Rename elided_lifetimes_in_paths to lifetimes_hidden_in_paths

Technically, `&u8` has a hidden lifetime that becomes the anonymous
lifetime `&'_ u8` which may then participate in elision in a function
signature. We specifically don't want to warn about usages of the
anonymous lifetime when it is part of elision.

Author: shepmaster

compiler/rustc_baked_icu_data/src/lib.rs

@@ -23,7 +23,8 @@
 #![allow(internal_features)]
 #![feature(rustdoc_internals)]
 #![doc(rust_logo)]
-#![allow(elided_lifetimes_in_paths)]
+#![cfg_attr(bootstrap, allow(elided_lifetimes_in_paths))]
+#![cfg_attr(not(bootstrap), allow(lifetimes_hidden_in_paths))]
 
 mod data {
     include!("data/mod.rs");

compiler/rustc_lint/src/lib.rs

@@ -303,8 +303,8 @@ fn register_builtins(store: &mut LintStore) {
         BARE_TRAIT_OBJECTS,
         UNUSED_EXTERN_CRATES,
         ELLIPSIS_INCLUSIVE_RANGE_PATTERNS,
-        ELIDED_LIFETIMES_IN_PATHS_TIED,
-        ELIDED_LIFETIMES_IN_PATHS_UNTIED,
+        TIED_LIFETIMES_HIDDEN_IN_PATHS,
+        UNTIED_LIFETIMES_HIDDEN_IN_PATHS,
         EXPLICIT_OUTLIVES_REQUIREMENTS,
         // FIXME(#52665, #47816) not always applicable and not all
         // macros are ready for this yet.
@@ -315,9 +315,9 @@ fn register_builtins(store: &mut LintStore) {
     );
 
     add_lint_group!(
-        "elided_lifetimes_in_paths",
-        ELIDED_LIFETIMES_IN_PATHS_TIED,
-        ELIDED_LIFETIMES_IN_PATHS_UNTIED,
+        "lifetimes_hidden_in_paths",
+        TIED_LIFETIMES_HIDDEN_IN_PATHS,
+        UNTIED_LIFETIMES_HIDDEN_IN_PATHS,
     );
 
     // Register renamed and removed lints.
@@ -336,7 +336,8 @@ fn register_builtins(store: &mut LintStore) {
     store.register_renamed("static_mut_ref", "static_mut_refs");
 
     // Register renamed lint groups
-    store.register_renamed_group("elided_lifetime_in_path", "elided_lifetimes_in_paths");
+    store.register_renamed_group("elided_lifetime_in_path", "lifetimes_hidden_in_paths");
+    store.register_renamed_group("elided_lifetimes_in_paths", "lifetimes_hidden_in_paths");
 
     // These were moved to tool lints, but rustc still sees them when compiling normally, before
     // tool lints are registered, so `check_tool_name_for_backwards_compat` doesn't work. Use

