compiler-port

Port Compiler Pass

Port a compiler pass from TypeScript to Rust end-to-end.

Arguments:

• $ARGUMENTS: Pass name exactly as it appears in Pipeline.ts log entries (e.g., PruneMaybeThrows, SSA, ConstantPropagation)

Step 0: Validate pass name

1. Read compiler/packages/babel-plugin-react-compiler/src/Entrypoint/Pipeline.ts
2. Search for name: '$ARGUMENTS' in log entries
3. If not found, list all available pass names from the log({...name: '...'}) calls and stop
4. Check the kind field of the matching log entry:
   • If kind: 'ast', report that test-rust-port only supports hir and reactive kind passes currently and stop
   • If kind: 'hir' or kind: 'reactive', proceed

Step 1: Determine TS source files and Rust crate

1. Follow the import in Pipeline.ts to find the actual TypeScript file(s) for the pass
2. Map the TS folder to a Rust crate using this mapping:

TypeScript Path	Rust Crate
src/HIR/ (excluding BuildHIR.ts, HIRBuilder.ts)	react_compiler_hir
src/HIR/BuildHIR.ts, src/HIR/HIRBuilder.ts	react_compiler_lowering
src/Babel/, src/Entrypoint/	react_compiler
src/CompilerError.ts	react_compiler_diagnostics
src/ReactiveScopes/	react_compiler_reactive_scopes
src/<Name>/	react_compiler_<name> (1:1, e.g., src/Optimization/ -> react_compiler_optimization)

1. Check if the pass is already ported:
   • Check if the corresponding Rust file exists in the target crate
   • Check if compiler/crates/react_compiler/src/entrypoint/pipeline.rs already calls it
   • If both are true, report the pass is already ported and stop

Step 2: Gather context

Read the following files (all reads happen in main context):

1. Architecture guide: compiler/docs/rust-port/rust-port-architecture.md
2. Pass documentation: Check compiler/packages/babel-plugin-react-compiler/docs/passes/ for docs about this pass
3. TypeScript source: All TypeScript source files for the pass + any helpers imported from the same folder
4. Rust pipeline: compiler/crates/react_compiler/src/entrypoint/pipeline.rs
5. Rust HIR types: Key type files in compiler/crates/react_compiler_hir/src/ (especially hir.rs, environment.rs)
6. Rust reactive types: For reactive passes, also read compiler/crates/react_compiler_hir/src/reactive_function.rs
7. Target crate: If the target crate already exists, read its Cargo.toml, src/lib.rs, and existing files to understand the current structure