| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | */ |
| 7 | |
| 8 | import * as t from '@babel/types'; |
| 9 | import {CompilerErrorDetail, ErrorCategory} from '../CompilerError'; |
| 10 | import {computeUnconditionalBlocks} from '../HIR/ComputeUnconditionalBlocks'; |
| 11 | import {Environment, isHookName} from '../HIR/Environment'; |
| 12 | import { |
| 13 | HIRFunction, |
| 14 | IdentifierId, |
| 15 | Place, |
| 16 | SourceLocation, |
| 17 | getHookKind, |
| 18 | } from '../HIR/HIR'; |
| 19 | import { |
| 20 | eachInstructionLValue, |
| 21 | eachInstructionOperand, |
| 22 | eachTerminalOperand, |
| 23 | } from '../HIR/visitors'; |
| 24 | import {assertExhaustive} from '../Utils/utils'; |
| 25 | |
| 26 | /** |
| 27 | * Represents the possible kinds of value which may be stored at a given Place during |
| 28 | * abstract interpretation. The kinds form a lattice, with earlier items taking |
| 29 | * precedence over later items (see joinKinds()). |
| 30 | */ |
| 31 | enum Kind { |
| 32 | // A potential/known hook which was already used in an invalid way |
| 33 | Error = 'Error', |
| 34 | |
| 35 | /* |
| 36 | * A known hook. Sources include: |
| 37 | * - LoadGlobal instructions whose type was inferred as a hook |
| 38 | * - PropertyLoad, ComputedLoad, and Destructuring instructions |
| 39 | * where the object is a KnownHook |
| 40 | * - PropertyLoad, ComputedLoad, and Destructuring instructions |
| 41 | * where the object is a Global and the property name is hook-like |
| 42 | */ |
| 43 | KnownHook = 'KnownHook', |
| 44 | |
| 45 | /* |
| 46 | * A potential hook. Sources include: |
| 47 | * - LValues (other than LoadGlobal) where the name is hook-like |
| 48 | * - PropertyLoad, ComputedLoad, and Destructuring instructions |
| 49 | * where the object is a potential hook or the property name |
| 50 | * is hook-like |
| 51 | */ |
| 52 | PotentialHook = 'PotentialHook', |
| 53 | |
| 54 | // LoadGlobal values whose type was not inferred as a hook |
| 55 | Global = 'Global', |
| 56 | |
| 57 | // All other values, ie local variables |
| 58 | Local = 'Local', |
| 59 | } |
| 60 | |
| 61 | function joinKinds(a: Kind, b: Kind): Kind { |
| 62 | if (a === Kind.Error || b === Kind.Error) { |
| 63 | return Kind.Error; |
| 64 | } else if (a === Kind.KnownHook || b === Kind.KnownHook) { |
| 65 | return Kind.KnownHook; |
| 66 | } else if (a === Kind.PotentialHook || b === Kind.PotentialHook) { |
| 67 | return Kind.PotentialHook; |
| 68 | } else if (a === Kind.Global || b === Kind.Global) { |
| 69 | return Kind.Global; |
| 70 | } else { |
| 71 | return Kind.Local; |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Validates that the function honors the [Rules of Hooks](https://react.dev/warnings/invalid-hook-call-warning) |
| 77 | * rule that hooks may only be called and not otherwise referenced as first-class values. |
| 78 | * |
| 79 | * Specifically this pass implements the following rules: |
| 80 | * - Known hooks may only be called unconditionally, and cannot be used as first-class values. |
| 81 | * See the note for Kind.KnownHook for sources of known hooks |
| 82 | * - Potential hooks may be referenced as first-class values, with the exception that they |
| 83 | * may not appear as the callee of a conditional call. |
| 84 | * See the note for Kind.PotentialHook for sources of potential hooks |
| 85 | */ |
