Extend declare_lint_pass! macro (#228)

BD103 · TimJentzsch · web-flow · commit 12635b759780 · 2025-01-17T23:18:51.000Z
Often lints need to compare [`Symbol`](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/symbol/struct.Symbol.html)s. Some lints take the inefficient route by interning the string each time: ```rust if ident.name == Symbol::intern("component") { // ... } // Also seen as... if ident.name == sym!(component) { // ... } ``` This is bad because interning a string is quite expensive. To avoid this, lint passes cache the `Symbol`: ```rust struct MyLintPass { component_sym: Symbol, } impl Default for MyLintPass { fn default() -> Self { Self { component_sym: Symbol::intern("component") } } } impl<'tcx> LateLintPass<'tcx> for MyLintPass { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &Expr<'tcx>) { // ... if ident.name == self.component_sym { // ... } } } ``` This requires a lot of boilerplate. To shorten this, this PR introduces a custom `declare_bevy_lint_pass!` macro that supports cached values: ```rust declare_bevy_lint_pass! { MyLintPass => [MY_LINT.lint], @default = { component: Symbol = sym!("component"), }, } ``` Eventually this macro will be used to declare custom lint config, but for now it just supports default values. I've migrated all existing lints to use `declare_bevy_lint_pass!`. --------- Co-authored-by: TimJentzsch <commits@timjen.net>
diff --git a/bevy_lint/src/lib.rs b/bevy_lint/src/lib.rs
@@ -21,6 +21,7 @@ extern crate rustc_hir;
 extern crate rustc_hir_analysis;
 extern crate rustc_interface;
 extern crate rustc_lint;
+extern crate rustc_lint_defs;
 extern crate rustc_middle;
 extern crate rustc_session;
 extern crate rustc_span;
diff --git a/bevy_lint/src/lint.rs b/bevy_lint/src/lint.rs
@@ -101,3 +101,53 @@ macro_rules! declare_bevy_lint {
         };
     };
 }
+
+/// Creates a new [`LintPass`](rustc_lint::LintPass).
+///
+/// This is based on [`declare_lint_pass!`](rustc_lint_defs::declare_lint_pass), but supports more
+/// options.
+///
+/// # Example
+///
+/// ```ignore
+/// declare_bevy_lint_pass! {
+///     // Declares which lints are emitted by this lint pass.
+///     pub LintPassName => [LINT_NAME.lint],
+///
+///     // The following are optional fields, and may be omitted.
+///     //
+///     // Declares fields of the lint pass that are set when `LintPassName::default()` is called.
+///     @default = {
+///         component: Symbol = Symbol::intern("component"),
+///     },
+/// }
+/// ```
+#[macro_export]
+#[doc(hidden)]
+macro_rules! declare_bevy_lint_pass {
+    (
+        $(#[$attr:meta])*
+        $vis:vis $name:ident => [$($lint:expr),* $(,)?],
+
+        $(
+            @default = {
+                $($default_field:ident: $default_ty:ty = $default_value:expr),* $(,)?
+            },
+        )?
+    ) => {
+        $(#[$attr])*
+        $vis struct $name {
+            $($($default_field: $default_ty),*)?
+        }
+
+        impl ::std::default::Default for $name {
+            fn default() -> Self {
+                Self {
+                    $($($default_field: $default_value),*)?
+                }
+            }
+        }
+
+        ::rustc_lint_defs::impl_lint_pass!($name => [$($lint),*]);
+    };
+}
diff --git a/bevy_lint/src/lints/borrowed_reborrowable.rs b/bevy_lint/src/lints/borrowed_reborrowable.rs
@@ -78,13 +78,12 @@
 
 use std::ops::ControlFlow;
 
-use crate::declare_bevy_lint;
+use crate::{declare_bevy_lint, declare_bevy_lint_pass};
 use clippy_utils::{diagnostics::span_lint_and_sugg, ty::match_type};
 use rustc_errors::Applicability;
 use rustc_hir::{intravisit::FnKind, Body, FnDecl, Mutability};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{Interner, Ty, TyKind, TypeVisitable, TypeVisitor};
-use rustc_session::declare_lint_pass;
 use rustc_span::{
     def_id::LocalDefId,
     symbol::{kw, Ident},
@@ -97,8 +96,8 @@ declare_bevy_lint! {
     "parameter takes a mutable reference to a re-borrowable type",
 }
 
-declare_lint_pass! {
-    BorrowedReborrowable => [BORROWED_REBORROWABLE.lint]
+declare_bevy_lint_pass! {
+    pub BorrowedReborrowable => [BORROWED_REBORROWABLE.lint],
 }
 
 impl<'tcx> LateLintPass<'tcx> for BorrowedReborrowable {
diff --git a/bevy_lint/src/lints/insert_event_resource.rs b/bevy_lint/src/lints/insert_event_resource.rs
@@ -35,16 +35,15 @@
 //! App::new().add_event::<MyEvent>().run();
 //! ```
 
