-// 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::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use crate::rustc::{declare_tool_lint, lint_array};
-use crate::rustc_errors::Applicability;
-use crate::syntax::ast::{Expr, ExprKind, UnOp};
-use crate::utils::{snippet_with_applicability, span_lint_and_sugg};
+use crate::utils::sugg::Sugg;
+use crate::utils::{in_macro, snippet_opt, snippet_with_applicability, span_lint_and_sugg};
use if_chain::if_chain;
+use rustc_ast::ast::{Expr, ExprKind, Mutability, UnOp};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::BytePos;
-/// **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
+ /// // Bad
+ /// let a = f(*&mut b);
+ /// let c = *&d;
+ ///
+ /// // Good
+ /// let a = f(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 {
+ while let ExprKind::Paren(ref child_e) = e.kind {
e = child_e;
}
e
}
-impl EarlyLintPass for Pass {
+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 let ExprKind::Unary(UnOp::Deref, ref deref_target) = e.kind;
+ if let ExprKind::AddrOf(_, ref mutability, ref addrof_target) = without_parens(deref_target).kind;
+ 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_with_applicability(cx, addrof_target.span, "_", &mut applicability)),
- applicability,
- );
+ let sugg = if e.span.from_expansion() {
+ if let Ok(macro_source) = cx.sess.source_map().span_to_snippet(e.span) {
+ // Remove leading whitespace from the given span
+ // e.g: ` $visitor` turns into `$visitor`
+ let trim_leading_whitespaces = |span| {
+ snippet_opt(cx, span).and_then(|snip| {
+ #[allow(clippy::cast_possible_truncation)]
+ snip.find(|c: char| !c.is_whitespace()).map(|pos| {
+ span.lo() + BytePos(pos as u32)
+ })
+ }).map_or(span, |start_no_whitespace| e.span.with_lo(start_no_whitespace))
+ };
+
+ let mut generate_snippet = |pattern: &str| {
+ #[allow(clippy::cast_possible_truncation)]
+ macro_source.rfind(pattern).map(|pattern_pos| {
+ let rpos = pattern_pos + pattern.len();
+ let span_after_ref = e.span.with_lo(BytePos(e.span.lo().0 + rpos as u32));
+ let span = trim_leading_whitespaces(span_after_ref);
+ snippet_with_applicability(cx, span, "_", &mut applicability)
+ })
+ };
+
+ if *mutability == Mutability::Mut {
+ generate_snippet("mut")
+ } else {
+ generate_snippet("&")
+ }
+ } else {
+ Some(snippet_with_applicability(cx, e.span, "_", &mut applicability))
+ }
+ } else {
+ Some(snippet_with_applicability(cx, addrof_target.span, "_", &mut applicability))
+ };
+ if let Some(sugg) = sugg {
+ span_lint_and_sugg(
+ cx,
+ DEREF_ADDROF,
+ e.span,
+ "immediately dereferencing a reference",
+ "try this",
+ sugg.to_string(),
+ 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;
+ /// ```
+ /// Use instead:
+ /// ```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;
+declare_lint_pass!(RefInDeref => [REF_IN_DEREF]);
-impl LintPass for DerefPass {
- fn get_lints(&self) -> LintArray {
- lint_array!(REF_IN_DEREF)
- }
-}
-
-impl EarlyLintPass for DerefPass {
+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::Paren(ref parened) = object.node;
- if let ExprKind::AddrOf(_, ref inner) = parened.node;
+ if let ExprKind::Field(ref object, _) = e.kind;
+ if let ExprKind::Paren(ref parened) = object.kind;
+ if let ExprKind::AddrOf(_, _, ref inner) = parened.kind;
then {
- let mut applicability = Applicability::MachineApplicable;
+ let applicability = if inner.span.from_expansion() {
+ Applicability::MaybeIncorrect
+ } else {
+ Applicability::MachineApplicable
+ };
+ let sugg = Sugg::ast(cx, inner, "_").maybe_par();
span_lint_and_sugg(
cx,
REF_IN_DEREF,
object.span,
- "Creating a reference that is immediately dereferenced.",
+ "creating a reference that is immediately dereferenced",
"try this",
- format!(
- "{}.{}",
- snippet_with_applicability(cx, inner.span, "_", &mut applicability),
- snippet_with_applicability(cx, field_name.span, "_", &mut applicability)
- ),
+ sugg.to_string(),
applicability,
);
}
projects / rust.git / blobdiff