| 1 | 'use strict'; |
| 2 | |
| 3 | //------------------------------------------------------------------------------ |
| 4 | // Requirements |
| 5 | //------------------------------------------------------------------------------ |
| 6 | |
| 7 | // eslint-disable-next-line |
| 8 | const CodePathSegment = require('./code-path-segment'); |
| 9 | // eslint-disable-next-line |
| 10 | const ForkContext = require('./fork-context'); |
| 11 | |
| 12 | //------------------------------------------------------------------------------ |
| 13 | // Helpers |
| 14 | //------------------------------------------------------------------------------ |
| 15 | |
| 16 | /** |
| 17 | * Adds given segments into the `dest` array. |
| 18 | * If the `others` array does not includes the given segments, adds to the `all` |
| 19 | * array as well. |
| 20 | * |
| 21 | * This adds only reachable and used segments. |
| 22 | * @param {CodePathSegment[]} dest A destination array (`returnedSegments` or `thrownSegments`). |
| 23 | * @param {CodePathSegment[]} others Another destination array (`returnedSegments` or `thrownSegments`). |
| 24 | * @param {CodePathSegment[]} all The unified destination array (`finalSegments`). |
| 25 | * @param {CodePathSegment[]} segments Segments to add. |
| 26 | * @returns {void} |
| 27 | */ |
| 28 | function addToReturnedOrThrown(dest, others, all, segments) { |
| 29 | for (let i = 0; i < segments.length; ++i) { |
| 30 | const segment = segments[i]; |
| 31 | |
| 32 | dest.push(segment); |
| 33 | if (!others.includes(segment)) { |
| 34 | all.push(segment); |
| 35 | } |
| 36 | } |
| 37 | } |
| 38 | |
| 39 | /** |
| 40 | * Gets a loop-context for a `continue` statement. |
| 41 | * @param {CodePathState} state A state to get. |
| 42 | * @param {string} label The label of a `continue` statement. |
| 43 | * @returns {LoopContext} A loop-context for a `continue` statement. |
| 44 | */ |
| 45 | function getContinueContext(state, label) { |
| 46 | if (!label) { |
| 47 | return state.loopContext; |
| 48 | } |
| 49 | |
| 50 | let context = state.loopContext; |
| 51 | |
| 52 | while (context) { |
| 53 | if (context.label === label) { |
| 54 | return context; |
| 55 | } |
| 56 | context = context.upper; |
| 57 | } |
| 58 | |
| 59 | /* c8 ignore next */ |
| 60 | return null; |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * Gets a context for a `break` statement. |
| 65 | * @param {CodePathState} state A state to get. |
| 66 | * @param {string} label The label of a `break` statement. |
| 67 | * @returns {LoopContext|SwitchContext} A context for a `break` statement. |
| 68 | */ |
| 69 | function getBreakContext(state, label) { |
| 70 | let context = state.breakContext; |
| 71 | |
| 72 | while (context) { |
| 73 | if (label ? context.label === label : context.breakable) { |
| 74 | return context; |
| 75 | } |
| 76 | context = context.upper; |
| 77 | } |
| 78 | |
| 79 | /* c8 ignore next */ |
| 80 | return null; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Gets a context for a `return` statement. |
| 85 | * @param {CodePathState} state A state to get. |
| 86 | * @returns {TryContext|CodePathState} A context for a `return` statement. |
| 87 | */ |
| 88 | function getReturnContext(state) { |
| 89 | let context = state.tryContext; |
| 90 | |
| 91 | while (context) { |
| 92 | if (context.hasFinalizer && context.position !== 'finally') { |
| 93 | return context; |
| 94 | } |
| 95 | context = context.upper; |
| 96 | } |
| 97 | |
| 98 | return state; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Gets a context for a `throw` statement. |
| 103 | * @param {CodePathState} state A state to get. |
| 104 | * @returns {TryContext|CodePathState} A context for a `throw` statement. |
| 105 | */ |
| 106 | function getThrowContext(state) { |
| 107 | let context = state.tryContext; |
| 108 | |
| 109 | while (context) { |
| 110 | if ( |
| 111 | context.position === 'try' || |
| 112 | (context.hasFinalizer && context.position === 'catch') |
| 113 | ) { |
| 114 | return context; |
| 115 | } |
| 116 | context = context.upper; |
| 117 | } |
| 118 | |
| 119 | return state; |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * Removes a given element from a given array. |
| 124 | * @param {any[]} xs An array to remove the specific element. |
| 125 | * @param {any} x An element to be removed. |
| 126 | * @returns {void} |
| 127 | */ |
| 128 | function remove(xs, x) { |
| 129 | xs.splice(xs.indexOf(x), 1); |
| 130 | } |
| 131 | |
| 132 | /** |
| 133 | * Disconnect given segments. |
| 134 | * |
| 135 | * This is used in a process for switch statements. |
| 136 | * If there is the "default" chunk before other cases, the order is different |
| 137 | * between node's and running's. |
| 138 | * @param {CodePathSegment[]} prevSegments Forward segments to disconnect. |
| 139 | * @param {CodePathSegment[]} nextSegments Backward segments to disconnect. |
| 140 | * @returns {void} |
| 141 | */ |
| 142 | function removeConnection(prevSegments, nextSegments) { |
| 143 | for (let i = 0; i < prevSegments.length; ++i) { |
| 144 | const prevSegment = prevSegments[i]; |
| 145 | const nextSegment = nextSegments[i]; |
| 146 | |
| 147 | remove(prevSegment.nextSegments, nextSegment); |
| 148 | remove(prevSegment.allNextSegments, nextSegment); |
| 149 | remove(nextSegment.prevSegments, prevSegment); |
| 150 | remove(nextSegment.allPrevSegments, prevSegment); |
| 151 | } |
| 152 | } |
| 153 | |
| 154 | /** |
| 155 | * Creates looping path. |
| 156 | * @param {CodePathState} state The instance. |
| 157 | * @param {CodePathSegment[]} unflattenedFromSegments Segments which are source. |
| 158 | * @param {CodePathSegment[]} unflattenedToSegments Segments which are destination. |
| 159 | * @returns {void} |
| 160 | */ |
| 161 | function makeLooped(state, unflattenedFromSegments, unflattenedToSegments) { |
| 162 | const fromSegments = CodePathSegment.flattenUnusedSegments( |
| 163 | unflattenedFromSegments, |
| 164 | ); |
| 165 | const toSegments = CodePathSegment.flattenUnusedSegments( |
| 166 | unflattenedToSegments, |
| 167 | ); |
| 168 | |
| 169 | const end = Math.min(fromSegments.length, toSegments.length); |
| 170 | |
| 171 | for (let i = 0; i < end; ++i) { |
| 172 | const fromSegment = fromSegments[i]; |
| 173 | const toSegment = toSegments[i]; |
| 174 | |
| 175 | if (toSegment.reachable) { |
| 176 | fromSegment.nextSegments.push(toSegment); |
| 177 | } |
