mirror of https://github.com/rust-lang/rust.git
Rollup merge of #118391 - compiler-errors:lifetimes-eq, r=lcnr
Add `REDUNDANT_LIFETIMES` lint to detect lifetimes which are semantically redundant There already is a `UNUSED_LIFETIMES` lint which is fired when we detect where clause bounds like `where 'a: 'static`, however, it doesn't use the full power of lexical region resolution to detect failures. Right now `UNUSED_LIFETIMES` is an `Allow` lint, though presumably we could bump it to warn? I can (somewhat) easily implement a structured suggestion so this can be rustfix'd automatically, since we can just walk through the HIR body, replacing instances of the redundant lifetime. Fixes #118376 r? lcnr
This commit is contained in:
commit
fa696a3629
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@ -46,6 +46,7 @@ impl<'a, T: Clone + IntoDiagArg> IntoDiagArg for &'a T {
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}
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}
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}
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}
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#[macro_export]
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macro_rules! into_diag_arg_using_display {
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macro_rules! into_diag_arg_using_display {
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($( $ty:ty ),+ $(,)?) => {
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($( $ty:ty ),+ $(,)?) => {
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$(
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$(
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@ -355,6 +355,9 @@ hir_analysis_pattern_type_wild_pat = "wildcard patterns are not permitted for pa
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hir_analysis_placeholder_not_allowed_item_signatures = the placeholder `_` is not allowed within types on item signatures for {$kind}
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hir_analysis_placeholder_not_allowed_item_signatures = the placeholder `_` is not allowed within types on item signatures for {$kind}
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.label = not allowed in type signatures
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.label = not allowed in type signatures
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hir_analysis_redundant_lifetime_args = unnecessary lifetime parameter `{$victim}`
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.note = you can use the `{$candidate}` lifetime directly, in place of `{$victim}`
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hir_analysis_requires_note = the `{$trait_name}` impl for `{$ty}` requires that `{$error_predicate}`
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hir_analysis_requires_note = the `{$trait_name}` impl for `{$ty}` requires that `{$error_predicate}`
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hir_analysis_return_type_notation_equality_bound =
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hir_analysis_return_type_notation_equality_bound =
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@ -8,11 +8,13 @@ use rustc_ast as ast;
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use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
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use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexSet};
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use rustc_errors::{codes::*, pluralize, struct_span_code_err, Applicability, ErrorGuaranteed};
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use rustc_errors::{codes::*, pluralize, struct_span_code_err, Applicability, ErrorGuaranteed};
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use rustc_hir as hir;
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use rustc_hir as hir;
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use rustc_hir::def::DefKind;
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use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
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use rustc_hir::def_id::{DefId, LocalDefId, LocalModDefId};
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use rustc_hir::lang_items::LangItem;
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use rustc_hir::lang_items::LangItem;
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use rustc_hir::ItemKind;
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use rustc_hir::ItemKind;
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use rustc_infer::infer::outlives::env::OutlivesEnvironment;
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use rustc_infer::infer::outlives::env::OutlivesEnvironment;
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use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
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use rustc_infer::infer::{self, InferCtxt, TyCtxtInferExt};
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use rustc_macros::LintDiagnostic;
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use rustc_middle::query::Providers;
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use rustc_middle::query::Providers;
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use rustc_middle::ty::print::with_no_trimmed_paths;
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use rustc_middle::ty::print::with_no_trimmed_paths;
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use rustc_middle::ty::trait_def::TraitSpecializationKind;
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use rustc_middle::ty::trait_def::TraitSpecializationKind;
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@ -136,6 +138,8 @@ where
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infcx.implied_bounds_tys_compat(param_env, body_def_id, &assumed_wf_types, false);
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infcx.implied_bounds_tys_compat(param_env, body_def_id, &assumed_wf_types, false);
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let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
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let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
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lint_redundant_lifetimes(tcx, body_def_id, &outlives_env);
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let errors = infcx.resolve_regions(&outlives_env);
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let errors = infcx.resolve_regions(&outlives_env);
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if errors.is_empty() {
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if errors.is_empty() {
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return Ok(());
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return Ok(());
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@ -2010,6 +2014,137 @@ fn check_mod_type_wf(tcx: TyCtxt<'_>, module: LocalModDefId) -> Result<(), Error
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res
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res
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}
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}
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fn lint_redundant_lifetimes<'tcx>(
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tcx: TyCtxt<'tcx>,
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owner_id: LocalDefId,
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outlives_env: &OutlivesEnvironment<'tcx>,
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) {
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let def_kind = tcx.def_kind(owner_id);
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match def_kind {
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DefKind::Struct
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| DefKind::Union
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| DefKind::Enum
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| DefKind::Trait
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| DefKind::TraitAlias
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| DefKind::Fn
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| DefKind::Const
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| DefKind::Impl { of_trait: _ } => {
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// Proceed
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}
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DefKind::AssocFn | DefKind::AssocTy | DefKind::AssocConst => {
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let parent_def_id = tcx.local_parent(owner_id);
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if matches!(tcx.def_kind(parent_def_id), DefKind::Impl { of_trait: true }) {
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// Don't check for redundant lifetimes for associated items of trait
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// implementations, since the signature is required to be compatible
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// with the trait, even if the implementation implies some lifetimes
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// are redundant.