| 86 | export function validateHooksUsage(fn: HIRFunction): void { |
| 87 | const unconditionalBlocks = computeUnconditionalBlocks(fn); |
| 88 | |
| 89 | const errorsByPlace = new Map<t.SourceLocation, CompilerErrorDetail>(); |
| 90 | |
| 91 | function trackError( |
| 92 | loc: SourceLocation, |
| 93 | errorDetail: CompilerErrorDetail, |
| 94 | ): void { |
| 95 | if (typeof loc === 'symbol') { |
| 96 | fn.env.recordError(errorDetail); |
| 97 | } else { |
| 98 | errorsByPlace.set(loc, errorDetail); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | function recordConditionalHookError(place: Place): void { |
| 103 | // Once a particular hook has a conditional call error, don't report any further issues for this hook |
| 104 | setKind(place, Kind.Error); |
| 105 | |
| 106 | const reason = |
| 107 | 'Hooks must always be called in a consistent order, and may not be called conditionally. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)'; |
| 108 | const previousError = |
| 109 | typeof place.loc !== 'symbol' ? errorsByPlace.get(place.loc) : undefined; |
| 110 | |
| 111 | /* |
| 112 | * In some circumstances such as optional calls, we may first encounter a "hook may not be referenced as normal values" error. |
| 113 | * If that same place is also used as a conditional call, upgrade the error to a conditonal hook error |
| 114 | */ |
| 115 | if (previousError === undefined || previousError.reason !== reason) { |
| 116 | trackError( |
| 117 | place.loc, |
| 118 | new CompilerErrorDetail({ |
| 119 | category: ErrorCategory.Hooks, |
| 120 | description: null, |
| 121 | reason, |
| 122 | loc: place.loc, |
| 123 | suggestions: null, |
| 124 | }), |
| 125 | ); |
| 126 | } |
| 127 | } |
| 128 | function recordInvalidHookUsageError(place: Place): void { |
| 129 | const previousError = |
| 130 | typeof place.loc !== 'symbol' ? errorsByPlace.get(place.loc) : undefined; |
| 131 | if (previousError === undefined) { |
| 132 | trackError( |
| 133 | place.loc, |
| 134 | new CompilerErrorDetail({ |
| 135 | category: ErrorCategory.Hooks, |
| 136 | description: null, |
| 137 | reason: |
| 138 | 'Hooks may not be referenced as normal values, they must be called. See https://react.dev/reference/rules/react-calls-components-and-hooks#never-pass-around-hooks-as-regular-values', |
| 139 | loc: place.loc, |
| 140 | suggestions: null, |
| 141 | }), |
| 142 | ); |
| 143 | } |
| 144 | } |
| 145 | function recordDynamicHookUsageError(place: Place): void { |
| 146 | const previousError = |
| 147 | typeof place.loc !== 'symbol' ? errorsByPlace.get(place.loc) : undefined; |
| 148 | if (previousError === undefined) { |
| 149 | trackError( |
| 150 | place.loc, |
| 151 | new CompilerErrorDetail({ |
| 152 | category: ErrorCategory.Hooks, |
| 153 | description: null, |
| 154 | reason: |
| 155 | 'Hooks must be the same function on every render, but this value may change over time to a different function. See https://react.dev/reference/rules/react-calls-components-and-hooks#dont-dynamically-use-hooks', |
| 156 | loc: place.loc, |
| 157 | suggestions: null, |
| 158 | }), |
| 159 | ); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | const valueKinds = new Map<IdentifierId, Kind>(); |
| 164 | function getKindForPlace(place: Place): Kind { |
| 165 | const knownKind = valueKinds.get(place.identifier.id); |
| 166 | if ( |
| 167 | place.identifier.name !== null && |
