elided_named_lifetimes: allow elided 'static in const/static type annotations

Author: GrigorenkoPV

compiler/rustc_resolve/src/late.rs

@@ -704,6 +704,13 @@ struct LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     /// [`elided_named_lifetimes`](lint::builtin::ELIDED_NAMED_LIFETIMES).
     /// See comments in [`MissingLifetime::id_if_not_fake_or`].
     crate_node_id: NodeId,
+    /// Don't emit [`elided_named_lifetimes`](lint::builtin::ELIDED_NAMED_LIFETIMES)
+    /// when we are in a type annotation for a `const` or `static`.
+    /// ```rust
+    /// const HELLO_WORLD: &str = "Hello, world!";
+    /// static ZEROES: &[u8] = &[0, 0, 0];
+    /// ```
+    allow_elided_static: bool,
 }
 
 /// Walks the whole crate in DFS order, visiting each item, resolving names as it goes.
@@ -1349,6 +1356,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             in_func_body: false,
             lifetime_uses: Default::default(),
             crate_node_id: krate.id,
+            allow_elided_static: false,
         }
     }
 
@@ -1559,6 +1567,13 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         ret
     }
 
+    #[instrument(level = "debug", skip(self))]
+    fn visit_ty_allow_elided_static(&mut self, ty: &'ast Ty) {
+        self.allow_elided_static = true;
+        self.visit_ty(ty);
+        self.allow_elided_static = false;
+    }
+
     #[instrument(level = "debug", skip(self))]
     fn resolve_lifetime(&mut self, lifetime: &'ast Lifetime, use_ctxt: visit::LifetimeCtxt) {
         let ident = lifetime.ident;
@@ -2054,12 +2069,14 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                 debug_assert_eq!(id, missing.id);
                 match res {
                     LifetimeRes::Static => {
-                        self.r.lint_buffer.buffer_lint(
-                            lint::builtin::ELIDED_NAMED_LIFETIMES,
-                            missing.id_if_not_fake_or(self.crate_node_id),
-                            missing.span,
-                            BuiltinLintDiag::ElidedIsStatic { elided: missing.span },
-                        );
+                        if !self.allow_elided_static {
+                            self.r.lint_buffer.buffer_lint(
+                                lint::builtin::ELIDED_NAMED_LIFETIMES,
+                                missing.id_if_not_fake_or(self.crate_node_id),
+                                missing.span,
+                                BuiltinLintDiag::ElidedIsStatic { elided: missing.span },
+                            );
+                        }
                     }
                     LifetimeRes::Param { param, binder } => {
                         self.r.lint_buffer.buffer_lint(
@@ -2606,7 +2623,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             ItemKind::Static(box ast::StaticItem { ref ty, ref expr, .. }) => {
                 self.with_static_rib(def_kind, |this| {
                     this.with_lifetime_rib(LifetimeRibKind::Elided(LifetimeRes::Static), |this| {
-                        this.visit_ty(ty);
+                        this.visit_ty_allow_elided_static(ty);
                     });
                     if let Some(expr) = expr {
                         // We already forbid generic params because of the above item rib,
@@ -2637,7 +2654,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
 
                         this.with_lifetime_rib(
                             LifetimeRibKind::Elided(LifetimeRes::Static),
-                            |this| this.visit_ty(ty),
+                            |this| this.visit_ty_allow_elided_static(ty),
                         );
 
                         if let Some(expr) = expr {