Auto merge of #105416 - nnethercote:more-linting-tweaks, r=cjgillot

More linting tweaks

Squeeze a little more blood from this stone.

r? `@cjgillot`

compiler/rustc_lint/src/builtin.rs

@@ -97,6 +97,7 @@ fn pierce_parens(mut expr: &ast::Expr) -> &ast::Expr {
 }
 
 impl EarlyLintPass for WhileTrue {
+    #[inline]
     fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
         if let ast::ExprKind::While(cond, _, label) = &e.kind
             && let cond = pierce_parens(cond)
@@ -361,6 +362,7 @@ impl EarlyLintPass for UnsafeCode {
         }
     }
 
+    #[inline]
     fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
         if let ast::ExprKind::Block(ref blk, _) = e.kind {
             // Don't warn about generated blocks; that'll just pollute the output.
@@ -583,6 +585,7 @@ impl MissingDoc {
 }
 
 impl<'tcx> LateLintPass<'tcx> for MissingDoc {
+    #[inline]
     fn enter_lint_attrs(&mut self, _cx: &LateContext<'_>, attrs: &[ast::Attribute]) {
         let doc_hidden = self.doc_hidden()
             || attrs.iter().any(|attr| {

compiler/rustc_lint/src/early.rs

@@ -37,7 +37,9 @@ pub struct EarlyContextAndPasses<'a> {
 }
 
 impl<'a> EarlyContextAndPasses<'a> {
-    fn check_id(&mut self, id: ast::NodeId) {
+    // This always-inlined function is for the hot call site.
+    #[inline(always)]
+    fn inlined_check_id(&mut self, id: ast::NodeId) {
         for early_lint in self.context.buffered.take(id) {
             let BufferedEarlyLint { span, msg, node_id: _, lint_id, diagnostic } = early_lint;
             self.context.lookup_with_diagnostics(
@@ -50,6 +52,11 @@ impl<'a> EarlyContextAndPasses<'a> {
         }
     }
 
+    // This non-inlined function is for the cold call sites.
+    fn check_id(&mut self, id: ast::NodeId) {
+        self.inlined_check_id(id)
+    }
+
     /// Merge the lints specified by any lint attributes into the
     /// current lint context, call the provided function, then reset the
     /// lints in effect to their previous state.
@@ -61,7 +68,7 @@ impl<'a> EarlyContextAndPasses<'a> {
         debug!(?id);
         let push = self.context.builder.push(attrs, is_crate_node, None);
 
-        self.check_id(id);
+        self.inlined_check_id(id);
         debug!("early context: enter_attrs({:?})", attrs);
         run_early_passes!(self, enter_lint_attrs, attrs);
         f(self);

compiler/rustc_lint/src/hidden_unicode_codepoints.rs

@@ -121,6 +121,7 @@ impl EarlyLintPass for HiddenUnicodeCodepoints {
         }
     }
 
+    #[inline]
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
         // byte strings are already handled well enough by `EscapeError::NonAsciiCharInByteString`
         match &expr.kind {

compiler/rustc_lint/src/lib.rs

@@ -127,6 +127,7 @@ fn lint_mod(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
     late::late_lint_mod(tcx, module_def_id, BuiltinCombinedModuleLateLintPass::new());
 }
 
+// See the comment on `BuiltinCombinedEarlyLintPass`, which is similar.
 early_lint_methods!(
     declare_combined_early_lint_pass,
     [
@@ -137,6 +138,9 @@ early_lint_methods!(
     ]
 );
 
+// Declare `BuiltinCombinedEarlyLintPass`, a lint pass that combines multiple
+// lint passes into a single pass for maximum speed. Each `check_foo` method
+// within this pass simply calls `check_foo` once per listed lint.
 early_lint_methods!(
     declare_combined_early_lint_pass,
     [
@@ -162,7 +166,9 @@ early_lint_methods!(
     ]
 );
 
