use rustc_errors::Applicability;
use std::ops::Deref;
-/// **What it does:** Checks for statements which have no effect.
-///
-/// **Why is this bad?** Similar to dead code, these statements are actually
-/// executed. However, as they have no effect, all they do is make the code less
-/// readable.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// 0;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for statements which have no effect.
+ ///
+ /// **Why is this bad?** Similar to dead code, these statements are actually
+ /// executed. However, as they have no effect, all they do is make the code less
+ /// readable.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// 0;
+ /// ```
pub NO_EFFECT,
complexity,
"statements with no effect"
}
-/// **What it does:** Checks for expression statements that can be reduced to a
-/// sub-expression.
-///
-/// **Why is this bad?** Expressions by themselves often have no side-effects.
-/// Having such expressions reduces readability.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// compute_array()[0];
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for expression statements that can be reduced to a
+ /// sub-expression.
+ ///
+ /// **Why is this bad?** Expressions by themselves often have no side-effects.
+ /// Having such expressions reduces readability.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// compute_array()[0];
+ /// ```
pub UNNECESSARY_OPERATION,
complexity,
"outer expressions with no effect"
if let ExprKind::Path(ref qpath) = callee.node {
let def = cx.tables.qpath_def(qpath, callee.hir_id);
match def {
- Def::Struct(..) | Def::Variant(..) | Def::StructCtor(..) | Def::VariantCtor(..) => {
+ Def::Struct(..) | Def::Variant(..) | Def::Ctor(..) => {
!has_drop(cx, cx.tables.expr_ty(expr)) && args.iter().all(|arg| has_no_effect(cx, arg))
},
_ => false,
fn get_lints(&self) -> LintArray {
lint_array!(NO_EFFECT, UNNECESSARY_OPERATION)
}
+
+ fn name(&self) -> &'static str {
+ "NoEffect"
+ }
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
if let ExprKind::Path(ref qpath) = callee.node {
let def = cx.tables.qpath_def(qpath, callee.hir_id);
match def {
- Def::Struct(..) | Def::Variant(..) | Def::StructCtor(..) | Def::VariantCtor(..)
- if !has_drop(cx, cx.tables.expr_ty(expr)) =>
- {
+ Def::Struct(..) | Def::Variant(..) | Def::Ctor(..) if !has_drop(cx, cx.tables.expr_ty(expr)) => {
Some(args.iter().collect())
},
_ => None,