| 178 | if (fromSegment.reachable) { |
| 179 | toSegment.prevSegments.push(fromSegment); |
| 180 | } |
| 181 | fromSegment.allNextSegments.push(toSegment); |
| 182 | toSegment.allPrevSegments.push(fromSegment); |
| 183 | |
| 184 | if (toSegment.allPrevSegments.length >= 2) { |
| 185 | CodePathSegment.markPrevSegmentAsLooped(toSegment, fromSegment); |
| 186 | } |
| 187 | |
| 188 | state.notifyLooped(fromSegment, toSegment); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * Finalizes segments of `test` chunk of a ForStatement. |
| 194 | * |
| 195 | * - Adds `false` paths to paths which are leaving from the loop. |
| 196 | * - Sets `true` paths to paths which go to the body. |
| 197 | * @param {LoopContext} context A loop context to modify. |
| 198 | * @param {ChoiceContext} choiceContext A choice context of this loop. |
| 199 | * @param {CodePathSegment[]} head The current head paths. |
| 200 | * @returns {void} |
| 201 | */ |
| 202 | function finalizeTestSegmentsOfFor(context, choiceContext, head) { |
| 203 | if (!choiceContext.processed) { |
| 204 | choiceContext.trueForkContext.add(head); |
| 205 | choiceContext.falseForkContext.add(head); |
| 206 | choiceContext.qqForkContext.add(head); |
| 207 | } |
| 208 | |
| 209 | if (context.test !== true) { |
| 210 | context.brokenForkContext.addAll(choiceContext.falseForkContext); |
| 211 | } |
| 212 | context.endOfTestSegments = choiceContext.trueForkContext.makeNext(0, -1); |
| 213 | } |
| 214 | |
| 215 | //------------------------------------------------------------------------------ |
| 216 | // Public Interface |
| 217 | //------------------------------------------------------------------------------ |
| 218 | |
| 219 | /** |
| 220 | * A class which manages state to analyze code paths. |
| 221 | */ |
| 222 | class CodePathState { |
| 223 | /** |
| 224 | * @param {IdGenerator} idGenerator An id generator to generate id for code |
| 225 | * path segments. |
| 226 | * @param {Function} onLooped A callback function to notify looping. |
| 227 | */ |
| 228 | constructor(idGenerator, onLooped) { |
| 229 | this.idGenerator = idGenerator; |
| 230 | this.notifyLooped = onLooped; |
| 231 | this.forkContext = ForkContext.newRoot(idGenerator); |
| 232 | this.choiceContext = null; |
| 233 | this.switchContext = null; |
| 234 | this.tryContext = null; |
| 235 | this.loopContext = null; |
| 236 | this.breakContext = null; |
| 237 | this.chainContext = null; |
| 238 | |
| 239 | this.currentSegments = []; |
| 240 | this.initialSegment = this.forkContext.head[0]; |
| 241 | |
| 242 | // returnedSegments and thrownSegments push elements into finalSegments also. |
| 243 | const final = (this.finalSegments = []); |
| 244 | const returned = (this.returnedForkContext = []); |
| 245 | const thrown = (this.thrownForkContext = []); |
| 246 | |
| 247 | returned.add = addToReturnedOrThrown.bind(null, returned, thrown, final); |
| 248 | thrown.add = addToReturnedOrThrown.bind(null, thrown, returned, final); |
| 249 | } |
| 250 | |
| 251 | /** |
| 252 | * The head segments. |
| 253 | * @type {CodePathSegment[]} |
| 254 | */ |
| 255 | get headSegments() { |
| 256 | return this.forkContext.head; |
| 257 | } |
| 258 | |
| 259 | /** |
| 260 | * The parent forking context. |
| 261 | * This is used for the root of new forks. |
| 262 | * @type {ForkContext} |
| 263 | */ |
| 264 | get parentForkContext() { |
| 265 | const current = this.forkContext; |
| 266 | |
| 267 | return current && current.upper; |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * Creates and stacks new forking context. |
| 272 | * @param {boolean} forkLeavingPath A flag which shows being in a |
| 273 | * "finally" block. |
| 274 | * @returns {ForkContext} The created context. |
| 275 | */ |
| 276 | pushForkContext(forkLeavingPath) { |
| 277 | this.forkContext = ForkContext.newEmpty(this.forkContext, forkLeavingPath); |
| 278 | |
| 279 | return this.forkContext; |
| 280 | } |
| 281 | |
| 282 | /** |
| 283 | * Pops and merges the last forking context. |
| 284 | * @returns {ForkContext} The last context. |
| 285 | */ |
| 286 | popForkContext() { |
| 287 | const lastContext = this.forkContext; |
| 288 | |
| 289 | this.forkContext = lastContext.upper; |
| 290 | this.forkContext.replaceHead(lastContext.makeNext(0, -1)); |
| 291 | |
| 292 | return lastContext; |
| 293 | } |
| 294 | |
| 295 | /** |
| 296 | * Creates a new path. |
| 297 | * @returns {void} |
| 298 | */ |
| 299 | forkPath() { |
| 300 | this.forkContext.add(this.parentForkContext.makeNext(-1, -1)); |
| 301 | } |
| 302 | |
| 303 | /** |
| 304 | * Creates a bypass path. |
| 305 | * This is used for such as IfStatement which does not have "else" chunk. |
| 306 | * @returns {void} |
| 307 | */ |
| 308 | forkBypassPath() { |
| 309 | this.forkContext.add(this.parentForkContext.head); |
| 310 | } |
| 311 | |
| 312 | //-------------------------------------------------------------------------- |
| 313 | // ConditionalExpression, LogicalExpression, IfStatement |
| 314 | //-------------------------------------------------------------------------- |
| 315 | |
| 316 | /** |
| 317 | * Creates a context for ConditionalExpression, LogicalExpression, AssignmentExpression (logical assignments only), |
| 318 | * IfStatement, WhileStatement, DoWhileStatement, or ForStatement. |
| 319 | * |
| 320 | * LogicalExpressions have cases that it goes different paths between the |
| 321 | * `true` case and the `false` case. |
| 322 | * |
| 323 | * For Example: |
| 324 | * |
| 325 | * if (a || b) { |
| 326 | * foo(); |
| 327 | * } else { |
| 328 | * bar(); |
| 329 | * } |
| 330 | * |
| 331 | * In this case, `b` is evaluated always in the code path of the `else` |
| 332 | * block, but it's not so in the code path of the `if` block. |
| 333 | * So there are 3 paths. |
| 334 | * |
| 335 | * a -> foo(); |
| 336 | * a -> b -> foo(); |
| 337 | * a -> b -> bar(); |
| 338 | * @param {string} kind A kind string. |
| 339 | * If the new context is LogicalExpression's or AssignmentExpression's, this is `"&&"` or `"||"` or `"??"`. |
| 340 | * If it's IfStatement's or ConditionalExpression's, this is `"test"`. |
| 341 | * Otherwise, this is `"loop"`. |
| 342 | * @param {boolean} isForkingAsResult A flag that shows that goes different |
| 343 | * paths between `true` and `false`. |
| 344 | * @returns {void} |
| 345 | */ |
| 346 | pushChoiceContext(kind, isForkingAsResult) { |
| 347 | this.choiceContext = { |
