-use crate::utils::{snippet_with_applicability, span_lint, span_lint_and_then};
+use clippy_utils::diagnostics::{span_lint, span_lint_and_then};
+use clippy_utils::source::snippet_with_applicability;
use if_chain::if_chain;
use rustc_ast::ast;
use rustc_ast::visit as ast_visit;
use rustc_hir::intravisit as hir_visit;
use rustc_hir::intravisit::Visitor as HirVisitor;
use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
-use rustc_middle::hir::map::Map;
+use rustc_middle::hir::nested_filter;
use rustc_middle::lint::in_external_macro;
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:** Detects closures called in the same expression where they
+ /// ### What it does
+ /// Detects closures called in the same expression where they
/// are defined.
///
- /// **Why is this bad?** It is unnecessarily adding to the expression's
+ /// ### Why is this bad?
+ /// It is unnecessarily adding to the expression's
/// complexity.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust,ignore
/// // Bad
/// let a = (|| 42)()
/// // Good
/// let a = 42
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub REDUNDANT_CLOSURE_CALL,
complexity,
"throwaway closures called in the expression they are defined"
impl<'ast> ast_visit::Visitor<'ast> for ReturnVisitor {
fn visit_expr(&mut self, ex: &'ast ast::Expr) {
- if let ast::ExprKind::Ret(_) = ex.kind {
- self.found_return = true;
- } else if let ast::ExprKind::Try(_) = ex.kind {
+ if let ast::ExprKind::Ret(_) | ast::ExprKind::Try(_) = ex.kind {
self.found_return = true;
}
- ast_visit::walk_expr(self, ex)
+ ast_visit::walk_expr(self, ex);
}
}
count: usize,
}
impl<'a, 'tcx> hir_visit::Visitor<'tcx> for ClosureUsageCount<'a, 'tcx> {
- type Map = Map<'tcx>;
+ type NestedFilter = nested_filter::OnlyBodies;
fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
if_chain! {
- if let hir::ExprKind::Call(ref closure, _) = expr.kind;
- if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = closure.kind;
- if self.path.segments[0].ident == path.segments[0].ident
- && self.path.res == path.res;
+ if let hir::ExprKind::Call(closure, _) = expr.kind;
+ if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = closure.kind;
+ if self.path.segments[0].ident == path.segments[0].ident;
+ if self.path.res == path.res;
then {
self.count += 1;
}
hir_visit::walk_expr(self, expr);
}
- fn nested_visit_map(&mut self) -> hir_visit::NestedVisitorMap<Self::Map> {
- hir_visit::NestedVisitorMap::OnlyBodies(self.cx.tcx.hir())
+ fn nested_visit_map(&mut self) -> Self::Map {
+ self.cx.tcx.hir()
}
}
let mut closure_usage_count = ClosureUsageCount { cx, path, count: 0 };
for w in block.stmts.windows(2) {
if_chain! {
- if let hir::StmtKind::Local(ref local) = w[0].kind;
- if let Option::Some(ref t) = local.init;
+ if let hir::StmtKind::Local(local) = w[0].kind;
+ if let Option::Some(t) = local.init;
if let hir::ExprKind::Closure(..) = t.kind;
if let hir::PatKind::Binding(_, _, ident, _) = local.pat.kind;
- if let hir::StmtKind::Semi(ref second) = w[1].kind;
- if let hir::ExprKind::Assign(_, ref call, _) = second.kind;
- if let hir::ExprKind::Call(ref closure, _) = call.kind;
- if let hir::ExprKind::Path(hir::QPath::Resolved(_, ref path)) = closure.kind;
+ if let hir::StmtKind::Semi(second) = w[1].kind;
+ if let hir::ExprKind::Assign(_, call, _) = second.kind;
+ if let hir::ExprKind::Call(closure, _) = call.kind;
+ if let hir::ExprKind::Path(hir::QPath::Resolved(_, path)) = closure.kind;
if ident == path.segments[0].ident;
if count_closure_usage(cx, block, path) == 1;
then {