
| 1508 | return self._ast_expr_from_str(m.group(0), begin_text_loc) |
| 1509 | |
| 1510 | # Constant integer? |
| 1511 | if accept_const_int: |
| 1512 | m = self._try_parse_pat(_const_int_pat) |
| 1513 | |
| 1514 | if m is not None: |
| 1515 | # Negative and allowed? |
| 1516 | if m.group("neg") == "-" and not allow_neg_int: |
| 1517 | _raise_error( |
| 1518 | "Expecting a positive constant integer", begin_text_loc |
| 1519 | ) |
| 1520 | |
| 1521 | expr_str = _norm_const_int(m.group(0)) |
| 1522 | return self._ast_expr_from_str(expr_str, begin_text_loc) |
| 1523 | |
| 1524 | # Name? |
| 1525 | m = self._try_parse_pat(_py_name_pat) |
| 1526 | |
| 1527 | if m is not None: |
| 1528 | return self._ast_expr_from_str(m.group(0), begin_text_loc) |
| 1529 | |
| 1530 | # Literal string |
| 1531 | if accept_lit_str: |
| 1532 | val = self._try_parse_lit_str(True) |
| 1533 | |
| 1534 | if val is not None: |
| 1535 | return self._ast_expr_from_str(repr(val), begin_text_loc) |
| 1536 | |
| 1537 | # Expect `{` |
| 1538 | msg_accepted_parts = ["a name", "or `{`"] |
| 1539 | |
| 1540 | if accept_lit_str: |
| 1541 | msg_accepted_parts.insert(0, "a literal string") |
| 1542 | |
| 1543 | if accept_const_float: |
| 1544 | msg_accepted_parts.insert(0, "a constant floating point number") |
| 1545 | |
| 1546 | if accept_const_int: |
| 1547 | msg_pos = "" if allow_neg_int else "positive " |
| 1548 | msg_accepted_parts.insert(0, "a {}constant integer".format(msg_pos)) |
| 1549 | |
| 1550 | if len(msg_accepted_parts) == 2: |
| 1551 | msg_accepted = " ".join(msg_accepted_parts) |
| 1552 | else: |
| 1553 | msg_accepted = ", ".join(msg_accepted_parts) |
| 1554 | |
| 1555 | self._expect_pat( |
| 1556 | self._inner_expr_prefix_pat, |
| 1557 | "Expecting {}".format(msg_accepted), |
| 1558 | ) |
| 1559 | |
| 1560 | # Expect an expression |
| 1561 | self._skip_ws_and_comments() |
| 1562 | expr_text_loc = self._text_loc |
| 1563 | m = self._expect_pat(self._inner_expr_pat, "Expecting an expression") |
| 1564 | expr_str = m.group(0) |
| 1565 | |
| 1566 | # Expect `}` |
| 1567 | self._skip_ws_and_comments() |
| 1568 | self._expect_pat(self._inner_expr_suffix_pat, "Expecting `}`") |
| 1569 | |
| 1570 | return self._ast_expr_from_str(expr_str, expr_text_loc) |
| 1571 | |
| 1572 | # Patterns for _try_parse_fill_until() |
| 1573 | _fill_until_prefix_pat = re.compile(r"\+") |
| 1574 | _fill_until_pad_val_prefix_pat = re.compile(r"~") |
| 1575 | |
| 1576 | # Tries to parse a filling, returning a filling item on success. |
| 1577 | def _try_parse_fill_until(self): |
| 1578 | begin_text_loc = self._text_loc |
| 1579 | |
| 1580 | # Match prefix |
| 1581 | if self._try_parse_pat(self._fill_until_prefix_pat) is None: |
| 1582 | # No match |
| 1583 | return |
| 1584 | |
| 1585 | # Expect expression |
| 1586 | self._skip_ws_and_comments() |
| 1587 | expr_str, expr = self._expect_expr(accept_const_int=True) |
| 1588 | |
| 1589 | # Padding value |
| 1590 | pad_val = self._parse_pad_val() |
| 1591 | |
| 1592 | # Return item |
| 1593 | return _FillUntil(expr_str, expr, pad_val, begin_text_loc) |
| 1594 | |
| 1595 | # Parses the multiplier expression of a repetition (block or |
| 1596 | # post-item) and returns the expression string and AST node. |
| 1597 | def _expect_rep_mul_expr(self): |
| 1598 | return self._expect_expr(accept_const_int=True) |
| 1599 | |
| 1600 | # Common block end pattern |
| 1601 | _block_end_pat = re.compile(r"!end\b") |
| 1602 | |
| 1603 | # Pattern for _try_parse_rep_block() |
| 1604 | _rep_block_prefix_pat = re.compile(r"!r(?:epeat)?\b") |
| 1605 | |
| 1606 | # Tries to parse a repetition block, returning a repetition item on |
| 1607 | # success. |
| 1608 | def _try_parse_rep_block(self): |
| 1609 | begin_text_loc = self._text_loc |
| 1610 | |
| 1611 | # Match prefix |
| 1612 | if self._try_parse_pat(self._rep_block_prefix_pat) is None: |
| 1613 | # No match |
| 1614 | return |
| 1615 | |
| 1616 | # Expect expression |
| 1617 | self._skip_ws_and_comments() |
| 1618 | expr_str, expr = self._expect_rep_mul_expr() |
| 1619 | |
| 1620 | # Parse items |
| 1621 | self._skip_ws_and_comments_and_syms() |
| 1622 | items = self._parse_items() |
| 1623 | |
| 1624 | # Expect end of block |
| 1625 | self._skip_ws_and_comments_and_syms() |
| 1626 | self._expect_pat( |
| 1627 | self._block_end_pat, "Expecting an item or `!end` (end of repetition block)" |
| 1628 | ) |
| 1629 | |
| 1630 | # Return item |
| 1631 | return _Rep(items, expr_str, expr, begin_text_loc) |
| 1632 | |
| 1633 | # Pattern for _try_parse_cond_block() |
| 1634 | _cond_block_prefix_pat = re.compile(r"!if\b") |
| 1635 | _cond_block_else_pat = re.compile(r"!else\b") |
| 1636 | |
| 1637 | # Tries to parse a conditional block, returning a conditional item |
| 1638 | # on success. |
| 1639 | def _try_parse_cond_block(self): |
| 1640 | begin_text_loc = self._text_loc |
| 1641 | |
| 1642 | # Match prefix |
| 1643 | if self._try_parse_pat(self._cond_block_prefix_pat) is None: |
| 1644 | # No match |
| 1645 | return |
| 1646 | |
| 1647 | # Expect expression |
| 1648 | self._skip_ws_and_comments() |
| 1649 | expr_str, expr = self._expect_expr() |
| 1650 | |
| 1651 | # Parse "true" items |
| 1652 | self._skip_ws_and_comments_and_syms() |
| 1653 | true_items_text_loc = self._text_loc |
| 1654 | true_items = self._parse_items() |
| 1655 | false_items = [] # type: List[_Item] |
| 1656 | false_items_text_loc = begin_text_loc |
| 1657 | |
| 1658 | # `!else`? |
| 1659 | self._skip_ws_and_comments_and_syms() |
| 1660 | |
| 1661 | if self._try_parse_pat(self._cond_block_else_pat) is not None: |
| 1662 | # Parse "false" items |
| 1663 | self._skip_ws_and_comments_and_syms() |
| 1664 | false_items_text_loc = self._text_loc |
| 1665 | false_items = self._parse_items() |
| 1666 | |
| 1667 | # Expect end of block |
| 1668 | self._expect_pat( |
| 1669 | self._block_end_pat, |
| 1670 | "Expecting an item, `!else`, or `!end` (end of conditional block)", |
| 1671 | ) |
| 1672 | |
| 1673 | # Return item |
| 1674 | return _Cond( |
| 1675 | _Group(true_items, true_items_text_loc), |
| 1676 | _Group(false_items, false_items_text_loc), |
| 1677 | expr_str, |
| 1678 | expr, |
| 1679 | begin_text_loc, |
| 1680 | ) |
| 1681 | |
| 1682 | # Pattern for _try_parse_trans_block() |
| 1683 | _trans_block_prefix_pat = re.compile(r"!t(?:ransform)?\b") |
| 1684 | _trans_block_type_pat = re.compile( |
| 1685 | r"(?:(?:base|b)64(?:u)?|(?:base|b)(?:16|32)|(?:ascii|a|base|b)85(?:p)?|(?:quopri|qp)(?:t)?|gzip|gz|bzip2|bz2)\b" |
| 1686 | ) |
| 1687 | |
| 1688 | # Tries to parse a transformation block, returning a transformation |
| 1689 | # block item on success. |
| 1690 | def _try_parse_trans_block(self): |
| 1691 | begin_text_loc = self._text_loc |
| 1692 | |
| 1693 | # Match prefix |
| 1694 | if self._try_parse_pat(self._trans_block_prefix_pat) is None: |