compiler/rustc_lint_defs/src/builtin.rs

@@ -39,8 +39,6 @@ declare_lint_pass! {
         DEPRECATED_WHERE_CLAUSE_LOCATION,
         DUPLICATE_MACRO_ATTRIBUTES,
         ELIDED_LIFETIMES_IN_ASSOCIATED_CONSTANT,
-        ELIDED_LIFETIMES_IN_PATHS_TIED,
-        ELIDED_LIFETIMES_IN_PATHS_UNTIED,
         EXPORTED_PRIVATE_DEPENDENCIES,
         FFI_UNWIND_CALLS,
         FORBIDDEN_LINT_GROUPS,
@@ -93,6 +91,7 @@ declare_lint_pass! {
         STATIC_MUT_REFS,
         TEST_UNSTABLE_LINT,
         TEXT_DIRECTION_CODEPOINT_IN_COMMENT,
+        TIED_LIFETIMES_HIDDEN_IN_PATHS,
         TRIVIAL_CASTS,
         TRIVIAL_NUMERIC_CASTS,
         TYVAR_BEHIND_RAW_POINTER,
@@ -113,6 +112,7 @@ declare_lint_pass! {
         UNSTABLE_NAME_COLLISIONS,
         UNSTABLE_SYNTAX_PRE_EXPANSION,
         UNSUPPORTED_CALLING_CONVENTIONS,
+        UNTIED_LIFETIMES_HIDDEN_IN_PATHS,
         UNUSED_ASSIGNMENTS,
         UNUSED_ASSOCIATED_TYPE_BOUNDS,
         UNUSED_ATTRIBUTES,
@@ -1731,14 +1731,14 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `elided_lifetimes_in_paths_tied` lint detects the use of
+    /// The `tied_lifetimes_hidden_in_paths` lint detects the use of
     /// hidden lifetime parameters when those lifetime parameters tie
     /// an input lifetime parameter to an output lifetime parameter.
     ///
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// #![deny(elided_lifetimes_in_paths_tied)]
+    /// #![deny(tied_lifetimes_hidden_in_paths)]
     /// #![deny(warnings)]
     /// struct Foo<'a> {
     ///     x: &'a u32
@@ -1753,7 +1753,7 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// Elided lifetime parameters can make it difficult to see at a glance
+    /// Hidden lifetime parameters can make it difficult to see at a glance
     /// that borrowing is occurring. This lint ensures that lifetime
     /// parameters are always explicitly stated, even if it is the `'_`
     /// [placeholder lifetime].
@@ -1762,22 +1762,22 @@ declare_lint! {
     /// may require a significant transition for old code.
     ///
     /// [placeholder lifetime]: https://doc.rust-lang.org/reference/lifetime-elision.html#lifetime-elision-in-functions
-    pub ELIDED_LIFETIMES_IN_PATHS_TIED,
+    pub TIED_LIFETIMES_HIDDEN_IN_PATHS,
     Allow,
     "hidden lifetime parameters in types are deprecated",
     crate_level_only
 }
 
 declare_lint! {
-    /// The `elided_lifetimes_in_paths_untied` lint detects the use of
+    /// The `untied_lifetimes_hidden_in_paths` lint detects the use of
     /// hidden lifetime parameters when those lifetime parameters do
     /// not tie an input lifetime parameter to an output lifetime
     /// parameter.
     ///
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// #![deny(elided_lifetimes_in_paths_untied)]
+    /// #![deny(untied_lifetimes_hidden_in_paths)]
     /// #![deny(warnings)]
     /// struct Foo<'a> {
     ///     x: &'a u32
@@ -1792,7 +1792,7 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// Elided lifetime parameters can make it difficult to see at a glance
+    /// Hidden lifetime parameters can make it difficult to see at a glance
     /// that borrowing is occurring. This lint ensures that lifetime
     /// parameters are always explicitly stated, even if it is the `'_`
     /// [placeholder lifetime].
@@ -1801,7 +1801,7 @@ declare_lint! {
     /// may require a significant transition for old code.
     ///
     /// [placeholder lifetime]: https://doc.rust-lang.org/reference/lifetime-elision.html#lifetime-elision-in-functions
-    pub ELIDED_LIFETIMES_IN_PATHS_UNTIED,
+    pub UNTIED_LIFETIMES_HIDDEN_IN_PATHS,
     Allow,
     "hidden lifetime parameters in types make it hard to tell when borrowing is happening",
     crate_level_only

compiler/rustc_resolve/src/late.rs

@@ -646,26 +646,26 @@ struct DiagMetadata<'ast> {
 }
 
 #[derive(Debug)]
-enum ResolvedElisionTarget {
-    /// Elision in `&u8` -> `&'_ u8`
+enum HiddenLifetimeTarget {
+    /// Lifetime in `&u8` is hidden (becomes `&'_ u8`)
     TopLevel(NodeId),
-    /// Elision in `Foo` -> `Foo<'_>`
-    Nested(NestedResolvedElisionTarget),
+    /// Lifetime in `Foo` is hidden (becomes `Foo<'_>`)
+    Nested(NestedHiddenLifetimeTarget),
 }
 
