refactor(codegen): split codegen/artifacts.rs under the file-size cap

changelog.d/11093-artifacts-size-cap.md

@@ -0,0 +1,54 @@
+`crates/perry-codegen/src/codegen/artifacts.rs` sat at 1999 lines — one line
+under the hard 2000-line cap enforced by `scripts/check_file_size.sh`, a
+required `lint` step. With that much headroom, any PR that added even two lines
+to it was blocked outright; #11087 hit exactly that.
+
+Split it along the phase boundaries the single 1958-line `emit_module_artifacts`
+function already marked with `progress.checkpoint(...)`:
+
+- `artifacts.rs` (1999 → 1044 lines): the closure-body loop, the method /
+  fallback / imported-function wrappers, namespace globals and dynamic-import
+  externs, the module entry call, the runtime registration metadata, and the
+  string-pool emission.
+- `class_artifacts.rs` (new, 572 lines): the per-class walk — instance methods
+  and their typed-f64/i32/i1/string, indexed, and proven-`this` clones;
+  computed members; instance and static accessors; the standalone cross-module
+  constructor, including the synthesized `super(...args)` forwarding ctor; and
+  static methods.
+- `export_value_wrappers.rs` (new, 530 lines): the exported function-value
+  surface — live ESM getters for re-exported native named imports, the
+  `__perry_wrap_*` closure-ABI wrapper per top-level user function, the
+  exported-alias wrappers, the renamed-export wrappers (#837), and the
+  sanitize-mismatch raw aliases (#836).
+
+This is a pure move: both extracted blocks are byte-identical to the originals
+(verified by diffing the extracted line ranges against `git show HEAD:`), with
+no renames and no behavior change. Both new modules follow the convention
+already used by `ordinary_method_artifacts.rs` and
+`indexed_method_artifacts.rs` — a `pub(super) XxxCtx<'a>` struct of borrowed
+inputs plus a `pub(super) fn` that destructures it, declared as a plain `mod`
+in `codegen/mod.rs` and imported with explicit named `use`. The new functions
+take their context as `c` so that the class walk's `c.cross_module`
+partial-move read carries over unchanged.
+
+Two edits are not moves:
+
+- `#[derive(Clone, Copy)]` on `OptsView` in `artifact_context.rs`, so the class
+  phase can take the same by-value view without the artifact tail losing its
+  own; every field was already a shared borrow or a scalar.
+- `scripts/shape_descriptor_census_baseline.json` repoints its
+  `object_header_size_bytes(target_triple)` callsite from `artifacts.rs` to
+  `class_artifacts.rs`. That census pins callsites by file path, so a pure move
+  reads to it as one site removed and one added; the multiset is otherwise
+  unchanged (43 `codegen_object_header_size_sites`, as before).
+
+Verified with `bash scripts/check_file_size.sh` (`OK: no Rust source files
+exceed 2000 lines.`), `cargo fmt --all -- --check`, `cargo check -p perry
+--bins`, `cargo test -p perry-codegen --lib` (1674 passed, 0 failed — this
+covers the crate's source-scanning ratchets, `pshape_symbol_reachability` and
+`spec_abi_symbol_reachability` among them, which hold hardcoded file-path
+allowlists), and all 35 static `lint` gates including
+`shape_descriptor_census.py`, `addr_class_inventory.py`,
+`raw_handle_debt.py` (both the plain and the `--no-raise-vs` merge-base
+invocation), `gc_runtime_root_holders.py`, `check_gc_header_constants.py`,
+`workspace_architecture.py` and `check_test_registration.py`.

crates/perry-codegen/src/codegen/artifact_context.rs

@@ -11,6 +11,11 @@ use super::opts::CrossModuleCtx;
 
 /// Read-only view of the `CompileOptions` fields that artifact emission still
 /// references after the pipeline has moved other fields into `CrossModuleCtx`.
+///
+/// `Copy` so a phase module (`class_artifacts`) can take the same view by
+/// value without the artifact tail losing its own; every field is already a
+/// shared borrow or a scalar.
+#[derive(Clone, Copy)]
 pub(super) struct OptsView<'a> {
     pub(super) import_function_prefixes: &'a HashMap<String, String>,
     pub(super) constructor_param_counts: &'a std::collections::BTreeMap<String, usize>,