-// FIXME: Make a separate lint type which do not require typeck tables
+// FIXME: Make a separate lint type which does not require typeck tables.
+
+// See the comment on `BuiltinCombinedEarlyLintPass`, which is similar.
 late_lint_methods!(
     declare_combined_late_lint_pass,
     [
@@ -179,10 +185,10 @@ late_lint_methods!(
             // Keeps a global list of foreign declarations.
             ClashingExternDeclarations: ClashingExternDeclarations::new(),
         ]
-    ],
+    ]
-    ['tcx]
 );
 
+// See the comment on `BuiltinCombinedEarlyLintPass`, which is similar.
 late_lint_methods!(
     declare_combined_late_lint_pass,
     [
@@ -229,8 +235,7 @@ late_lint_methods!(
             NamedAsmLabels: NamedAsmLabels,
             OpaqueHiddenInferredBound: OpaqueHiddenInferredBound,
         ]
-    ],
+    ]
-    ['tcx]
 );
 
 pub fn new_lint_store(internal_lints: bool) -> LintStore {

compiler/rustc_lint/src/passes.rs

@@ -9,49 +9,49 @@ use rustc_span::Span;
 
 #[macro_export]
 macro_rules! late_lint_methods {
-    ($macro:path, $args:tt, [$hir:tt]) => (
+    ($macro:path, $args:tt) => (
-        $macro!($args, [$hir], [
+        $macro!($args, [
-            fn check_body(a: &$hir hir::Body<$hir>);
+            fn check_body(a: &'tcx hir::Body<'tcx>);
-            fn check_body_post(a: &$hir hir::Body<$hir>);
+            fn check_body_post(a: &'tcx hir::Body<'tcx>);
             fn check_crate();
             fn check_crate_post();
-            fn check_mod(a: &$hir hir::Mod<$hir>, b: hir::HirId);
+            fn check_mod(a: &'tcx hir::Mod<'tcx>, b: hir::HirId);
-            fn check_foreign_item(a: &$hir hir::ForeignItem<$hir>);
+            fn check_foreign_item(a: &'tcx hir::ForeignItem<'tcx>);
-            fn check_item(a: &$hir hir::Item<$hir>);
+            fn check_item(a: &'tcx hir::Item<'tcx>);
-            fn check_item_post(a: &$hir hir::Item<$hir>);
+            fn check_item_post(a: &'tcx hir::Item<'tcx>);
-            fn check_local(a: &$hir hir::Local<$hir>);
+            fn check_local(a: &'tcx hir::Local<'tcx>);
-            fn check_block(a: &$hir hir::Block<$hir>);
+            fn check_block(a: &'tcx hir::Block<'tcx>);
-            fn check_block_post(a: &$hir hir::Block<$hir>);
+            fn check_block_post(a: &'tcx hir::Block<'tcx>);
-            fn check_stmt(a: &$hir hir::Stmt<$hir>);
+            fn check_stmt(a: &'tcx hir::Stmt<'tcx>);
-            fn check_arm(a: &$hir hir::Arm<$hir>);
+            fn check_arm(a: &'tcx hir::Arm<'tcx>);
-            fn check_pat(a: &$hir hir::Pat<$hir>);
+            fn check_pat(a: &'tcx hir::Pat<'tcx>);
-            fn check_expr(a: &$hir hir::Expr<$hir>);
+            fn check_expr(a: &'tcx hir::Expr<'tcx>);
-            fn check_expr_post(a: &$hir hir::Expr<$hir>);
+            fn check_expr_post(a: &'tcx hir::Expr<'tcx>);
-            fn check_ty(a: &$hir hir::Ty<$hir>);
+            fn check_ty(a: &'tcx hir::Ty<'tcx>);
-            fn check_generic_param(a: &$hir hir::GenericParam<$hir>);
+            fn check_generic_param(a: &'tcx hir::GenericParam<'tcx>);
-            fn check_generics(a: &$hir hir::Generics<$hir>);
+            fn check_generics(a: &'tcx hir::Generics<'tcx>);
-            fn check_poly_trait_ref(a: &$hir hir::PolyTraitRef<$hir>);
+            fn check_poly_trait_ref(a: &'tcx hir::PolyTraitRef<'tcx>);
             fn check_fn(
-                a: rustc_hir::intravisit::FnKind<$hir>,
+                a: rustc_hir::intravisit::FnKind<'tcx>,
-                b: &$hir hir::FnDecl<$hir>,
+                b: &'tcx hir::FnDecl<'tcx>,
-                c: &$hir hir::Body<$hir>,
+                c: &'tcx hir::Body<'tcx>,
                 d: Span,
                 e: hir::HirId);
-            fn check_trait_item(a: &$hir hir::TraitItem<$hir>);
+            fn check_trait_item(a: &'tcx hir::TraitItem<'tcx>);
-            fn check_impl_item(a: &$hir hir::ImplItem<$hir>);
+            fn check_impl_item(a: &'tcx hir::ImplItem<'tcx>);
-            fn check_impl_item_post(a: &$hir hir::ImplItem<$hir>);
+            fn check_impl_item_post(a: &'tcx hir::ImplItem<'tcx>);
-            fn check_struct_def(a: &$hir hir::VariantData<$hir>);
+            fn check_struct_def(a: &'tcx hir::VariantData<'tcx>);
-            fn check_field_def(a: &$hir hir::FieldDef<$hir>);
+            fn check_field_def(a: &'tcx hir::FieldDef<'tcx>);
-            fn check_variant(a: &$hir hir::Variant<$hir>);
+            fn check_variant(a: &'tcx hir::Variant<'tcx>);
-            fn check_path(a: &hir::Path<$hir>, b: hir::HirId);
+            fn check_path(a: &hir::Path<'tcx>, b: hir::HirId);
-            fn check_attribute(a: &$hir ast::Attribute);
+            fn check_attribute(a: &'tcx ast::Attribute);
 
