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4 Commits

Author SHA1 Message Date
Joe Savona
77f30d6f61 [commit] Better error message for invalid hoisting
We're already tracking which variables are hoisted context variables, so if we see a mutation of a frozen value we can emit a custom error message to help users identify the problem.
2025-06-18 13:00:42 -07:00
Joe Savona
8f54b8aea5 [compiler] Fix AnalyzeFunctions to fully reset context identifiers
AnalyzeFunctions had logic to reset the mutable ranges of context variables after visiting inner function expressions. However, there was a bug in that logic: InferReactiveScopeVariables makes all the identifiers in a scope point to the same mutable range instance. That meant that it was possible for a later function expression to indirectly cause an earlier function expressions' context variables to get a non-zero mutable range.

The fix is to not just reset start/end of context var ranges, but assign a new range instance. Thanks for the help on debugging, @mofeiz!
2025-06-18 13:00:42 -07:00
Joe Savona
f3789e4caf [compiler] Enable new inference by default 2025-06-18 13:00:42 -07:00
Joe Savona
cebe9dc9e2 [compiler] Update fixtures for new inference 2025-06-18 13:00:42 -07:00
15 changed files with 89 additions and 192 deletions

View File

@@ -72,7 +72,7 @@ export function lower(
env: Environment,
// Bindings captured from the outer function, in case lower() is called recursively (for lambdas)
bindings: Bindings | null = null,
capturedRefs: Map<t.Identifier, SourceLocation> = new Map(),
capturedRefs: Array<t.Identifier> = [],
): Result<HIRFunction, CompilerError> {
const builder = new HIRBuilder(env, {
bindings,
@@ -80,13 +80,13 @@ export function lower(
});
const context: HIRFunction['context'] = [];
for (const [ref, loc] of capturedRefs ?? []) {
for (const ref of capturedRefs ?? []) {
context.push({
kind: 'Identifier',
identifier: builder.resolveBinding(ref),
effect: Effect.Unknown,
reactive: false,
loc,
loc: ref.loc ?? GeneratedSource,
});
}
@@ -3439,12 +3439,10 @@ function lowerFunction(
* This isn't a problem in practice because use Babel's scope analysis to
* identify the correct references.
*/
const lowering = lower(
expr,
builder.environment,
builder.bindings,
new Map([...builder.context, ...capturedContext]),
);
const lowering = lower(expr, builder.environment, builder.bindings, [
...builder.context,
...capturedContext,
]);
let loweredFunc: HIRFunction;
if (lowering.isErr()) {
lowering
@@ -4162,11 +4160,6 @@ function captureScopes({from, to}: {from: Scope; to: Scope}): Set<Scope> {
return scopes;
}
/**
* Returns a mapping of "context" identifiers — references to free variables that
* will become part of the function expression's `context` array — along with the
* source location of their first reference within the function.
*/
function gatherCapturedContext(
fn: NodePath<
| t.FunctionExpression
@@ -4175,8 +4168,8 @@ function gatherCapturedContext(
| t.ObjectMethod
>,
componentScope: Scope,
): Map<t.Identifier, SourceLocation> {
const capturedIds = new Map<t.Identifier, SourceLocation>();
): Array<t.Identifier> {
const capturedIds = new Set<t.Identifier>();
/*
* Capture all the scopes from the parent of this function up to and including
@@ -4219,15 +4212,8 @@ function gatherCapturedContext(
// Add the base identifier binding as a dependency.
const binding = baseIdentifier.scope.getBinding(baseIdentifier.node.name);
if (
binding !== undefined &&
pureScopes.has(binding.scope) &&
!capturedIds.has(binding.identifier)
) {
capturedIds.set(
binding.identifier,
path.node.loc ?? binding.identifier.loc ?? GeneratedSource,
);
if (binding !== undefined && pureScopes.has(binding.scope)) {
capturedIds.add(binding.identifier);
}
}
@@ -4264,7 +4250,7 @@ function gatherCapturedContext(
},
});
return capturedIds;
return [...capturedIds.keys()];
}
function notNull<T>(value: T | null): value is T {

View File

@@ -1388,16 +1388,6 @@ export enum ValueReason {
*/
JsxCaptured = 'jsx-captured',
/**
* Argument to a hook
*/
HookCaptured = 'hook-captured',
/**
* Return value of a hook
*/
HookReturn = 'hook-return',
/**
* Passed to an effect
*/