| 1695 | # No match |
| 1696 | return |
| 1697 | |
| 1698 | # Expect type |
| 1699 | self._skip_ws_and_comments() |
| 1700 | m = self._expect_pat( |
| 1701 | self._trans_block_type_pat, "Expecting a known transformation type" |
| 1702 | ) |
| 1703 | |
| 1704 | # Parse items |
| 1705 | self._skip_ws_and_comments_and_syms() |
| 1706 | items = self._parse_items() |
| 1707 | |
| 1708 | # Expect end of block |
| 1709 | self._expect_pat( |
| 1710 | self._block_end_pat, |
| 1711 | "Expecting an item or `!end` (end of transformation block)", |
| 1712 | ) |
| 1713 | |
| 1714 | # Choose encoding function |
| 1715 | enc = m.group(0) |
| 1716 | |
| 1717 | if enc in ("base64", "b64"): |
| 1718 | func = base64.standard_b64encode |
| 1719 | name = "standard Base64" |
| 1720 | elif enc in ("base64u", "b64u"): |
| 1721 | func = base64.urlsafe_b64encode |
| 1722 | name = "URL-safe Base64" |
| 1723 | elif enc in ("base32", "b32"): |
| 1724 | func = base64.b32encode |
| 1725 | name = "Base32" |
| 1726 | elif enc in ("base16", "b16"): |
| 1727 | func = base64.b16encode |
| 1728 | name = "Base16" |
| 1729 | elif enc in ("ascii85", "a85"): |
| 1730 | func = base64.a85encode |
| 1731 | name = "Ascii85" |
| 1732 | elif enc in ("ascii85p", "a85p"): |
| 1733 | func = functools.partial(base64.a85encode, pad=True) |
| 1734 | name = "padded Ascii85" |
| 1735 | elif enc in ("base85", "b85"): |
| 1736 | func = base64.b85encode |
| 1737 | name = "Base85" |
| 1738 | elif enc in ("base85p", "b85p"): |
| 1739 | func = functools.partial(base64.b85encode, pad=True) |
| 1740 | name = "padded Base85" |
| 1741 | elif enc in ("quopri", "qp"): |
| 1742 | func = quopri.encodestring |
| 1743 | name = "MIME quoted-printable" |
| 1744 | elif enc in ("quoprit", "qpt"): |
| 1745 | func = functools.partial(quopri.encodestring, quotetabs=True) |
| 1746 | name = "MIME quoted-printable (with quoted tabs)" |
| 1747 | elif enc in ("gzip", "gz"): |
| 1748 | func = gzip.compress |
| 1749 | name = "gzip" |
| 1750 | else: |
| 1751 | assert enc in ("bzip2", "bz2") |
| 1752 | func = bz2.compress |
| 1753 | name = "bzip2" |
| 1754 | |
| 1755 | # Return item |
| 1756 | return _Trans( |
| 1757 | items, |
| 1758 | name, |
| 1759 | func, |
| 1760 | begin_text_loc, |
| 1761 | ) |
| 1762 | |
| 1763 | # Common left parenthesis pattern |
| 1764 | _left_paren_pat = re.compile(r"\(") |
| 1765 | |
| 1766 | # Patterns for _try_parse_macro_def() and _try_parse_macro_exp() |
| 1767 | _macro_params_comma_pat = re.compile(",") |
| 1768 | |
| 1769 | # Patterns for _try_parse_macro_def() |
| 1770 | _macro_def_prefix_pat = re.compile(r"!m(?:acro)?\b") |
| 1771 | |
| 1772 | # Tries to parse a macro definition, adding it to `self._macro_defs` |
| 1773 | # and returning `True` on success. |
| 1774 | def _try_parse_macro_def(self): |
| 1775 | begin_text_loc = self._text_loc |
| 1776 | |
| 1777 | # Match prefix |
| 1778 | if self._try_parse_pat(self._macro_def_prefix_pat) is None: |
| 1779 | # No match |
| 1780 | return False |
| 1781 | |
| 1782 | # Expect a name |
| 1783 | self._skip_ws_and_comments() |
| 1784 | name_text_loc = self._text_loc |
| 1785 | m = self._expect_pat(_py_name_pat, "Expecting a valid macro name") |
| 1786 | |
| 1787 | # Validate name |
| 1788 | name = m.group(0) |
| 1789 | |
| 1790 | if name in self._macro_defs: |
| 1791 | _raise_error("Duplicate macro named `{}`".format(name), name_text_loc) |
| 1792 | |
| 1793 | # Expect `(` |
| 1794 | self._skip_ws_and_comments() |
| 1795 | self._expect_pat(self._left_paren_pat, "Expecting `(`") |
| 1796 | |
| 1797 | # Try to parse comma-separated parameter names |
| 1798 | param_names = [] # type: List[str] |
| 1799 | expect_comma = False |
| 1800 | |
| 1801 | while True: |
| 1802 | self._skip_ws_and_comments() |
| 1803 | |
| 1804 | # End? |
| 1805 | if self._try_parse_pat(self._right_paren_pat) is not None: |
| 1806 | # End |
| 1807 | break |
| 1808 | |
| 1809 | # Comma? |
| 1810 | if expect_comma: |
| 1811 | self._expect_pat(self._macro_params_comma_pat, "Expecting `,`") |
| 1812 | |
| 1813 | # Expect parameter name |
| 1814 | self._skip_ws_and_comments() |
| 1815 | param_text_loc = self._text_loc |
| 1816 | m = self._expect_pat(_py_name_pat, "Expecting valid parameter name") |
| 1817 | |
| 1818 | if m.group(0) in param_names: |
| 1819 | _raise_error( |
| 1820 | "Duplicate macro parameter named `{}`".format(m.group(0)), |
| 1821 | param_text_loc, |
| 1822 | ) |
| 1823 | |
| 1824 | param_names.append(m.group(0)) |
| 1825 | expect_comma = True |
| 1826 | |
| 1827 | # Expect items |
| 1828 | self._skip_ws_and_comments_and_syms() |
| 1829 | old_var_names = self._var_names.copy() |
| 1830 | old_label_names = self._label_names.copy() |
| 1831 | self._var_names = set() # type: Set[str] |
| 1832 | self._label_names = set() # type: Set[str] |
| 1833 | items = self._parse_items() |
| 1834 | self._var_names = old_var_names |
| 1835 | self._label_names = old_label_names |
| 1836 | |
| 1837 | # Expect suffix |
| 1838 | self._expect_pat( |
| 1839 | self._block_end_pat, "Expecting an item or `!end` (end of macro block)" |
| 1840 | ) |
| 1841 | |
| 1842 | # Register macro |
| 1843 | self._macro_defs[name] = _MacroDef(name, param_names, items, begin_text_loc) |
| 1844 | |
| 1845 | return True |
| 1846 | |
| 1847 | # Patterns for _try_parse_macro_exp() |
| 1848 | _macro_exp_prefix_pat = re.compile(r"m\b") |
| 1849 | _macro_exp_colon_pat = re.compile(r":") |
| 1850 | |
| 1851 | # Tries to parse a macro expansion, returning a macro expansion item |
| 1852 | # on success. |
| 1853 | def _try_parse_macro_exp(self): |
| 1854 | begin_text_loc = self._text_loc |
| 1855 | |
| 1856 | # Match prefix |
| 1857 | if self._try_parse_pat(self._macro_exp_prefix_pat) is None: |
| 1858 | # No match |
| 1859 | return |
| 1860 | |
| 1861 | # Expect `:` |
| 1862 | self._skip_ws_and_comments() |
| 1863 | self._expect_pat(self._macro_exp_colon_pat, "Expecting `:`") |
| 1864 | |
| 1865 | # Expect a macro name |
| 1866 | self._skip_ws_and_comments() |
| 1867 | name_text_loc = self._text_loc |
| 1868 | m = self._expect_pat(_py_name_pat, "Expecting a valid macro name") |
| 1869 | |
| 1870 | # Validate name |
| 1871 | name = m.group(0) |
| 1872 | macro_def = self._macro_defs.get(name) |
| 1873 | |
| 1874 | if macro_def is None: |
| 1875 | _raise_error("Unknown macro name `{}`".format(name), name_text_loc) |
| 1876 | |
| 1877 | # Expect `(` |
| 1878 | self._skip_ws_and_comments() |
| 1879 | self._expect_pat(self._left_paren_pat, "Expecting `(`") |
| 1880 | |
| 1881 | # Try to parse comma-separated parameter values |
| 1882 | params_text_loc = self._text_loc |
| 1883 | params = [] # type: List[_MacroExpParam] |
| 1884 | expect_comma = False |
| 1885 | |
| 1886 | while True: |
| 1887 | self._skip_ws_and_comments() |
| 1888 | |
| 1889 | # End? |
