use crate::utils::paths;
use crate::utils::{
- is_copy, match_trait_method, match_type, remove_blocks, snippet_with_applicability, span_lint_and_sugg,
+ is_copy, is_type_diagnostic_item, match_trait_method, remove_blocks, snippet_with_applicability, span_lint_and_sugg,
};
use if_chain::if_chain;
-use rustc::hir;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::ty;
-use rustc::{declare_lint_pass, declare_tool_lint};
use rustc_errors::Applicability;
-use syntax::ast::Ident;
-use syntax::source_map::Span;
+use rustc_hir as hir;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::mir::Mutability;
+use rustc_middle::ty;
+use rustc_middle::ty::adjustment::Adjust;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::Ident;
+use rustc_span::{sym, Span};
declare_clippy_lint! {
- /// **What it does:** Checks for usage of `iterator.map(|x| x.clone())` and suggests
- /// `iterator.cloned()` instead
+ /// **What it does:** Checks for usage of `map(|x| x.clone())` or
+ /// dereferencing closures for `Copy` types, on `Iterator` or `Option`,
+ /// and suggests `cloned()` or `copied()` instead
///
/// **Why is this bad?** Readability, this can be written more concisely
///
declare_lint_pass!(MapClone => [MAP_CLONE]);
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MapClone {
- fn check_expr(&mut self, cx: &LateContext<'_, '_>, e: &hir::Expr) {
+impl<'tcx> LateLintPass<'tcx> for MapClone {
+ fn check_expr(&mut self, cx: &LateContext<'_>, e: &hir::Expr<'_>) {
if e.span.from_expansion() {
return;
}
if_chain! {
- if let hir::ExprKind::MethodCall(ref method, _, ref args) = e.node;
+ if let hir::ExprKind::MethodCall(ref method, _, ref args, _) = e.kind;
if args.len() == 2;
if method.ident.as_str() == "map";
- let ty = cx.tables.expr_ty(&args[0]);
- if match_type(cx, ty, &paths::OPTION) || match_trait_method(cx, e, &paths::ITERATOR);
- if let hir::ExprKind::Closure(_, _, body_id, _, _) = args[1].node;
+ let ty = cx.typeck_results().expr_ty(&args[0]);
+ if is_type_diagnostic_item(cx, ty, sym::option_type) || match_trait_method(cx, e, &paths::ITERATOR);
+ if let hir::ExprKind::Closure(_, _, body_id, _, _) = args[1].kind;
let closure_body = cx.tcx.hir().body(body_id);
let closure_expr = remove_blocks(&closure_body.value);
then {
- match closure_body.params[0].pat.node {
- hir::PatKind::Ref(ref inner, _) => if let hir::PatKind::Binding(
+ match closure_body.params[0].pat.kind {
+ hir::PatKind::Ref(ref inner, hir::Mutability::Not) => if let hir::PatKind::Binding(
hir::BindingAnnotation::Unannotated, .., name, None
- ) = inner.node {
+ ) = inner.kind {
if ident_eq(name, closure_expr) {
lint(cx, e.span, args[0].span, true);
}
},
hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, .., name, None) => {
- match closure_expr.node {
+ match closure_expr.kind {
hir::ExprKind::Unary(hir::UnOp::UnDeref, ref inner) => {
- if ident_eq(name, inner) && !cx.tables.expr_ty(inner).is_box() {
- lint(cx, e.span, args[0].span, true);
+ if ident_eq(name, inner) {
+ if let ty::Ref(.., Mutability::Not) = cx.typeck_results().expr_ty(inner).kind() {
+ lint(cx, e.span, args[0].span, true);
+ }
}
},
- hir::ExprKind::MethodCall(ref method, _, ref obj) => {
- if ident_eq(name, &obj[0]) && method.ident.as_str() == "clone"
- && match_trait_method(cx, closure_expr, &paths::CLONE_TRAIT) {
-
- let obj_ty = cx.tables.expr_ty(&obj[0]);
- if let ty::Ref(_, ty, _) = obj_ty.sty {
- let copy = is_copy(cx, ty);
- lint(cx, e.span, args[0].span, copy);
+ hir::ExprKind::MethodCall(ref method, _, [obj], _) => if_chain! {
+ if ident_eq(name, obj) && method.ident.name == sym::clone;
+ if match_trait_method(cx, closure_expr, &paths::CLONE_TRAIT);
+ // no autoderefs
+ if !cx.typeck_results().expr_adjustments(obj).iter()
+ .any(|a| matches!(a.kind, Adjust::Deref(Some(..))));
+ then {
+ let obj_ty = cx.typeck_results().expr_ty(obj);
+ if let ty::Ref(_, ty, mutability) = obj_ty.kind() {
+ if matches!(mutability, Mutability::Not) {
+ let copy = is_copy(cx, ty);
+ lint(cx, e.span, args[0].span, copy);
+ }
} else {
lint_needless_cloning(cx, e.span, args[0].span);
}
}
}
-fn ident_eq(name: Ident, path: &hir::Expr) -> bool {
- if let hir::ExprKind::Path(hir::QPath::Resolved(None, ref path)) = path.node {
+fn ident_eq(name: Ident, path: &hir::Expr<'_>) -> bool {
+ if let hir::ExprKind::Path(hir::QPath::Resolved(None, ref path)) = path.kind {
path.segments.len() == 1 && path.segments[0].ident == name
} else {
false
}
}
-fn lint_needless_cloning(cx: &LateContext<'_, '_>, root: Span, receiver: Span) {
+fn lint_needless_cloning(cx: &LateContext<'_>, root: Span, receiver: Span) {
span_lint_and_sugg(
cx,
MAP_CLONE,
root.trim_start(receiver).unwrap(),
- "You are needlessly cloning iterator elements",
- "Remove the map call",
+ "you are needlessly cloning iterator elements",
+ "remove the `map` call",
String::new(),
Applicability::MachineApplicable,
)
}
-fn lint(cx: &LateContext<'_, '_>, replace: Span, root: Span, copied: bool) {
+fn lint(cx: &LateContext<'_>, replace: Span, root: Span, copied: bool) {
let mut applicability = Applicability::MachineApplicable;
if copied {
span_lint_and_sugg(
cx,
MAP_CLONE,
replace,
- "You are using an explicit closure for copying elements",
- "Consider calling the dedicated `copied` method",
+ "you are using an explicit closure for copying elements",
+ "consider calling the dedicated `copied` method",
format!(
"{}.copied()",
snippet_with_applicability(cx, root, "..", &mut applicability)
cx,
MAP_CLONE,
replace,
- "You are using an explicit closure for cloning elements",
- "Consider calling the dedicated `cloned` method",
+ "you are using an explicit closure for cloning elements",
+ "consider calling the dedicated `cloned` method",
format!(
"{}.cloned()",
snippet_with_applicability(cx, root, "..", &mut applicability)
projects / rust.git / blobdiff