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return;
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}
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}
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DefKind::Mod
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| DefKind::Variant
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| DefKind::TyAlias
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| DefKind::ForeignTy
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| DefKind::TyParam
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| DefKind::ConstParam
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| DefKind::Static { .. }
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| DefKind::Ctor(_, _)
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| DefKind::Macro(_)
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| DefKind::ExternCrate
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| DefKind::Use
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| DefKind::ForeignMod
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| DefKind::AnonConst
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| DefKind::InlineConst
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| DefKind::OpaqueTy
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| DefKind::Field
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| DefKind::LifetimeParam
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| DefKind::GlobalAsm
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| DefKind::Closure => return,
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}
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// The ordering of this lifetime map is a bit subtle.
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//
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// Specifically, we want to find a "candidate" lifetime that precedes a "victim" lifetime,
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// where we can prove that `'candidate = 'victim`.
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//
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// `'static` must come first in this list because we can never replace `'static` with
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// something else, but if we find some lifetime `'a` where `'a = 'static`, we want to
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// suggest replacing `'a` with `'static`.
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let mut lifetimes = vec![tcx.lifetimes.re_static];
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lifetimes.extend(
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ty::GenericArgs::identity_for_item(tcx, owner_id).iter().filter_map(|arg| arg.as_region()),
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);
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// If we are in a function, add its late-bound lifetimes too.
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if matches!(def_kind, DefKind::Fn | DefKind::AssocFn) {
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for var in tcx.fn_sig(owner_id).instantiate_identity().bound_vars() {
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let ty::BoundVariableKind::Region(kind) = var else { continue };
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lifetimes.push(ty::Region::new_late_param(tcx, owner_id.to_def_id(), kind));
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}
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}
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lifetimes.retain(|candidate| candidate.has_name());
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// Keep track of lifetimes which have already been replaced with other lifetimes.
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// This makes sure that if `'a = 'b = 'c`, we don't say `'c` should be replaced by
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// both `'a` and `'b`.
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let mut shadowed = FxHashSet::default();
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for (idx, &candidate) in lifetimes.iter().enumerate() {
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// Don't suggest removing a lifetime twice. We only need to check this
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// here and not up in the `victim` loop because equality is transitive,
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// so if A = C and B = C, then A must = B, so it'll be shadowed too in
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// A's victim loop.
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if shadowed.contains(&candidate) {
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continue;
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}
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for &victim in &lifetimes[(idx + 1)..] {
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// We should only have late-bound lifetimes of the `BrNamed` variety,
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// since we get these signatures straight from `hir_lowering`. And any
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// other regions (ReError/ReStatic/etc.) shouldn't matter, since we
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// can't really suggest to remove them.
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let (ty::ReEarlyParam(ty::EarlyParamRegion { def_id, .. })
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| ty::ReLateParam(ty::LateParamRegion {
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bound_region: ty::BoundRegionKind::BrNamed(def_id, _),
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..
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})) = victim.kind()
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else {
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continue;
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};
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// Do not rename lifetimes not local to this item since they'll overlap
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// with the lint running on the parent. We still want to consider parent
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// lifetimes which make child lifetimes redundant, otherwise we would
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// have truncated the `identity_for_item` args above.
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if tcx.parent(def_id) != owner_id.to_def_id() {
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continue;
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}
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// If `candidate <: victim` and `victim <: candidate`, then they're equal.
