From 89409494e3cf0ece89116b4838de609e07290ff1 Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Mon, 27 Nov 2023 21:54:03 +0000 Subject: [PATCH] Actually, just reuse the UNUSED_LIFETIMES lint --- .../src/collect/resolve_bound_vars.rs | 26 ------------- compiler/rustc_lint/messages.ftl | 3 +- .../rustc_lint/src/redundant_lifetime_args.rs | 17 +++----- .../unsatisfied-item-lifetime-bound.rs | 3 -- .../unsatisfied-item-lifetime-bound.stderr | 31 +++++---------- ...on-outlives-static-outlives-free-region.rs | 4 +- ...utlives-static-outlives-free-region.stderr | 8 ++-- .../ui/regions/regions-static-bound-rpass.rs | 7 ++-- .../regions/regions-static-bound-rpass.stderr | 34 +++++++++------- tests/ui/regions/regions-static-bound.rs | 5 --- tests/ui/regions/regions-static-bound.stderr | 38 ++---------------- .../transitively-redundant-lifetimes.rs | 16 ++++++++ .../transitively-redundant-lifetimes.stderr | 39 +++++++++++++++++++ 13 files changed, 107 insertions(+), 124 deletions(-) create mode 100644 tests/ui/regions/transitively-redundant-lifetimes.rs create mode 100644 tests/ui/regions/transitively-redundant-lifetimes.stderr diff --git a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs index 0b8ac9926e4..affd678fc6c 100644 --- a/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs +++ b/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs @@ -20,7 +20,6 @@ use rustc_middle::middle::resolve_bound_vars::*; use rustc_middle::query::Providers; use rustc_middle::ty::{self, TyCtxt, TypeSuperVisitable, TypeVisitor}; -use rustc_session::lint; use rustc_span::def_id::DefId; use rustc_span::symbol::{sym, Ident}; use rustc_span::Span; @@ -867,31 +866,6 @@ fn visit_where_predicate(&mut self, predicate: &'tcx hir::WherePredicate<'tcx>) }) => { self.visit_lifetime(lifetime); walk_list!(self, visit_param_bound, bounds); - - if lifetime.res != hir::LifetimeName::Static { - for bound in bounds { - let hir::GenericBound::Outlives(lt) = bound else { - continue; - }; - if lt.res != hir::LifetimeName::Static { - continue; - } - self.insert_lifetime(lt, ResolvedArg::StaticLifetime); - self.tcx.node_span_lint( - lint::builtin::UNUSED_LIFETIMES, - lifetime.hir_id, - lifetime.ident.span, - format!("unnecessary lifetime parameter `{}`", lifetime.ident), - |lint| { - let help = format!( - "you can use the `'static` lifetime directly, in place of `{}`", - lifetime.ident, - ); - lint.help(help); - }, - ); - } - } } &hir::WherePredicate::EqPredicate(hir::WhereEqPredicate { lhs_ty, rhs_ty, .. }) => { self.visit_ty(lhs_ty); diff --git a/compiler/rustc_lint/messages.ftl b/compiler/rustc_lint/messages.ftl index ad0a5a2b624..cc7a87544bc 100644 --- a/compiler/rustc_lint/messages.ftl +++ b/compiler/rustc_lint/messages.ftl @@ -534,7 +534,8 @@ lint_reason_must_be_string_literal = reason must be a string literal lint_reason_must_come_last = reason in lint attribute must come last -lint_redundant_lifetime_args = lifetime `{$victim}` is required to be equal to `{$candidate}`, and is redundant and can be removed +lint_redundant_lifetime_args = unnecessary lifetime parameter `{$victim}` + .note = you can use the `{$candidate}` lifetime directly, in place of `{$victim}` lint_redundant_semicolons = unnecessary trailing {$multiple -> diff --git a/compiler/rustc_lint/src/redundant_lifetime_args.rs b/compiler/rustc_lint/src/redundant_lifetime_args.rs index 7a7c5387369..59d2edba124 100644 --- a/compiler/rustc_lint/src/redundant_lifetime_args.rs +++ b/compiler/rustc_lint/src/redundant_lifetime_args.rs @@ -8,19 +8,13 @@ use rustc_infer::infer::{SubregionOrigin, TyCtxtInferExt}; use rustc_macros::LintDiagnostic; use rustc_middle::ty::{self, TyCtxt}; +use rustc_session::lint::builtin::UNUSED_LIFETIMES; use rustc_span::DUMMY_SP; use rustc_trait_selection::traits::{outlives_bounds::InferCtxtExt, ObligationCtxt}; use crate::{LateContext, LateLintPass}; -declare_lint! { - /// Docs - pub REDUNDANT_LIFETIME_ARGS, - Allow, - "do something" -} - -declare_lint_pass!