| 1890 | if self._try_parse_pat(self._right_paren_pat) is not None: |
| 1891 | # End |
| 1892 | break |
| 1893 | |
| 1894 | # Expect a value |
| 1895 | if expect_comma: |
| 1896 | self._expect_pat(self._macro_params_comma_pat, "Expecting `,`") |
| 1897 | |
| 1898 | self._skip_ws_and_comments() |
| 1899 | param_text_loc = self._text_loc |
| 1900 | params.append( |
| 1901 | _MacroExpParam( |
| 1902 | *self._expect_expr( |
| 1903 | accept_const_int=True, |
| 1904 | allow_neg_int=True, |
| 1905 | accept_const_float=True, |
| 1906 | accept_lit_str=True, |
| 1907 | ), |
| 1908 | text_loc=param_text_loc |
| 1909 | ) |
| 1910 | ) |
| 1911 | expect_comma = True |
| 1912 | |
| 1913 | # Validate parameter values |
| 1914 | if len(params) != len(macro_def.param_names): |
| 1915 | sing_plur = "" if len(params) == 1 else "s" |
| 1916 | _raise_error( |
| 1917 | "Macro expansion passes {} parameter{} while the definition expects {}".format( |
| 1918 | len(params), sing_plur, len(macro_def.param_names) |
| 1919 | ), |
| 1920 | params_text_loc, |
| 1921 | ) |
| 1922 | |
| 1923 | # Return item |
| 1924 | return _MacroExp(name, params, begin_text_loc) |
| 1925 | |
| 1926 | # Tries to parse a base item (anything except a post-item |
| 1927 | # repetition), returning it on success. |
| 1928 | def _try_parse_base_item(self): |
| 1929 | for func in self._base_item_parse_funcs: |
| 1930 | item = func() |
| 1931 | |
| 1932 | if item is not None: |
| 1933 | return item |
| 1934 | |
| 1935 | # Pattern for _try_parse_rep_post() |
| 1936 | _rep_post_prefix_pat = re.compile(r"\*") |
| 1937 | |
| 1938 | # Tries to parse a post-item repetition, returning the expression |
| 1939 | # string and AST expression node on success. |
| 1940 | def _try_parse_rep_post(self): |
| 1941 | # Match prefix |
| 1942 | if self._try_parse_pat(self._rep_post_prefix_pat) is None: |
| 1943 | # No match |
| 1944 | return |
| 1945 | |
| 1946 | # Return expression string and AST expression |
| 1947 | self._skip_ws_and_comments() |
| 1948 | return self._expect_rep_mul_expr() |
| 1949 | |
| 1950 | # Tries to parse an item, possibly followed by a repetition, |
| 1951 | # returning `True` on success. |
| 1952 | # |
| 1953 | # Appends any parsed item to `items`. |
| 1954 | def _try_append_item(self, items: List[_Item]): |
| 1955 | self._skip_ws_and_comments_and_syms() |
| 1956 | |
| 1957 | # Base item |
| 1958 | item = self._try_parse_base_item() |
| 1959 | |
| 1960 | if item is None: |
| 1961 | return |
| 1962 | |
| 1963 | # Parse repetition if the base item is repeatable |
| 1964 | if isinstance(item, _RepableItem): |
| 1965 | self._skip_ws_and_comments() |
| 1966 | rep_text_loc = self._text_loc |
| 1967 | rep_ret = self._try_parse_rep_post() |
| 1968 | |
| 1969 | if rep_ret is not None: |
| 1970 | item = _Rep([item], *rep_ret, text_loc=rep_text_loc) |
| 1971 | |
| 1972 | items.append(item) |
| 1973 | return True |
| 1974 | |
| 1975 | # Parses and returns items, skipping whitespaces, insignificant |
| 1976 | # symbols, and comments when allowed, and stopping at the first |
| 1977 | # unknown character. |
| 1978 | # |
| 1979 | # Accepts and registers macro definitions if `accept_macro_defs` |
| 1980 | # is `True`. |
| 1981 | def _parse_items(self, accept_macro_defs: bool = False) -> List[_Item]: |
| 1982 | items = [] # type: List[_Item] |
| 1983 | |
| 1984 | while self._isnt_done(): |
| 1985 | # Try to append item |
| 1986 | if not self._try_append_item(items): |
| 1987 | if accept_macro_defs and self._try_parse_macro_def(): |
| 1988 | continue |
| 1989 | |
| 1990 | # Unknown at this point |
| 1991 | break |
| 1992 | |
| 1993 | return items |
| 1994 | |
| 1995 | # Parses the whole Normand input, setting `self._res` to the main |
| 1996 | # group item on success. |
| 1997 | def _parse(self): |
| 1998 | if len(self._normand.strip()) == 0: |
| 1999 | # Special case to make sure there's something to consume |
| 2000 | self._res = _Group([], self._text_loc) |
| 2001 | return |
| 2002 | |
| 2003 | # Parse first level items |
| 2004 | items = self._parse_items(True) |
| 2005 | |
| 2006 | # Make sure there's nothing left |
| 2007 | self._skip_ws_and_comments_and_syms() |
| 2008 | |
| 2009 | if self._isnt_done(): |
| 2010 | self._raise_error( |
| 2011 | "Unexpected character `{}`".format(self._normand[self._at]) |
| 2012 | ) |
| 2013 | |
| 2014 | # Set main group item |
| 2015 | self._res = _Group(items, self._text_loc) |
| 2016 | |
| 2017 | |
| 2018 | # The return type of parse(). |
| 2019 | class ParseResult: |
| 2020 | @classmethod |
| 2021 | def _create( |
| 2022 | cls, |
| 2023 | data: bytearray, |
| 2024 | variables: VariablesT, |
| 2025 | labels: LabelsT, |
| 2026 | offset: int, |
| 2027 | bo: Optional[ByteOrder], |
| 2028 | ): |
| 2029 | self = cls.__new__(cls) |
| 2030 | self._init(data, variables, labels, offset, bo) |
| 2031 | return self |
| 2032 | |
| 2033 | def __init__(self, *args, **kwargs): # type: ignore |
| 2034 | raise NotImplementedError |
| 2035 | |
| 2036 | def _init( |
| 2037 | self, |
| 2038 | data: bytearray, |
| 2039 | variables: VariablesT, |
| 2040 | labels: LabelsT, |
| 2041 | offset: int, |
| 2042 | bo: Optional[ByteOrder], |
| 2043 | ): |
| 2044 | self._data = data |
| 2045 | self._vars = variables |
| 2046 | self._labels = labels |
| 2047 | self._offset = offset |
| 2048 | self._bo = bo |
| 2049 | |
| 2050 | # Generated data. |
| 2051 | @property |
| 2052 | def data(self): |
| 2053 | return self._data |
| 2054 | |
| 2055 | # Dictionary of updated variable names to their last computed value. |
| 2056 | @property |
| 2057 | def variables(self): |
| 2058 | return self._vars |
| 2059 | |
| 2060 | # Dictionary of updated main group label names to their computed |
| 2061 | # value. |
| 2062 | @property |
| 2063 | def labels(self): |
| 2064 | return self._labels |
| 2065 | |
| 2066 | # Updated offset. |
| 2067 | @property |
| 2068 | def offset(self): |
| 2069 | return self._offset |
| 2070 | |
| 2071 | # Updated byte order. |
| 2072 | @property |
| 2073 | def byte_order(self): |
| 2074 | return self._bo |
| 2075 | |
| 2076 | |
| 2077 | # Raises a parse error for the item `item`, creating it using the |
| 2078 | # message `msg`. |
| 2079 | def _raise_error_for_item(msg: str, item: _Item) -> NoReturn: |
| 2080 | _raise_error(msg, item.text_loc) |
| 2081 | |
| 2082 | |
| 2083 | # The `ICITTE` reserved name. |
| 2084 | _icitte_name = "ICITTE" |
| 2085 | |
| 2086 | |
| 2087 | # Base node visitor. |
| 2088 | # |
| 2089 | # Calls the _visit_name() method for each name node which isn't the name |
| 2090 | # of a call. |
| 2091 | class _NodeVisitor(ast.NodeVisitor): |
| 2092 | def __init__(self): |
| 2093 | self._parent_is_call = False |
| 2094 | |
| 2095 | def generic_visit(self, node: ast.AST): |
| 2096 | if type(node) is ast.Call: |
| 2097 | self._parent_is_call = True |