View File

@@ -106,7 +106,7 @@ export default class HIRBuilder {
#current: WipBlock;
#entry: BlockId;
#scopes: Array<Scope> = [];
#context: Map<t.Identifier, SourceLocation>;
#context: Array<t.Identifier>;
#bindings: Bindings;
#env: Environment;
#exceptionHandlerStack: Array<BlockId> = [];
@@ -121,7 +121,7 @@ export default class HIRBuilder {
return this.#env.nextIdentifierId;
}
get context(): Map<t.Identifier, SourceLocation> {
get context(): Array<t.Identifier> {
return this.#context;
}
@@ -137,13 +137,13 @@ export default class HIRBuilder {
env: Environment,
options?: {
bindings?: Bindings | null;
context?: Map<t.Identifier, SourceLocation>;
context?: Array<t.Identifier>;
entryBlockKind?: BlockKind;
},
) {
this.#env = env;
this.#bindings = options?.bindings ?? new Map();
this.#context = options?.context ?? new Map();
this.#context = options?.context ?? [];
this.#entry = makeBlockId(env.nextBlockId);
this.#current = newBlock(this.#entry, options?.entryBlockKind ?? 'block');
}

View File

@@ -1302,34 +1302,6 @@ export const DefaultNonmutatingHook = addHook(
calleeEffect: Effect.Read,
hookKind: 'Custom',
returnValueKind: ValueKind.Frozen,
aliasing: {
receiver: makeIdentifierId(0),
params: [],
rest: makeIdentifierId(1),
returns: makeIdentifierId(2),
temporaries: [],
effects: [
// Freeze the arguments
{
kind: 'Freeze',
value: signatureArgument(1),
reason: ValueReason.HookCaptured,
},
// Returns a frozen value
{
kind: 'Create',
into: signatureArgument(2),
value: ValueKind.Frozen,
reason: ValueReason.HookReturn,
},
// May alias any arguments into the return
{
kind: 'Alias',
from: signatureArgument(1),
into: signatureArgument(2),
},
],
},
},
'DefaultNonmutatingHook',
);

View File

@@ -341,10 +341,6 @@ export function getWriteErrorReason(abstractValue: AbstractValue): string {
return "Mutating a value returned from 'useReducer()', which should not be mutated. Use the dispatch function to update instead";
} else if (abstractValue.reason.has(ValueReason.Effect)) {
return 'Updating a value used previously in an effect function or as an effect dependency is not allowed. Consider moving the mutation before calling useEffect()';
} else if (abstractValue.reason.has(ValueReason.HookCaptured)) {
return 'Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook';
} else if (abstractValue.reason.has(ValueReason.HookReturn)) {
return 'Updating a value returned from a hook is not allowed. Consider moving the mutation into the hook where the value is constructed';
} else {
return 'This mutates a variable that React considers immutable';
}

