refactor: split gc/layout.rs and codegen/artifacts.rs under the 2000-line cap (unblocks lint on main)

changelog.d/8212-file-size-cap-split.md

@@ -0,0 +1,7 @@
+**Split `gc/layout.rs` and `codegen/artifacts.rs` back under the 2000-line file cap** (#8212). #8204's header shrink pushed `crates/perry-runtime/src/gc/layout.rs` to 2110 lines and `crates/perry-codegen/src/codegen/artifacts.rs` — which had been sitting at exactly 2000 — to 2005, turning the required `lint` context red on `main` for every open PR. Pure code moves, no behaviour change:
+
+- the typed-shape layout installation protocol (`TypedShapeProof`, `init_typed_shape_layout`, `install_typed_shape_layout_slow`, `js_gc_init_typed_shape_layout`, `js_gc_declare_typed_shape_layout`) moves from `gc/layout.rs` into the new `gc/layout/typed_shape.rs` (2110 → 1778), next to the existing `layout/slot_mask.rs` split; the two extern "C" entry points keep their `crate::gc::` paths via an explicit named re-export;
+- `synthesized_ctor_param_count` moves from `codegen/artifacts.rs` into the new `codegen/ctor_arity.rs` (2005 → 1930);
+- `scripts/shape_descriptor_census_baseline.json` is refreshed mechanically for the one `keys_array` callsite whose file path changed (`raw_member_files` 65 → 66, same site and count).
+
+Validated as relocation-only: zero-warning rebuild of both crates; `perry-runtime --lib` 2522/0/4; full `perry-codegen --no-fail-fast` failure set byte-identical by name to `origin/main` (1493/9 both); `perry --bin perry` 987/0; all GC script gates green.

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

@@ -16,6 +16,7 @@ use super::closure::{
     compile_closure, compile_typed_f64_closure, compile_typed_i1_closure,
     compile_typed_i32_closure, compile_typed_string_closure,
 };
+use super::ctor_arity::synthesized_ctor_param_count;
 use super::entry::compile_module_entry;
 use super::helpers::{
     function_body_returns_generator_object, sanitize, scoped_fn_name, unknown_func_wrapper_name,
@@ -96,82 +97,6 @@ pub(super) struct ModuleArtifactsCtx<'a> {
     pub cross_module: &'a CrossModuleCtx,
 }
 
-/// The standalone-constructor arity Perry emits for `class`, accounting for the
-/// JS spec default ctor `constructor(...args) { super(...args) }` that a class
-/// with NO own constructor but WITH heritage inherits. Walks the ancestor chain
-/// (local `class_table` + cross-module `imported_classes` ctor-param counts +
-/// imported stubs) for the nearest ctor-bearing parent's user arity, mirroring
-/// the `found_params` walk in the per-class ctor emission below.
-///
-/// This MUST agree with the synthesized standalone ctor's actual LLVM signature,
-/// otherwise the runtime registers a different `total_params` than the function
-/// declares and `replay_registered_class_constructor` forwards the wrong number
-/// of args (Next.js wall 51: `class AppRouteRouteMatcher extends
-/// _mod.RouteMatcher {}` emitted a 1-param forwarding ctor but registered it as
-/// 0 params, so `new mod.AppRouteRouteMatcher(def)` dropped `def` before
-/// `RouteMatcher(definition)` ran and every matcher's `this.definition` was a
-/// garbage number).
-fn synthesized_ctor_param_count(
-    class: &perry_hir::Class,
-    class_table: &HashMap<String, &perry_hir::Class>,
-    imported_class_stubs: &[perry_hir::Class],
-    imported_classes: &[super::opts::ImportedClass],
-) -> usize {
-    if let Some(c) = class.constructor.as_ref() {
-        return c.params.len();
-    }
-    // A native parent (`extends Error` / `extends events.EventEmitter`) has its
-    // own native construction path that consumes the construction args directly;
-    // don't synthesize a forwarding ctor for it.
-    if class.native_extends.is_some() {
-        return 0;
-    }
-    // No heritage at all → nothing to forward.
-    if class.extends_name.is_none() && class.extends_expr.is_none() {
-        return 0;
-    }
-    // Walk ancestors for the nearest ctor-bearing parent's user arity.
-    let mut cur = class.extends_name.clone();
-    while let Some(pname) = cur {
-        let imported_ctor_params = imported_classes
-            .iter()
-            .find(|i| i.local_alias.as_deref().unwrap_or(&i.name) == pname.as_str())
-            .map(|ic| ic.constructor_param_count)
-            .unwrap_or(0);
-        if let Some(pclass) = class_table.get(pname.as_str()) {
-            if let Some(pctor) = &pclass.constructor {
-                return pctor.params.len();
-            }
-            if imported_ctor_params > 0 {
-                return imported_ctor_params;
-            }
-            cur = pclass.extends_name.clone();
-        } else if let Some(stub) = imported_class_stubs.iter().find(|c| c.name == pname) {
-            if imported_ctor_params > 0 {
-                return imported_ctor_params;
-            }
-            cur = stub.extends_name.clone();
-        } else {
-            break;
-        }
-    }
-    // The parent's exact ctor arity is genuinely unavailable here in some build
-    // modes: the auto-optimize / standalone path compiles each nested
-    // `node_modules` module with an EMPTY `imported_classes` list and resolves
-    // the cross-module parent purely as a runtime DYNAMIC parent
-    // (`extends_expr` + `js_register_class_parent_dynamic`), so it is absent
-    // from `class_table` and `imported_class_stubs` here. Without a forwarding
-    // signature the synthesized `super()` dropped every construction arg
-    // (Next.js wall 51: `class PagesRouteMatcher extends _mod.RouteMatcher {}`
-    // → `RouteMatcher(definition)` saw garbage → every matcher's
-    // `this.definition` was undefined). Forward a generous fixed band of
-    // positional params: the `new` site pads missing slots with `undefined`,
-    // and a parent ctor reading fewer params ignores the trailing `undefined`s,
-    // so over-declaring is correct for any (non-native) parent up to this band.
-    const UNRESOLVED_PARENT_FWD_ARITY: usize = 8;
-    UNRESOLVED_PARENT_FWD_ARITY
-}
-
 /// Emit the artifact tail: bodies, wrappers, namespace globals, entry
 /// function, string pool. Mirrors the in-prelude execution order of
 /// the original `compile_module`.