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if outlives_env.free_region_map().sub_free_regions(tcx, candidate, victim)
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&& outlives_env.free_region_map().sub_free_regions(tcx, victim, candidate)
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{
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shadowed.insert(victim);
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tcx.emit_node_span_lint(
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rustc_lint_defs::builtin::REDUNDANT_LIFETIMES,
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tcx.local_def_id_to_hir_id(def_id.expect_local()),
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tcx.def_span(def_id),
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RedundantLifetimeArgsLint { candidate, victim },
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);
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}
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}
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}
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}
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#[derive(LintDiagnostic)]
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#[diag(hir_analysis_redundant_lifetime_args)]
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#[note]
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struct RedundantLifetimeArgsLint<'tcx> {
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/// The lifetime we have found to be redundant.
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victim: ty::Region<'tcx>,
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// The lifetime we can replace the victim with.
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candidate: ty::Region<'tcx>,
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}
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pub fn provide(providers: &mut Providers) {
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pub fn provide(providers: &mut Providers) {
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*providers = Providers { check_mod_type_wf, check_well_formed, ..*providers };
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*providers = Providers { check_mod_type_wf, check_well_formed, ..*providers };
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}
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}
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|
|
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@ -20,7 +20,6 @@ use rustc_middle::hir::nested_filter;
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use rustc_middle::middle::resolve_bound_vars::*;
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use rustc_middle::middle::resolve_bound_vars::*;
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use rustc_middle::query::Providers;
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use rustc_middle::query::Providers;
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use rustc_middle::ty::{self, TyCtxt, TypeSuperVisitable, TypeVisitor};
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use rustc_middle::ty::{self, TyCtxt, TypeSuperVisitable, TypeVisitor};
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use rustc_session::lint;
|
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use rustc_span::def_id::DefId;
|
use rustc_span::def_id::DefId;
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use rustc_span::symbol::{sym, Ident};
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use rustc_span::symbol::{sym, Ident};
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use rustc_span::Span;
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use rustc_span::Span;
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|
@ -867,31 +866,6 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
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}) => {
|
}) => {
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self.visit_lifetime(lifetime);
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self.visit_lifetime(lifetime);
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walk_list!(self, visit_param_bound, bounds);
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walk_list!(self, visit_param_bound, bounds);
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|
|
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if lifetime.res != hir::LifetimeName::Static {
|
|
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for bound in bounds {
|
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let hir::GenericBound::Outlives(lt) = bound else {
|
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continue;
|
|
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};
|
|
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if lt.res != hir::LifetimeName::Static {
|
|
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continue;
|
|
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}
|
|
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self.insert_lifetime(lt, ResolvedArg::StaticLifetime);
|
|
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self.tcx.node_span_lint(
|
|
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lint::builtin::UNUSED_LIFETIMES,
|
|
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lifetime.hir_id,
|
|
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lifetime.ident.span,
|
|
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format!("unnecessary lifetime parameter `{}`", lifetime.ident),
|
|
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|lint| {
|
|
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let help = format!(
|
|
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"you can use the `'static` lifetime directly, in place of `{}`",
|
|
||||||
lifetime.ident,
|
|
||||||
);
|
|
||||||
lint.help(help);
|
|
||||||
},
|
|
||||||
);
|
|
||||||
}
|
|
||||||
}
|
|
||||||
}
|
}
|
||||||
&hir::WherePredicate::EqPredicate(hir::WhereEqPredicate { lhs_ty, rhs_ty, .. }) => {
|
&hir::WherePredicate::EqPredicate(hir::WhereEqPredicate { lhs_ty, rhs_ty, .. }) => {
|
||||||
self.visit_ty(lhs_ty);
|
self.visit_ty(lhs_ty);
|
||||||
|
|
|
@ -79,6 +79,7 @@ declare_lint_pass! {
|
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PROC_MACRO_BACK_COMPAT,
|
PROC_MACRO_BACK_COMPAT,
|
||||||
PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
|
PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
|
||||||
PUB_USE_OF_PRIVATE_EXTERN_CRATE,
|
PUB_USE_OF_PRIVATE_EXTERN_CRATE,
|
||||||
|
REDUNDANT_LIFETIMES,
|
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REFINING_IMPL_TRAIT_INTERNAL,
|
REFINING_IMPL_TRAIT_INTERNAL,
|
||||||
REFINING_IMPL_TRAIT_REACHABLE,
|
REFINING_IMPL_TRAIT_REACHABLE,
|
||||||
RENAMED_AND_REMOVED_LINTS,
|
RENAMED_AND_REMOVED_LINTS,
|
||||||
|
@ -1707,6 +1708,33 @@ declare_lint! {
|
||||||
"detects lifetime parameters that are never used"
|
"detects lifetime parameters that are never used"
|
||||||
}
|
}
|
||||||
|
|
||||||
|
declare_lint! {
|
||||||
|
/// The `redundant_lifetimes` lint detects lifetime parameters that are
|
||||||
|
/// redundant because they are equal to another named lifetime.
