1 files changed, 251 insertions, 0 deletions
diff --git a/compiler/rustc_lint/src/passes.rs b/compiler/rustc_lint/src/passes.rs
new file mode 100644
index 00000000000..508f3e1ec31
--- /dev/null
+++ b/compiler/rustc_lint/src/passes.rs
@@ -0,0 +1,251 @@
+use crate::context::{EarlyContext, LateContext};
+
+use rustc_session::lint::builtin::HardwiredLints;
+use rustc_session::lint::LintPass;
+
+#[macro_export]
+macro_rules! late_lint_methods {
+    ($macro:path, $args:tt) => (
+        $macro!($args, [
+            fn check_body(a: &'tcx rustc_hir::Body<'tcx>);
+            fn check_body_post(a: &'tcx rustc_hir::Body<'tcx>);
+            fn check_crate();
+            fn check_crate_post();
+            fn check_mod(a: &'tcx rustc_hir::Mod<'tcx>, b: rustc_hir::HirId);
+            fn check_foreign_item(a: &'tcx rustc_hir::ForeignItem<'tcx>);
+            fn check_item(a: &'tcx rustc_hir::Item<'tcx>);
+            fn check_item_post(a: &'tcx rustc_hir::Item<'tcx>);
+            fn check_local(a: &'tcx rustc_hir::Local<'tcx>);
+            fn check_block(a: &'tcx rustc_hir::Block<'tcx>);
+            fn check_block_post(a: &'tcx rustc_hir::Block<'tcx>);
+            fn check_stmt(a: &'tcx rustc_hir::Stmt<'tcx>);
+            fn check_arm(a: &'tcx rustc_hir::Arm<'tcx>);
+            fn check_pat(a: &'tcx rustc_hir::Pat<'tcx>);
+            fn check_expr(a: &'tcx rustc_hir::Expr<'tcx>);
+            fn check_expr_post(a: &'tcx rustc_hir::Expr<'tcx>);
+            fn check_ty(a: &'tcx rustc_hir::Ty<'tcx>);
+            fn check_generic_param(a: &'tcx rustc_hir::GenericParam<'tcx>);
+            fn check_generics(a: &'tcx rustc_hir::Generics<'tcx>);
+            fn check_poly_trait_ref(a: &'tcx rustc_hir::PolyTraitRef<'tcx>);
+            fn check_fn(
+                a: rustc_hir::intravisit::FnKind<'tcx>,
+                b: &'tcx rustc_hir::FnDecl<'tcx>,
+                c: &'tcx rustc_hir::Body<'tcx>,
+                d: rustc_span::Span,
+                e: rustc_span::def_id::LocalDefId);
+            fn check_trait_item(a: &'tcx rustc_hir::TraitItem<'tcx>);
+            fn check_impl_item(a: &'tcx rustc_hir::ImplItem<'tcx>);
+            fn check_impl_item_post(a: &'tcx rustc_hir::ImplItem<'tcx>);
+            fn check_struct_def(a: &'tcx rustc_hir::VariantData<'tcx>);
+            fn check_field_def(a: &'tcx rustc_hir::FieldDef<'tcx>);
+            fn check_variant(a: &'tcx rustc_hir::Variant<'tcx>);
+            fn check_path(a: &rustc_hir::Path<'tcx>, b: rustc_hir::HirId);
+            fn check_attribute(a: &'tcx rustc_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: &'tcx [rustc_ast::Attribute]);
+
+            /// Counterpart to `enter_lint_attrs`.
+            fn exit_lint_attrs(a: &'tcx [rustc_ast::Attribute]);
+        ]);
+    )
+}
+
+/// Trait for types providing lint checks.
+///
+/// Each `check` method checks a single syntax node, and should not
+/// invoke methods recursively (unlike `Visitor`). By default they
+/// do nothing.
+//
+// FIXME: eliminate the duplication with `Visitor`. But this also
+// contains a few lint-specific methods with no equivalent in `Visitor`.
+
+macro_rules! declare_late_lint_pass {
+    ([], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
+        pub trait LateLintPass<'tcx>: LintPass {
+            $(#[inline(always)] fn $name(&mut self, _: &LateContext<'tcx>, $(_: $arg),*) {})*
+        }
+    )
+}
+
+// Declare the `LateLintPass` trait, which contains empty default definitions
+// for all the `check_*` methods.
+late_lint_methods!(declare_late_lint_pass, []);
+
+impl LateLintPass<'_> for HardwiredLints {}
+
+#[macro_export]
+macro_rules! expand_combined_late_lint_pass_method {
+    ([$($pass:ident),*], $self: ident, $name: ident, $params:tt) => ({
+        $($self.$pass.$name $params;)*
+    })
+}
+
+#[macro_export]
+macro_rules! expand_combined_late_lint_pass_methods {
+    ($passes:tt, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
+        $(fn $name(&mut self, context: &$crate::LateContext<'tcx>, $($param: $arg),*) {
+            $crate::expand_combined_late_lint_pass_method!($passes, self, $name, (context, $($param),*));
+        })*
+    )
+}
+
+/// Combines multiple lints passes into a single lint pass, at compile time,
+/// for maximum speed. Each `check_foo` method in `$methods` within this pass
+/// simply calls `check_foo` once per `$pass`. Compare with
+/// `LateLintPassObjects`, which is similar, but combines lint passes at
+/// runtime.