| 348 | upper: this.choiceContext, |
| 349 | kind, |
| 350 | isForkingAsResult, |
| 351 | trueForkContext: ForkContext.newEmpty(this.forkContext), |
| 352 | falseForkContext: ForkContext.newEmpty(this.forkContext), |
| 353 | qqForkContext: ForkContext.newEmpty(this.forkContext), |
| 354 | processed: false, |
| 355 | }; |
| 356 | } |
| 357 | |
| 358 | /** |
| 359 | * Pops the last choice context and finalizes it. |
| 360 | * @throws {Error} (Unreachable.) |
| 361 | * @returns {ChoiceContext} The popped context. |
| 362 | */ |
| 363 | popChoiceContext() { |
| 364 | const context = this.choiceContext; |
| 365 | |
| 366 | this.choiceContext = context.upper; |
| 367 | |
| 368 | const forkContext = this.forkContext; |
| 369 | const headSegments = forkContext.head; |
| 370 | |
| 371 | switch (context.kind) { |
| 372 | case '&&': |
| 373 | case '||': |
| 374 | case '??': |
| 375 | /* |
| 376 | * If any result were not transferred from child contexts, |
| 377 | * this sets the head segments to both cases. |
| 378 | * The head segments are the path of the right-hand operand. |
| 379 | */ |
| 380 | if (!context.processed) { |
| 381 | context.trueForkContext.add(headSegments); |
| 382 | context.falseForkContext.add(headSegments); |
| 383 | context.qqForkContext.add(headSegments); |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | * Transfers results to upper context if this context is in |
| 388 | * test chunk. |
| 389 | */ |
| 390 | if (context.isForkingAsResult) { |
| 391 | const parentContext = this.choiceContext; |
| 392 | |
| 393 | parentContext.trueForkContext.addAll(context.trueForkContext); |
| 394 | parentContext.falseForkContext.addAll(context.falseForkContext); |
| 395 | parentContext.qqForkContext.addAll(context.qqForkContext); |
| 396 | parentContext.processed = true; |
| 397 | |
| 398 | return context; |
| 399 | } |
| 400 | |
| 401 | break; |
| 402 | |
| 403 | case 'test': |
| 404 | if (!context.processed) { |
| 405 | /* |
| 406 | * The head segments are the path of the `if` block here. |
| 407 | * Updates the `true` path with the end of the `if` block. |
| 408 | */ |
| 409 | context.trueForkContext.clear(); |
| 410 | context.trueForkContext.add(headSegments); |
| 411 | } else { |
| 412 | /* |
| 413 | * The head segments are the path of the `else` block here. |
| 414 | * Updates the `false` path with the end of the `else` |
| 415 | * block. |
| 416 | */ |
| 417 | context.falseForkContext.clear(); |
| 418 | context.falseForkContext.add(headSegments); |
| 419 | } |
| 420 | |
| 421 | break; |
| 422 | |
| 423 | case 'loop': |
| 424 | /* |
| 425 | * Loops are addressed in popLoopContext(). |
| 426 | * This is called from popLoopContext(). |
| 427 | */ |
| 428 | return context; |
| 429 | |
| 430 | /* c8 ignore next */ |
| 431 | default: |
| 432 | throw new Error('unreachable'); |
| 433 | } |
| 434 | |
| 435 | // Merges all paths. |
| 436 | const prevForkContext = context.trueForkContext; |
| 437 | |
| 438 | prevForkContext.addAll(context.falseForkContext); |
| 439 | forkContext.replaceHead(prevForkContext.makeNext(0, -1)); |
| 440 | |
| 441 | return context; |
| 442 | } |
| 443 | |
| 444 | /** |
| 445 | * Makes a code path segment of the right-hand operand of a logical |
| 446 | * expression. |
| 447 | * @throws {Error} (Unreachable.) |
| 448 | * @returns {void} |
| 449 | */ |
| 450 | makeLogicalRight() { |
| 451 | const context = this.choiceContext; |
| 452 | const forkContext = this.forkContext; |
| 453 | |
| 454 | if (context.processed) { |
| 455 | /* |
| 456 | * This got segments already from the child choice context. |
| 457 | * Creates the next path from own true/false fork context. |
| 458 | */ |
| 459 | let prevForkContext; |
| 460 | |
| 461 | switch (context.kind) { |
| 462 | case '&&': // if true then go to the right-hand side. |
| 463 | prevForkContext = context.trueForkContext; |
| 464 | break; |
| 465 | case '||': // if false then go to the right-hand side. |
| 466 | prevForkContext = context.falseForkContext; |
| 467 | break; |
| 468 | case '??': // Both true/false can short-circuit, so needs the third path to go to the right-hand side. That's qqForkContext. |
| 469 | prevForkContext = context.qqForkContext; |
| 470 | break; |
| 471 | default: |
| 472 | throw new Error('unreachable'); |
| 473 | } |
| 474 | |
| 475 | forkContext.replaceHead(prevForkContext.makeNext(0, -1)); |
| 476 | prevForkContext.clear(); |
| 477 | context.processed = false; |
| 478 | } else { |
| 479 | /* |
| 480 | * This did not get segments from the child choice context. |
| 481 | * So addresses the head segments. |
| 482 | * The head segments are the path of the left-hand operand. |
| 483 | */ |
| 484 | switch (context.kind) { |
| 485 | case '&&': // the false path can short-circuit. |
| 486 | context.falseForkContext.add(forkContext.head); |
| 487 | break; |
| 488 | case '||': // the true path can short-circuit. |
| 489 | context.trueForkContext.add(forkContext.head); |
| 490 | break; |
| 491 | case '??': // both can short-circuit. |
| 492 | context.trueForkContext.add(forkContext.head); |
| 493 | context.falseForkContext.add(forkContext.head); |
| 494 | break; |
| 495 | default: |
| 496 | throw new Error('unreachable'); |
| 497 | } |
| 498 | |
| 499 | forkContext.replaceHead(forkContext.makeNext(-1, -1)); |
| 500 | } |
| 501 | } |
| 502 | |
| 503 | /** |
| 504 | * Makes a code path segment of the `if` block. |
| 505 | * @returns {void} |
| 506 | */ |
| 507 | makeIfConsequent() { |
| 508 | const context = this.choiceContext; |
| 509 | const forkContext = this.forkContext; |
| 510 | |
| 511 | /* |
| 512 | * If any result were not transferred from child contexts, |
| 513 | * this sets the head segments to both cases. |
| 514 | * The head segments are the path of the test expression. |
| 515 | */ |
| 516 | if (!context.processed) { |
| 517 | context.trueForkContext.add(forkContext.head); |
| 518 | context.falseForkContext.add(forkContext.head); |
| 519 | context.qqForkContext.add(forkContext.head); |
| 520 | } |
| 521 | |
| 522 | context.processed = false; |
| 523 | |
| 524 | // Creates new path from the `true` case. |
| 525 | forkContext.replaceHead(context.trueForkContext.makeNext(0, -1)); |
| 526 | } |
| 527 | |
| 528 | /** |
| 529 | * Makes a code path segment of the `else` block. |
| 530 | * @returns {void} |
| 531 | */ |
| 532 | makeIfAlternate() { |
| 533 | const context = this.choiceContext; |
| 534 | const forkContext = this.forkContext; |