|
||||||
|
///
|
||||||
|
/// ### Example
|
||||||
|
///
|
||||||
|
/// ```rust,compile_fail
|
||||||
|
/// #[deny(redundant_lifetimes)]
|
||||||
|
///
|
||||||
|
/// // `'a = 'static`, so all usages of `'a` can be replaced with `'static`
|
||||||
|
/// pub fn bar<'a: 'static>() {}
|
||||||
|
///
|
||||||
|
/// // `'a = 'b`, so all usages of `'b` can be replaced with `'a`
|
||||||
|
/// pub fn bar<'a: 'b, 'b: 'a>() {}
|
||||||
|
/// ```
|
||||||
|
///
|
||||||
|
/// {{produces}}
|
||||||
|
///
|
||||||
|
/// ### Explanation
|
||||||
|
///
|
||||||
|
/// Unused lifetime parameters may signal a mistake or unfinished code.
|
||||||
|
/// Consider removing the parameter.
|
||||||
|
pub REDUNDANT_LIFETIMES,
|
||||||
|
Allow,
|
||||||
|
"detects lifetime parameters that are redundant because they are equal to some other named lifetime"
|
||||||
|
}
|
||||||
|
|
||||||
declare_lint! {
|
declare_lint! {
|
||||||
/// The `tyvar_behind_raw_pointer` lint detects raw pointer to an
|
/// The `tyvar_behind_raw_pointer` lint detects raw pointer to an
|
||||||
/// inference variable.
|
/// inference variable.
|
||||||
|
|
|
@ -757,7 +757,7 @@ pub struct GlobalCtxt<'tcx> {
|
||||||
impl<'tcx> GlobalCtxt<'tcx> {
|
impl<'tcx> GlobalCtxt<'tcx> {
|
||||||
/// Installs `self` in a `TyCtxt` and `ImplicitCtxt` for the duration of
|
/// Installs `self` in a `TyCtxt` and `ImplicitCtxt` for the duration of
|
||||||
/// `f`.
|
/// `f`.
|
||||||
pub fn enter<'a: 'tcx, F, R>(&'a self, f: F) -> R
|
pub fn enter<F, R>(&'tcx self, f: F) -> R
|
||||||
where
|
where
|
||||||
F: FnOnce(TyCtxt<'tcx>) -> R,
|
F: FnOnce(TyCtxt<'tcx>) -> R,
|
||||||
{
|
{
|
||||||
|
|
|
@ -5,13 +5,13 @@ use std::fmt::Write;
|
||||||
use std::ops::ControlFlow;
|
use std::ops::ControlFlow;
|
||||||
|
|
||||||
use crate::ty::{
|
use crate::ty::{
|
||||||
AliasTy, Const, ConstKind, FallibleTypeFolder, InferConst, InferTy, Opaque, PolyTraitPredicate,
|
self, AliasTy, Const, ConstKind, FallibleTypeFolder, InferConst, InferTy, Opaque,
|
||||||
Projection, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable, TypeSuperVisitable, TypeVisitable,
|
PolyTraitPredicate, Projection, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable,
|
||||||
TypeVisitor,
|
TypeSuperVisitable, TypeVisitable, TypeVisitor,
|
||||||
};
|
};
|
||||||
|
|
||||||
use rustc_data_structures::fx::FxHashMap;
|
use rustc_data_structures::fx::FxHashMap;
|
||||||
use rustc_errors::{Applicability, Diag, DiagArgValue, IntoDiagArg};
|
use rustc_errors::{into_diag_arg_using_display, Applicability, Diag, DiagArgValue, IntoDiagArg};
|
||||||
use rustc_hir as hir;
|
use rustc_hir as hir;
|
||||||
use rustc_hir::def::DefKind;
|
use rustc_hir::def::DefKind;
|
||||||
use rustc_hir::def_id::DefId;
|
use rustc_hir::def_id::DefId;
|
||||||
|
@ -19,10 +19,9 @@ use rustc_hir::{PredicateOrigin, WherePredicate};
|
||||||
use rustc_span::{BytePos, Span};
|
use rustc_span::{BytePos, Span};
|
||||||
use rustc_type_ir::TyKind::*;
|
use rustc_type_ir::TyKind::*;
|
||||||
|
|
||||||
impl<'tcx> IntoDiagArg for Ty<'tcx> {
|
into_diag_arg_using_display! {
|
||||||
fn into_diag_arg(self) -> DiagArgValue {
|
Ty<'_>,
|
||||||
self.to_string().into_diag_arg()
|
ty::Region<'_>,
|
||||||
}
|
|
||||||
}
|
}
|
||||||
|
|
||||||
impl<'tcx> Ty<'tcx> {
|
impl<'tcx> Ty<'tcx> {
|
||||||