(RedundantLifetimeArgs => [REDUNDANT_LIFETIME_ARGS]); +declare_lint_pass!(RedundantLifetimeArgs => []); impl<'tcx> LateLintPass<'tcx> for RedundantLifetimeArgs { fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) { @@ -142,10 +136,10 @@ fn check<'tcx>(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, owner_id: hir:: if infcx.resolve_regions(outlives_env).is_empty() { shadowed.insert(victim); tcx.emit_spanned_lint( - REDUNDANT_LIFETIME_ARGS, + UNUSED_LIFETIMES, tcx.local_def_id_to_hir_id(def_id.expect_local()), tcx.def_span(def_id), - RedundantLifetimeArgsList { candidate, victim }, + RedundantLifetimeArgsLint { candidate, victim }, ); } } @@ -154,7 +148,8 @@ fn check<'tcx>(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, owner_id: hir:: #[derive(LintDiagnostic)] #[diag(lint_redundant_lifetime_args)] -struct RedundantLifetimeArgsList<'tcx> { +#[note] +struct RedundantLifetimeArgsLint<'tcx> { candidate: ty::Region<'tcx>, victim: ty::Region<'tcx>, } diff --git a/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.rs b/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.rs index a3f3b1a6d4d..1d427e89c21 100644 --- a/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.rs +++ b/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.rs @@ -1,8 +1,5 @@ -#![warn(unused_lifetimes)] - pub trait X { type Y<'a: 'static>; - //~^ WARNING unnecessary lifetime parameter } impl X for () { diff --git a/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.stderr b/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.stderr index 8d21b9172c8..cd2422b4f2d 100644 --- a/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.stderr +++ b/tests/ui/generic-associated-types/unsatisfied-item-lifetime-bound.stderr @@ -1,18 +1,5 @@ -warning: unnecessary lifetime parameter `'a` - --> $DIR/unsatisfied-item-lifetime-bound.rs:4:12 - | -LL | type Y<'a: 'static>; - | ^^ - | - = help: you can use the `'static` lifetime directly, in place of `'a` -note: the lint level is defined here - --> $DIR/unsatisfied-item-lifetime-bound.rs:1:9 - | -LL | #![warn(unused_lifetimes)] - | ^^^^^^^^^^^^^^^^ - error[E0478]: lifetime bound not satisfied - --> $DIR/unsatisfied-item-lifetime-bound.rs:9:18 + --> $DIR/unsatisfied-item-lifetime-bound.rs:6:18 | LL | type Y<'a: 'static>; | ------------------- definition of `Y` from trait @@ -21,7 +8,7 @@ LL | type Y<'a> = &'a (); | ^^^^^^ | note: lifetime parameter instantiated with the lifetime `'a` as defined here - --> $DIR/unsatisfied-item-lifetime-bound.rs:9:12 + --> $DIR/unsatisfied-item-lifetime-bound.rs:6:12 | LL | type Y<'a> = &'a (); | ^^ @@ -32,44 +19,44 @@ LL | type Y<'a> = &'a () where 'a: 'static; | +++++++++++++++++ error[E0478]: lifetime bound not satisfied - --> $DIR/unsatisfied-item-lifetime-bound.rs:14:8 + --> $DIR/unsatisfied-item-lifetime-bound.rs:11:8 | LL | f: ::Y<'a>, | ^^^^^^^^^^^^^^^ | note: lifetime parameter instantiated with the lifetime `'a` as defined here - --> $DIR/unsatisfied-item-lifetime-bound.rs:13:10 + --> $DIR/unsatisfied-item-lifetime-bound.rs:10:10 | LL | struct B<'a, T: for<'r> X = &'r ()>> { | ^^ = note: but lifetime parameter must outlive the static lifetime error[E0478]: lifetime bound not satisfied - --> $DIR/unsatisfied-item-lifetime-bound.rs:19:8 + --> $DIR/unsatisfied-item-lifetime-bound.rs:16:8 | LL | f: ::Y<'a>, | ^^^^^^^^^^^^^^^ | note: lifetime parameter instantiated with the lifetime `'a` as defined here - --> $DIR/unsatisfied-item-lifetime-bound.rs:18:10 + --> $DIR/unsatisfied-item-lifetime-bound.rs:15:10 | LL | struct C<'a, T: X> { | ^^ = note: but lifetime parameter must outlive the static lifetime error[E0478]: lifetime bound not satisfied - --> $DIR/unsatisfied-item-lifetime-bound.rs:24:8 + --> $DIR/unsatisfied-item-lifetime-bound.rs:21:8 | LL | f: <() as X>::Y<'a>, | ^^^^^^^^^^^^^^^^ | note: lifetime parameter instantiated with the lifetime `'a` as defined here - --> $DIR/unsatisfied-item-lifetime-bound.rs:23:10 + --> $DIR/unsatisfied-item-lifetime-bound.rs:20:10 | LL | struct D<'a> { | ^^ = note: but lifetime parameter must outlive the static lifetime -error: aborting due to 4 previous errors; 1 warning emitted +error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0478`. diff --git a/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.rs b/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.rs index f6a628e97f5..5778466f92e 100644 --- a/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.rs +++ b/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.rs @@ -10,8 +10,8 @@ #![warn(unused_lifetimes)] -fn test<'a,'b>(x: &'a i32) -> &'b i32 - where 'a: 'static //~ WARN unnecessary lifetime parameter `'a` +fn test<'a,'b>(x: &'a i32) -> &'b i32 //~ WARN unnecessary lifetime parameter `'a` + where 'a: 'static { x } diff --git a/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.stderr b/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.stderr index 9f03a6553ba..69f409f436e 100644 --- a/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.stderr +++ b/tests/ui/regions/regions-free-region-outlives-static-outlives-free-region.stderr @@ -1,10 +1,10 @@ warning: unnecessary lifetime parameter `'a` - --> $DIR/regions-free-region-outlives-static-outlives-free-region.rs:14:11 + --> $DIR/regions-free-region-outlives-static-outlives-free-region.rs:13:9 | -LL | where 'a: 'static - | ^^ +LL | fn test<'a,'b>(x: &'a i32) -> &'b i32 + | ^^ | - = help: you can use the `'static` lifetime directly, in place of `'a` + = note: you can use the `'static` lifetime directly, in place of `'a` note: the lint level is defined here --> $DIR/regions-free-region-outlives-static-outlives-free-region.rs:11:9 | diff --git a/tests/ui/regions/regions-static-bound-rpass.rs b/tests/ui/regions/regions-static-bound-rpass.rs index 27da42882f3..028df1ac598 100644 --- a/tests/ui/regions/regions-static-bound-rpass.rs +++ b/tests/ui/regions/regions-static-bound-rpass.rs @@ -3,16 +3,17 @@ #![warn(unused_lifetimes)] fn invariant_id<'a,'b>(t: &'b mut &'static ()) -> &'b mut &'a () - where 'a: 'static { t } //~^ WARN unnecessary lifetime parameter `'a` + where 'a: 'static { t } fn static_id<'a>(t: &'a ()) -> &'static () - where 'a: 'static { t } //~^ WARN unnecessary lifetime parameter `'a` + where 'a: 'static { t } fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static () +//~^ WARN unnecessary lifetime parameter `'a` +//~| WARN unnecessary lifetime parameter `'b` where 'a: 