| 2098 | elif type(node) is ast.Name and not self._parent_is_call: |
| 2099 | self._visit_name(node.id) |
| 2100 | |
| 2101 | super().generic_visit(node) |
| 2102 | self._parent_is_call = False |
| 2103 | |
| 2104 | @abc.abstractmethod |
| 2105 | def _visit_name(self, name: str): |
| 2106 | ... |
| 2107 | |
| 2108 | |
| 2109 | # Expression validator: validates that all the names within the |
| 2110 | # expression are allowed. |
| 2111 | class _ExprValidator(_NodeVisitor): |
| 2112 | def __init__(self, expr_str: str, text_loc: TextLocation, allowed_names: Set[str]): |
| 2113 | super().__init__() |
| 2114 | self._expr_str = expr_str |
| 2115 | self._text_loc = text_loc |
| 2116 | self._allowed_names = allowed_names |
| 2117 | |
| 2118 | def _visit_name(self, name: str): |
| 2119 | # Make sure the name refers to a known and reachable |
| 2120 | # variable/label name. |
| 2121 | if name != _icitte_name and name not in self._allowed_names: |
| 2122 | msg = "Illegal (unknown or unreachable) variable/label name `{}` in expression `{}`".format( |
| 2123 | name, self._expr_str |
| 2124 | ) |
| 2125 | |
| 2126 | allowed_names = self._allowed_names.copy() |
| 2127 | allowed_names.add(_icitte_name) |
| 2128 | |
| 2129 | if len(allowed_names) > 0: |
| 2130 | allowed_names_str = ", ".join( |
| 2131 | sorted(["`{}`".format(name) for name in allowed_names]) |
| 2132 | ) |
| 2133 | msg += "; the legal names are {{{}}}".format(allowed_names_str) |
| 2134 | |
| 2135 | _raise_error( |
| 2136 | msg, |
| 2137 | self._text_loc, |
| 2138 | ) |
| 2139 | |
| 2140 | |
| 2141 | # Generator state. |
| 2142 | class _GenState: |
| 2143 | def __init__( |
| 2144 | self, |
| 2145 | variables: VariablesT, |
| 2146 | labels: LabelsT, |
| 2147 | offset: int, |
| 2148 | bo: Optional[ByteOrder], |
| 2149 | ): |
| 2150 | self.variables = variables.copy() |
| 2151 | self.labels = labels.copy() |
| 2152 | self.offset = offset |
| 2153 | self.bo = bo |
| 2154 | |
| 2155 | def __repr__(self): |
| 2156 | return "_GenState({}, {}, {}, {})".format( |
| 2157 | repr(self.variables), repr(self.labels), repr(self.offset), repr(self.bo) |
| 2158 | ) |
| 2159 | |
| 2160 | |
| 2161 | # Fixed-length number item instance. |
| 2162 | class _FlNumItemInst: |
| 2163 | def __init__( |
| 2164 | self, |
| 2165 | item: _FlNum, |
| 2166 | offset_in_data: int, |
| 2167 | state: _GenState, |
| 2168 | parse_error_msgs: List[ParseErrorMessage], |
| 2169 | ): |
| 2170 | self._item = item |
| 2171 | self._offset_in_data = offset_in_data |
| 2172 | self._state = state |
| 2173 | self._parse_error_msgs = parse_error_msgs |
| 2174 | |
| 2175 | @property |
| 2176 | def item(self): |
| 2177 | return self._item |
| 2178 | |
| 2179 | @property |
| 2180 | def offset_in_data(self): |
| 2181 | return self._offset_in_data |
| 2182 | |
| 2183 | @property |
| 2184 | def state(self): |
| 2185 | return self._state |
| 2186 | |
| 2187 | @property |
| 2188 | def parse_error_msgs(self): |
| 2189 | return self._parse_error_msgs |
| 2190 | |
| 2191 | |
| 2192 | # Generator of data and final state from a group item. |
| 2193 | # |
| 2194 | # Generation happens in memory at construction time. After building, use |
| 2195 | # the `data`, `variables`, `labels`, `offset`, and `bo` properties to |
| 2196 | # get the resulting context. |
| 2197 | # |
| 2198 | # The steps of generation are: |
| 2199 | # |
| 2200 | # 1. Handle each item in prefix order. |
| 2201 | # |
| 2202 | # The handlers append bytes to `self._data` and update some current |
| 2203 | # state object (`_GenState` instance). |
| 2204 | # |
| 2205 | # When handling a fixed-length number item, try to evaluate its |
| 2206 | # expression using the current state. If this fails, then it might be |
| 2207 | # because the expression refers to a "future" label: save the current |
| 2208 | # offset in `self._data` (generated data) and a snapshot of the |
| 2209 | # current state within `self._fl_num_item_insts` (`_FlNumItemInst` |
| 2210 | # object). _gen_fl_num_item_insts() will deal with this later. A |
| 2211 | # `_FlNumItemInst` instance also contains a snapshot of the current |
| 2212 | # parsing error messages (`self._parse_error_msgs`) which need to be |
| 2213 | # taken into account when handling the instance later. |
| 2214 | # |
| 2215 | # When handling the items of a group, keep a map of immediate label |
| 2216 | # names to their offset. Then, after having processed all the items, |
| 2217 | # update the relevant saved state snapshots in |
| 2218 | # `self._fl_num_item_insts` with those immediate label values. |
| 2219 | # _gen_fl_num_item_insts() will deal with this later. |
| 2220 | # |
| 2221 | # 2. Handle all the fixed-length number item instances of which the |
| 2222 | # expression evaluation failed before. |
| 2223 | # |
| 2224 | # At this point, `self._fl_num_item_insts` contains everything that's |
| 2225 | # needed to evaluate the expressions, including the values of |
| 2226 | # "future" labels from the point of view of some fixed-length number |
| 2227 | # item instance. |
| 2228 | # |
| 2229 | # If an evaluation fails at this point, then it's a user error. Add |
| 2230 | # to the parsing error all the saved parsing error messages of the |
| 2231 | # instance. Those additional messages add precious context to the |
| 2232 | # error. |
| 2233 | class _Gen: |
| 2234 | def __init__( |
| 2235 | self, |
| 2236 | group: _Group, |
| 2237 | macro_defs: _MacroDefsT, |
| 2238 | variables: VariablesT, |
| 2239 | labels: LabelsT, |
| 2240 | offset: int, |
| 2241 | bo: Optional[ByteOrder], |
| 2242 | ): |
| 2243 | self._macro_defs = macro_defs |
| 2244 | self._fl_num_item_insts = [] # type: List[_FlNumItemInst] |
| 2245 | self._parse_error_msgs = [] # type: List[ParseErrorMessage] |
| 2246 | self._in_trans = False |
| 2247 | self._gen(group, _GenState(variables, labels, offset, bo)) |
| 2248 | |
| 2249 | # Generated bytes. |
| 2250 | @property |
| 2251 | def data(self): |
| 2252 | return self._data |
| 2253 | |
| 2254 | # Updated variables. |
| 2255 | @property |
| 2256 | def variables(self): |
| 2257 | return self._final_state.variables |
| 2258 | |
| 2259 | # Updated main group labels. |
| 2260 | @property |
| 2261 | def labels(self): |
| 2262 | return self._final_state.labels |
| 2263 | |
| 2264 | # Updated offset. |
| 2265 | @property |
| 2266 | def offset(self): |
| 2267 | return self._final_state.offset |
| 2268 | |
| 2269 | # Updated byte order. |
| 2270 | @property |
| 2271 | def bo(self): |
| 2272 | return self._final_state.bo |
| 2273 | |
| 2274 | # Evaluates the expression `expr` of which the original string is |
| 2275 | # `expr_str` at the location `text_loc` considering the current |
| 2276 | # generation state `state`. |
| 2277 | # |
| 2278 | # If `accept_float` is `True`, then the type of the result may be |
| 2279 | # `float` too. |
| 2280 | # |