|
|
|
@ -1,8 +1,7 @@
|
||||||
#![warn(unused_lifetimes)]
|
#![warn(unused_lifetimes, redundant_lifetimes)]
|
||||||
|
|
||||||
pub trait X {
|
pub trait X {
|
||||||
type Y<'a: 'static>;
|
type Y<'a: 'static>; //~ WARN unnecessary lifetime parameter `'a`
|
||||||
//~^ WARNING unnecessary lifetime parameter
|
|
||||||
}
|
}
|
||||||
|
|
||||||
impl X for () {
|
impl X for () {
|
||||||
|
|
|
@ -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
|
error[E0478]: lifetime bound not satisfied
|
||||||
--> $DIR/unsatisfied-item-lifetime-bound.rs:9:18
|
--> $DIR/unsatisfied-item-lifetime-bound.rs:8:18
|
||||||
|
|
|
|
||||||
LL | type Y<'a: 'static>;
|
LL | type Y<'a: 'static>;
|
||||||
| ------------------- definition of `Y` from trait
|
| ------------------- 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
|
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:8:12
|
||||||
|
|
|
|
||||||
LL | type Y<'a> = &'a ();
|
LL | type Y<'a> = &'a ();
|
||||||
| ^^
|
| ^^
|
||||||
|
@ -32,44 +19,57 @@ LL | type Y<'a> = &'a () where 'a: 'static;
|
||||||
| +++++++++++++++++
|
| +++++++++++++++++
|
||||||
|
|
||||||
error[E0478]: lifetime bound not satisfied
|
error[E0478]: lifetime bound not satisfied
|
||||||
--> $DIR/unsatisfied-item-lifetime-bound.rs:14:8
|
--> $DIR/unsatisfied-item-lifetime-bound.rs:13:8
|
||||||
|
|
|
|
||||||
LL | f: <T as X>::Y<'a>,
|
LL | f: <T as X>::Y<'a>,
|
||||||
| ^^^^^^^^^^^^^^^
|
| ^^^^^^^^^^^^^^^
|
||||||
|
|
|
|
||||||
note: lifetime parameter instantiated with the lifetime `'a` as defined here
|
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:12:10
|
||||||
|
|
|
|
||||||
LL | struct B<'a, T: for<'r> X<Y<'r> = &'r ()>> {
|
LL | struct B<'a, T: for<'r> X<Y<'r> = &'r ()>> {
|
||||||
| ^^
|
| ^^
|
||||||
= note: but lifetime parameter must outlive the static lifetime
|
= note: but lifetime parameter must outlive the static lifetime
|
||||||
|
|
||||||
error[E0478]: lifetime bound not satisfied
|
error[E0478]: lifetime bound not satisfied
|
||||||
--> $DIR/unsatisfied-item-lifetime-bound.rs:19:8
|
--> $DIR/unsatisfied-item-lifetime-bound.rs:18:8
|
||||||
|
|
|
|
||||||
LL | f: <T as X>::Y<'a>,
|
LL | f: <T as X>::Y<'a>,
|
||||||
| ^^^^^^^^^^^^^^^
|
| ^^^^^^^^^^^^^^^
|
||||||
|
|
|
|
||||||
note: lifetime parameter instantiated with the lifetime `'a` as defined here
|
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:17:10
|
||||||
|
|
|
|
||||||
LL | struct C<'a, T: X> {
|
LL | struct C<'a, T: X> {
|
||||||
| ^^
|
| ^^
|
||||||
= note: but lifetime parameter must outlive the static lifetime
|
= note: but lifetime parameter must outlive the static lifetime
|
||||||
|
|
||||||
error[E0478]: lifetime bound not satisfied
|
error[E0478]: lifetime bound not satisfied
|
||||||
--> $DIR/unsatisfied-item-lifetime-bound.rs:24:8
|
--> $DIR/unsatisfied-item-lifetime-bound.rs:23:8
|
||||||
|
|
|
|
||||||
LL | f: <() as X>::Y<'a>,
|
LL | f: <() as X>::Y<'a>,
|
||||||
| ^^^^^^^^^^^^^^^^
|
| ^^^^^^^^^^^^^^^^
|
||||||
|
|
|
|
||||||
note: lifetime parameter instantiated with the lifetime `'a` as defined here
|
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:22:10
|
||||||
|
|
|
|
||||||
LL | struct D<'a> {
|
LL | struct D<'a> {
|
||||||
| ^^
|
| ^^
|
||||||
= note: but lifetime parameter must outlive the static lifetime
|