| 168 | isHookName(place.identifier.name.value) |
| 169 | ) { |
| 170 | return joinKinds(knownKind ?? Kind.Local, Kind.PotentialHook); |
| 171 | } else { |
| 172 | return knownKind ?? Kind.Local; |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | function visitPlace(place: Place): void { |
| 177 | const kind = valueKinds.get(place.identifier.id); |
| 178 | if (kind === Kind.KnownHook) { |
| 179 | recordInvalidHookUsageError(place); |
| 180 | } |
| 181 | } |
| 182 | |
| 183 | function setKind(place: Place, kind: Kind): void { |
| 184 | valueKinds.set(place.identifier.id, kind); |
| 185 | } |
| 186 | |
| 187 | for (const param of fn.params) { |
| 188 | const place = param.kind === 'Identifier' ? param : param.place; |
| 189 | const kind = getKindForPlace(place); |
| 190 | setKind(place, kind); |
| 191 | } |
| 192 | |
| 193 | for (const [, block] of fn.body.blocks) { |
| 194 | for (const phi of block.phis) { |
| 195 | let kind: Kind = |
| 196 | phi.place.identifier.name !== null && |
| 197 | isHookName(phi.place.identifier.name.value) |
| 198 | ? Kind.PotentialHook |
| 199 | : Kind.Local; |
| 200 | for (const [, operand] of phi.operands) { |
| 201 | const operandKind = valueKinds.get(operand.identifier.id); |
| 202 | /* |
| 203 | * NOTE: we currently skip operands whose value is unknown |
| 204 | * (which can only occur for functions with loops), we may |
| 205 | * cause us to miss invalid code in some cases. We should |
| 206 | * expand this to a fixpoint iteration in a follow-up. |
| 207 | */ |
| 208 | if (operandKind !== undefined) { |
| 209 | kind = joinKinds(kind, operandKind); |
| 210 | } |
| 211 | } |
| 212 | valueKinds.set(phi.place.identifier.id, kind); |
| 213 | } |
| 214 | for (const instr of block.instructions) { |
| 215 | switch (instr.value.kind) { |
| 216 | case 'LoadGlobal': { |
| 217 | /* |
| 218 | * Globals are the one source of known hooks: they are either |
| 219 | * directly a hook, or infer a Global kind from which knownhooks |
| 220 | * can be derived later via property access (PropertyLoad etc) |
| 221 | */ |
| 222 | if (getHookKind(fn.env, instr.lvalue.identifier) != null) { |
| 223 | setKind(instr.lvalue, Kind.KnownHook); |
| 224 | } else { |
| 225 | setKind(instr.lvalue, Kind.Global); |
| 226 | } |
| 227 | break; |
| 228 | } |
| 229 | case 'LoadContext': |
| 230 | case 'LoadLocal': { |
| 231 | visitPlace(instr.value.place); |
| 232 | const kind = getKindForPlace(instr.value.place); |
| 233 | setKind(instr.lvalue, kind); |
| 234 | break; |
| 235 | } |
| 236 | case 'StoreLocal': |
| 237 | case 'StoreContext': { |
| 238 | visitPlace(instr.value.value); |
| 239 | const kind = joinKinds( |
| 240 | getKindForPlace(instr.value.value), |
| 241 | getKindForPlace(instr.value.lvalue.place), |
| 242 | ); |
| 243 | setKind(instr.value.lvalue.place, kind); |
| 244 | setKind(instr.lvalue, kind); |
| 245 | break; |
| 246 | } |
| 247 | case 'ComputedLoad': { |
| 248 | visitPlace(instr.value.object); |
| 249 | const kind = getKindForPlace(instr.value.object); |
| 250 | setKind(instr.lvalue, joinKinds(getKindForPlace(instr.lvalue), kind)); |
| 251 | break; |
| 252 | } |
| 253 | case 'PropertyLoad': { |
| 254 | const objectKind = getKindForPlace(instr.value.object); |
| 255 | const isHookProperty = |
| 256 | typeof instr.value.property === 'string' && |
| 257 | isHookName(instr.value.property); |