| 2281 | # If `accept_str` is `True`, then the type of the result may be |
| 2282 | # `str` too. |
| 2283 | @staticmethod |
| 2284 | def _eval_expr( |
| 2285 | expr_str: str, |
| 2286 | expr: ast.Expression, |
| 2287 | text_loc: TextLocation, |
| 2288 | state: _GenState, |
| 2289 | accept_float: bool = False, |
| 2290 | accept_str: bool = False, |
| 2291 | ): |
| 2292 | syms = {} # type: VariablesT |
| 2293 | syms.update(state.labels) |
| 2294 | |
| 2295 | # Set the `ICITTE` name to the current offset |
| 2296 | syms[_icitte_name] = state.offset |
| 2297 | |
| 2298 | # Add the current variables |
| 2299 | syms.update(state.variables) |
| 2300 | |
| 2301 | # Validate the node and its children |
| 2302 | _ExprValidator(expr_str, text_loc, set(syms.keys())).visit(expr) |
| 2303 | |
| 2304 | # Compile and evaluate expression node |
| 2305 | try: |
| 2306 | val = eval(compile(expr, "", "eval"), None, syms) |
| 2307 | except Exception as exc: |
| 2308 | _raise_error( |
| 2309 | "Failed to evaluate expression `{}`: {}".format(expr_str, exc), |
| 2310 | text_loc, |
| 2311 | ) |
| 2312 | |
| 2313 | # Convert `bool` result type to `int` to normalize |
| 2314 | if type(val) is bool: |
| 2315 | val = int(val) |
| 2316 | |
| 2317 | # Validate result type |
| 2318 | expected_types = {int} # type: Set[type] |
| 2319 | |
| 2320 | if accept_float: |
| 2321 | expected_types.add(float) |
| 2322 | |
| 2323 | if accept_str: |
| 2324 | expected_types.add(str) |
| 2325 | |
| 2326 | if type(val) not in expected_types: |
| 2327 | expected_types_str = sorted( |
| 2328 | ["`{}`".format(t.__name__) for t in expected_types] |
| 2329 | ) |
| 2330 | |
| 2331 | if len(expected_types_str) == 1: |
| 2332 | msg_expected = expected_types_str[0] |
| 2333 | elif len(expected_types_str) == 2: |
| 2334 | msg_expected = " or ".join(expected_types_str) |
| 2335 | else: |
| 2336 | expected_types_str[-1] = "or {}".format(expected_types_str[-1]) |
| 2337 | msg_expected = ", ".join(expected_types_str) |
| 2338 | |
| 2339 | _raise_error( |
| 2340 | "Invalid expression `{}`: expecting result type {}, not `{}`".format( |
| 2341 | expr_str, msg_expected, type(val).__name__ |
| 2342 | ), |
| 2343 | text_loc, |
| 2344 | ) |
| 2345 | |
| 2346 | return val |
| 2347 | |
| 2348 | # Forwards to _eval_expr() with the expression and text location of |
| 2349 | # `item`. |
| 2350 | @staticmethod |
| 2351 | def _eval_item_expr( |
| 2352 | item: Union[_Cond, _FillUntil, _FlNum, _Leb128Int, _Rep, _Str, _VarAssign], |
| 2353 | state: _GenState, |
| 2354 | accept_float: bool = False, |
| 2355 | accept_str: bool = False, |
| 2356 | ): |
| 2357 | return _Gen._eval_expr( |
| 2358 | item.expr_str, item.expr, item.text_loc, state, accept_float, accept_str |
| 2359 | ) |
| 2360 | |
| 2361 | # Handles the byte item `item`. |
| 2362 | def _handle_byte_item(self, item: _Byte, state: _GenState): |
| 2363 | self._data.append(item.val) |
| 2364 | state.offset += item.size |
| 2365 | |
| 2366 | # Handles the literal string item `item`. |
| 2367 | def _handle_lit_str_item(self, item: _LitStr, state: _GenState): |
| 2368 | self._data += item.data |
| 2369 | state.offset += item.size |
| 2370 | |
| 2371 | # Handles the byte order setting item `item`. |
| 2372 | def _handle_set_bo_item(self, item: _SetBo, state: _GenState): |
| 2373 | # Update current byte order |
| 2374 | state.bo = item.bo |
| 2375 | |
| 2376 | # Handles the variable assignment item `item`. |
| 2377 | def _handle_var_assign_item(self, item: _VarAssign, state: _GenState): |
| 2378 | # Update variable |
| 2379 | state.variables[item.name] = self._eval_item_expr( |
| 2380 | item, state, accept_float=True, accept_str=True |
| 2381 | ) |
| 2382 | |
| 2383 | # Returns the effective byte order to use to encode the fixed-length |
| 2384 | # number `item` considering the current state `state`. |
| 2385 | @staticmethod |
| 2386 | def _fl_num_item_effective_bo(item: _FlNum, state: _GenState): |
| 2387 | return state.bo if item.bo is None else item.bo |
| 2388 | |
| 2389 | # Handles the fixed-length number item `item`. |
| 2390 | def _handle_fl_num_item(self, item: _FlNum, state: _GenState): |
| 2391 | # Effective byte order |
| 2392 | bo = self._fl_num_item_effective_bo(item, state) |
| 2393 | |
| 2394 | # Validate current byte order |
| 2395 | if bo is None and item.len > 8: |
| 2396 | _raise_error_for_item( |
| 2397 | "Current byte order isn't defined at first fixed-length number (`{}`) to encode on more than 8 bits".format( |
| 2398 | item.expr_str |
| 2399 | ), |
| 2400 | item, |
| 2401 | ) |
| 2402 | |
| 2403 | # Try an immediate evaluation. If it fails, then keep everything |
| 2404 | # needed to (try to) generate the bytes of this item later. |
| 2405 | try: |
| 2406 | data = self._gen_fl_num_item_inst_data(item, state) |
| 2407 | except Exception: |
| 2408 | if self._in_trans: |
| 2409 | _raise_error_for_item( |
| 2410 | "Invalid expression `{}`: failed to evaluate within a transformation block".format( |
| 2411 | item.expr_str |
| 2412 | ), |
| 2413 | item, |
| 2414 | ) |
| 2415 | |
| 2416 | self._fl_num_item_insts.append( |
| 2417 | _FlNumItemInst( |
| 2418 | item, |
| 2419 | len(self._data), |
| 2420 | copy.deepcopy(state), |
| 2421 | copy.deepcopy(self._parse_error_msgs), |
| 2422 | ) |
| 2423 | ) |
| 2424 | |
| 2425 | # Reserve space in `self._data` for this instance |
| 2426 | data = bytes([0] * (item.len // 8)) |
| 2427 | |
| 2428 | # Append bytes |
| 2429 | self._data += data |
| 2430 | |
| 2431 | # Update offset |
| 2432 | state.offset += len(data) |
| 2433 | |
| 2434 | # Returns the size, in bytes, required to encode the value `val` |
| 2435 | # with LEB128 (signed version if `is_signed` is `True`). |
| 2436 | @staticmethod |
| 2437 | def _leb128_size_for_val(val: int, is_signed: bool): |
| 2438 | if val < 0: |
| 2439 | # Equivalent upper bound. |
| 2440 | # |
| 2441 | # For example, if `val` is -128, then the full integer for |
| 2442 | # this number of bits would be [-128, 127]. |
| 2443 | val = -val - 1 |
| 2444 | |
| 2445 | # Number of bits (add one for the sign if needed) |
| 2446 | bits = val.bit_length() + int(is_signed) |
| 2447 | |
| 2448 | if bits == 0: |
| 2449 | bits = 1 |
| 2450 | |
| 2451 | # Seven bits per byte |
| 2452 | return math.ceil(bits / 7) |
| 2453 | |
| 2454 | # Handles the LEB128 integer item `item`. |
| 2455 | def _handle_leb128_int_item(self, item: _Leb128Int, state: _GenState): |
| 2456 | # Compute value |
| 2457 | val = self._eval_item_expr(item, state) |
| 2458 | |
| 2459 | # Size in bytes |
| 2460 | size = self._leb128_size_for_val(val, type(item) is _SLeb128Int) |
| 2461 | |
| 2462 | # For each byte |
| 2463 | for _ in range(size): |
| 2464 | # Seven LSBs, MSB of the byte set (continue) |
| 2465 | self._data.append((val & 0x7F) | 0x80) |
| 2466 | val >>= 7 |
| 2467 | |
| 2468 | # Clear MSB of last byte (stop) |