= note: but lifetime parameter must outlive the static lifetime
|
||||||
|
|
||||||
|
warning: unnecessary lifetime parameter `'a`
|
||||||
|
--> $DIR/unsatisfied-item-lifetime-bound.rs:4:12
|
||||||
|
|
|
||||||
|
LL | type Y<'a: 'static>;
|
||||||
|
| ^^
|
||||||
|
|
|
||||||
|
= note: you can use the `'static` lifetime directly, in place of `'a`
|
||||||
|
note: the lint level is defined here
|
||||||
|
--> $DIR/unsatisfied-item-lifetime-bound.rs:1:27
|
||||||
|
|
|
||||||
|
LL | #![warn(unused_lifetimes, redundant_lifetimes)]
|
||||||
|
| ^^^^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
error: aborting due to 4 previous errors; 1 warning emitted
|
error: aborting due to 4 previous errors; 1 warning emitted
|
||||||
|
|
||||||
For more information about this error, try `rustc --explain E0478`.
|
For more information about this error, try `rustc --explain E0478`.
|
||||||
|
|
|
@ -8,10 +8,10 @@
|
||||||
//
|
//
|
||||||
// 'a : 'b
|
// 'a : 'b
|
||||||
|
|
||||||
#![warn(unused_lifetimes)]
|
#![warn(redundant_lifetimes)]
|
||||||
|
|
||||||
fn test<'a,'b>(x: &'a i32) -> &'b i32
|
fn test<'a,'b>(x: &'a i32) -> &'b i32 //~ WARN unnecessary lifetime parameter `'a`
|
||||||
where 'a: 'static //~ WARN unnecessary lifetime parameter `'a`
|
where 'a: 'static
|
||||||
{
|
{
|
||||||
x
|
x
|
||||||
}
|
}
|
||||||
|
|
|
@ -1,15 +1,15 @@
|
||||||
warning: unnecessary lifetime parameter `'a`
|
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
|
note: the lint level is defined here
|
||||||
--> $DIR/regions-free-region-outlives-static-outlives-free-region.rs:11:9
|
--> $DIR/regions-free-region-outlives-static-outlives-free-region.rs:11:9
|
||||||
|
|
|
|
||||||
LL | #![warn(unused_lifetimes)]
|
LL | #![warn(redundant_lifetimes)]
|
||||||
| ^^^^^^^^^^^^^^^^
|
| ^^^^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
warning: 1 warning emitted
|
warning: 1 warning emitted
|
||||||
|
|
||||||
|
|
|
@ -1,18 +1,19 @@
|
||||||
//@ run-pass
|
//@ run-pass
|
||||||
|
|
||||||
#![warn(unused_lifetimes)]
|
#![warn(redundant_lifetimes)]
|
||||||
|
|
||||||
fn invariant_id<'a,'b>(t: &'b mut &'static ()) -> &'b mut &'a ()
|
fn invariant_id<'a,'b>(t: &'b mut &'static ()) -> &'b mut &'a ()
|
||||||
where 'a: 'static { t }
|
|
||||||
//~^ WARN unnecessary lifetime parameter `'a`
|
//~^ WARN unnecessary lifetime parameter `'a`
|
||||||
|
where 'a: 'static { t }
|
||||||
|
|
||||||
fn static_id<'a>(t: &'a ()) -> &'static ()
|
fn static_id<'a>(t: &'a ()) -> &'static ()
|
||||||
where 'a: 'static { t }
|
|
||||||
//~^ WARN unnecessary lifetime parameter `'a`
|
//~^ WARN unnecessary lifetime parameter `'a`
|
||||||
|
where 'a: 'static { t }
|
||||||
|
|
||||||
fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static ()
|
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 }
|
where 'a: 'b, 'b: 'static { t }
|
||||||
//~^ WARN unnecessary lifetime parameter `'b`
|
|
||||||
|
|
||||||
fn ref_id<'a>(t: &'a ()) -> &'a () where 'static: 'a { t }
|
fn ref_id<'a>(t: &'a ()) -> &'a () where 'static: 'a { t }
|
||||||
|
|
||||||
|
|
|
@ -1,31 +1,39 @@
|
||||||
warning: unnecessary lifetime parameter `'a`
|
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
|
note: the lint level is defined here
|
||||||
--> $DIR/regions-static-bound-rpass.rs:3:9
|
--> $DIR/regions-static-bound-rpass.rs:3:9