| 535 | |
| 536 | /* |
| 537 | * The head segments are the path of the `if` block. |
| 538 | * Updates the `true` path with the end of the `if` block. |
| 539 | */ |
| 540 | context.trueForkContext.clear(); |
| 541 | context.trueForkContext.add(forkContext.head); |
| 542 | context.processed = true; |
| 543 | |
| 544 | // Creates new path from the `false` case. |
| 545 | forkContext.replaceHead(context.falseForkContext.makeNext(0, -1)); |
| 546 | } |
| 547 | |
| 548 | //-------------------------------------------------------------------------- |
| 549 | // ChainExpression |
| 550 | //-------------------------------------------------------------------------- |
| 551 | |
| 552 | /** |
| 553 | * Push a new `ChainExpression` context to the stack. |
| 554 | * This method is called on entering to each `ChainExpression` node. |
| 555 | * This context is used to count forking in the optional chain then merge them on the exiting from the `ChainExpression` node. |
| 556 | * @returns {void} |
| 557 | */ |
| 558 | pushChainContext() { |
| 559 | this.chainContext = { |
| 560 | upper: this.chainContext, |
| 561 | countChoiceContexts: 0, |
| 562 | }; |
| 563 | } |
| 564 | |
| 565 | /** |
| 566 | * Pop a `ChainExpression` context from the stack. |
| 567 | * This method is called on exiting from each `ChainExpression` node. |
| 568 | * This merges all forks of the last optional chaining. |
| 569 | * @returns {void} |
| 570 | */ |
| 571 | popChainContext() { |
| 572 | const context = this.chainContext; |
| 573 | |
| 574 | this.chainContext = context.upper; |
| 575 | |
| 576 | // pop all choice contexts of this. |
| 577 | for (let i = context.countChoiceContexts; i > 0; --i) { |
| 578 | this.popChoiceContext(); |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | /** |
| 583 | * Create a choice context for optional access. |
| 584 | * This method is called on entering to each `(Call|Member)Expression[optional=true]` node. |
| 585 | * This creates a choice context as similar to `LogicalExpression[operator="??"]` node. |
| 586 | * @returns {void} |
| 587 | */ |
| 588 | makeOptionalNode() { |
| 589 | if (this.chainContext) { |
| 590 | this.chainContext.countChoiceContexts += 1; |
| 591 | this.pushChoiceContext('??', false); |
| 592 | } |
| 593 | } |
| 594 | |
| 595 | /** |
| 596 | * Create a fork. |
| 597 | * This method is called on entering to the `arguments|property` property of each `(Call|Member)Expression` node. |
| 598 | * @returns {void} |
| 599 | */ |
| 600 | makeOptionalRight() { |
| 601 | if (this.chainContext) { |
| 602 | this.makeLogicalRight(); |
| 603 | } |
| 604 | } |
| 605 | |
| 606 | //-------------------------------------------------------------------------- |
| 607 | // SwitchStatement |
| 608 | //-------------------------------------------------------------------------- |
| 609 | |
| 610 | /** |
| 611 | * Creates a context object of SwitchStatement and stacks it. |
| 612 | * @param {boolean} hasCase `true` if the switch statement has one or more |
| 613 | * case parts. |
| 614 | * @param {string|null} label The label text. |
| 615 | * @returns {void} |
| 616 | */ |
| 617 | pushSwitchContext(hasCase, label) { |
| 618 | this.switchContext = { |
| 619 | upper: this.switchContext, |
| 620 | hasCase, |
| 621 | defaultSegments: null, |
| 622 | defaultBodySegments: null, |
| 623 | foundDefault: false, |
| 624 | lastIsDefault: false, |
| 625 | countForks: 0, |
| 626 | }; |
| 627 | |
| 628 | this.pushBreakContext(true, label); |
| 629 | } |
| 630 | |
| 631 | /** |
| 632 | * Pops the last context of SwitchStatement and finalizes it. |
| 633 | * |
| 634 | * - Disposes all forking stack for `case` and `default`. |
| 635 | * - Creates the next code path segment from `context.brokenForkContext`. |
| 636 | * - If the last `SwitchCase` node is not a `default` part, creates a path |
| 637 | * to the `default` body. |
| 638 | * @returns {void} |
| 639 | */ |
| 640 | popSwitchContext() { |
| 641 | const context = this.switchContext; |
| 642 | |
| 643 | this.switchContext = context.upper; |
| 644 | |
| 645 | const forkContext = this.forkContext; |
| 646 | const brokenForkContext = this.popBreakContext().brokenForkContext; |
| 647 | |
| 648 | if (context.countForks === 0) { |
| 649 | /* |
| 650 | * When there is only one `default` chunk and there is one or more |
| 651 | * `break` statements, even if forks are nothing, it needs to merge |
| 652 | * those. |
| 653 | */ |
| 654 | if (!brokenForkContext.empty) { |
| 655 | brokenForkContext.add(forkContext.makeNext(-1, -1)); |
| 656 | forkContext.replaceHead(brokenForkContext.makeNext(0, -1)); |
| 657 | } |
| 658 | |
| 659 | return; |
| 660 | } |
| 661 | |
| 662 | const lastSegments = forkContext.head; |
| 663 | |
| 664 | this.forkBypassPath(); |
| 665 | const lastCaseSegments = forkContext.head; |
| 666 | |
| 667 | /* |
| 668 | * `brokenForkContext` is used to make the next segment. |
| 669 | * It must add the last segment into `brokenForkContext`. |
| 670 | */ |
| 671 | brokenForkContext.add(lastSegments); |
| 672 | |
| 673 | /* |
| 674 | * A path which is failed in all case test should be connected to path |
| 675 | * of `default` chunk. |
| 676 | */ |
| 677 | if (!context.lastIsDefault) { |
| 678 | if (context.defaultBodySegments) { |
| 679 | /* |
| 680 | * Remove a link from `default` label to its chunk. |
| 681 | * It's false route. |
| 682 | */ |
| 683 | removeConnection(context.defaultSegments, context.defaultBodySegments); |
| 684 | makeLooped(this, lastCaseSegments, context.defaultBodySegments); |
| 685 | } else { |
| 686 | /* |
| 687 | * It handles the last case body as broken if `default` chunk |
| 688 | * does not exist. |
| 689 | */ |
| 690 | brokenForkContext.add(lastCaseSegments); |
| 691 | } |
| 692 | } |
| 693 | |
| 694 | // Pops the segment context stack until the entry segment. |
| 695 | for (let i = 0; i < context.countForks; ++i) { |
| 696 | this.forkContext = this.forkContext.upper; |
| 697 | } |
| 698 | |
| 699 | /* |
| 700 | * Creates a path from all brokenForkContext paths. |
| 701 | * This is a path after switch statement. |
| 702 | */ |
| 703 | this.forkContext.replaceHead(brokenForkContext.makeNext(0, -1)); |
| 704 | } |
| 705 | |
| 706 | /** |
| 707 | * Makes a code path segment for a `SwitchCase` node. |
| 708 | * @param {boolean} isEmpty `true` if the body is empty. |
| 709 | * @param {boolean} isDefault `true` if the body is the default case. |