| 258 | let kind: Kind; |
| 259 | switch (objectKind) { |
| 260 | case Kind.Error: { |
| 261 | kind = Kind.Error; |
| 262 | break; |
| 263 | } |
| 264 | case Kind.KnownHook: { |
| 265 | /** |
| 266 | * const useFoo; |
| 267 | * function Component() { |
| 268 | * let x = useFoo.useBar; // useFoo is KnownHook, any property from it inherits KnownHook |
| 269 | * } |
| 270 | */ |
| 271 | kind = isHookProperty ? Kind.KnownHook : Kind.Local; |
| 272 | break; |
| 273 | } |
| 274 | case Kind.PotentialHook: { |
| 275 | /** |
| 276 | * function Component(props) { |
| 277 | * let useFoo; |
| 278 | * let x = useFoo.useBar; // useFoo is PotentialHook, any property from it inherits PotentialHook |
| 279 | * } |
| 280 | */ |
| 281 | kind = Kind.PotentialHook; |
| 282 | break; |
| 283 | } |
| 284 | case Kind.Global: { |
| 285 | /** |
| 286 | * function Component() { |
| 287 | * let x = React.useState; // hook-named property of global is knownhook |
| 288 | * let y = React.foo; // else inherit Global |
| 289 | * } |
| 290 | */ |
| 291 | kind = isHookProperty ? Kind.KnownHook : Kind.Global; |
| 292 | break; |
| 293 | } |
| 294 | case Kind.Local: { |
| 295 | /** |
| 296 | * function Component() { |
| 297 | * let o = createObject(); |
| 298 | * let x = o.useState; // hook-named property of local is potentialhook |
| 299 | * let y = o.foo; // else inherit local |
| 300 | * } |
| 301 | */ |
| 302 | kind = isHookProperty ? Kind.PotentialHook : Kind.Local; |
| 303 | break; |
| 304 | } |
| 305 | default: { |
| 306 | assertExhaustive(objectKind, `Unexpected kind \`${objectKind}\``); |
| 307 | } |
| 308 | } |
| 309 | setKind(instr.lvalue, kind); |
| 310 | break; |
| 311 | } |
| 312 | case 'CallExpression': { |
| 313 | const calleeKind = getKindForPlace(instr.value.callee); |
| 314 | const isHookCallee = |
| 315 | calleeKind === Kind.KnownHook || calleeKind === Kind.PotentialHook; |
| 316 | if (isHookCallee && !unconditionalBlocks.has(block.id)) { |
| 317 | recordConditionalHookError(instr.value.callee); |
| 318 | } else if (calleeKind === Kind.PotentialHook) { |
| 319 | recordDynamicHookUsageError(instr.value.callee); |
| 320 | } |
| 321 | /** |
| 322 | * We intentionally skip the callee because it's validated above |
| 323 | */ |
| 324 | for (const operand of eachInstructionOperand(instr)) { |
| 325 | if (operand === instr.value.callee) { |
| 326 | continue; |
| 327 | } |
| 328 | visitPlace(operand); |
| 329 | } |
| 330 | break; |
| 331 | } |
| 332 | case 'MethodCall': { |
| 333 | const calleeKind = getKindForPlace(instr.value.property); |
| 334 | const isHookCallee = |
| 335 | calleeKind === Kind.KnownHook || calleeKind === Kind.PotentialHook; |
| 336 | if (isHookCallee && !unconditionalBlocks.has(block.id)) { |
| 337 | recordConditionalHookError(instr.value.property); |
| 338 | } else if (calleeKind === Kind.PotentialHook) { |
| 339 | recordDynamicHookUsageError(instr.value.property); |
| 340 | } |
| 341 | /* |
| 342 | * We intentionally skip the property because it's validated above |
| 343 | */ |
| 344 | for (const operand of eachInstructionOperand(instr)) { |
| 345 | if (operand === instr.value.property) { |
| 346 | continue; |
| 347 | } |
| 348 | visitPlace(operand); |
| 349 | } |
| 350 | break; |
| 351 | } |
| 352 | case 'Destructure': { |
| 353 | visitPlace(instr.value.value); |
| 354 | const objectKind = getKindForPlace(instr.value.value); |