+#[macro_export]
+macro_rules! declare_combined_late_lint_pass {
+    ([$v:vis $name:ident, [$($pass:ident: $constructor:expr,)*]], $methods:tt) => (
+        #[allow(non_snake_case)]
+        $v struct $name {
+            $($pass: $pass,)*
+        }
+
+        impl $name {
+            $v fn new() -> Self {
+                Self {
+                    $($pass: $constructor,)*
+                }
+            }
+
+            $v fn get_lints() -> $crate::LintVec {
+                let mut lints = Vec::new();
+                $(lints.extend_from_slice(&$pass::get_lints());)*
+                lints
+            }
+        }
+
+        impl<'tcx> $crate::LateLintPass<'tcx> for $name {
+            $crate::expand_combined_late_lint_pass_methods!([$($pass),*], $methods);
+        }
+
+        #[allow(rustc::lint_pass_impl_without_macro)]
+        impl $crate::LintPass for $name {
+            fn name(&self) -> &'static str {
+                panic!()
+            }
+        }
+    )
+}
+
+#[macro_export]
+macro_rules! early_lint_methods {
+    ($macro:path, $args:tt) => (
+        $macro!($args, [
+            fn check_param(a: &rustc_ast::Param);
+            fn check_ident(a: rustc_span::symbol::Ident);
+            fn check_crate(a: &rustc_ast::Crate);
+            fn check_crate_post(a: &rustc_ast::Crate);
+            fn check_item(a: &rustc_ast::Item);
+            fn check_item_post(a: &rustc_ast::Item);
+            fn check_local(a: &rustc_ast::Local);
+            fn check_block(a: &rustc_ast::Block);
+            fn check_stmt(a: &rustc_ast::Stmt);
+            fn check_arm(a: &rustc_ast::Arm);
+            fn check_pat(a: &rustc_ast::Pat);
+            fn check_pat_post(a: &rustc_ast::Pat);
+            fn check_expr(a: &rustc_ast::Expr);
+            fn check_expr_post(a: &rustc_ast::Expr);
+            fn check_ty(a: &rustc_ast::Ty);
+            fn check_generic_arg(a: &rustc_ast::GenericArg);
+            fn check_generic_param(a: &rustc_ast::GenericParam);
+            fn check_generics(a: &rustc_ast::Generics);
+            fn check_poly_trait_ref(a: &rustc_ast::PolyTraitRef);
+            fn check_fn(
+                a: rustc_ast::visit::FnKind<'_>,
+                c: rustc_span::Span,
+                d_: rustc_ast::NodeId);
+            fn check_trait_item(a: &rustc_ast::AssocItem);
+            fn check_impl_item(a: &rustc_ast::AssocItem);
+            fn check_variant(a: &rustc_ast::Variant);
+            fn check_attribute(a: &rustc_ast::Attribute);
+            fn check_mac_def(a: &rustc_ast::MacroDef);
+            fn check_mac(a: &rustc_ast::MacCall);
+
+            /// 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: &[rustc_ast::Attribute]);
+
+            /// Counterpart to `enter_lint_attrs`.
+            fn exit_lint_attrs(a: &[rustc_ast::Attribute]);
+
+            fn enter_where_predicate(a: &rustc_ast::WherePredicate);
+            fn exit_where_predicate(a: &rustc_ast::WherePredicate);
+        ]);
+    )
+}
+
+macro_rules! declare_early_lint_pass {
+    ([], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
+        pub trait EarlyLintPass: LintPass {
+            $(#[inline(always)] fn $name(&mut self, _: &EarlyContext<'_>, $(_: $arg),*) {})*
+        }
+    )
+}
+
+// Declare the `EarlyLintPass` trait, which contains empty default definitions
+// for all the `check_*` methods.
+early_lint_methods!(declare_early_lint_pass, []);
+
+#[macro_export]
+macro_rules! expand_combined_early_lint_pass_method {
+    ([$($pass:ident),*], $self: ident, $name: ident, $params:tt) => ({
+        $($self.$pass.$name $params;)*
+    })
+}
+
+#[macro_export]
+macro_rules! expand_combined_early_lint_pass_methods {
+    ($passes:tt, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
+        $(fn $name(&mut self, context: &$crate::EarlyContext<'_>, $($param: $arg),*) {
+            $crate::expand_combined_early_lint_pass_method!($passes, self, $name, (context, $($param),*));
+        })*
+    )
+}
+
+/// Combines multiple lints passes into a single lint pass, at compile time,
+/// for maximum speed. Each `check_foo` method in `$methods` within this pass
+/// simply calls `check_foo` once per `$pass`. Compare with
+/// `EarlyLintPassObjects`, which is similar, but combines lint passes at
+/// runtime.
+#[macro_export]
+macro_rules! declare_combined_early_lint_pass {
+    ([$v:vis $name:ident, [$($pass:ident: $constructor:expr,)*]], $methods:tt) => (
+        #[allow(non_snake_case)]
+        $v struct $name {
+            $($pass: $pass,)*
+        }
+
+        impl $name {
+            $v fn new() -> Self {
+                Self {
+                    $($pass: $constructor,)*
+                }
+            }
+
+            $v fn get_lints() -> $crate::LintVec {
+                let mut lints = Vec::new();
+                $(lints.extend_from_slice(&$pass::get_lints());)*
+                lints
+            }
+        }
+
+        impl $crate::EarlyLintPass for $name {
+            $crate::expand_combined_early_lint_pass_methods!([$($pass),*], $methods);
+        }
+
+        #[allow(rustc::lint_pass_impl_without_macro)]
+        impl $crate::LintPass for $name {
+            fn name(&self) -> &'static str {
+                panic!()
+            }
+        }
+    )
+}
+
+/// A lint pass boxed up as a trait object.
+pub type EarlyLintPassObject = Box<dyn EarlyLintPass + 'static>;
+pub type LateLintPassObject<'tcx> = Box<dyn LateLintPass<'tcx> + 'tcx>;