| 710 | * @returns {void} |
| 711 | */ |
| 712 | makeSwitchCaseBody(isEmpty, isDefault) { |
| 713 | const context = this.switchContext; |
| 714 | |
| 715 | if (!context.hasCase) { |
| 716 | return; |
| 717 | } |
| 718 | |
| 719 | /* |
| 720 | * Merge forks. |
| 721 | * The parent fork context has two segments. |
| 722 | * Those are from the current case and the body of the previous case. |
| 723 | */ |
| 724 | const parentForkContext = this.forkContext; |
| 725 | const forkContext = this.pushForkContext(); |
| 726 | |
| 727 | forkContext.add(parentForkContext.makeNext(0, -1)); |
| 728 | |
| 729 | /* |
| 730 | * Save `default` chunk info. |
| 731 | * If the `default` label is not at the last, we must make a path from |
| 732 | * the last `case` to the `default` chunk. |
| 733 | */ |
| 734 | if (isDefault) { |
| 735 | context.defaultSegments = parentForkContext.head; |
| 736 | if (isEmpty) { |
| 737 | context.foundDefault = true; |
| 738 | } else { |
| 739 | context.defaultBodySegments = forkContext.head; |
| 740 | } |
| 741 | } else { |
| 742 | if (!isEmpty && context.foundDefault) { |
| 743 | context.foundDefault = false; |
| 744 | context.defaultBodySegments = forkContext.head; |
| 745 | } |
| 746 | } |
| 747 | |
| 748 | context.lastIsDefault = isDefault; |
| 749 | context.countForks += 1; |
| 750 | } |
| 751 | |
| 752 | //-------------------------------------------------------------------------- |
| 753 | // TryStatement |
| 754 | //-------------------------------------------------------------------------- |
| 755 | |
| 756 | /** |
| 757 | * Creates a context object of TryStatement and stacks it. |
| 758 | * @param {boolean} hasFinalizer `true` if the try statement has a |
| 759 | * `finally` block. |
| 760 | * @returns {void} |
| 761 | */ |
| 762 | pushTryContext(hasFinalizer) { |
| 763 | this.tryContext = { |
| 764 | upper: this.tryContext, |
| 765 | position: 'try', |
| 766 | hasFinalizer, |
| 767 | |
| 768 | returnedForkContext: hasFinalizer |
| 769 | ? ForkContext.newEmpty(this.forkContext) |
| 770 | : null, |
| 771 | |
| 772 | thrownForkContext: ForkContext.newEmpty(this.forkContext), |
| 773 | lastOfTryIsReachable: false, |
| 774 | lastOfCatchIsReachable: false, |
| 775 | }; |
| 776 | } |
| 777 | |
| 778 | /** |
| 779 | * Pops the last context of TryStatement and finalizes it. |
| 780 | * @returns {void} |
| 781 | */ |
| 782 | popTryContext() { |
| 783 | const context = this.tryContext; |
| 784 | |
| 785 | this.tryContext = context.upper; |
| 786 | |
| 787 | if (context.position === 'catch') { |
| 788 | // Merges two paths from the `try` block and `catch` block merely. |
| 789 | this.popForkContext(); |
| 790 | return; |
| 791 | } |
| 792 | |
| 793 | /* |
| 794 | * The following process is executed only when there is the `finally` |
| 795 | * block. |
| 796 | */ |
| 797 | |
| 798 | const returned = context.returnedForkContext; |
| 799 | const thrown = context.thrownForkContext; |
| 800 | |
| 801 | if (returned.empty && thrown.empty) { |
| 802 | return; |
| 803 | } |
| 804 | |
| 805 | // Separate head to normal paths and leaving paths. |
| 806 | const headSegments = this.forkContext.head; |
| 807 | |
| 808 | this.forkContext = this.forkContext.upper; |
| 809 | const normalSegments = headSegments.slice(0, (headSegments.length / 2) | 0); |
| 810 | const leavingSegments = headSegments.slice((headSegments.length / 2) | 0); |
| 811 | |
| 812 | // Forwards the leaving path to upper contexts. |
| 813 | if (!returned.empty) { |
| 814 | getReturnContext(this).returnedForkContext.add(leavingSegments); |
| 815 | } |
| 816 | if (!thrown.empty) { |
| 817 | getThrowContext(this).thrownForkContext.add(leavingSegments); |
| 818 | } |
| 819 | |
| 820 | // Sets the normal path as the next. |
| 821 | this.forkContext.replaceHead(normalSegments); |
| 822 | |
| 823 | /* |
| 824 | * If both paths of the `try` block and the `catch` block are |
| 825 | * unreachable, the next path becomes unreachable as well. |
| 826 | */ |
| 827 | if (!context.lastOfTryIsReachable && !context.lastOfCatchIsReachable) { |
| 828 | this.forkContext.makeUnreachable(); |
| 829 | } |
| 830 | } |
| 831 | |
| 832 | /** |
| 833 | * Makes a code path segment for a `catch` block. |
| 834 | * @returns {void} |
| 835 | */ |
| 836 | makeCatchBlock() { |
| 837 | const context = this.tryContext; |
| 838 | const forkContext = this.forkContext; |
| 839 | const thrown = context.thrownForkContext; |
| 840 | |
| 841 | // Update state. |
| 842 | context.position = 'catch'; |
| 843 | context.thrownForkContext = ForkContext.newEmpty(forkContext); |
| 844 | context.lastOfTryIsReachable = forkContext.reachable; |
| 845 | |
| 846 | // Merge thrown paths. |
| 847 | thrown.add(forkContext.head); |
| 848 | const thrownSegments = thrown.makeNext(0, -1); |
| 849 | |
| 850 | // Fork to a bypass and the merged thrown path. |
| 851 | this.pushForkContext(); |
| 852 | this.forkBypassPath(); |
| 853 | this.forkContext.add(thrownSegments); |
| 854 | } |
| 855 | |
| 856 | /** |
| 857 | * Makes a code path segment for a `finally` block. |
| 858 | * |
| 859 | * In the `finally` block, parallel paths are created. The parallel paths |
| 860 | * are used as leaving-paths. The leaving-paths are paths from `return` |
| 861 | * statements and `throw` statements in a `try` block or a `catch` block. |
| 862 | * @returns {void} |
| 863 | */ |
| 864 | makeFinallyBlock() { |
| 865 | const context = this.tryContext; |
| 866 | let forkContext = this.forkContext; |
| 867 | const returned = context.returnedForkContext; |
| 868 | const thrown = context.thrownForkContext; |
| 869 | const headOfLeavingSegments = forkContext.head; |
| 870 | |
| 871 | // Update state. |
| 872 | if (context.position === 'catch') { |
| 873 | // Merges two paths from the `try` block and `catch` block. |
| 874 | this.popForkContext(); |
| 875 | forkContext = this.forkContext; |
| 876 | |
| 877 | context.lastOfCatchIsReachable = forkContext.reachable; |
| 878 | } else { |
| 879 | context.lastOfTryIsReachable = forkContext.reachable; |
| 880 | } |
| 881 | context.position = 'finally'; |
| 882 | |
| 883 | if (returned.empty && thrown.empty) { |
| 884 | // This path does not leave. |
| 885 | return; |
| 886 | } |
| 887 | |
| 888 | /* |
| 889 | * Create a parallel segment from merging returned and thrown. |
| 890 | * This segment will leave at the end of this finally block. |
| 891 | */ |
| 892 | const segments = forkContext.makeNext(-1, -1); |