| 355 | for (const lvalue of eachInstructionLValue(instr)) { |
| 356 | const isHookProperty = |
| 357 | lvalue.identifier.name !== null && |
| 358 | isHookName(lvalue.identifier.name.value); |
| 359 | let kind: Kind; |
| 360 | switch (objectKind) { |
| 361 | case Kind.Error: { |
| 362 | kind = Kind.Error; |
| 363 | break; |
| 364 | } |
| 365 | case Kind.KnownHook: { |
| 366 | kind = Kind.KnownHook; |
| 367 | break; |
| 368 | } |
| 369 | case Kind.PotentialHook: { |
| 370 | kind = Kind.PotentialHook; |
| 371 | break; |
| 372 | } |
| 373 | case Kind.Global: { |
| 374 | kind = isHookProperty ? Kind.KnownHook : Kind.Global; |
| 375 | break; |
| 376 | } |
| 377 | case Kind.Local: { |
| 378 | kind = isHookProperty ? Kind.PotentialHook : Kind.Local; |
| 379 | break; |
| 380 | } |
| 381 | default: { |
| 382 | assertExhaustive( |
| 383 | objectKind, |
| 384 | `Unexpected kind \`${objectKind}\``, |
| 385 | ); |
| 386 | } |
| 387 | } |
| 388 | setKind(lvalue, kind); |
| 389 | } |
| 390 | break; |
| 391 | } |
| 392 | case 'ObjectMethod': |
| 393 | case 'FunctionExpression': { |
| 394 | visitFunctionExpression(fn.env, instr.value.loweredFunc.func); |
| 395 | break; |
| 396 | } |
| 397 | default: { |
| 398 | /* |
| 399 | * Else check usages of operands, but do *not* flow properties |
| 400 | * from operands into the lvalues. For example, `let x = identity(y)` |
| 401 | * does not infer `x` as a potential hook even if `y` is a potential hook. |
| 402 | */ |
| 403 | for (const operand of eachInstructionOperand(instr)) { |
| 404 | visitPlace(operand); |
| 405 | } |
| 406 | for (const lvalue of eachInstructionLValue(instr)) { |
| 407 | const kind = getKindForPlace(lvalue); |
| 408 | setKind(lvalue, kind); |
| 409 | } |
| 410 | } |
| 411 | } |
| 412 | } |
| 413 | for (const operand of eachTerminalOperand(block.terminal)) { |
| 414 | visitPlace(operand); |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | for (const [, error] of errorsByPlace) { |
| 419 | fn.env.recordError(error); |
| 420 | } |
| 421 | } |
| 422 | |
| 423 | function visitFunctionExpression(env: Environment, fn: HIRFunction): void { |
| 424 | for (const [, block] of fn.body.blocks) { |
| 425 | for (const instr of block.instructions) { |
| 426 | switch (instr.value.kind) { |
| 427 | case 'ObjectMethod': |
| 428 | case 'FunctionExpression': { |
| 429 | visitFunctionExpression(env, instr.value.loweredFunc.func); |
| 430 | break; |
| 431 | } |
| 432 | case 'MethodCall': |
| 433 | case 'CallExpression': { |
| 434 | const callee = |
| 435 | instr.value.kind === 'CallExpression' |
| 436 | ? instr.value.callee |
| 437 | : instr.value.property; |
| 438 | const hookKind = getHookKind(fn.env, callee.identifier); |
| 439 | if (hookKind != null) { |
| 440 | env.recordError( |
| 441 | new CompilerErrorDetail({ |
| 442 | category: ErrorCategory.Hooks, |
| 443 | reason: |
| 444 | 'Hooks must be called at the top level in the body of a function component or custom hook, and may not be called within function expressions. See the Rules of Hooks (https://react.dev/warnings/invalid-hook-call-warning)', |
| 445 | loc: callee.loc, |
| 446 | description: `Cannot call ${hookKind === 'Custom' ? 'hook' : hookKind} within a function expression`, |
| 447 | suggestions: null, |
| 448 | }), |
| 449 | ); |
| 450 | } |
| 451 | break; |
| 452 | } |
| 453 | } |
| 454 | } |
| 455 | } |
| 456 | } |