|
||||||
|
|
|
|
||||||
LL | #![warn(unused_lifetimes)]
|
LL | #![warn(redundant_lifetimes)]
|
||||||
| ^^^^^^^^^^^^^^^^
|
| ^^^^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
warning: unnecessary lifetime parameter `'a`
|
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`
|
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
|
||||||
|
|
||||||
|
|
|
@ -1,12 +1,13 @@
|
||||||
#![warn(unused_lifetimes)]
|
#![warn(unused_lifetimes, redundant_lifetimes)]
|
||||||
|
|
||||||
fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t }
|
fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t }
|
||||||
//~^ WARN lifetime parameter `'b` never used
|
//~^ WARN unnecessary lifetime parameter `'a`
|
||||||
//~| WARN unnecessary lifetime parameter `'a`
|
//~| WARN lifetime parameter `'b` never used
|
||||||
|
|
||||||
fn static_id_indirect<'a,'b>(t: &'a ()) -> &'static ()
|
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 }
|
where 'a: 'b, 'b: 'static { t }
|
||||||
//~^ WARN unnecessary lifetime parameter `'b`
|
|
||||||
|
|
||||||
fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a {
|
fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a {
|
||||||
t
|
t
|
||||||
|
|
|
@ -9,27 +9,40 @@ LL | fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t }
|
||||||
note: the lint level is defined here
|
note: the lint level is defined here
|
||||||
--> $DIR/regions-static-bound.rs:1:9
|
--> $DIR/regions-static-bound.rs:1:9
|
||||||
|
|
|
|
||||||
LL | #![warn(unused_lifetimes)]
|
LL | #![warn(unused_lifetimes, redundant_lifetimes)]
|
||||||
| ^^^^^^^^^^^^^^^^
|
| ^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
warning: unnecessary lifetime parameter `'a`
|
warning: unnecessary lifetime parameter `'a`
|
||||||
--> $DIR/regions-static-bound.rs:3:53
|
--> $DIR/regions-static-bound.rs:3:14
|
||||||
|
|
|
|
||||||
LL | fn static_id<'a,'b>(t: &'a ()) -> &'static () where 'a: 'static { t }
|
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`
|
= note: you can use the `'static` lifetime directly, in place of `'a`
|
||||||
|
note: the lint level is defined here
|
||||||
|
--> $DIR/regions-static-bound.rs:1:27
|
||||||
|
|
|
||||||
|
LL | #![warn(unused_lifetimes, redundant_lifetimes)]
|
||||||
|
| ^^^^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
|
warning: unnecessary lifetime parameter `'a`
|
||||||
|
--> $DIR/regions-static-bound.rs:7:23
|
||||||
|
|
|
||||||
|
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`
|
warning: unnecessary lifetime parameter `'b`
|
||||||
--> $DIR/regions-static-bound.rs:8:19
|
--> $DIR/regions-static-bound.rs:7:26
|
||||||
|
|
|
|
||||||
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`
|
||||||
|
|
||||||
error: lifetime may not live long enough
|
error: lifetime may not live long enough
|
||||||
--> $DIR/regions-static-bound.rs:12:5
|
--> $DIR/regions-static-bound.rs:13:5
|
||||||
|
|
|
|
||||||
LL | fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a {
|
LL | fn static_id_wrong_way<'a>(t: &'a ()) -> &'static () where 'static: 'a {
|
||||||
| -- lifetime `'a` defined here
|
| -- lifetime `'a` defined here
|
||||||
|
@ -37,7 +50,7 @@ LL | t
|
||||||
| ^ returning this value requires that `'a` must outlive `'static`
|
| ^ returning this value requires that `'a` must outlive `'static`
|
||||||