| 2469 | self._data[-1] &= ~0x80 |
| 2470 | |
| 2471 | # Update offset |
| 2472 | state.offset += size |
| 2473 | |
| 2474 | # Handles the string item `item`. |
| 2475 | def _handle_str_item(self, item: _Str, state: _GenState): |
| 2476 | # Compute value |
| 2477 | val = str(self._eval_item_expr(item, state, accept_float=True, accept_str=True)) |
| 2478 | |
| 2479 | # Encode |
| 2480 | data = _encode_str(val, item.codec, item.text_loc) |
| 2481 | |
| 2482 | # Add to data |
| 2483 | self._data += data |
| 2484 | |
| 2485 | # Update offset |
| 2486 | state.offset += len(data) |
| 2487 | |
| 2488 | # Handles the group item `item`, removing the immediate labels from |
| 2489 | # `state` at the end if `remove_immediate_labels` is `True`. |
| 2490 | def _handle_group_item( |
| 2491 | self, item: _Group, state: _GenState, remove_immediate_labels: bool = True |
| 2492 | ): |
| 2493 | first_fl_num_item_inst_index = len(self._fl_num_item_insts) |
| 2494 | immediate_labels = {} # type: LabelsT |
| 2495 | |
| 2496 | # Handle each item |
| 2497 | for subitem in item.items: |
| 2498 | if type(subitem) is _Label: |
| 2499 | # Add to local immediate labels |
| 2500 | immediate_labels[subitem.name] = state.offset |
| 2501 | |
| 2502 | self._handle_item(subitem, state) |
| 2503 | |
| 2504 | # Remove immediate labels from current state if needed |
| 2505 | if remove_immediate_labels: |
| 2506 | for name in immediate_labels: |
| 2507 | del state.labels[name] |
| 2508 | |
| 2509 | # Add all immediate labels to all state snapshots since |
| 2510 | # `first_fl_num_item_inst_index`. |
| 2511 | for inst in self._fl_num_item_insts[first_fl_num_item_inst_index:]: |
| 2512 | inst.state.labels.update(immediate_labels) |
| 2513 | |
| 2514 | # Handles the repetition item `item`. |
| 2515 | def _handle_rep_item(self, item: _Rep, state: _GenState): |
| 2516 | # Compute the repetition count |
| 2517 | mul = _Gen._eval_item_expr(item, state) |
| 2518 | |
| 2519 | # Validate result |
| 2520 | if mul < 0: |
| 2521 | _raise_error_for_item( |
| 2522 | "Invalid expression `{}`: unexpected negative result {:,}".format( |
| 2523 | item.expr_str, mul |
| 2524 | ), |
| 2525 | item, |
| 2526 | ) |
| 2527 | |
| 2528 | # Generate group data `mul` times |
| 2529 | for _ in range(mul): |
| 2530 | self._handle_group_item(item, state) |
| 2531 | |
| 2532 | # Handles the conditional item `item`. |
| 2533 | def _handle_cond_item(self, item: _Cond, state: _GenState): |
| 2534 | # Compute the conditional value |
| 2535 | val = _Gen._eval_item_expr(item, state) |
| 2536 | |
| 2537 | # Generate selected group data |
| 2538 | if val: |
| 2539 | self._handle_group_item(item.true_item, state) |
| 2540 | else: |
| 2541 | self._handle_group_item(item.false_item, state) |
| 2542 | |
| 2543 | # Handles the transformation item `item`. |
| 2544 | def _handle_trans_item(self, item: _Trans, state: _GenState): |
| 2545 | init_in_trans = self._in_trans |
| 2546 | self._in_trans = True |
| 2547 | init_data_len = len(self._data) |
| 2548 | init_offset = state.offset |
| 2549 | |
| 2550 | # Generate group data |
| 2551 | self._handle_group_item(item, state) |
| 2552 | |
| 2553 | # Remove and keep group data |
| 2554 | to_trans = self._data[init_data_len:] |
| 2555 | del self._data[init_data_len:] |
| 2556 | |
| 2557 | # Encode group data and append to current data |
| 2558 | try: |
| 2559 | transformed = item.trans(to_trans) |
| 2560 | except Exception as exc: |
| 2561 | _raise_error_for_item( |
| 2562 | "Cannot apply the {} transformation to this data: {}".format( |
| 2563 | item.name, exc |
| 2564 | ), |
| 2565 | item, |
| 2566 | ) |
| 2567 | |
| 2568 | self._data += transformed |
| 2569 | |
| 2570 | # Update offset and restore |
| 2571 | state.offset = init_offset + len(transformed) |
| 2572 | self._in_trans = init_in_trans |
| 2573 | |
| 2574 | # Evaluates the parameters of the macro expansion item `item` |
| 2575 | # considering the initial state `init_state` and returns a new state |
| 2576 | # to handle the items of the macro. |
| 2577 | def _eval_macro_exp_params(self, item: _MacroExp, init_state: _GenState): |
| 2578 | # New state |
| 2579 | exp_state = _GenState({}, {}, init_state.offset, init_state.bo) |
| 2580 | |
| 2581 | # Evaluate the parameter expressions |
| 2582 | macro_def = self._macro_defs[item.name] |
| 2583 | |
| 2584 | for param_name, param in zip(macro_def.param_names, item.params): |
| 2585 | exp_state.variables[param_name] = _Gen._eval_expr( |
| 2586 | param.expr_str, |
| 2587 | param.expr, |
| 2588 | param.text_loc, |
| 2589 | init_state, |
| 2590 | accept_float=True, |
| 2591 | accept_str=True, |
| 2592 | ) |
| 2593 | |
| 2594 | return exp_state |
| 2595 | |
| 2596 | # Handles the macro expansion item `item`. |
| 2597 | def _handle_macro_exp_item(self, item: _MacroExp, state: _GenState): |
| 2598 | parse_error_msg_text = "While expanding the macro `{}`:".format(item.name) |
| 2599 | |
| 2600 | try: |
| 2601 | # New state |
| 2602 | exp_state = self._eval_macro_exp_params(item, state) |
| 2603 | |
| 2604 | # Process the contained group |
| 2605 | init_data_size = len(self._data) |
| 2606 | parse_error_msg = ( |
| 2607 | ParseErrorMessage._create( # pyright: ignore[reportPrivateUsage] |
| 2608 | parse_error_msg_text, item.text_loc |
| 2609 | ) |
| 2610 | ) |
| 2611 | self._parse_error_msgs.append(parse_error_msg) |
| 2612 | self._handle_group_item(self._macro_defs[item.name], exp_state) |
| 2613 | self._parse_error_msgs.pop() |
| 2614 | except ParseError as exc: |
| 2615 | _augment_error(exc, parse_error_msg_text, item.text_loc) |
| 2616 | |
| 2617 | # Update state offset and return |
| 2618 | state.offset += len(self._data) - init_data_size |
| 2619 | |
| 2620 | # Handles the offset setting item `item`. |
| 2621 | def _handle_set_offset_item(self, item: _SetOffset, state: _GenState): |
| 2622 | state.offset = item.val |
| 2623 | |
| 2624 | # Handles the offset alignment item `item` (adds padding). |
| 2625 | def _handle_align_offset_item(self, item: _AlignOffset, state: _GenState): |
| 2626 | init_offset = state.offset |
| 2627 | align_bytes = item.val // 8 |
| 2628 | state.offset = (state.offset + align_bytes - 1) // align_bytes * align_bytes |
| 2629 | self._data += bytes([item.pad_val] * (state.offset - init_offset)) |
| 2630 | |
| 2631 | # Handles the filling item `item` (adds padding). |
| 2632 | def _handle_fill_until_item(self, item: _FillUntil, state: _GenState): |
| 2633 | # Compute the new offset |
| 2634 | new_offset = _Gen._eval_item_expr(item, state) |
| 2635 | |
| 2636 | # Validate the new offset |
| 2637 | if new_offset < state.offset: |
| 2638 | _raise_error_for_item( |
| 2639 | "Invalid expression `{}`: new offset {:,} is less than current offset {:,}".format( |
| 2640 | item.expr_str, new_offset, state.offset |
| 2641 | ), |
| 2642 | item, |
| 2643 | ) |