-use crate::declare_bevy_lint;
+use crate::{declare_bevy_lint, declare_bevy_lint_pass};
 use clippy_utils::{
     diagnostics::span_lint_and_sugg, source::snippet_with_applicability, sym, ty::match_type,
 };
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, GenericArg, GenericArgs, Path, PathSegment, QPath};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{Ty, TyKind};
-use rustc_session::declare_lint_pass;
-use rustc_span::Span;
+use rustc_span::{Span, Symbol};
 use std::borrow::Cow;
 
 declare_bevy_lint! {
@@ -53,8 +52,12 @@ declare_bevy_lint! {
     "called `App::insert_resource(Events<T>)` or `App::init_resource::<Events<T>>()` instead of `App::add_event::<T>()`",
 }
 
-declare_lint_pass! {
-    InsertEventResource => [INSERT_EVENT_RESOURCE.lint]
+declare_bevy_lint_pass! {
+    pub InsertEventResource => [INSERT_EVENT_RESOURCE.lint],
+    @default = {
+        insert_resource: Symbol = sym!(insert_resource),
+        init_resource: Symbol = sym!(init_resource),
+    },
 }
 
 impl<'tcx> LateLintPass<'tcx> for InsertEventResource {
@@ -73,10 +76,10 @@ impl<'tcx> LateLintPass<'tcx> for InsertEventResource {
             // If the method is `App::insert_resource()` or `App::init_resource()`, check it with
             // its corresponding function.
             match path.ident.name {
-                symbol if symbol == sym!(insert_resource) => {
+                symbol if symbol == self.insert_resource => {
                     check_insert_resource(cx, args, method_span)
                 }
-                symbol if symbol == sym!(init_resource) => {
+                symbol if symbol == self.init_resource => {
                     check_init_resource(cx, path, method_span)
                 }
                 _ => {}
diff --git a/bevy_lint/src/lints/main_return_without_appexit.rs b/bevy_lint/src/lints/main_return_without_appexit.rs
@@ -30,7 +30,7 @@
 //! }
 //! ```
 
-use crate::declare_bevy_lint;
+use crate::{declare_bevy_lint, declare_bevy_lint_pass};
 use clippy_utils::{
     diagnostics::span_lint_hir_and_then, is_entrypoint_fn, sym, ty::match_type,
     visitors::for_each_expr,
@@ -40,8 +40,7 @@ use rustc_hir::{
     def_id::LocalDefId, intravisit::FnKind, Body, ExprKind, FnDecl, FnRetTy, Ty, TyKind,
 };
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::declare_lint_pass;
-use rustc_span::Span;
+use rustc_span::{Span, Symbol};
 use std::ops::ControlFlow;
 
 declare_bevy_lint! {
@@ -50,8 +49,11 @@ declare_bevy_lint! {
     "an entrypoint that calls `App::run()` does not return `AppExit`",
 }
 
-declare_lint_pass! {
-    MainReturnWithoutAppExit => [MAIN_RETURN_WITHOUT_APPEXIT.lint]
+declare_bevy_lint_pass! {
+    pub MainReturnWithoutAppExit => [MAIN_RETURN_WITHOUT_APPEXIT.lint],
+    @default = {
+        run: Symbol = sym!(run),
+    },
 }
 
 impl<'tcx> LateLintPass<'tcx> for MainReturnWithoutAppExit {
@@ -81,7 +83,7 @@ impl<'tcx> LateLintPass<'tcx> for MainReturnWithoutAppExit {
             for_each_expr(cx, body, |expr| {
                 // Find a method call that matches `.run()`.
                 if let ExprKind::MethodCall(path, src, _, method_span) = expr.kind
-                    && path.ident.name == sym!(run)
+                    && path.ident.name == self.run
                 {
                     // Get the type of `src` for `src.run()`. We peel away all references because
                     // both `App` and `&mut App` are allowed.
diff --git a/bevy_lint/src/lints/missing_reflect.rs b/bevy_lint/src/lints/missing_reflect.rs
@@ -31,7 +31,7 @@
 //! struct MyComponent;
 //! ```
 
-use crate::declare_bevy_lint;
+use crate::{declare_bevy_lint, declare_bevy_lint_pass};
 use clippy_utils::{def_path_res, diagnostics::span_lint_hir_and_then, sugg::DiagExt};
 use rustc_errors::Applicability;
 use rustc_hir::{
@@ -40,7 +40,6 @@ use rustc_hir::{
 };
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::TyCtxt;
-use rustc_session::declare_lint_pass;
 use rustc_span::Span;
 
 declare_bevy_lint! {
@@ -51,8 +50,8 @@ declare_bevy_lint! {
     @crate_level_only = true,
 }
 