-impl ResolvedElisionTarget {
+impl HiddenLifetimeTarget {
     fn node_id(&self) -> NodeId {
         match *self {
             Self::TopLevel(n) => n,
-            Self::Nested(NestedResolvedElisionTarget { segment_id, .. }) => segment_id,
+            Self::Nested(NestedHiddenLifetimeTarget { segment_id, .. }) => segment_id,
         }
     }
 }
 
 #[derive(Debug)]
-struct NestedResolvedElisionTarget {
+struct NestedHiddenLifetimeTarget {
     segment_id: NodeId,
-    elided_lifetime_span: Span,
+    lifetime_span: Span,
     diagnostic: lint::BuiltinLintDiag,
 }
 
@@ -710,8 +710,8 @@ struct LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
     /// Count the number of places a lifetime is used.
     lifetime_uses: FxHashMap<LocalDefId, LifetimeUseSet>,
 
-    /// Track which types participated in lifetime elision
-    resolved_lifetime_elisions: Vec<ResolvedElisionTarget>,
+    /// Track which parameters/return values had hidden lifetimes.
+    hidden_lifetimes: Vec<HiddenLifetimeTarget>,
 }
 
 /// Walks the whole crate in DFS order, visiting each item, resolving names as it goes.
@@ -1325,7 +1325,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             // errors at module scope should always be reported
             in_func_body: false,
             lifetime_uses: Default::default(),
-            resolved_lifetime_elisions: Vec::new(),
+            hidden_lifetimes: Vec::new(),
         }
     }
 
@@ -1760,7 +1760,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         );
         self.resolve_anonymous_lifetime(&lt, true);
 
-        self.resolved_lifetime_elisions.push(ResolvedElisionTarget::TopLevel(anchor_id));
+        self.hidden_lifetimes.push(HiddenLifetimeTarget::TopLevel(anchor_id));
     }
 
     #[instrument(level = "debug", skip(self))]
@@ -1972,10 +1972,10 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             }
 
             if should_lint {
-                self.resolved_lifetime_elisions.push(ResolvedElisionTarget::Nested(
-                    NestedResolvedElisionTarget {
+                self.hidden_lifetimes.push(HiddenLifetimeTarget::Nested(
+                    NestedHiddenLifetimeTarget {
                         segment_id,
-                        elided_lifetime_span,
+                        lifetime_span: elided_lifetime_span,
                         diagnostic: lint::BuiltinLintDiag::ElidedLifetimesInPaths(
                             expected_lifetimes,
                             path_span,
@@ -2026,12 +2026,12 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
         inputs: impl Iterator<Item = (Option<&'ast Pat>, &'ast Ty)> + Clone,
         output_ty: &'ast FnRetTy,
     ) {
-        let outer_resolved_lifetime_elisions = take(&mut self.resolved_lifetime_elisions);
+        let outer_hidden_lifetimes = take(&mut self.hidden_lifetimes);
 
         // Add each argument to the rib.
         let elision_lifetime = self.resolve_fn_params(has_self, inputs);
         debug!(?elision_lifetime);
-        let param_resolved_lifetime_elisions = take(&mut self.resolved_lifetime_elisions);
+        let param_hidden_lifetimes = take(&mut self.hidden_lifetimes);
 
         let outer_failures = take(&mut self.diag_metadata.current_elision_failures);
 
@@ -2059,31 +2059,30 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             }
         };
 
-        // We've recorded all elisions that occurred in the params and
-        // outputs, categorized by top-level or nested.
+        // We've recorded all hidden lifetimes that occurred in the
+        // params and outputs, categorized by top-level or nested.
         //
         // Our primary lint case is when an output lifetime is tied to
         // an input lifetime. In that case, we want to warn about any
         // nested hidden lifetimes in those params or outputs.
         //
-        // The secondary case is for nested elisions that are not part
-        // of the tied lifetime relationship.
+        // The secondary case is for nested hidden lifetimes that are
+        // not part of the tied lifetime relationship.
 
