-// 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::rustc::hir::def::Def;
-use crate::rustc::hir::{BinOpKind, BlockCheckMode, Expr, ExprKind, Stmt, StmtKind, UnsafeSource};
-use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::rustc_errors::Applicability;
use crate::utils::{has_drop, in_macro, snippet_opt, span_lint, span_lint_and_sugg};
+use rustc::hir::def::Def;
+use rustc::hir::{BinOpKind, BlockCheckMode, Expr, ExprKind, Stmt, StmtKind, UnsafeSource};
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+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 {
fn check_stmt(&mut self, cx: &LateContext<'a, 'tcx>, stmt: &'tcx Stmt) {
- if let StmtKind::Semi(ref expr, _) = stmt.node {
+ if let StmtKind::Semi(ref expr) = stmt.node {
if has_no_effect(cx, expr) {
span_lint(cx, NO_EFFECT, stmt.span, "statement with no effect");
} else if let Some(reduced) = reduce_expression(cx, expr) {
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,