-declare_lint_pass! {
-    MissingReflect => [MISSING_REFLECT.lint]
+declare_bevy_lint_pass! {
+    pub MissingReflect => [MISSING_REFLECT.lint],
 }
 
 impl<'tcx> LateLintPass<'tcx> for MissingReflect {
diff --git a/bevy_lint/src/lints/mod.rs b/bevy_lint/src/lints/mod.rs
@@ -32,11 +32,15 @@ pub(crate) fn register_lints(store: &mut LintStore) {
 }
 
 pub(crate) fn register_passes(store: &mut LintStore) {
-    store.register_late_pass(|_| Box::new(borrowed_reborrowable::BorrowedReborrowable));
-    store.register_late_pass(|_| Box::new(insert_event_resource::InsertEventResource));
-    store.register_late_pass(|_| Box::new(main_return_without_appexit::MainReturnWithoutAppExit));
-    store.register_late_pass(|_| Box::new(missing_reflect::MissingReflect));
-    store.register_late_pass(|_| Box::new(panicking_methods::PanickingMethods));
-    store.register_late_pass(|_| Box::new(plugin_not_ending_in_plugin::PluginNotEndingInPlugin));
-    store.register_late_pass(|_| Box::new(zst_query::ZstQuery));
+    store.register_late_pass(|_| Box::new(borrowed_reborrowable::BorrowedReborrowable::default()));
+    store.register_late_pass(|_| Box::new(insert_event_resource::InsertEventResource::default()));
+    store.register_late_pass(|_| {
+        Box::new(main_return_without_appexit::MainReturnWithoutAppExit::default())
+    });
+    store.register_late_pass(|_| Box::new(missing_reflect::MissingReflect::default()));
+    store.register_late_pass(|_| Box::new(panicking_methods::PanickingMethods::default()));
+    store.register_late_pass(|_| {
+        Box::new(plugin_not_ending_in_plugin::PluginNotEndingInPlugin::default())
+    });
+    store.register_late_pass(|_| Box::new(zst_query::ZstQuery::default()));
 }
diff --git a/bevy_lint/src/lints/panicking_methods.rs b/bevy_lint/src/lints/panicking_methods.rs
@@ -76,7 +76,7 @@
 //! # bevy::ecs::system::assert_is_system(graceful_world);
 //! ```
 
-use crate::declare_bevy_lint;
+use crate::{declare_bevy_lint, declare_bevy_lint_pass};
 use clippy_utils::{
     diagnostics::span_lint_and_help,
     source::{snippet, snippet_opt},
@@ -85,7 +85,6 @@ use clippy_utils::{
 use rustc_hir::{Expr, ExprKind, GenericArgs};
 use rustc_lint::{LateContext, LateLintPass, Lint};
 use rustc_middle::ty::Ty;
-use rustc_session::declare_lint_pass;
 use rustc_span::{Span, Symbol};
 
 declare_bevy_lint! {
@@ -100,8 +99,8 @@ declare_bevy_lint! {
     "called a `World` method that can panic when a non-panicking alternative exists",
 }
 
-declare_lint_pass! {
-    PanickingMethods => [PANICKING_QUERY_METHODS.lint, PANICKING_WORLD_METHODS.lint]
+declare_bevy_lint_pass! {
+    pub PanickingMethods => [PANICKING_QUERY_METHODS.lint, PANICKING_WORLD_METHODS.lint],
 }
 
 impl<'tcx> LateLintPass<'tcx> for PanickingMethods {
diff --git a/bevy_lint/src/lints/plugin_not_ending_in_plugin.rs b/bevy_lint/src/lints/plugin_not_ending_in_plugin.rs
@@ -37,12 +37,11 @@
 //! }
 //! ```
 
-use crate::declare_bevy_lint;
+use crate::{declare_bevy_lint, declare_bevy_lint_pass};
 use clippy_utils::{diagnostics::span_lint_hir_and_then, match_def_path, path_res};
 use rustc_errors::Applicability;
 use rustc_hir::{def::Res, HirId, Item, ItemKind, OwnerId};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::declare_lint_pass;
 use rustc_span::symbol::Ident;
 
 declare_bevy_lint! {
@@ -51,8 +50,8 @@ declare_bevy_lint! {
     "implemented `Plugin` for a structure whose name does not end in \"Plugin\"",
 }
 
-declare_lint_pass! {
-    PluginNotEndingInPlugin => [PLUGIN_NOT_ENDING_IN_PLUGIN.lint]
+declare_bevy_lint_pass! {
+    pub PluginNotEndingInPlugin => [PLUGIN_NOT_ENDING_IN_PLUGIN.lint],
 }
 
 impl<'tcx> LateLintPass<'tcx> for PluginNotEndingInPlugin {
diff --git a/bevy_lint/src/lints/zst_query.rs b/bevy_lint/src/lints/zst_query.rs
@@ -32,7 +32,7 @@
 //! ```
 
 use crate::{
-    declare_bevy_lint,
+    declare_bevy_lint, declare_bevy_lint_pass,
     utils::hir_parse::{detuple, generic_type_at},
 };
 use clippy_utils::{
@@ -46,16 +46,15 @@ use rustc_middle::ty::{
     layout::{LayoutOf, TyAndLayout},
     Ty,
 };
-use rustc_session::declare_lint_pass;
 
 declare_bevy_lint! {
     pub ZST_QUERY,
     RESTRICTION,
     "query for a zero-sized type",
 }
 
-declare_lint_pass! {
-    ZstQuery => [ZST_QUERY.lint]
+declare_bevy_lint_pass! {
+    pub ZstQuery => [ZST_QUERY.lint],
 }
 
 impl<'tcx> LateLintPass<'tcx> for ZstQuery {
