+use crate::utils::{in_macro, snippet_with_applicability, span_lint_and_sugg};
+use if_chain::if_chain;
+use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
+use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_errors::Applicability;
use syntax::ast::{Expr, ExprKind, UnOp};
-use rustc::lint::*;
-use utils::{snippet, span_lint_and_sugg};
-/// **What it does:** Checks for usage of `*&` and `*&mut` in expressions.
-///
-/// **Why is this bad?** Immediately dereferencing a reference is no-op and
-/// makes the code less clear.
-///
-/// **Known problems:** Multiple dereference/addrof pairs are not handled so
-/// the suggested fix for `x = **&&y` is `x = *&y`, which is still incorrect.
-///
-/// **Example:**
-/// ```rust
-/// let a = f(*&mut b);
-/// let c = *&d;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for usage of `*&` and `*&mut` in expressions.
+ ///
+ /// **Why is this bad?** Immediately dereferencing a reference is no-op and
+ /// makes the code less clear.
+ ///
+ /// **Known problems:** Multiple dereference/addrof pairs are not handled so
+ /// the suggested fix for `x = **&&y` is `x = *&y`, which is still incorrect.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let a = f(*&mut b);
+ /// let c = *&d;
+ /// ```
pub DEREF_ADDROF,
complexity,
"use of `*&` or `*&mut` in an expression"
}
-pub struct Pass;
-
-impl LintPass for Pass {
- fn get_lints(&self) -> LintArray {
- lint_array!(DEREF_ADDROF)
- }
-}
+declare_lint_pass!(DerefAddrOf => [DEREF_ADDROF]);
fn without_parens(mut e: &Expr) -> &Expr {
while let ExprKind::Paren(ref child_e) = e.node {
e
}
-impl EarlyLintPass for Pass {
- fn check_expr(&mut self, cx: &EarlyContext, e: &Expr) {
- if let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.node {
- if let ExprKind::AddrOf(_, ref addrof_target) = without_parens(deref_target).node {
+impl EarlyLintPass for DerefAddrOf {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
+ if_chain! {
+ if let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.node;
+ if let ExprKind::AddrOf(_, ref addrof_target) = without_parens(deref_target).node;
+ if !in_macro(addrof_target.span);
+ then {
+ let mut applicability = Applicability::MachineApplicable;
span_lint_and_sugg(
cx,
DEREF_ADDROF,
e.span,
"immediately dereferencing a reference",
"try this",
- format!("{}", snippet(cx, addrof_target.span, "_")),
+ format!("{}", snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability)),
+ applicability,
);
}
}
}
}
-/// **What it does:** Checks for references in expressions that use
-/// auto dereference.
-///
-/// **Why is this bad?** The reference is a no-op and is automatically
-/// dereferenced by the compiler and makes the code less clear.
-///
-/// **Example:**
-/// ```rust
-/// struct Point(u32, u32);
-/// let point = Foo(30, 20);
-/// let x = (&point).x;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for references in expressions that use
+ /// auto dereference.
+ ///
+ /// **Why is this bad?** The reference is a no-op and is automatically
+ /// dereferenced by the compiler and makes the code less clear.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// struct Point(u32, u32);
+ /// let point = Point(30, 20);
+ /// let x = (&point).0;
+ /// ```
pub REF_IN_DEREF,
complexity,
"Use of reference in auto dereference expression."
}
-pub struct DerefPass;
-
-impl LintPass for DerefPass {
- fn get_lints(&self) -> LintArray {
- lint_array!(REF_IN_DEREF)
- }
-}
+declare_lint_pass!(RefInDeref => [REF_IN_DEREF]);
-impl EarlyLintPass for DerefPass {
- fn check_expr(&mut self, cx: &EarlyContext, e: &Expr) {
+impl EarlyLintPass for RefInDeref {
+ fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &Expr) {
if_chain! {
- if let ExprKind::Field(ref object, ref field_name) = e.node;
+ if let ExprKind::Field(ref object, _) = e.node;
if let ExprKind::Paren(ref parened) = object.node;
if let ExprKind::AddrOf(_, ref inner) = parened.node;
then {
+ let mut applicability = Applicability::MachineApplicable;
span_lint_and_sugg(
cx,
REF_IN_DEREF,
object.span,
"Creating a reference that is immediately dereferenced.",
"try this",
- format!(
- "{}.{}",
- snippet(cx, inner.span, "_"),
- snippet(cx, field_name.span, "_")
- )
+ snippet_with_applicability(cx, inner.span, "_", &mut applicability).to_string(),
+ applicability,
);
}
}