| 893 | |
| 894 | for (let i = 0; i < forkContext.count; ++i) { |
| 895 | const prevSegsOfLeavingSegment = [headOfLeavingSegments[i]]; |
| 896 | |
| 897 | for (let j = 0; j < returned.segmentsList.length; ++j) { |
| 898 | prevSegsOfLeavingSegment.push(returned.segmentsList[j][i]); |
| 899 | } |
| 900 | for (let j = 0; j < thrown.segmentsList.length; ++j) { |
| 901 | prevSegsOfLeavingSegment.push(thrown.segmentsList[j][i]); |
| 902 | } |
| 903 | |
| 904 | segments.push( |
| 905 | CodePathSegment.newNext( |
| 906 | this.idGenerator.next(), |
| 907 | prevSegsOfLeavingSegment, |
| 908 | ), |
| 909 | ); |
| 910 | } |
| 911 | |
| 912 | this.pushForkContext(true); |
| 913 | this.forkContext.add(segments); |
| 914 | } |
| 915 | |
| 916 | /** |
| 917 | * Makes a code path segment from the first throwable node to the `catch` |
| 918 | * block or the `finally` block. |
| 919 | * @returns {void} |
| 920 | */ |
| 921 | makeFirstThrowablePathInTryBlock() { |
| 922 | const forkContext = this.forkContext; |
| 923 | |
| 924 | if (!forkContext.reachable) { |
| 925 | return; |
| 926 | } |
| 927 | |
| 928 | const context = getThrowContext(this); |
| 929 | |
| 930 | if ( |
| 931 | context === this || |
| 932 | context.position !== 'try' || |
| 933 | !context.thrownForkContext.empty |
| 934 | ) { |
| 935 | return; |
| 936 | } |
| 937 | |
| 938 | context.thrownForkContext.add(forkContext.head); |
| 939 | forkContext.replaceHead(forkContext.makeNext(-1, -1)); |
| 940 | } |
| 941 | |
| 942 | //-------------------------------------------------------------------------- |
| 943 | // Loop Statements |
| 944 | //-------------------------------------------------------------------------- |
| 945 | |
| 946 | /** |
| 947 | * Creates a context object of a loop statement and stacks it. |
| 948 | * @param {string} type The type of the node which was triggered. One of |
| 949 | * `WhileStatement`, `DoWhileStatement`, `ForStatement`, `ForInStatement`, |
| 950 | * and `ForStatement`. |
| 951 | * @param {string|null} label A label of the node which was triggered. |
| 952 | * @throws {Error} (Unreachable - unknown type.) |
| 953 | * @returns {void} |
| 954 | */ |
| 955 | pushLoopContext(type, label) { |
| 956 | const forkContext = this.forkContext; |
| 957 | const breakContext = this.pushBreakContext(true, label); |
| 958 | |
| 959 | switch (type) { |
| 960 | case 'WhileStatement': |
| 961 | this.pushChoiceContext('loop', false); |
| 962 | this.loopContext = { |
| 963 | upper: this.loopContext, |
| 964 | type, |
| 965 | label, |
| 966 | test: void 0, |
| 967 | continueDestSegments: null, |
| 968 | brokenForkContext: breakContext.brokenForkContext, |
| 969 | }; |
| 970 | break; |
| 971 | |
| 972 | case 'DoWhileStatement': |
| 973 | this.pushChoiceContext('loop', false); |
| 974 | this.loopContext = { |
| 975 | upper: this.loopContext, |
| 976 | type, |
| 977 | label, |
| 978 | test: void 0, |
| 979 | entrySegments: null, |
| 980 | continueForkContext: ForkContext.newEmpty(forkContext), |
| 981 | brokenForkContext: breakContext.brokenForkContext, |
| 982 | }; |
| 983 | break; |
| 984 | |
| 985 | case 'ForStatement': |
| 986 | this.pushChoiceContext('loop', false); |
| 987 | this.loopContext = { |
| 988 | upper: this.loopContext, |
| 989 | type, |
| 990 | label, |
| 991 | test: void 0, |
| 992 | endOfInitSegments: null, |
| 993 | testSegments: null, |
| 994 | endOfTestSegments: null, |
| 995 | updateSegments: null, |
| 996 | endOfUpdateSegments: null, |
| 997 | continueDestSegments: null, |
| 998 | brokenForkContext: breakContext.brokenForkContext, |
| 999 | }; |
| 1000 | break; |
| 1001 | |
| 1002 | case 'ForInStatement': |
| 1003 | case 'ForOfStatement': |
| 1004 | this.loopContext = { |
| 1005 | upper: this.loopContext, |
| 1006 | type, |
| 1007 | label, |
| 1008 | prevSegments: null, |
| 1009 | leftSegments: null, |
| 1010 | endOfLeftSegments: null, |
| 1011 | continueDestSegments: null, |
| 1012 | brokenForkContext: breakContext.brokenForkContext, |
| 1013 | }; |
| 1014 | break; |
| 1015 | |
| 1016 | /* c8 ignore next */ |
| 1017 | default: |
| 1018 | throw new Error(`unknown type: "${type}"`); |
| 1019 | } |
| 1020 | } |
| 1021 | |
| 1022 | /** |
| 1023 | * Pops the last context of a loop statement and finalizes it. |
| 1024 | * @throws {Error} (Unreachable - unknown type.) |
| 1025 | * @returns {void} |
| 1026 | */ |
| 1027 | popLoopContext() { |
| 1028 | const context = this.loopContext; |
| 1029 | |
| 1030 | this.loopContext = context.upper; |
| 1031 | |
| 1032 | const forkContext = this.forkContext; |
| 1033 | const brokenForkContext = this.popBreakContext().brokenForkContext; |
| 1034 | |
| 1035 | // Creates a looped path. |
| 1036 | switch (context.type) { |
| 1037 | case 'WhileStatement': |
| 1038 | case 'ForStatement': |
| 1039 | this.popChoiceContext(); |
| 1040 | makeLooped(this, forkContext.head, context.continueDestSegments); |
| 1041 | break; |
| 1042 | |
| 1043 | case 'DoWhileStatement': { |
| 1044 | const choiceContext = this.popChoiceContext(); |
| 1045 | |
| 1046 | if (!choiceContext.processed) { |
| 1047 | choiceContext.trueForkContext.add(forkContext.head); |
| 1048 | choiceContext.falseForkContext.add(forkContext.head); |
| 1049 | } |
| 1050 | if (context.test !== true) { |
| 1051 | brokenForkContext.addAll(choiceContext.falseForkContext); |
| 1052 | } |
| 1053 | |
| 1054 | // `true` paths go to looping. |
| 1055 | const segmentsList = choiceContext.trueForkContext.segmentsList; |
| 1056 | |
| 1057 | for (let i = 0; i < segmentsList.length; ++i) { |
| 1058 | makeLooped(this, segmentsList[i], context.entrySegments); |
| 1059 | } |
| 1060 | break; |
| 1061 | } |
| 1062 | |
| 1063 | case 'ForInStatement': |
| 1064 | case 'ForOfStatement': |
| 1065 | brokenForkContext.add(forkContext.head); |
| 1066 | makeLooped(this, forkContext.head, context.leftSegments); |
| 1067 | break; |
| 1068 | |
| 1069 | /* c8 ignore next */ |
| 1070 | default: |
| 1071 | throw new Error('unreachable'); |
| 1072 | } |
| 1073 | |
| 1074 | // Go next. |
| 1075 | if (brokenForkContext.empty) { |
| 1076 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1)); |
| 1077 | } else { |
| 1078 | forkContext.replaceHead(brokenForkContext.makeNext(0, -1)); |
| 1079 | } |
| 1080 | } |
| 1081 | |
| 1082 | /** |
| 1083 | * Makes a code path segment for the test part of a WhileStatement. |
| 1084 | * @param {boolean|undefined} test The test value (only when constant). |