-        let output_resolved_lifetime_elisions =
-            replace(&mut self.resolved_lifetime_elisions, outer_resolved_lifetime_elisions);
+        let output_hidden_lifetimes = replace(&mut self.hidden_lifetimes, outer_hidden_lifetimes);
 
-        match (output_resolved_lifetime_elisions.is_empty(), elision_lifetime) {
+        match (output_hidden_lifetimes.is_empty(), elision_lifetime) {
             (true, _) | (_, None) => {
                 // Treat all parameters as untied
-                self.report_elided_lifetimes_in_paths(
-                    param_resolved_lifetime_elisions,
-                    lint::builtin::ELIDED_LIFETIMES_IN_PATHS_UNTIED,
+                self.report_lifetimes_hidden_in_paths(
+                    param_hidden_lifetimes,
+                    lint::builtin::UNTIED_LIFETIMES_HIDDEN_IN_PATHS,
                 );
             }
             (false, Some(elision_lifetime)) => {
                 let (primary, secondary): (Vec<_>, Vec<_>) =
-                    param_resolved_lifetime_elisions.into_iter().partition(|re| {
-                        // Recover the `NodeId` of an elided lifetime
+                    param_hidden_lifetimes.into_iter().partition(|re| {
+                        // Recover the `NodeId` of a hidden lifetime
                         let lvl1 = &self.r.lifetimes_res_map[&re.node_id()];
                         let lvl2 = match lvl1 {
                             LifetimeRes::ElidedAnchor { start, .. } => {
@@ -2095,32 +2094,32 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
                         lvl2 == &elision_lifetime
                     });
 
-                self.report_elided_lifetimes_in_paths(
-                    primary.into_iter().chain(output_resolved_lifetime_elisions),
-                    lint::builtin::ELIDED_LIFETIMES_IN_PATHS_TIED,
+                self.report_lifetimes_hidden_in_paths(
+                    primary.into_iter().chain(output_hidden_lifetimes),
+                    lint::builtin::TIED_LIFETIMES_HIDDEN_IN_PATHS,
                 );
-                self.report_elided_lifetimes_in_paths(
+                self.report_lifetimes_hidden_in_paths(
                     secondary,
-                    lint::builtin::ELIDED_LIFETIMES_IN_PATHS_UNTIED,
+                    lint::builtin::UNTIED_LIFETIMES_HIDDEN_IN_PATHS,
                 );
             }
         }
     }
 
-    fn report_elided_lifetimes_in_paths(
+    fn report_lifetimes_hidden_in_paths(
         &mut self,
-        resolved_elisions: impl IntoIterator<Item = ResolvedElisionTarget>,
+        hidden_lifetimes: impl IntoIterator<Item = HiddenLifetimeTarget>,
         lint: &'static lint::Lint,
     ) {
-        for re in resolved_elisions {
-            let ResolvedElisionTarget::Nested(d) = re else { continue };
+        for hl in hidden_lifetimes {
+            let HiddenLifetimeTarget::Nested(n) = hl else { continue };
 
-            let NestedResolvedElisionTarget { segment_id, elided_lifetime_span, diagnostic } = d;
+            let NestedHiddenLifetimeTarget { segment_id, lifetime_span, diagnostic } = n;
 
             self.r.lint_buffer.buffer_lint_with_diagnostic(
                 lint,
                 segment_id,
-                elided_lifetime_span,
+                lifetime_span,
                 "hidden lifetime parameters in types are deprecated",
                 diagnostic,
             );

src/tools/lint-docs/src/groups.rs

@@ -11,7 +11,7 @@ static GROUP_DESCRIPTIONS: &[(&str, &str)] = &[
     ("let-underscore", "Lints that detect wildcard let bindings that are likely to be invalid"),
     ("rustdoc", "Rustdoc-specific lints"),
     ("rust-2018-idioms", "Lints to nudge you toward idiomatic features of Rust 2018"),
-    ("elided-lifetimes-in-paths", "Lints that detect the use of hidden lifetime parameters"),
+    ("lifetimes-hidden-in-paths", "Lints that detect the use of hidden lifetime parameters"),
     ("nonstandard-style", "Violation of standard naming conventions"),
     ("future-incompatible", "Lints that detect code that has future-compatibility problems"),
     ("rust-2018-compatibility", "Lints used to transition code from the 2015 edition to 2018"),

