-// 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::utils::{in_macro, match_path_ast, snippet_opt, span_lint_and_then, span_note_and_lint};
use if_chain::if_chain;
use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass};
use rustc::{declare_tool_lint, lint_array};
use syntax::visit::FnKind;
use syntax_pos::BytePos;
-/// **What it does:** Checks for return statements at the end of a block.
-///
-/// **Why is this bad?** Removing the `return` and semicolon will make the code
-/// more rusty.
-///
-/// **Known problems:** If the computation returning the value borrows a local
-/// variable, removing the `return` may run afoul of the borrow checker.
-///
-/// **Example:**
-/// ```rust
-/// fn foo(x: usize) {
-/// return x;
-/// }
-/// ```
-/// simplify to
-/// ```rust
-/// fn foo(x: usize) {
-/// x
-/// }
-/// ```
+use crate::utils::{in_macro, match_path_ast, snippet_opt, span_lint_and_then, span_note_and_lint};
+
declare_clippy_lint! {
+ /// **What it does:** Checks for return statements at the end of a block.
+ ///
+ /// **Why is this bad?** Removing the `return` and semicolon will make the code
+ /// more rusty.
+ ///
+ /// **Known problems:** If the computation returning the value borrows a local
+ /// variable, removing the `return` may run afoul of the borrow checker.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn foo(x: usize) -> usize {
+ /// return x;
+ /// }
+ /// ```
+ /// simplify to
+ /// ```rust
+ /// fn foo(x: usize) -> usize {
+ /// x
+ /// }
+ /// ```
pub NEEDLESS_RETURN,
style,
"using a return statement like `return expr;` where an expression would suffice"
}
-/// **What it does:** Checks for `let`-bindings, which are subsequently
-/// returned.
-///
-/// **Why is this bad?** It is just extraneous code. Remove it to make your code
-/// more rusty.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// fn foo() -> String {
-/// let x = String::new();
-/// x
-/// }
-/// ```
-/// instead, use
-/// ```
-/// fn foo() -> String {
-/// String::new()
-/// }
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `let`-bindings, which are subsequently
+ /// returned.
+ ///
+ /// **Why is this bad?** It is just extraneous code. Remove it to make your code
+ /// more rusty.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn foo() -> String {
+ /// let x = String::new();
+ /// x
+ /// }
+ /// ```
+ /// instead, use
+ /// ```
+ /// fn foo() -> String {
+ /// String::new()
+ /// }
+ /// ```
pub LET_AND_RETURN,
style,
"creating a let-binding and then immediately returning it like `let x = expr; x` at the end of a block"
}
-/// **What it does:** Checks for unit (`()`) expressions that can be removed.
-///
-/// **Why is this bad?** Such expressions add no value, but can make the code
-/// less readable. Depending on formatting they can make a `break` or `return`
-/// statement look like a function call.
-///
-/// **Known problems:** The lint currently misses unit return types in types,
-/// e.g. the `F` in `fn generic_unit<F: Fn() -> ()>(f: F) { .. }`.
-///
-/// **Example:**
-/// ```rust
-/// fn return_unit() -> () {
-/// ()
-/// }
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for unit (`()`) expressions that can be removed.
+ ///
+ /// **Why is this bad?** Such expressions add no value, but can make the code
+ /// less readable. Depending on formatting they can make a `break` or `return`
+ /// statement look like a function call.
+ ///
+ /// **Known problems:** The lint currently misses unit return types in types,
+ /// e.g., the `F` in `fn generic_unit<F: Fn() -> ()>(f: F) { .. }`.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn return_unit() -> () {
+ /// ()
+ /// }
+ /// ```
pub UNUSED_UNIT,
style,
"needless unit expression"
}
span_lint_and_then(cx, NEEDLESS_RETURN, ret_span, "unneeded return statement", |db| {
if let Some(snippet) = snippet_opt(cx, inner_span) {
- db.span_suggestion_with_applicability(
+ db.span_suggestion(
ret_span,
"remove `return` as shown",
snippet,
fn get_lints(&self) -> LintArray {
lint_array!(NEEDLESS_RETURN, LET_AND_RETURN, UNUSED_UNIT)
}
+
+ fn name(&self) -> &'static str {
+ "Return"
+ }
}
impl EarlyLintPass for ReturnPass {
(ty.span, Applicability::MaybeIncorrect)
};
span_lint_and_then(cx, UNUSED_UNIT, rspan, "unneeded unit return type", |db| {
- db.span_suggestion_with_applicability(
+ db.span_suggestion(
rspan,
"remove the `-> ()`",
String::new(),
then {
let sp = expr.span;
span_lint_and_then(cx, UNUSED_UNIT, sp, "unneeded unit expression", |db| {
- db.span_suggestion_with_applicability(
+ db.span_suggestion(
sp,
"remove the final `()`",
String::new(),
ast::ExprKind::Ret(Some(ref expr)) | ast::ExprKind::Break(_, Some(ref expr)) => {
if is_unit_expr(expr) && !in_macro(expr.span) {
span_lint_and_then(cx, UNUSED_UNIT, expr.span, "unneeded `()`", |db| {
- db.span_suggestion_with_applicability(
+ db.span_suggestion(
expr.span,
"remove the `()`",
String::new(),
}
fn attr_is_cfg(attr: &ast::Attribute) -> bool {
- attr.meta_item_list().is_some() && attr.name() == "cfg"
+ attr.meta_item_list().is_some() && attr.check_name("cfg")
}
// get the def site
projects / rust.git / blobdiff