View File

@@ -38,7 +38,6 @@ import {
import {
eachInstructionValueLValue,
eachInstructionValueOperand,
eachTerminalOperand,
eachTerminalSuccessor,
} from '../HIR/visitors';
import {Ok, Result} from '../Utils/Result';
@@ -222,19 +221,8 @@ export function inferMutationAliasingEffects(
return Ok(undefined);
}
function findHoistedContextDeclarations(
fn: HIRFunction,
): Map<DeclarationId, Place | null> {
const hoisted = new Map<DeclarationId, Place | null>();
function visit(place: Place): void {
if (
hoisted.has(place.identifier.declarationId) &&
hoisted.get(place.identifier.declarationId) == null
) {
// If this is the first load of the value, store the location
hoisted.set(place.identifier.declarationId, place);
}
}
function findHoistedContextDeclarations(fn: HIRFunction): Set<DeclarationId> {
const hoisted = new Set<DeclarationId>();
for (const block of fn.body.blocks.values()) {
for (const instr of block.instructions) {
if (instr.value.kind === 'DeclareContext') {
@@ -244,17 +232,10 @@ function findHoistedContextDeclarations(
kind == InstructionKind.HoistedFunction ||
kind == InstructionKind.HoistedLet
) {
hoisted.set(instr.value.lvalue.place.identifier.declarationId, null);
}
} else {
for (const operand of eachInstructionValueOperand(instr.value)) {
visit(operand);
hoisted.add(instr.value.lvalue.place.identifier.declarationId);
}
}
}
for (const operand of eachTerminalOperand(block.terminal)) {
visit(operand);
}
}
return hoisted;
}
@@ -267,12 +248,12 @@ class Context {
catchHandlers: Map<BlockId, Place> = new Map();
isFuctionExpression: boolean;
fn: HIRFunction;
hoistedContextDeclarations: Map<DeclarationId, Place | null>;
hoistedContextDeclarations: Set<DeclarationId>;
constructor(
isFunctionExpression: boolean,
fn: HIRFunction,
hoistedContextDeclarations: Map<DeclarationId, Place | null>,
hoistedContextDeclarations: Set<DeclarationId>,
) {
this.isFuctionExpression = isFunctionExpression;
this.fn = fn;
@@ -920,69 +901,48 @@ function applyEffect(
console.log(prettyFormat(state.debugAbstractValue(value)));
}
let reason: string;
let description: string | null = null;
if (
mutationKind === 'mutate-frozen' &&
context.hoistedContextDeclarations.has(
effect.value.identifier.declarationId,
)
) {
const description =
reason = `This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time`;
if (
effect.value.identifier.name !== null &&
effect.value.identifier.name.kind === 'named'
? `Variable \`${effect.value.identifier.name.value}\` is accessed before it is declared`
: null;
const hoistedAccess = context.hoistedContextDeclarations.get(
effect.value.identifier.declarationId,
);
if (hoistedAccess != null && hoistedAccess.loc != effect.value.loc) {
effects.push({
kind: 'MutateFrozen',
place: effect.value,
error: {
severity: ErrorSeverity.InvalidReact,
reason: `This variable is accessed before it is declared, which may prevent it from updating as the assigned value changes over time`,
description,
loc: hoistedAccess.loc,
suggestions: null,
},
});
) {
description = `Move the declaration of \`${effect.value.identifier.name.value}\` to before it is first referenced`;
}
effects.push({
kind: 'MutateFrozen',
place: effect.value,
error: {
severity: ErrorSeverity.InvalidReact,
reason: `This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time`,
description,
loc: effect.value.loc,
suggestions: null,
},
});
} else {
const reason = getWriteErrorReason({
reason = getWriteErrorReason({
kind: value.kind,
reason: value.reason,
context: new Set(),
});
const description =
if (
effect.value.identifier.name !== null &&
effect.value.identifier.name.kind === 'named'
? `Found mutation of \`${effect.value.identifier.name.value}\``
: null;
effects.push({
kind:
value.kind === ValueKind.Frozen ? 'MutateFrozen' : 'MutateGlobal',
place: effect.value,
error: {
severity: ErrorSeverity.InvalidReact,
reason,
description,
loc: effect.value.loc,
suggestions: null,
},
});
) {
description = `Found mutation of \`${effect.value.identifier.name.value}\``;
}
}
effects.push({
kind:
value.kind === ValueKind.Frozen ? 'MutateFrozen' : 'MutateGlobal',
place: effect.value,
error: {
severity: ErrorSeverity.InvalidReact,
reason,
description,
loc: effect.value.loc,
suggestions: null,
},
});
}
break;
}
@@ -2020,17 +1980,28 @@ function computeEffectsForLegacySignature(
break;
}
case Effect.ConditionallyMutateIterator: {
const mutateIterator = conditionallyMutateIterator(place);
if (mutateIterator != null) {
effects.push(mutateIterator);
// TODO: should we always push to captures?
if (
isArrayType(place.identifier) ||
isSetType(place.identifier) ||
isMapType(place.identifier)
) {
effects.push({
kind: 'Capture',
from: place,
into: lvalue,
});
} else {
effects.push({
kind: 'Capture',
from: place,
into: lvalue,
});
captures.push(place);
effects.push({
kind: 'MutateTransitiveConditionally',
value: place,
});
}
effects.push({
kind: 'Capture',
from: place,
into: lvalue,
});
break;
}
case Effect.Freeze: {
@@ -2220,7 +2191,6 @@ function computeEffectsForSignature(
return null;
}
// Build substitutions
const mutableSpreads = new Set<IdentifierId>();
const substitutions: Map<IdentifierId, Array<Place>> = new Map();
substitutions.set(signature.receiver, [receiver]);
substitutions.set(signature.returns, [lvalue]);
@@ -2238,13 +2208,6 @@ function computeEffectsForSignature(
}
const place = arg.kind === 'Identifier' ? arg : arg.place;
getOrInsertWith(substitutions, signature.rest, () => []).push(place);
if (arg.kind === 'Spread') {
const mutateIterator = conditionallyMutateIterator(arg.place);
if (mutateIterator != null) {
mutableSpreads.add(arg.place.identifier.id);
}
}
} else {
const param = params[i];
substitutions.set(param, [arg]);
@@ -2316,12 +2279,6 @@ function computeEffectsForSignature(
case 'Freeze': {
const values = substitutions.get(effect.value.identifier.id) ?? [];
for (const value of values) {
if (mutableSpreads.has(value.identifier.id)) {
CompilerError.throwTodo({
reason: 'Support spread syntax for hook arguments',
loc: value.loc,
});
}
effects.push({kind: 'Freeze', value, reason: effect.reason});
}
break;

