From 0a11c5c49ac7412492fc3bc73100912ea11c6360 Mon Sep 17 00:00:00 2001 From: Samuel Moelius Date: Sun, 18 Aug 2024 07:04:22 -0400 Subject: [PATCH] Reorder functions --- clippy_lints/src/lifetimes.rs | 274 +++++++++++++++++----------------- 1 file changed, 137 insertions(+), 137 deletions(-) diff --git a/clippy_lints/src/lifetimes.rs b/clippy_lints/src/lifetimes.rs index dc6043ae981..42083b1a879 100644 --- a/clippy_lints/src/lifetimes.rs +++ b/clippy_lints/src/lifetimes.rs @@ -202,143 +202,6 @@ fn check_fn_inner<'tcx>( } } -/// Generate diagnostic messages for elidable lifetimes. -fn report_elidable_lifetimes( - cx: &LateContext<'_>, - generics: &Generics<'_>, - elidable_lts: &[LocalDefId], - usages: &[Lifetime], - include_suggestions: bool, -) { - let lts = elidable_lts - .iter() - // In principle, the result of the call to `Node::ident` could be `unwrap`ped, as `DefId` should refer to a - // `Node::GenericParam`. - .filter_map(|&def_id| cx.tcx.hir_node_by_def_id(def_id).ident()) - .map(|ident| ident.to_string()) - .collect::>() - .join(", "); - - span_lint_and_then( - cx, - NEEDLESS_LIFETIMES, - elidable_lts - .iter() - .map(|<| cx.tcx.def_span(lt)) - .chain(usages.iter().filter_map(|usage| { - if let LifetimeName::Param(def_id) = usage.res - && elidable_lts.contains(&def_id) - { - return Some(usage.ident.span); - } - - None - })) - .collect_vec(), - format!("the following explicit lifetimes could be elided: {lts}"), - |diag| { - if !include_suggestions { - return; - }; - - if let Some(suggestions) = elision_suggestions(cx, generics, elidable_lts, usages) { - diag.multipart_suggestion("elide the lifetimes", suggestions, Applicability::MachineApplicable); - } - }, - ); -} - -fn elision_suggestions( - cx: &LateContext<'_>, - generics: &Generics<'_>, - elidable_lts: &[LocalDefId], - usages: &[Lifetime], -) -> Option> { - let explicit_params = generics - .params - .iter() - .filter(|param| !param.is_elided_lifetime() && !param.is_impl_trait()) - .collect::>(); - - let mut suggestions = if elidable_lts.len() == explicit_params.len() { - // if all the params are elided remove the whole generic block - // - // fn x<'a>() {} - // ^^^^ - vec![(generics.span, String::new())] - } else { - elidable_lts - .iter() - .map(|&id| { - let pos = explicit_params.iter().position(|param| param.def_id == id)?; - let param = explicit_params.get(pos)?; - - let span = if let Some(next) = explicit_params.get(pos + 1) { - // fn x<'prev, 'a, 'next>() {} - // ^^^^ - param.span.until(next.span) - } else { - // `pos` should be at least 1 here, because the param in position 0 would either have a `next` - // param or would have taken the `elidable_lts.len() == explicit_params.len()` branch. - let prev = explicit_params.get(pos - 1)?; - - // fn x<'prev, 'a>() {} - // ^^^^ - param.span.with_lo(prev.span.hi()) - }; - - Some((span, String::new())) - }) - .collect::>>()? - }; - - suggestions.extend( - usages - .iter() - .filter(|usage| named_lifetime(usage).map_or(false, |id| elidable_lts.contains(&id))) - .map(|usage| { - match cx.tcx.parent_hir_node(usage.hir_id) { - Node::Ty(Ty { - kind: TyKind::Ref(..), .. - }) => { - // expand `&'a T` to `&'a T` - // ^^ ^^^ - let span = cx.sess().source_map().span_extend_while_whitespace(usage.ident.span); - - (span, String::new()) - }, - // `T<'a>` and `impl Foo + 'a` should be replaced by `'_` - _ => (usage.ident.span, String::from("'_")), - } - }), - ); - - Some(suggestions) -} - -// elision doesn't work for explicit self types, see rust-lang/rust#69064 -fn explicit_self_type<'tcx>(cx: &LateContext<'tcx>, func: &FnDecl<'tcx>, ident: Option) -> bool { - if let Some(ident) = ident - && ident.name == kw::SelfLower - && !func.implicit_self.has_implicit_self() - && let Some(self_ty) = func.inputs.first() - { - let mut visitor = RefVisitor::new(cx); - visitor.visit_ty(self_ty); - - !visitor.all_lts().is_empty() - } else { - false - } -} - -fn named_lifetime(lt: &Lifetime) -> Option { - match lt.res { - LifetimeName::Param(id) if !lt.is_anonymous() => Some(id), - _ => None, - } -} - fn could_use_elision<'tcx>( cx: &LateContext<'tcx>, func: &'tcx FnDecl<'_>, @@ -461,6 +324,22 @@ fn allowed_lts_from(named_generics: &[GenericParam<'_>]) -> FxHashSet(cx: &LateContext<'tcx>, func: &FnDecl<'tcx>, ident: Option) -> bool { + if let Some(ident) = ident + && ident.name == kw::SelfLower + && !func.implicit_self.has_implicit_self() + && let Some(self_ty) = func.inputs.first() + { + let mut visitor = RefVisitor::new(cx); + visitor.visit_ty(self_ty); + + !visitor.all_lts().is_empty() + } else { + false + } +} + /// Number of times each named lifetime occurs in the given slice. Returns a vector to preserve /// relative order. #[must_use] @@ -481,6 +360,13 @@ fn named_lifetime_occurrences(lts: &[Lifetime]) -> Vec<(LocalDefId, usize)> { occurrences } +fn named_lifetime(lt: &Lifetime) -> Option { + match lt.res { + LifetimeName::Param(id) if !lt.is_anonymous() => Some(id), + _ => None, + } +} + struct RefVisitor<'a, 'tcx> { cx: &'a LateContext<'tcx>, lts: Vec, @@ -781,6 +667,120 @@ fn report_elidable_impl_lifetimes<'tcx>( report_elidable_lifetimes(cx, impl_.generics, &elidable_lts, &usages, true); } +/// Generate diagnostic messages for elidable lifetimes. +fn report_elidable_lifetimes( + cx: &LateContext<'_>, + generics: &Generics<'_>, + elidable_lts: &[LocalDefId], + usages: &[Lifetime], + include_suggestions: bool, +) { + let lts = elidable_lts + .iter() + // In principle, the result of the call to `Node::ident` could be `unwrap`ped, as `DefId` should refer to a + // `Node::GenericParam`. + .filter_map(|&def_id| cx.tcx.hir_node_by_def_id(def_id).ident()) + .map(|ident| ident.to_string()) + .collect::>() + .join(", "); + + span_lint_and_then( + cx, + NEEDLESS_LIFETIMES, + elidable_lts + .iter() + .map(|<| cx.tcx.def_span(lt)) + .chain(usages.iter().filter_map(|usage| { + if let LifetimeName::Param(def_id) = usage.res + && elidable_lts.contains(&def_id) + { + return Some(usage.ident.span); + } + + None + })) + .collect_vec(), + format!("the following explicit lifetimes could be elided: {lts}"), + |diag| { + if !include_suggestions { + return; + }; + + if let Some(suggestions) = elision_suggestions(cx, generics, elidable_lts, usages) { + diag.multipart_suggestion("elide the lifetimes", suggestions, Applicability::MachineApplicable); + } + }, + ); +} + +fn elision_suggestions( + cx: &LateContext<'_>, + generics: &Generics<'_>, + elidable_lts: &[LocalDefId], + usages: &[Lifetime], +) -> Option> { + let explicit_params = generics + .params + .iter() + .filter(|param| !param.is_elided_lifetime() && !param.is_impl_trait()) + .collect::>(); + + let mut suggestions = if elidable_lts.len() == explicit_params.len() { + // if all the params are elided remove the whole generic block + // + // fn x<'a>() {} + // ^^^^ + vec![(generics.span, String::new())] + } else { + elidable_lts + .iter() + .map(|&id| { + let pos = explicit_params.iter().position(|param| param.def_id == id)?; + let param = explicit_params.get(pos)?; + + let span = if let Some(next) = explicit_params.get(pos + 1) { + // fn x<'prev, 'a, 'next>() {} + // ^^^^ + param.span.until(next.span) + } else { + // `pos` should be at least 1 here, because the param in position 0 would either have a `next` + // param or would have taken the `elidable_lts.len() == explicit_params.len()` branch. + let prev = explicit_params.get(pos - 1)?; + + // fn x<'prev, 'a>() {} + // ^^^^ + param.span.with_lo(prev.span.hi()) + }; + + Some((span, String::new())) + }) + .collect::>>()? + }; + + suggestions.extend( + usages + .iter() + .filter(|usage| named_lifetime(usage).map_or(false, |id| elidable_lts.contains(&id))) + .map(|usage| { + match cx.tcx.parent_hir_node(usage.hir_id) { + Node::Ty(Ty { + kind: TyKind::Ref(..), .. + }) => { + // expand `&'a T` to `&'a T` + // ^^ ^^^ + let span = cx.sess().source_map().span_extend_while_whitespace(usage.ident.span); + + (span, String::new()) + }, + // `T<'a>` and `impl Foo + 'a` should be replaced by `'_` + _ => (usage.ident.span, String::from("'_")), + } + }), + ); + + Some(suggestions) +} + struct BodyLifetimeChecker; impl<'tcx> Visitor<'tcx> for BodyLifetimeChecker {