| 2644 | |
| 2645 | # Fill |
| 2646 | self._data += bytes([item.pad_val] * (new_offset - state.offset)) |
| 2647 | |
| 2648 | # Update offset |
| 2649 | state.offset = new_offset |
| 2650 | |
| 2651 | # Handles the label item `item`. |
| 2652 | def _handle_label_item(self, item: _Label, state: _GenState): |
| 2653 | state.labels[item.name] = state.offset |
| 2654 | |
| 2655 | # Handles the item `item`, returning the updated next repetition |
| 2656 | # instance. |
| 2657 | def _handle_item(self, item: _Item, state: _GenState): |
| 2658 | return self._item_handlers[type(item)](item, state) |
| 2659 | |
| 2660 | # Generates the data for a fixed-length integer item instance having |
| 2661 | # the value `val` and the effective byte order `bo` and returns it. |
| 2662 | def _gen_fl_int_item_inst_data( |
| 2663 | self, val: int, bo: Optional[ByteOrder], item: _FlNum |
| 2664 | ): |
| 2665 | # Validate range |
| 2666 | if val < -(2 ** (item.len - 1)) or val > 2**item.len - 1: |
| 2667 | _raise_error_for_item( |
| 2668 | "Value {:,} is outside the {}-bit range when evaluating expression `{}`".format( |
| 2669 | val, item.len, item.expr_str |
| 2670 | ), |
| 2671 | item, |
| 2672 | ) |
| 2673 | |
| 2674 | # Encode result on 64 bits (to extend the sign bit whatever the |
| 2675 | # value of `item.len`). |
| 2676 | data = struct.pack( |
| 2677 | "{}{}".format( |
| 2678 | ">" if bo in (None, ByteOrder.BE) else "<", |
| 2679 | "Q" if val >= 0 else "q", |
| 2680 | ), |
| 2681 | val, |
| 2682 | ) |
| 2683 | |
| 2684 | # Keep only the requested length |
| 2685 | len_bytes = item.len // 8 |
| 2686 | |
| 2687 | if bo in (None, ByteOrder.BE): |
| 2688 | # Big endian: keep last bytes |
| 2689 | data = data[-len_bytes:] |
| 2690 | else: |
| 2691 | # Little endian: keep first bytes |
| 2692 | assert bo == ByteOrder.LE |
| 2693 | data = data[:len_bytes] |
| 2694 | |
| 2695 | # Return data |
| 2696 | return data |
| 2697 | |
| 2698 | # Generates the data for a fixed-length floating point number item |
| 2699 | # instance having the value `val` and the effective byte order `bo` |
| 2700 | # and returns it. |
| 2701 | def _gen_fl_float_item_inst_data( |
| 2702 | self, val: float, bo: Optional[ByteOrder], item: _FlNum |
| 2703 | ): |
| 2704 | # Validate length |
| 2705 | if item.len not in (32, 64): |
| 2706 | _raise_error_for_item( |
| 2707 | "Invalid {}-bit length for a fixed-length floating point number (value {:,})".format( |
| 2708 | item.len, val |
| 2709 | ), |
| 2710 | item, |
| 2711 | ) |
| 2712 | |
| 2713 | # Encode and return result |
| 2714 | return struct.pack( |
| 2715 | "{}{}".format( |
| 2716 | ">" if bo in (None, ByteOrder.BE) else "<", |
| 2717 | "f" if item.len == 32 else "d", |
| 2718 | ), |
| 2719 | val, |
| 2720 | ) |
| 2721 | |
| 2722 | # Generates the data for a fixed-length number item instance and |
| 2723 | # returns it. |
| 2724 | def _gen_fl_num_item_inst_data(self, item: _FlNum, state: _GenState): |
| 2725 | # Effective byte order |
| 2726 | bo = self._fl_num_item_effective_bo(item, state) |
| 2727 | |
| 2728 | # Compute value |
| 2729 | val = self._eval_item_expr(item, state, True) |
| 2730 | |
| 2731 | # Handle depending on type |
| 2732 | if type(val) is int: |
| 2733 | return self._gen_fl_int_item_inst_data(val, bo, item) |
| 2734 | else: |
| 2735 | assert type(val) is float |
| 2736 | return self._gen_fl_float_item_inst_data(val, bo, item) |
| 2737 | |
| 2738 | # Generates the data for all the fixed-length number item instances |
| 2739 | # and writes it at the correct offset within `self._data`. |
| 2740 | def _gen_fl_num_item_insts(self): |
| 2741 | for inst in self._fl_num_item_insts: |
| 2742 | # Generate bytes |
| 2743 | try: |
| 2744 | data = self._gen_fl_num_item_inst_data(inst.item, inst.state) |
| 2745 | except ParseError as exc: |
| 2746 | # Add all the saved parse error messages for this |
| 2747 | # instance. |
| 2748 | for msg in reversed(inst.parse_error_msgs): |
| 2749 | _add_error_msg(exc, msg.text, msg.text_location) |
| 2750 | |
| 2751 | raise |
| 2752 | |
| 2753 | # Insert bytes into `self._data` |
| 2754 | self._data[inst.offset_in_data : inst.offset_in_data + len(data)] = data |
| 2755 | |
| 2756 | # Generates the data (`self._data`) and final state |
| 2757 | # (`self._final_state`) from `group` and the initial state `state`. |
| 2758 | def _gen(self, group: _Group, state: _GenState): |
| 2759 | # Initial state |
| 2760 | self._data = bytearray() |
| 2761 | |
| 2762 | # Item handlers |
| 2763 | self._item_handlers = { |
| 2764 | _AlignOffset: self._handle_align_offset_item, |
| 2765 | _Byte: self._handle_byte_item, |
| 2766 | _Cond: self._handle_cond_item, |
| 2767 | _FillUntil: self._handle_fill_until_item, |
| 2768 | _FlNum: self._handle_fl_num_item, |
| 2769 | _Group: self._handle_group_item, |
| 2770 | _Label: self._handle_label_item, |
| 2771 | _LitStr: self._handle_lit_str_item, |
| 2772 | _MacroExp: self._handle_macro_exp_item, |
| 2773 | _Rep: self._handle_rep_item, |
| 2774 | _SetBo: self._handle_set_bo_item, |
| 2775 | _SetOffset: self._handle_set_offset_item, |
| 2776 | _SLeb128Int: self._handle_leb128_int_item, |
| 2777 | _Str: self._handle_str_item, |
| 2778 | _Trans: self._handle_trans_item, |
| 2779 | _ULeb128Int: self._handle_leb128_int_item, |
| 2780 | _VarAssign: self._handle_var_assign_item, |
| 2781 | } # type: Dict[type, Callable[[Any, _GenState], None]] |
| 2782 | |
| 2783 | # Handle the group item, _not_ removing the immediate labels |
| 2784 | # because the `labels` property offers them. |
| 2785 | self._handle_group_item(group, state, False) |
| 2786 | |
| 2787 | # This is actually the final state |
| 2788 | self._final_state = state |
| 2789 | |
| 2790 | # Generate all the fixed-length number bytes now that we know |
| 2791 | # their full state |
| 2792 | self._gen_fl_num_item_insts() |
| 2793 | |
| 2794 | |
| 2795 | # Returns a `ParseResult` instance containing the bytes encoded by the |
| 2796 | # input string `normand`. |
| 2797 | # |
| 2798 | # `init_variables` is a dictionary of initial variable names (valid |
| 2799 | # Python names) to integral values. A variable name must not be the |
| 2800 | # reserved name `ICITTE`. |
| 2801 | # |
| 2802 | # `init_labels` is a dictionary of initial label names (valid Python |
| 2803 | # names) to integral values. A label name must not be the reserved name |
| 2804 | # `ICITTE`. |
| 2805 | # |
| 2806 | # `init_offset` is the initial offset. |
| 2807 | # |
| 2808 | # `init_byte_order` is the initial byte order. |
| 2809 | # |
| 2810 | # Raises `ParseError` on any parsing error. |
| 2811 | def parse( |
| 2812 | normand: str, |
| 2813 | init_variables: Optional[VariablesT] = None, |
| 2814 | init_labels: Optional[LabelsT] = None, |
| 2815 | init_offset: int = 0, |
| 2816 | init_byte_order: Optional[ByteOrder] = None, |
