react/compiler
mofeiZ f457d0b4c6
[compiler][ez] Only fail gating hoisting check for referenced identifiers (#32596)
Reduce false positive bailouts by using the same
`isReferencedIdentifier` logic that the compiler also uses for
determining context variables and a function's own hoisted declarations.

Details:
Previously, we counted every babel identifier as a reference. This is
problematic because babel counts most string symbols as an identifier.

```js
print(x);  // x is an identifier as expected
obj.x      // x is.. also an identifier here
{x: 2}     // x is also an identifier here
```

This PR adds a check for `isReferencedIdentifier`. Note that only
non-lval
references pass this check. This should be fine as we don't need to
hoist function declarations before writes to the same lvalue (which
should error in strict mode anyways)
```js
print(x);  // isReferencedIdentifier(x) -> true
obj.x      // isReferencedIdentifier(x) -> false
{x: 2}     // isReferencedIdentifier(x) -> false
x = 2      // isReferencedIdentifier(x) -> false
```
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/32596).
* __->__ #32596
* #32595
* #32594
* #32593
* #32522
* #32521
2025-03-13 12:10:22 -04:00
..
apps/playground feat(eslint-plugin-react-hooks): merge rule from eslint-plugin-react-compiler into react-hooks plugin (#32416) 2025-03-12 21:43:06 -04:00
docs Update DEVELOPMENT_GUIDE.md (#32281) 2025-03-13 11:45:26 -04:00
fixtures [cleanup] Remove compiler runtime-compat fixture library (#31430) 2024-11-05 14:14:39 -05:00
packages [compiler][ez] Only fail gating hoisting check for referenced identifiers (#32596) 2025-03-13 12:10:22 -04:00
scripts [compiler] Migrate compiler packages to tsup (#32550) 2025-03-07 16:41:55 -05:00
.eslintrc.js [compiler:codegen] Wrap non-ascii characters in JsxExpressionContainer 2024-06-21 10:08:15 -04:00
.gitignore [forgive] Init (#31918) 2025-02-25 12:19:11 -05:00
package.json [compiler] Dedupe @babel/types (#32581) 2025-03-12 17:02:10 -04:00
README.md Update readme and other docs 2024-05-06 14:53:47 -07:00
yarn.lock feat(eslint-plugin-react-hooks): merge rule from eslint-plugin-react-compiler into react-hooks plugin (#32416) 2025-03-12 21:43:06 -04:00

React Compiler

React Compiler is a compiler that optimizes React applications, ensuring that only the minimal parts of components and hooks will re-render when state changes. The compiler also validates that components and hooks follow the Rules of React.

More information about the design and architecture of the compiler are covered in the Design Goals.

More information about developing the compiler itself is covered in the Development Guide.