tests/ui/lifetimes/elided-lifetime-in-path-details.rs

@@ -1,7 +1,7 @@
 //@revisions: tied untied
 
-#![cfg_attr(tied, deny(elided_lifetimes_in_paths_tied))]
-#![cfg_attr(untied, deny(elided_lifetimes_in_paths_untied))]
+#![cfg_attr(tied, deny(tied_lifetimes_hidden_in_paths))]
+#![cfg_attr(untied, deny(untied_lifetimes_hidden_in_paths))]
 
 struct ContainsLifetime<'a>(&'a u8);
 

tests/ui/lifetimes/elided-lifetime-in-path-details.tied.stderr

@@ -7,7 +7,7 @@ LL |     ContainsLifetime
 note: the lint level is defined here
   --> $DIR/elided-lifetime-in-path-details.rs:3:24
    |
-LL | #![cfg_attr(tied, deny(elided_lifetimes_in_paths_tied))]
+LL | #![cfg_attr(tied, deny(tied_lifetimes_hidden_in_paths))]
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: indicate the anonymous lifetime
    |

tests/ui/lifetimes/elided-lifetime-in-path-details.untied.stderr

@@ -7,7 +7,7 @@ LL | fn nested_parameter(v: ContainsLifetime) {}
 note: the lint level is defined here
   --> $DIR/elided-lifetime-in-path-details.rs:4:26
    |
-LL | #![cfg_attr(untied, deny(elided_lifetimes_in_paths_untied))]
+LL | #![cfg_attr(untied, deny(untied_lifetimes_hidden_in_paths))]
    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 help: indicate the anonymous lifetime
    |

tests/ui/lifetimes/issue-91763.rs

@@ -1,6 +1,6 @@
 //@ aux-build:issue-91763-aux.rs
 
-#![deny(elided_lifetimes_in_paths)]
+#![deny(lifetimes_hidden_in_paths)]
 
 extern crate issue_91763_aux;
 

tests/ui/lifetimes/issue-91763.stderr

@@ -7,9 +7,9 @@ LL | fn f() -> Ptr<Thing>;
 note: the lint level is defined here
   --> $DIR/issue-91763.rs:3:9
    |
-LL | #![deny(elided_lifetimes_in_paths)]
+LL | #![deny(lifetimes_hidden_in_paths)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
-   = note: `#[deny(elided_lifetimes_in_paths_untied)]` implied by `#[deny(elided_lifetimes_in_paths)]`
+   = note: `#[deny(untied_lifetimes_hidden_in_paths)]` implied by `#[deny(lifetimes_hidden_in_paths)]`
 help: indicate the anonymous lifetime
    |
 LL | fn f() -> Ptr<Thing><'_>;

tests/ui/lint/force-warn/allowed-by-default-lint.rs

@@ -1,5 +1,5 @@
 // --force-warn $LINT causes $LINT (which is allow-by-default) to warn
-//@ compile-flags: --force-warn elided_lifetimes_in_paths
+//@ compile-flags: --force-warn lifetimes_hidden_in_paths
 //@ check-pass
 
 struct Foo<'a> {

tests/ui/lint/force-warn/allowed-by-default-lint.stderr

@@ -4,8 +4,8 @@ warning: hidden lifetime parameters in types are deprecated
 LL | fn foo(x: &Foo) {}
    |            ^^^ expected lifetime parameter
    |
-   = note: `--force-warn elided-lifetimes-in-paths-untied` implied by `--force-warn elided-lifetimes-in-paths`
-   = help: to override `--force-warn elided-lifetimes-in-paths` add `#[allow(elided_lifetimes_in_paths_untied)]`
+   = note: `--force-warn untied-lifetimes-hidden-in-paths` implied by `--force-warn lifetimes-hidden-in-paths`
+   = help: to override `--force-warn lifetimes-hidden-in-paths` add `#[allow(untied_lifetimes_hidden_in_paths)]`
 help: indicate the anonymous lifetime
    |
 LL | fn foo(x: &Foo<'_>) {}