             /// Called when entering a syntax node that can have lint attributes such
             /// as `#[allow(...)]`. Called with *all* the attributes of that node.
-            fn enter_lint_attrs(a: &$hir [ast::Attribute]);
+            fn enter_lint_attrs(a: &'tcx [ast::Attribute]);
 
             /// Counterpart to `enter_lint_attrs`.
-            fn exit_lint_attrs(a: &$hir [ast::Attribute]);
+            fn exit_lint_attrs(a: &'tcx [ast::Attribute]);
         ]);
     )
 }
@@ -66,21 +66,23 @@ macro_rules! late_lint_methods {
 // contains a few lint-specific methods with no equivalent in `Visitor`.
 
 macro_rules! declare_late_lint_pass {
-    ([], [$hir:tt], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
+    ([], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
-        pub trait LateLintPass<$hir>: LintPass {
+        pub trait LateLintPass<'tcx>: LintPass {
-            $(#[inline(always)] fn $name(&mut self, _: &LateContext<$hir>, $(_: $arg),*) {})*
+            $(#[inline(always)] fn $name(&mut self, _: &LateContext<'tcx>, $(_: $arg),*) {})*
         }
     )
 }
 
-late_lint_methods!(declare_late_lint_pass, [], ['tcx]);
+// Declare the `LateLintPass` trait, which contains empty default definitions
+// for all the `check_*` methods.
+late_lint_methods!(declare_late_lint_pass, []);
 
 impl LateLintPass<'_> for HardwiredLints {}
 
 #[macro_export]
 macro_rules! expand_combined_late_lint_pass_method {
-    ([$($passes:ident),*], $self: ident, $name: ident, $params:tt) => ({
+    ([$($pass:ident),*], $self: ident, $name: ident, $params:tt) => ({
-        $($self.$passes.$name $params;)*
+        $($self.$pass.$name $params;)*
     })
 }
 