| 1085 | * @returns {void} |
| 1086 | */ |
| 1087 | makeWhileTest(test) { |
| 1088 | const context = this.loopContext; |
| 1089 | const forkContext = this.forkContext; |
| 1090 | const testSegments = forkContext.makeNext(0, -1); |
| 1091 | |
| 1092 | // Update state. |
| 1093 | context.test = test; |
| 1094 | context.continueDestSegments = testSegments; |
| 1095 | forkContext.replaceHead(testSegments); |
| 1096 | } |
| 1097 | |
| 1098 | /** |
| 1099 | * Makes a code path segment for the body part of a WhileStatement. |
| 1100 | * @returns {void} |
| 1101 | */ |
| 1102 | makeWhileBody() { |
| 1103 | const context = this.loopContext; |
| 1104 | const choiceContext = this.choiceContext; |
| 1105 | const forkContext = this.forkContext; |
| 1106 | |
| 1107 | if (!choiceContext.processed) { |
| 1108 | choiceContext.trueForkContext.add(forkContext.head); |
| 1109 | choiceContext.falseForkContext.add(forkContext.head); |
| 1110 | } |
| 1111 | |
| 1112 | // Update state. |
| 1113 | if (context.test !== true) { |
| 1114 | context.brokenForkContext.addAll(choiceContext.falseForkContext); |
| 1115 | } |
| 1116 | forkContext.replaceHead(choiceContext.trueForkContext.makeNext(0, -1)); |
| 1117 | } |
| 1118 | |
| 1119 | /** |
| 1120 | * Makes a code path segment for the body part of a DoWhileStatement. |
| 1121 | * @returns {void} |
| 1122 | */ |
| 1123 | makeDoWhileBody() { |
| 1124 | const context = this.loopContext; |
| 1125 | const forkContext = this.forkContext; |
| 1126 | const bodySegments = forkContext.makeNext(-1, -1); |
| 1127 | |
| 1128 | // Update state. |
| 1129 | context.entrySegments = bodySegments; |
| 1130 | forkContext.replaceHead(bodySegments); |
| 1131 | } |
| 1132 | |
| 1133 | /** |
| 1134 | * Makes a code path segment for the test part of a DoWhileStatement. |
| 1135 | * @param {boolean|undefined} test The test value (only when constant). |
| 1136 | * @returns {void} |
| 1137 | */ |
| 1138 | makeDoWhileTest(test) { |
| 1139 | const context = this.loopContext; |
| 1140 | const forkContext = this.forkContext; |
| 1141 | |
| 1142 | context.test = test; |
| 1143 | |
| 1144 | // Creates paths of `continue` statements. |
| 1145 | if (!context.continueForkContext.empty) { |
| 1146 | context.continueForkContext.add(forkContext.head); |
| 1147 | const testSegments = context.continueForkContext.makeNext(0, -1); |
| 1148 | |
| 1149 | forkContext.replaceHead(testSegments); |
| 1150 | } |
| 1151 | } |
| 1152 | |
| 1153 | /** |
| 1154 | * Makes a code path segment for the test part of a ForStatement. |
| 1155 | * @param {boolean|undefined} test The test value (only when constant). |
| 1156 | * @returns {void} |
| 1157 | */ |
| 1158 | makeForTest(test) { |
| 1159 | const context = this.loopContext; |
| 1160 | const forkContext = this.forkContext; |
| 1161 | const endOfInitSegments = forkContext.head; |
| 1162 | const testSegments = forkContext.makeNext(-1, -1); |
| 1163 | |
| 1164 | // Update state. |
| 1165 | context.test = test; |
| 1166 | context.endOfInitSegments = endOfInitSegments; |
| 1167 | context.continueDestSegments = context.testSegments = testSegments; |
| 1168 | forkContext.replaceHead(testSegments); |
| 1169 | } |
| 1170 | |
| 1171 | /** |
| 1172 | * Makes a code path segment for the update part of a ForStatement. |
| 1173 | * @returns {void} |
| 1174 | */ |
| 1175 | makeForUpdate() { |
| 1176 | const context = this.loopContext; |
| 1177 | const choiceContext = this.choiceContext; |
| 1178 | const forkContext = this.forkContext; |
| 1179 | |
| 1180 | // Make the next paths of the test. |
| 1181 | if (context.testSegments) { |
| 1182 | finalizeTestSegmentsOfFor(context, choiceContext, forkContext.head); |
| 1183 | } else { |
| 1184 | context.endOfInitSegments = forkContext.head; |
| 1185 | } |
| 1186 | |
| 1187 | // Update state. |
| 1188 | const updateSegments = forkContext.makeDisconnected(-1, -1); |
| 1189 | |
| 1190 | context.continueDestSegments = context.updateSegments = updateSegments; |
| 1191 | forkContext.replaceHead(updateSegments); |
| 1192 | } |
| 1193 | |
| 1194 | /** |
| 1195 | * Makes a code path segment for the body part of a ForStatement. |
| 1196 | * @returns {void} |
| 1197 | */ |
| 1198 | makeForBody() { |
| 1199 | const context = this.loopContext; |
| 1200 | const choiceContext = this.choiceContext; |
| 1201 | const forkContext = this.forkContext; |
| 1202 | |
| 1203 | // Update state. |
| 1204 | if (context.updateSegments) { |
| 1205 | context.endOfUpdateSegments = forkContext.head; |
| 1206 | |
| 1207 | // `update` -> `test` |
| 1208 | if (context.testSegments) { |
| 1209 | makeLooped(this, context.endOfUpdateSegments, context.testSegments); |
| 1210 | } |
| 1211 | } else if (context.testSegments) { |
| 1212 | finalizeTestSegmentsOfFor(context, choiceContext, forkContext.head); |
| 1213 | } else { |
| 1214 | context.endOfInitSegments = forkContext.head; |
| 1215 | } |
| 1216 | |
| 1217 | let bodySegments = context.endOfTestSegments; |
| 1218 | |
| 1219 | if (!bodySegments) { |
| 1220 | /* |
| 1221 | * If there is not the `test` part, the `body` path comes from the |
| 1222 | * `init` part and the `update` part. |
| 1223 | */ |
| 1224 | const prevForkContext = ForkContext.newEmpty(forkContext); |
| 1225 | |
| 1226 | prevForkContext.add(context.endOfInitSegments); |
| 1227 | if (context.endOfUpdateSegments) { |
| 1228 | prevForkContext.add(context.endOfUpdateSegments); |
| 1229 | } |
| 1230 | |
| 1231 | bodySegments = prevForkContext.makeNext(0, -1); |
| 1232 | } |
| 1233 | context.continueDestSegments = context.continueDestSegments || bodySegments; |
| 1234 | forkContext.replaceHead(bodySegments); |
| 1235 | } |
| 1236 | |
| 1237 | /** |
| 1238 | * Makes a code path segment for the left part of a ForInStatement and a |
| 1239 | * ForOfStatement. |
| 1240 | * @returns {void} |
| 1241 | */ |
| 1242 | makeForInOfLeft() { |
| 1243 | const context = this.loopContext; |
| 1244 | const forkContext = this.forkContext; |
| 1245 | const leftSegments = forkContext.makeDisconnected(-1, -1); |
| 1246 | |
| 1247 | // Update state. |
| 1248 | context.prevSegments = forkContext.head; |
| 1249 | context.leftSegments = context.continueDestSegments = leftSegments; |
| 1250 | forkContext.replaceHead(leftSegments); |
| 1251 | } |
| 1252 | |
| 1253 | /** |
| 1254 | * Makes a code path segment for the right part of a ForInStatement and a |
| 1255 | * ForOfStatement. |
| 1256 | * @returns {void} |