|
|
||||||
error[E0521]: borrowed data escapes outside of function
|
error[E0521]: borrowed data escapes outside of function
|
||||||
--> $DIR/regions-static-bound.rs:17:5
|
--> $DIR/regions-static-bound.rs:18:5
|
||||||
|
|
|
|
||||||
LL | fn error(u: &(), v: &()) {
|
LL | fn error(u: &(), v: &()) {
|
||||||
| - - let's call the lifetime of this reference `'1`
|
| - - let's call the lifetime of this reference `'1`
|
||||||
|
@ -50,7 +63,7 @@ LL | static_id(&u);
|
||||||
| argument requires that `'1` must outlive `'static`
|
| argument requires that `'1` must outlive `'static`
|
||||||
|
|
||||||
error[E0521]: borrowed data escapes outside of function
|
error[E0521]: borrowed data escapes outside of function
|
||||||
--> $DIR/regions-static-bound.rs:19:5
|
--> $DIR/regions-static-bound.rs:20:5
|
||||||
|
|
|
|
||||||
LL | fn error(u: &(), v: &()) {
|
LL | fn error(u: &(), v: &()) {
|
||||||
| - - let's call the lifetime of this reference `'2`
|
| - - let's call the lifetime of this reference `'2`
|
||||||
|
@ -63,6 +76,6 @@ LL | static_id_indirect(&v);
|
||||||
| `v` escapes the function body here
|
| `v` escapes the function body here
|
||||||
| argument requires that `'2` must outlive `'static`
|
| argument requires that `'2` must outlive `'static`
|
||||||
|
|
||||||
error: aborting due to 3 previous errors; 3 warnings emitted
|
error: aborting due to 3 previous errors; 4 warnings emitted
|
||||||
|
|
||||||
For more information about this error, try `rustc --explain E0521`.
|
For more information about this error, try `rustc --explain E0521`.
|
||||||
|
|
|
@ -0,0 +1,20 @@
|
||||||
|
#![deny(redundant_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: 'static>(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 ok(x: &'static &()) {}
|
||||||
|
|
||||||
|
trait Tr<'a> {}
|
||||||
|
impl<'a: 'static> Tr<'a> for () {} //~ ERROR unnecessary lifetime parameter `'a`
|
||||||
|
|
||||||
|
fn main() {}
|
|
@ -0,0 +1,47 @@
|
||||||
|
error: unnecessary lifetime parameter `'b`
|
||||||
|
--> $DIR/transitively-redundant-lifetimes.rs:3:10
|
||||||
|
|
|
||||||
|
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:1:9
|
||||||
|
|
|
||||||
|
LL | #![deny(redundant_lifetimes)]
|
||||||
|
| ^^^^^^^^^^^^^^^^^^^
|
||||||
|
|
||||||
|
error: unnecessary lifetime parameter `'b`
|
||||||
|
--> $DIR/transitively-redundant-lifetimes.rs:5:14
|
||||||
|
|
|
||||||
|
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:8:6
|
||||||
|
|
|
||||||
|
LL | fn c<'a>(_: Foo<&'a ()>) {}
|
||||||
|
| ^^
|
||||||
|
|
|
||||||
|
= note: you can use the `'static` lifetime directly, in place of `'a`
|
||||||
|
|
||||||
|
error: unnecessary lifetime parameter `'a`
|
||||||
|
--> $DIR/transitively-redundant-lifetimes.rs:18:6
|
||||||
|
|
|
||||||
|
LL | impl<'a: 'static> Tr<'a> for () {}
|
||||||
|
| ^^
|
||||||
|
|
|
||||||
|
= note: you can use the `'static` lifetime directly, in place of `'a`
|
||||||
|
|
||||||
|
error: unnecessary lifetime parameter `'b`
|
||||||
|
--> $DIR/transitively-redundant-lifetimes.rs:12:10
|
||||||
|
|
|
||||||
|
LL | fn d<'b: 'a>(&'b self) {}
|
||||||
|
| ^^
|
||||||
|
|
|
||||||
|
= note: you can use the `'a` lifetime directly, in place of `'b`
|
||||||
|
|
||||||
|
error: aborting due to 5 previous errors
|
||||||
|
|
Loading…
Reference in New Issue