View File

@@ -32,7 +32,7 @@ export const FIXTURE_ENTRYPOINT = {
11 | });
12 |
> 13 | x.value += count;
| ^ InvalidReact: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook (13:13)
| ^ InvalidReact: This mutates a variable that React considers immutable (13:13)
14 | return <Stringify x={x} cb={cb} />;
15 | }
16 |

View File

@@ -32,7 +32,7 @@ export const FIXTURE_ENTRYPOINT = {
11 | });
12 |
> 13 | x.value += count;
| ^ InvalidReact: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook (13:13)
| ^ InvalidReact: This mutates a variable that React considers immutable (13:13)
14 | return <Stringify x={x} cb={cb} />;
15 | }
16 |

View File

@@ -38,15 +38,13 @@ export const FIXTURE_ENTRYPOINT = {
## Error
```
17 | * $2 = Function context=setState
18 | */
> 19 | useEffect(() => setState(2), []);
| ^^^^^^^^ InvalidReact: This variable is accessed before it is declared, which may prevent it from updating as the assigned value changes over time. Variable `setState` is accessed before it is declared (19:19)
InvalidReact: This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time. Variable `setState` is accessed before it is declared (21:21)
19 | useEffect(() => setState(2), []);
20 |
21 | const [state, setState] = useState(0);
> 21 | const [state, setState] = useState(0);
| ^^^^^^^^ InvalidReact: This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time. Move the declaration of `setState` to before it is first referenced (21:21)
22 | return <Stringify state={state} />;
23 | }
24 |
```

View File

@@ -27,7 +27,7 @@ function SomeComponent() {
9 | return (
10 | <Button
> 11 | onPress={() => (sharedVal.value = Math.random())}
| ^^^^^^^^^ InvalidReact: Updating a value returned from a hook is not allowed. Consider moving the mutation into the hook where the value is constructed. Found mutation of `sharedVal` (11:11)
| ^^^^^^^^^ InvalidReact: This mutates a variable that React considers immutable. Found mutation of `sharedVal` (11:11)
12 | title="Randomize"
13 | />
14 | );

View File

@@ -34,13 +34,13 @@ export const FIXTURE_ENTRYPOINT = {
## Error
```
11 |
12 | function foo() {
> 13 | return bar();
| ^^^ Todo: [PruneHoistedContexts] Rewrite hoisted function references (13:13)
13 | return bar();
14 | }
15 | function bar() {
> 15 | function bar() {
| ^^^ Todo: [PruneHoistedContexts] Rewrite hoisted function references (15:15)
16 | return 42;
17 | }
18 |
```