@@ -95,28 +97,28 @@ macro_rules! expand_combined_late_lint_pass_methods {
 
 #[macro_export]
 macro_rules! declare_combined_late_lint_pass {
-    ([$v:vis $name:ident, [$($passes:ident: $constructor:expr,)*]], [$hir:tt], $methods:tt) => (
+    ([$v:vis $name:ident, [$($pass:ident: $constructor:expr,)*]], $methods:tt) => (
         #[allow(non_snake_case)]
         $v struct $name {
-            $($passes: $passes,)*
+            $($pass: $pass,)*
         }
 
         impl $name {
             $v fn new() -> Self {
                 Self {
-                    $($passes: $constructor,)*
+                    $($pass: $constructor,)*
                 }
             }
 
             $v fn get_lints() -> LintArray {
                 let mut lints = Vec::new();
-                $(lints.extend_from_slice(&$passes::get_lints());)*
+                $(lints.extend_from_slice(&$pass::get_lints());)*
                 lints
             }
         }
 
         impl<'tcx> LateLintPass<'tcx> for $name {
-            expand_combined_late_lint_pass_methods!([$($passes),*], $methods);
+            expand_combined_late_lint_pass_methods!([$($pass),*], $methods);
         }
 
         #[allow(rustc::lint_pass_impl_without_macro)]
@@ -176,12 +178,14 @@ macro_rules! declare_early_lint_pass {
     )
 }
 
+// Declare the `EarlyLintPass` trait, which contains empty default definitions
+// for all the `check_*` methods.
 early_lint_methods!(declare_early_lint_pass, []);
 
 #[macro_export]
 macro_rules! expand_combined_early_lint_pass_method {
-    ([$($passes:ident),*], $self: ident, $name: ident, $params:tt) => ({
+    ([$($pass:ident),*], $self: ident, $name: ident, $params:tt) => ({
-        $($self.$passes.$name $params;)*
+        $($self.$pass.$name $params;)*
     })
 }
 
@@ -196,28 +200,28 @@ macro_rules! expand_combined_early_lint_pass_methods {
 
 #[macro_export]
 macro_rules! declare_combined_early_lint_pass {
-    ([$v:vis $name:ident, [$($passes:ident: $constructor:expr,)*]], $methods:tt) => (
+    ([$v:vis $name:ident, [$($pass:ident: $constructor:expr,)*]], $methods:tt) => (
         #[allow(non_snake_case)]
         $v struct $name {
-            $($passes: $passes,)*
+            $($pass: $pass,)*
         }
 
         impl $name {
             $v fn new() -> Self {
                 Self {
-                    $($passes: $constructor,)*
+                    $($pass: $constructor,)*
                 }
             }
 
             $v fn get_lints() -> LintArray {
                 let mut lints = Vec::new();
-                $(lints.extend_from_slice(&$passes::get_lints());)*
+                $(lints.extend_from_slice(&$pass::get_lints());)*
                 lints
             }
         }
 
         impl EarlyLintPass for $name {
-            expand_combined_early_lint_pass_methods!([$($passes),*], $methods);
+            expand_combined_early_lint_pass_methods!([$($pass),*], $methods);
         }
 
         #[allow(rustc::lint_pass_impl_without_macro)]

compiler/rustc_lint/src/unused.rs

@@ -949,6 +949,7 @@ impl UnusedParens {
 }
 
 impl EarlyLintPass for UnusedParens {
+    #[inline]
     fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
         match e.kind {
             ExprKind::Let(ref pat, _, _) | ExprKind::ForLoop(ref pat, ..) => {
@@ -1167,6 +1168,7 @@ impl EarlyLintPass for UnusedBraces {
         <Self as UnusedDelimLint>::check_stmt(self, cx, s)
     }
 
+    #[inline]
     fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
         <Self as UnusedDelimLint>::check_expr(self, cx, e);