| 1257 | */ |
| 1258 | makeForInOfRight() { |
| 1259 | const context = this.loopContext; |
| 1260 | const forkContext = this.forkContext; |
| 1261 | const temp = ForkContext.newEmpty(forkContext); |
| 1262 | |
| 1263 | temp.add(context.prevSegments); |
| 1264 | const rightSegments = temp.makeNext(-1, -1); |
| 1265 | |
| 1266 | // Update state. |
| 1267 | context.endOfLeftSegments = forkContext.head; |
| 1268 | forkContext.replaceHead(rightSegments); |
| 1269 | } |
| 1270 | |
| 1271 | /** |
| 1272 | * Makes a code path segment for the body part of a ForInStatement and a |
| 1273 | * ForOfStatement. |
| 1274 | * @returns {void} |
| 1275 | */ |
| 1276 | makeForInOfBody() { |
| 1277 | const context = this.loopContext; |
| 1278 | const forkContext = this.forkContext; |
| 1279 | const temp = ForkContext.newEmpty(forkContext); |
| 1280 | |
| 1281 | temp.add(context.endOfLeftSegments); |
| 1282 | const bodySegments = temp.makeNext(-1, -1); |
| 1283 | |
| 1284 | // Make a path: `right` -> `left`. |
| 1285 | makeLooped(this, forkContext.head, context.leftSegments); |
| 1286 | |
| 1287 | // Update state. |
| 1288 | context.brokenForkContext.add(forkContext.head); |
| 1289 | forkContext.replaceHead(bodySegments); |
| 1290 | } |
| 1291 | |
| 1292 | //-------------------------------------------------------------------------- |
| 1293 | // Control Statements |
| 1294 | //-------------------------------------------------------------------------- |
| 1295 | |
| 1296 | /** |
| 1297 | * Creates new context for BreakStatement. |
| 1298 | * @param {boolean} breakable The flag to indicate it can break by |
| 1299 | * an unlabeled BreakStatement. |
| 1300 | * @param {string|null} label The label of this context. |
| 1301 | * @returns {Object} The new context. |
| 1302 | */ |
| 1303 | pushBreakContext(breakable, label) { |
| 1304 | this.breakContext = { |
| 1305 | upper: this.breakContext, |
| 1306 | breakable, |
| 1307 | label, |
| 1308 | brokenForkContext: ForkContext.newEmpty(this.forkContext), |
| 1309 | }; |
| 1310 | return this.breakContext; |
| 1311 | } |
| 1312 | |
| 1313 | /** |
| 1314 | * Removes the top item of the break context stack. |
| 1315 | * @returns {Object} The removed context. |
| 1316 | */ |
| 1317 | popBreakContext() { |
| 1318 | const context = this.breakContext; |
| 1319 | const forkContext = this.forkContext; |
| 1320 | |
| 1321 | this.breakContext = context.upper; |
| 1322 | |
| 1323 | // Process this context here for other than switches and loops. |
| 1324 | if (!context.breakable) { |
| 1325 | const brokenForkContext = context.brokenForkContext; |
| 1326 | |
| 1327 | if (!brokenForkContext.empty) { |
| 1328 | brokenForkContext.add(forkContext.head); |
| 1329 | forkContext.replaceHead(brokenForkContext.makeNext(0, -1)); |
| 1330 | } |
| 1331 | } |
| 1332 | |
| 1333 | return context; |
| 1334 | } |
| 1335 | |
| 1336 | /** |
| 1337 | * Makes a path for a `break` statement. |
| 1338 | * |
| 1339 | * It registers the head segment to a context of `break`. |
| 1340 | * It makes new unreachable segment, then it set the head with the segment. |
| 1341 | * @param {string} label A label of the break statement. |
| 1342 | * @returns {void} |
| 1343 | */ |
| 1344 | makeBreak(label) { |
| 1345 | const forkContext = this.forkContext; |
| 1346 | |
| 1347 | if (!forkContext.reachable) { |
| 1348 | return; |
| 1349 | } |
| 1350 | |
| 1351 | const context = getBreakContext(this, label); |
| 1352 | |
| 1353 | if (context) { |
| 1354 | context.brokenForkContext.add(forkContext.head); |
| 1355 | } |
| 1356 | |
| 1357 | /* c8 ignore next */ |
| 1358 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1)); |
| 1359 | } |
| 1360 | |
| 1361 | /** |
| 1362 | * Makes a path for a `continue` statement. |
| 1363 | * |
| 1364 | * It makes a looping path. |
| 1365 | * It makes new unreachable segment, then it set the head with the segment. |
| 1366 | * @param {string} label A label of the continue statement. |
| 1367 | * @returns {void} |
| 1368 | */ |
| 1369 | makeContinue(label) { |
| 1370 | const forkContext = this.forkContext; |
| 1371 | |
| 1372 | if (!forkContext.reachable) { |
| 1373 | return; |
| 1374 | } |
| 1375 | |
| 1376 | const context = getContinueContext(this, label); |
| 1377 | |
| 1378 | if (context) { |
| 1379 | if (context.continueDestSegments) { |
| 1380 | makeLooped(this, forkContext.head, context.continueDestSegments); |
| 1381 | |
| 1382 | // If the context is a for-in/of loop, this effects a break also. |
| 1383 | if ( |
| 1384 | context.type === 'ForInStatement' || |
| 1385 | context.type === 'ForOfStatement' |
| 1386 | ) { |
| 1387 | context.brokenForkContext.add(forkContext.head); |
| 1388 | } |
| 1389 | } else { |
| 1390 | context.continueForkContext.add(forkContext.head); |
| 1391 | } |
| 1392 | } |
| 1393 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1)); |
| 1394 | } |
| 1395 | |
| 1396 | /** |
| 1397 | * Makes a path for a `return` statement. |
| 1398 | * |
| 1399 | * It registers the head segment to a context of `return`. |
| 1400 | * It makes new unreachable segment, then it set the head with the segment. |
| 1401 | * @returns {void} |
| 1402 | */ |
| 1403 | makeReturn() { |
| 1404 | const forkContext = this.forkContext; |
| 1405 | |
| 1406 | if (forkContext.reachable) { |
| 1407 | getReturnContext(this).returnedForkContext.add(forkContext.head); |
| 1408 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1)); |
| 1409 | } |
| 1410 | } |
| 1411 | |
| 1412 | /** |
| 1413 | * Makes a path for a `throw` statement. |
| 1414 | * |
| 1415 | * It registers the head segment to a context of `throw`. |
| 1416 | * It makes new unreachable segment, then it set the head with the segment. |
| 1417 | * @returns {void} |
| 1418 | */ |
| 1419 | makeThrow() { |
| 1420 | const forkContext = this.forkContext; |
| 1421 | |
| 1422 | if (forkContext.reachable) { |
| 1423 | getThrowContext(this).thrownForkContext.add(forkContext.head); |
| 1424 | forkContext.replaceHead(forkContext.makeUnreachable(-1, -1)); |
| 1425 | } |
| 1426 | } |
| 1427 | |
| 1428 | /** |
| 1429 | * Makes the final path. |
| 1430 | * @returns {void} |
| 1431 | */ |
| 1432 | makeFinal() { |
| 1433 | const segments = this.currentSegments; |
| 1434 | |
| 1435 | if (segments.length > 0 && segments[0].reachable) { |
| 1436 | this.returnedForkContext.add(segments); |
| 1437 | } |
| 1438 | } |
| 1439 | } |
| 1440 | |
| 1441 | module.exports = CodePathState; |