'b, 'b: 'static { t } -//~^ WARN unnecessary lifetime parameter `'b` fn ref_id<'a>(t: &'a ()) -> &'a () where 'static: 'a { t } diff --git a/tests/ui/regions/regions-static-bound-rpass.stderr b/tests/ui/regions/regions-static-bound-rpass.stderr index f0f3a4c5261..d197266380a 100644 --- a/tests/ui/regions/regions-static-bound-rpass.stderr +++ b/tests/ui/regions/regions-static-bound-rpass.stderr @@ -1,10 +1,10 @@ warning: unnecessary lifetime parameter `'a` - --> $DIR/regions-static-bound-rpass.rs:6:11 + --> $DIR/regions-static-bound-rpass.rs:5:17 | -LL | where 'a: 'static { t } - | ^^ +LL | fn invariant_id<'a,'b>(t: &'b mut &'static ()) -> &'b mut &'a () + | ^^ | - = help: you can use the `'static` lifetime directly, in place of `'a` + = note: you can use the `'static` lifetime directly, in place of `'a` note: the lint level is defined here --> $DIR/regions-static-bound-rpass.rs:3:9 | @@ -12,20 +12,28 @@ LL | #![warn(unused_lifetimes)] | ^^^^^^^^^^^^^^^^ warning: unnecessary lifetime parameter `'a` - --> $DIR/regions-static-bound-rpass.rs:10:11 + --> $DIR/regions-static-bound-rpass.rs:9:14 | -LL | where 'a: 'static { t } - | ^^ +LL | fn static_id<'a>(t: &'a ()) -> &'static () + | ^^ | - = help: you can use the `'static` lifetime directly, in place of `'a` + = note: you can use the `'static` lifetime directly, in place of `'a` + +warning: unnecessary lifetime parameter `'a` + --> $DIR/regions-static-bound-rpass.rs:13:23 + | +LL | fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static () + | ^^ + | + = note: you can use the `'static` lifetime directly, in place of `'a` warning: unnecessary lifetime parameter `'b` - --> $DIR/regions-static-bound-rpass.rs:14:19 + --> $DIR/regions-static-bound-rpass.rs:13:26 | -LL | where 'a: 'b, 'b: 'static { t } - | ^^ +LL | fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static () + | ^^ | - = help: you can use the `'static` lifetime directly, in place of `'b` + = note: you can use the `'static` lifetime directly, in place of `'b` -warning: 3 warnings emitted +warning: 4 warnings emitted diff --git a/tests/ui/regions/regions-static-bound.rs b/tests/ui/regions/regions-static-bound.rs index e7aa8795f01..af6425971bd 100644 --- a/tests/ui/regions/regions-static-bound.rs +++ b/tests/ui/regions/regions-static-bound.rs @@ -1,12 +1,7 @@ -#![warn(unused_lifetimes)] - fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t } -//~^ WARN lifetime parameter `'b` never used -//~| WARN unnecessary lifetime parameter `'a` fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static () where 'a: 'b, 'b: 'static { t } -//~^ WARN unnecessary lifetime parameter `'b` fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a { t diff --git a/tests/ui/regions/regions-static-bound.stderr b/tests/ui/regions/regions-static-bound.stderr index b314e9fe85d..f7b48349e4a 100644 --- a/tests/ui/regions/regions-static-bound.stderr +++ b/tests/ui/regions/regions-static-bound.stderr @@ -1,35 +1,5 @@ -warning: lifetime parameter `'b` never used - --> $DIR/regions-static-bound.rs:3:17 - | -LL | fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t } - | -^^ - | | - | help: elide the unused lifetime - | -note: the lint level is defined here - --> $DIR/regions-static-bound.rs:1:9 - | -LL | #![warn(unused_lifetimes)] - | ^^^^^^^^^^^^^^^^ - -warning: unnecessary lifetime parameter `'a` - --> $DIR/regions-static-bound.rs:3:53 - | -LL | fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t } - | ^^ - | - = help: you can use the `'static` lifetime directly, in place of `'a` - -warning: unnecessary lifetime parameter `'b` - --> $DIR/regions-static-bound.rs:8:19 - | -LL | where 'a: 'b, 'b: 'static { t } - | ^^ - | - = help: you can use the `'static` lifetime directly, in place of `'b` - error: lifetime may not live long enough - --> $DIR/regions-static-bound.rs:12:5 + --> $DIR/regions-static-bound.rs:7:5 | LL | fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a { | -- lifetime `'a` defined here @@ -37,7 +7,7 @@ LL | t | ^ returning this value requires that `'a` must outlive `'static` error[E0521]: borrowed data escapes outside of function - --> $DIR/regions-static-bound.rs:17:5 + --> $DIR/regions-static-bound.rs:12:5 | LL | fn error(u: &(), v: &()) { | - - let's call the lifetime of this reference `'1` @@ -50,7 +20,7 @@ LL | static_id(&u); | argument requires that `'1` must outlive `'static` error[E0521]: borrowed data escapes outside of function - --> $DIR/regions-static-bound.rs:19:5 + --> $DIR/regions-static-bound.rs:14:5 | LL | fn error(u: &(), v: &()) { | - - let's call the lifetime of this reference `'2` @@ -63,6 +33,6 @@ LL | static_id_indirect(&v); | `v` escapes the function body here | argument requires that `'2` must outlive `'static` -error: aborting due to 3 previous errors; 3 warnings emitted +error: aborting due to 3 previous errors For more information about this error, try `rustc --explain E0521`. diff --git a/tests/ui/regions/transitively-redundant-lifetimes.rs b/tests/ui/regions/transitively-redundant-lifetimes.rs new file mode 100644 index 00000000000..3baf2a88abb --- /dev/null +++ b/tests/ui/regions/transitively-redundant-lifetimes.rs @@ -0,0 +1,16 @@ +#![allow(unused)] +#![deny(unused_lifetimes)] + +fn a<'a, 'b>(x: &'a &'b &'a ()) {} //~ ERROR unnecessary lifetime parameter `'b` + +fn b<'a: 'b, 'b: 'a>() {} //~ ERROR unnecessary lifetime parameter `'b` + +struct Foo(T); +fn c<'a>(_: Foo<&'a ()>) {} //~ ERROR unnecessary lifetime parameter `'a` + +struct Bar<'a>(&'a ()); +impl<'a> Bar<'a> { + fn d<'b: 'a>(&'b self) {} //~ ERROR unnecessary lifetime parameter `'b` +} + +fn main() {} diff --git a/tests/ui/regions/transitively-redundant-lifetimes.stderr b/tests/ui/regions/transitively-redundant-lifetimes.stderr new file mode 100644 index 00000000000..22a27115f7a --- /dev/null +++ b/tests/ui/regions/transitively-redundant-lifetimes.stderr @@ -0,0 +1,39 @@ +error: unnecessary lifetime parameter `'b` + --> $DIR/transitively-redundant-lifetimes.rs:4:10 + | +LL | fn a<'a, 'b>(x: &'a &'b &'a ()) {} + | ^^ + | + = note: you can use the `'a` lifetime directly, in place of `'b` +note: the lint level is defined here + --> $DIR/transitively-redundant-lifetimes.rs:2:9 + | +LL | #![deny(unused_lifetimes)] + | ^^^^^^^^^^^^^^^^ + +error: unnecessary lifetime parameter `'b` + --> $DIR/transitively-redundant-lifetimes.rs:6:14 + | +LL | fn b<'a: 'b, 'b: 'a>() {} + | ^^ + | + = note: you can use the `'a` lifetime directly, in place of `'b` + +error: unnecessary lifetime parameter `'a` + --> $DIR/transitively-redundant-lifetimes.rs:9:6 + | +LL | fn c<'a>(_: Foo<&'a ()>) {} + | ^^ + | + = note: you can use the `'static` lifetime directly, in place of `'a` + +error: unnecessary lifetime parameter `'b` + --> $DIR/transitively-redundant-lifetimes.rs:13:10 + | +LL | fn d<'b: 'a>(&'b self) {} + | ^^ + | + = note: you can use the `'a` lifetime directly, in place of `'b` + +error: aborting due to 4 previous errors +