| 2817 | ): |
| 2818 | if init_variables is None: |
| 2819 | init_variables = {} |
| 2820 | |
| 2821 | if init_labels is None: |
| 2822 | init_labels = {} |
| 2823 | |
| 2824 | parser = _Parser(normand, init_variables, init_labels) |
| 2825 | gen = _Gen( |
| 2826 | parser.res, |
| 2827 | parser.macro_defs, |
| 2828 | init_variables, |
| 2829 | init_labels, |
| 2830 | init_offset, |
| 2831 | init_byte_order, |
| 2832 | ) |
| 2833 | return ParseResult._create( # pyright: ignore[reportPrivateUsage] |
| 2834 | gen.data, gen.variables, gen.labels, gen.offset, gen.bo |
| 2835 | ) |
| 2836 | |
| 2837 | |
| 2838 | # Raises a command-line error with the message `msg`. |
| 2839 | def _raise_cli_error(msg: str) -> NoReturn: |
| 2840 | raise RuntimeError("Command-line error: {}".format(msg)) |
| 2841 | |
| 2842 | |
| 2843 | # Returns the `int` or `float` value out of a CLI assignment value. |
| 2844 | def _val_from_assign_val_str(s: str, is_label: bool): |
| 2845 | s = s.strip() |
| 2846 | |
| 2847 | # Floating point number? |
| 2848 | if not is_label: |
| 2849 | m = _const_float_pat.fullmatch(s) |
| 2850 | |
| 2851 | if m is not None: |
| 2852 | return float(m.group(0)) |
| 2853 | |
| 2854 | # Integer? |
| 2855 | m = _const_int_pat.fullmatch(s) |
| 2856 | |
| 2857 | if m is not None: |
| 2858 | return int(_norm_const_int(m.group(0)), 0) |
| 2859 | |
| 2860 | exp = "an integer" if is_label else "a number" |
| 2861 | _raise_cli_error("Invalid assignment value `{}`: expecting {}".format(s, exp)) |
| 2862 | |
| 2863 | |
| 2864 | # Returns a dictionary of string to numbers from the list of strings |
| 2865 | # `args` containing `NAME=VAL` entries. |
| 2866 | def _dict_from_arg(args: Optional[List[str]], is_label: bool, is_str_only: bool): |
| 2867 | d = {} # type: VariablesT |
| 2868 | |
| 2869 | if args is None: |
| 2870 | return d |
| 2871 | |
| 2872 | for arg in args: |
| 2873 | m = re.match(r"({})\s*=\s*(.*)$".format(_py_name_pat.pattern), arg) |
| 2874 | |
| 2875 | if m is None: |
| 2876 | _raise_cli_error("Invalid assignment `{}`".format(arg)) |
| 2877 | |
| 2878 | if is_str_only: |
| 2879 | val = m.group(2) |
| 2880 | else: |
| 2881 | val = _val_from_assign_val_str(m.group(2), is_label) |
| 2882 | |
| 2883 | d[m.group(1)] = val |
| 2884 | |
| 2885 | return d |
| 2886 | |
| 2887 | |
| 2888 | # Parses the command-line arguments and returns, in this order: |
| 2889 | # |
| 2890 | # 1. The input file path, or `None` if none. |
| 2891 | # 2. The Normand input text. |
| 2892 | # 3. The initial offset. |
| 2893 | # 4. The initial byte order. |
| 2894 | # 5. The initial variables. |
| 2895 | # 6. The initial labels. |
| 2896 | def _parse_cli_args(): |
| 2897 | import argparse |
| 2898 | |
| 2899 | # Build parser |
| 2900 | ap = argparse.ArgumentParser() |
| 2901 | ap.add_argument( |
| 2902 | "--offset", |
| 2903 | metavar="OFFSET", |
| 2904 | action="store", |
| 2905 | type=int, |
| 2906 | default=0, |
| 2907 | help="initial offset (positive)", |
| 2908 | ) |
| 2909 | ap.add_argument( |
| 2910 | "-b", |
| 2911 | "--byte-order", |
| 2912 | metavar="BO", |
| 2913 | choices=["be", "le"], |
| 2914 | type=str, |
| 2915 | help="initial byte order (`be` or `le`)", |
| 2916 | ) |
| 2917 | ap.add_argument( |
| 2918 | "-v", |
| 2919 | "--var", |
| 2920 | metavar="NAME=VAL", |
| 2921 | action="append", |
| 2922 | help="add an initial numeric variable (may be repeated)", |
| 2923 | ) |
| 2924 | ap.add_argument( |
| 2925 | "-s", |
| 2926 | "--var-str", |
| 2927 | metavar="NAME=VAL", |
| 2928 | action="append", |
| 2929 | help="add an initial string variable (may be repeated)", |
| 2930 | ) |
| 2931 | ap.add_argument( |
| 2932 | "-l", |
| 2933 | "--label", |
| 2934 | metavar="NAME=VAL", |
| 2935 | action="append", |
| 2936 | help="add an initial label (may be repeated)", |
| 2937 | ) |
| 2938 | ap.add_argument( |
| 2939 | "--version", action="version", version="Normand {}".format(__version__) |
| 2940 | ) |
| 2941 | ap.add_argument( |
| 2942 | "path", |
| 2943 | metavar="PATH", |
| 2944 | action="store", |
| 2945 | nargs="?", |
| 2946 | help="input path (none means standard input)", |
| 2947 | ) |
| 2948 | |
| 2949 | # Parse |
| 2950 | args = ap.parse_args() |
| 2951 | |
| 2952 | # Read input |
| 2953 | if args.path is None: |
| 2954 | normand = sys.stdin.read() |
| 2955 | else: |
| 2956 | with open(args.path) as f: |
| 2957 | normand = f.read() |
| 2958 | |
| 2959 | # Variables and labels |
| 2960 | variables = _dict_from_arg(args.var, False, False) |
| 2961 | variables.update(_dict_from_arg(args.var_str, False, True)) |
| 2962 | labels = _dict_from_arg(args.label, True, False) |
| 2963 | |
| 2964 | # Validate offset |
| 2965 | if args.offset < 0: |
| 2966 | _raise_cli_error("Invalid negative offset {}") |
| 2967 | |
| 2968 | # Validate and set byte order |
| 2969 | bo = None # type: Optional[ByteOrder] |
| 2970 | |
| 2971 | if args.byte_order is not None: |
| 2972 | if args.byte_order == "be": |
| 2973 | bo = ByteOrder.BE |
| 2974 | else: |
| 2975 | assert args.byte_order == "le" |
| 2976 | bo = ByteOrder.LE |
| 2977 | |
| 2978 | # Return input and initial state |
| 2979 | return args.path, normand, args.offset, bo, variables, typing.cast(LabelsT, labels) |
| 2980 | |
| 2981 | |
| 2982 | # CLI entry point without exception handling. |
| 2983 | def _run_cli_with_args( |
| 2984 | normand: str, |
| 2985 | offset: int, |
| 2986 | bo: Optional[ByteOrder], |
| 2987 | variables: VariablesT, |
| 2988 | labels: LabelsT, |
| 2989 | ): |
| 2990 | sys.stdout.buffer.write(parse(normand, variables, labels, offset, bo).data) |
| 2991 | |
| 2992 | |
| 2993 | # Prints the exception message `msg` and exits with status 1. |
| 2994 | def _fail(msg: str) -> NoReturn: |
| 2995 | if not msg.endswith("."): |
| 2996 | msg += "." |
| 2997 | |
| 2998 | print(msg.strip(), file=sys.stderr) |
| 2999 | sys.exit(1) |
| 3000 | |
| 3001 | |
| 3002 | # CLI entry point. |
| 3003 | def _run_cli(): |
| 3004 | try: |
| 3005 | args = _parse_cli_args() |
| 3006 | except Exception as exc: |
| 3007 | _fail(str(exc)) |
| 3008 | |
| 3009 | try: |
| 3010 | _run_cli_with_args(*args[1:]) |
| 3011 | except ParseError as exc: |
| 3012 | import os.path |
| 3013 | |
| 3014 | prefix = "" if args[0] is None else "{}:".format(os.path.abspath(args[0])) |
| 3015 | fail_msg = "" |
| 3016 | |
| 3017 | for msg in reversed(exc.messages): |
| 3018 | fail_msg += "{}{}:{} - {}".format( |
| 3019 | prefix, |
| 3020 | msg.text_location.line_no, |
| 3021 | msg.text_location.col_no, |
| 3022 | msg.text, |
| 3023 | ) |
| 3024 | |
| 3025 | if fail_msg[-1] not in ".:;": |
| 3026 | fail_msg += "." |
| 3027 | |
| 3028 | fail_msg += "\n" |
| 3029 | |
| 3030 | _fail(fail_msg.strip()) |
| 3031 | except Exception as exc: |
| 3032 | _fail(str(exc)) |
| 3033 | |
| 3034 | |
| 3035 | if __name__ == "__main__": |
| 3036 | _run_cli() |