+// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
use crate::reexport::*;
+use crate::utils::{last_path_segment, span_lint};
use matches::matches;
-use rustc::lint::*;
-use rustc::{declare_lint, lint_array};
use rustc::hir::def::Def;
-use rustc::hir::*;
use rustc::hir::intravisit::*;
-use std::collections::{HashMap, HashSet};
+use rustc::hir::*;
+use rustc::lint::{in_external_macro, LateContext, LateLintPass, LintArray, LintContext, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
use syntax::source_map::Span;
-use crate::utils::{last_path_segment, span_lint};
use syntax::symbol::keywords;
/// **What it does:** Checks for lifetime annotations which can be removed by
///
/// **Example:**
/// ```rust
-/// fn in_and_out<'a>(x: &'a u8, y: u8) -> &'a u8 { x }
+/// fn in_and_out<'a>(x: &'a u8, y: u8) -> &'a u8 {
+/// x
+/// }
/// ```
declare_clippy_lint! {
- pub NEEDLESS_LIFETIMES,
- complexity,
- "using explicit lifetimes for references in function arguments when elision rules \
- would allow omitting them"
+pub NEEDLESS_LIFETIMES,
+complexity,
+"using explicit lifetimes for references in function arguments when elision rules \
+ would allow omitting them"
}
/// **What it does:** Checks for lifetimes in generics that are never used
///
/// **Example:**
/// ```rust
-/// fn unused_lifetime<'a>(x: u8) { .. }
+/// fn unused_lifetime<'a>(x: u8) {
+/// ..
+/// }
/// ```
declare_clippy_lint! {
pub EXTRA_UNUSED_LIFETIMES,
}
let mut bounds_lts = Vec::new();
- let types = generics.params.iter().filter_map(|param| match param.kind {
- GenericParamKind::Type { .. } => Some(param),
- GenericParamKind::Lifetime { .. } => None,
+ let types = generics.params.iter().filter(|param| match param.kind {
+ GenericParamKind::Type { .. } => true,
+ GenericParamKind::Lifetime { .. } => false,
});
for typ in types {
for bound in &typ.bounds {
cx,
NEEDLESS_LIFETIMES,
span,
- "explicit lifetimes given in parameter types where they could be elided",
+ "explicit lifetimes given in parameter types where they could be elided \
+ (or replaced with `'_` if needed by type declaration)",
);
}
report_extra_lifetimes(cx, decl, generics);
let mut checker = BodyLifetimeChecker {
lifetimes_used_in_body: false,
};
- checker.visit_expr(&cx.tcx.hir.body(body_id).value);
+ checker.visit_expr(&cx.tcx.hir().body(body_id).value);
if checker.lifetimes_used_in_body {
return false;
}
// no output lifetimes, check distinctness of input lifetimes
// only unnamed and static, ok
- let unnamed_and_static = input_lts
- .iter()
- .all(|lt| *lt == RefLt::Unnamed || *lt == RefLt::Static);
+ let unnamed_and_static = input_lts.iter().all(|lt| *lt == RefLt::Unnamed || *lt == RefLt::Static);
if unnamed_and_static {
return false;
}
}
}
-fn allowed_lts_from(named_generics: &[GenericParam]) -> HashSet<RefLt> {
- let mut allowed_lts = HashSet::new();
+fn allowed_lts_from(named_generics: &[GenericParam]) -> FxHashSet<RefLt> {
+ let mut allowed_lts = FxHashSet::default();
for par in named_generics.iter() {
if let GenericParamKind::Lifetime { .. } = par.kind {
if par.bounds.is_empty() {
/// Number of unique lifetimes in the given vector.
fn unique_lifetimes(lts: &[RefLt]) -> usize {
- lts.iter().collect::<HashSet<_>>().len()
+ lts.iter().collect::<FxHashSet<_>>().len()
}
/// A visitor usable for `rustc_front::visit::walk_ty()`.
&& !last_path_segment.args.iter().any(|arg| match arg {
GenericArg::Lifetime(_) => true,
GenericArg::Type(_) => false,
- }) {
- let hir_id = self.cx.tcx.hir.node_to_hir_id(ty.id);
+ })
+ {
+ let hir_id = self.cx.tcx.hir().node_to_hir_id(ty.id);
match self.cx.tables.qpath_def(qpath, hir_id) {
Def::TyAlias(def_id) | Def::Struct(def_id) => {
let generics = self.cx.tcx.generics_of(def_id);
self.record(&None);
},
TyKind::Path(ref path) => {
- if let QPath::Resolved(_, ref path) = *path {
- if let Def::Existential(def_id) = path.def {
- let node_id = self.cx.tcx.hir.as_local_node_id(def_id).unwrap();
- if let ItemKind::Existential(ref exist_ty) = self.cx.tcx.hir.expect_item(node_id).node {
- for bound in &exist_ty.bounds {
- if let GenericBound::Outlives(_) = *bound {
- self.record(&None);
- }
- }
- } else {
- unreachable!()
+ self.collect_anonymous_lifetimes(path, ty);
+ },
+ TyKind::Def(item, _) => {
+ if let ItemKind::Existential(ref exist_ty) = self.cx.tcx.hir().expect_item(item.id).node {
+ for bound in &exist_ty.bounds {
+ if let GenericBound::Outlives(_) = *bound {
+ self.record(&None);
}
- walk_ty(self, ty);
- return;
}
+ } else {
+ unreachable!()
}
- self.collect_anonymous_lifetimes(path, ty);
- }
+ walk_ty(self, ty);
+ },
TyKind::TraitObject(ref bounds, ref lt) => {
if !lt.is_elided() {
self.abort = true;
// and check that all lifetimes are allowed
match visitor.into_vec() {
None => return false,
- Some(lts) => for lt in lts {
- if !allowed_lts.contains(<) {
- return true;
+ Some(lts) => {
+ for lt in lts {
+ if !allowed_lts.contains(<) {
+ return true;
+ }
}
},
}
}
struct LifetimeChecker {
- map: HashMap<Name, Span>,
+ map: FxHashMap<Name, Span>,
}
impl<'tcx> Visitor<'tcx> for LifetimeChecker {
}
fn report_extra_lifetimes<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, func: &'tcx FnDecl, generics: &'tcx Generics) {
- let hs = generics.params.iter()
+ let hs = generics
+ .params
+ .iter()
.filter_map(|par| match par.kind {
GenericParamKind::Lifetime { .. } => Some((par.name.ident().name, par.span)),
_ => None,
walk_fn_decl(&mut checker, func);
for &v in checker.map.values() {
- span_lint(cx, EXTRA_UNUSED_LIFETIMES, v, "this lifetime isn't used in the function definition");
+ span_lint(
+ cx,
+ EXTRA_UNUSED_LIFETIMES,
+ v,
+ "this lifetime isn't used in the function definition",
+ );
}
}
projects / rust.git / blobdiff