react/compiler/packages/babel-plugin-react-compiler
Joseph Savona adbc32de32
[compiler] More fbt compatibility (#34887)
In my previous PR I fixed some cases but broke others. So, new approach.
Two phase algorithm:

* First pass is forward data flow to determine all usages of macros.
This is necessary because many of Meta's macros have variants that can
be accessed via properties, eg you can do `macro(...)` but also
`macro.variant(...)`.
* Second pass is backwards data flow to find macro invocations (JSX and
calls) and then merge their operands into the same scope as the macro
call.

Note that this required updating PromoteUsedTemporaries to avoid
promoting macro calls that have interposing instructions between their
creation and usage. Macro calls in general are pure so it should be safe
to reorder them.

In addition, we're now more precise about `<fb:plural>`, `<fbt:param>`,
`fbt.plural()` and `fbt.param()`, which don't actually require all their
arguments to be inlined. The whole point is that the plural/param value
is an arbitrary value (along with a string name). So we no longer
transitively inline the arguments, we just make sure that they don't get
inadvertently promoted to named variables.

One caveat: we actually don't do anything to treat macro functions as
non-mutating, so `fbt.plural()` and friends (function form) may still
sometimes group arguments just due to mutability inference. In a
follow-up, i'll work to infer the types of nested macro functions as
non-mutating.

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[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/facebook/react/pull/34887).
* #34900
* __->__ #34887
2025-10-17 11:37:28 -07:00
..
scripts
src [compiler] More fbt compatibility (#34887) 2025-10-17 11:37:28 -07:00
jest.config.js
package.json [compiler] improve zod v3 backwards compat (#34877) 2025-10-16 09:46:55 -07:00
README.md
tsconfig.json [compiler] Don't leak global __DEV__ type (#34551) 2025-09-22 16:51:57 +02:00
tsup.config.ts

babel-plugin-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.

This package contains the React Compiler Babel plugin use in projects that make use of Babel. You can find instructions for using this plugin here: https://react.dev/learn/react-compiler