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

@@ -0,0 +1,83 @@
+//! Synthesized standalone-constructor arity for classes that inherit the JS
+//! spec default ctor `constructor(...args) { super(...args) }`.
+//!
+//! Split out of `codegen/artifacts.rs` for the 2000-line file cap (#8204 took
+//! it to 2005). Pure code move — no logic change.
+
+use std::collections::HashMap;
+
+/// The standalone-constructor arity Perry emits for `class`, accounting for the
+/// JS spec default ctor `constructor(...args) { super(...args) }` that a class
+/// with NO own constructor but WITH heritage inherits. Walks the ancestor chain
+/// (local `class_table` + cross-module `imported_classes` ctor-param counts +
+/// imported stubs) for the nearest ctor-bearing parent's user arity, mirroring
+/// the `found_params` walk in the per-class ctor emission below.
+///
+/// This MUST agree with the synthesized standalone ctor's actual LLVM signature,
+/// otherwise the runtime registers a different `total_params` than the function
+/// declares and `replay_registered_class_constructor` forwards the wrong number
+/// of args (Next.js wall 51: `class AppRouteRouteMatcher extends
+/// _mod.RouteMatcher {}` emitted a 1-param forwarding ctor but registered it as
+/// 0 params, so `new mod.AppRouteRouteMatcher(def)` dropped `def` before
+/// `RouteMatcher(definition)` ran and every matcher's `this.definition` was a
+/// garbage number).
+pub(super) fn synthesized_ctor_param_count(
+    class: &perry_hir::Class,
+    class_table: &HashMap<String, &perry_hir::Class>,
+    imported_class_stubs: &[perry_hir::Class],
+    imported_classes: &[super::opts::ImportedClass],
+) -> usize {
+    if let Some(c) = class.constructor.as_ref() {
+        return c.params.len();
+    }
+    // A native parent (`extends Error` / `extends events.EventEmitter`) has its
+    // own native construction path that consumes the construction args directly;
+    // don't synthesize a forwarding ctor for it.
+    if class.native_extends.is_some() {
+        return 0;
+    }
+    // No heritage at all → nothing to forward.
+    if class.extends_name.is_none() && class.extends_expr.is_none() {
+        return 0;
+    }
+    // Walk ancestors for the nearest ctor-bearing parent's user arity.
+    let mut cur = class.extends_name.clone();
+    while let Some(pname) = cur {
+        let imported_ctor_params = imported_classes
+            .iter()
+            .find(|i| i.local_alias.as_deref().unwrap_or(&i.name) == pname.as_str())
+            .map(|ic| ic.constructor_param_count)
+            .unwrap_or(0);
+        if let Some(pclass) = class_table.get(pname.as_str()) {
+            if let Some(pctor) = &pclass.constructor {
+                return pctor.params.len();
+            }
+            if imported_ctor_params > 0 {
+                return imported_ctor_params;
+            }
+            cur = pclass.extends_name.clone();
+        } else if let Some(stub) = imported_class_stubs.iter().find(|c| c.name == pname) {
+            if imported_ctor_params > 0 {
+                return imported_ctor_params;
+            }
+            cur = stub.extends_name.clone();
+        } else {
+            break;
+        }
+    }
+    // The parent's exact ctor arity is genuinely unavailable here in some build
+    // modes: the auto-optimize / standalone path compiles each nested
+    // `node_modules` module with an EMPTY `imported_classes` list and resolves
+    // the cross-module parent purely as a runtime DYNAMIC parent
+    // (`extends_expr` + `js_register_class_parent_dynamic`), so it is absent
+    // from `class_table` and `imported_class_stubs` here. Without a forwarding
+    // signature the synthesized `super()` dropped every construction arg
+    // (Next.js wall 51: `class PagesRouteMatcher extends _mod.RouteMatcher {}`
+    // → `RouteMatcher(definition)` saw garbage → every matcher's
+    // `this.definition` was undefined). Forward a generous fixed band of
+    // positional params: the `new` site pads missing slots with `undefined`,
+    // and a parent ctor reading fewer params ignores the trailing `undefined`s,
+    // so over-declaring is correct for any (non-native) parent up to this band.
+    const UNRESOLVED_PARENT_FWD_ARITY: usize = 8;
+    UNRESOLVED_PARENT_FWD_ARITY
+}

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

@@ -179,6 +179,7 @@ mod artifacts;
 mod boxed_locals;
 mod closure;
 mod closure_collect;
+mod ctor_arity;
 #[cfg(test)]
 mod emission_order_tests;
 mod entry;