View File

@@ -52,7 +52,7 @@ export const FIXTURE_ENTRYPOINT = {
## Logs
```
{"kind":"CompileError","fnLoc":{"start":{"line":5,"column":0,"index":163},"end":{"line":13,"column":1,"index":357},"filename":"retry-no-emit.ts"},"detail":{"reason":"Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook","description":null,"severity":"InvalidReact","suggestions":null,"loc":{"start":{"line":11,"column":2,"index":320},"end":{"line":11,"column":6,"index":324},"filename":"retry-no-emit.ts","identifierName":"arr2"}}}
{"kind":"CompileError","fnLoc":{"start":{"line":5,"column":0,"index":163},"end":{"line":13,"column":1,"index":357},"filename":"retry-no-emit.ts"},"detail":{"reason":"This mutates a variable that React considers immutable","description":null,"severity":"InvalidReact","suggestions":null,"loc":{"start":{"line":11,"column":2,"index":320},"end":{"line":11,"column":6,"index":324},"filename":"retry-no-emit.ts","identifierName":"arr2"}}}
{"kind":"AutoDepsDecorations","fnLoc":{"start":{"line":7,"column":2,"index":216},"end":{"line":7,"column":36,"index":250},"filename":"retry-no-emit.ts"},"decorations":[{"start":{"line":7,"column":31,"index":245},"end":{"line":7,"column":34,"index":248},"filename":"retry-no-emit.ts","identifierName":"arr"}]}
{"kind":"AutoDepsDecorations","fnLoc":{"start":{"line":10,"column":2,"index":274},"end":{"line":10,"column":44,"index":316},"filename":"retry-no-emit.ts"},"decorations":[{"start":{"line":10,"column":25,"index":297},"end":{"line":10,"column":29,"index":301},"filename":"retry-no-emit.ts","identifierName":"arr2"},{"start":{"line":10,"column":25,"index":297},"end":{"line":10,"column":29,"index":301},"filename":"retry-no-emit.ts","identifierName":"arr2"},{"start":{"line":10,"column":35,"index":307},"end":{"line":10,"column":42,"index":314},"filename":"retry-no-emit.ts","identifierName":"propVal"}]}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":163},"end":{"line":13,"column":1,"index":357},"filename":"retry-no-emit.ts"},"fnName":"Foo","memoSlots":0,"memoBlocks":0,"memoValues":0,"prunedMemoBlocks":0,"prunedMemoValues":0}

View File

@@ -31,15 +31,13 @@ function Component({content, refetch}) {
## Error
```
9 | // TDZ violation!
10 | const onRefetch = useCallback(() => {
> 11 | refetch(data);
| ^^^^ InvalidReact: This variable is accessed before it is declared, which may prevent it from updating as the assigned value changes over time. Variable `data` is accessed before it is declared (11:11)
InvalidReact: This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time. Variable `data` is accessed before it is declared (19:19)
12 | }, [refetch]);
13 |
14 | // The context variable gets frozen here since it's passed to a hook
17 | // This has to error: onRefetch needs to memoize with `content` as a
18 | // dependency, but the dependency comes later
> 19 | const {data = null} = content;
| ^^^^^^^^^^^ InvalidReact: This variable is accessed before it is declared, which prevents the earlier access from updating when this value changes over time. Move the declaration of `data` to before it is first referenced (19:19)
20 |
21 | return <Foo data={data} onSubmit={onSubmit} />;
22 | }
```

View File

@@ -19,7 +19,7 @@ function Component({a, b}) {
3 | const x = {a};
4 | useFreeze(x);
> 5 | x.y = true;
| ^ InvalidReact: Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook (5:5)
| ^ InvalidReact: This mutates a variable that React considers immutable (5:5)
6 | return <div>error</div>;
7 | }
8 |

View File

@@ -52,7 +52,7 @@ export const FIXTURE_ENTRYPOINT = {
## Logs
```
{"kind":"CompileError","fnLoc":{"start":{"line":5,"column":0,"index":195},"end":{"line":13,"column":1,"index":389},"filename":"retry-no-emit.ts"},"detail":{"reason":"Updating a value previously passed as an argument to a hook is not allowed. Consider moving the mutation before calling the hook","description":null,"severity":"InvalidReact","suggestions":null,"loc":{"start":{"line":11,"column":2,"index":352},"end":{"line":11,"column":6,"index":356},"filename":"retry-no-emit.ts","identifierName":"arr2"}}}
{"kind":"CompileError","fnLoc":{"start":{"line":5,"column":0,"index":195},"end":{"line":13,"column":1,"index":389},"filename":"retry-no-emit.ts"},"detail":{"reason":"This mutates a variable that React considers immutable","description":null,"severity":"InvalidReact","suggestions":null,"loc":{"start":{"line":11,"column":2,"index":352},"end":{"line":11,"column":6,"index":356},"filename":"retry-no-emit.ts","identifierName":"arr2"}}}
{"kind":"AutoDepsDecorations","fnLoc":{"start":{"line":7,"column":2,"index":248},"end":{"line":7,"column":36,"index":282},"filename":"retry-no-emit.ts"},"decorations":[{"start":{"line":7,"column":31,"index":277},"end":{"line":7,"column":34,"index":280},"filename":"retry-no-emit.ts","identifierName":"arr"}]}
{"kind":"AutoDepsDecorations","fnLoc":{"start":{"line":10,"column":2,"index":306},"end":{"line":10,"column":44,"index":348},"filename":"retry-no-emit.ts"},"decorations":[{"start":{"line":10,"column":25,"index":329},"end":{"line":10,"column":29,"index":333},"filename":"retry-no-emit.ts","identifierName":"arr2"},{"start":{"line":10,"column":25,"index":329},"end":{"line":10,"column":29,"index":333},"filename":"retry-no-emit.ts","identifierName":"arr2"},{"start":{"line":10,"column":35,"index":339},"end":{"line":10,"column":42,"index":346},"filename":"retry-no-emit.ts","identifierName":"propVal"}]}
{"kind":"CompileSuccess","fnLoc":{"start":{"line":5,"column":0,"index":195},"end":{"line":13,"column":1,"index":389},"filename":"retry-no-emit.ts"},"fnName":"Foo","memoSlots":0,"memoBlocks":0,"memoValues":0,"prunedMemoBlocks":0,"prunedMemoValues":0}