-// 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.
-
//! lint on inherent implementations
-use crate::utils::span_lint_and_then;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::utils::{in_macro, span_lint_and_then};
use rustc_data_structures::fx::FxHashMap;
-use std::default::Default;
-use syntax_pos::Span;
+use rustc_hir::{def_id, Crate, Impl, Item, ItemKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::Span;
-/// **What it does:** Checks for multiple inherent implementations of a struct
-///
-/// **Why is this bad?** Splitting the implementation of a type makes the code harder to navigate.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// struct X;
-/// impl X {
-/// fn one() {}
-/// }
-/// impl X {
-/// fn other() {}
-/// }
-/// ```
-///
-/// Could be written:
-///
-/// ```rust
-/// struct X;
-/// impl X {
-/// fn one() {}
-/// fn other() {}
-/// }
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for multiple inherent implementations of a struct
+ ///
+ /// **Why is this bad?** Splitting the implementation of a type makes the code harder to navigate.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// struct X;
+ /// impl X {
+ /// fn one() {}
+ /// }
+ /// impl X {
+ /// fn other() {}
+ /// }
+ /// ```
+ ///
+ /// Could be written:
+ ///
+ /// ```rust
+ /// struct X;
+ /// impl X {
+ /// fn one() {}
+ /// fn other() {}
+ /// }
+ /// ```
pub MULTIPLE_INHERENT_IMPL,
restriction,
"Multiple inherent impl that could be grouped"
}
-pub struct Pass {
- impls: FxHashMap<def_id::DefId, (Span, Generics)>,
-}
-
-impl Default for Pass {
- fn default() -> Self {
- Self {
- impls: FxHashMap::default(),
- }
- }
+#[allow(clippy::module_name_repetitions)]
+#[derive(Default)]
+pub struct MultipleInherentImpl {
+ impls: FxHashMap<def_id::DefId, Span>,
}
-impl LintPass for Pass {
- fn get_lints(&self) -> LintArray {
- lint_array!(MULTIPLE_INHERENT_IMPL)
- }
-}
+impl_lint_pass!(MultipleInherentImpl => [MULTIPLE_INHERENT_IMPL]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
- fn check_item(&mut self, _: &LateContext<'a, 'tcx>, item: &'tcx Item) {
- if let ItemKind::Impl(_, _, _, ref generics, None, _, _) = item.node {
- // Remember for each inherent implementation encoutered its span and generics
- self.impls
- .insert(item.hir_id.owner_def_id(), (item.span, generics.clone()));
+impl<'tcx> LateLintPass<'tcx> for MultipleInherentImpl {
+ fn check_item(&mut self, _: &LateContext<'tcx>, item: &'tcx Item<'_>) {
+ if let ItemKind::Impl(Impl {
+ ref generics,
+ of_trait: None,
+ ..
+ }) = item.kind
+ {
+ // Remember for each inherent implementation encountered its span and generics
+ // but filter out implementations that have generic params (type or lifetime)
+ // or are derived from a macro
+ if !in_macro(item.span) && generics.params.is_empty() {
+ self.impls.insert(item.def_id.to_def_id(), item.span);
+ }
}
}
- fn check_crate_post(&mut self, cx: &LateContext<'a, 'tcx>, krate: &'tcx Crate) {
- if let Some(item) = krate.items.values().nth(0) {
+ fn check_crate_post(&mut self, cx: &LateContext<'tcx>, krate: &'tcx Crate<'_>) {
+ if !krate.items.is_empty() {
// Retrieve all inherent implementations from the crate, grouped by type
- for impls in cx
- .tcx
- .crate_inherent_impls(item.hir_id.owner_def_id().krate)
- .inherent_impls
- .values()
- {
+ for impls in cx.tcx.crate_inherent_impls(def_id::LOCAL_CRATE).inherent_impls.values() {
// Filter out implementations that have generic params (type or lifetime)
- let mut impl_spans = impls
- .iter()
- .filter_map(|impl_def| self.impls.get(impl_def))
- .filter_map(|(span, generics)| if generics.params.len() == 0 { Some(span) } else { None });
- if let Some(initial_span) = impl_spans.nth(0) {
+ let mut impl_spans = impls.iter().filter_map(|impl_def| self.impls.get(impl_def));
+ if let Some(initial_span) = impl_spans.next() {
impl_spans.for_each(|additional_span| {
span_lint_and_then(
cx,
MULTIPLE_INHERENT_IMPL,
*additional_span,
- "Multiple implementations of this structure",
- |db| {
- db.span_note(*initial_span, "First implementation here");
+ "multiple implementations of this structure",
+ |diag| {
+ diag.span_note(*initial_span, "first implementation here");
},
)
})