-use crate::utils::{is_copy, match_def_path, paths, span_lint_and_note};
+use clippy_utils::diagnostics::span_lint_and_note;
+use clippy_utils::ty::is_copy;
+use clippy_utils::{match_def_path, paths};
use if_chain::if_chain;
use rustc_hir::{Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_session::{declare_lint_pass, declare_tool_lint};
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `std::mem::drop` with a reference
+ /// ### What it does
+ /// Checks for calls to `std::mem::drop` with a reference
/// instead of an owned value.
///
- /// **Why is this bad?** Calling `drop` on a reference will only drop the
+ /// ### Why is this bad?
+ /// Calling `drop` on a reference will only drop the
/// reference itself, which is a no-op. It will not call the `drop` method (from
/// the `Drop` trait implementation) on the underlying referenced value, which
/// is likely what was intended.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```ignore
/// let mut lock_guard = mutex.lock();
/// std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
/// // still locked
/// operation_that_requires_mutex_to_be_unlocked();
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub DROP_REF,
correctness,
"calls to `std::mem::drop` with a reference instead of an owned value"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `std::mem::forget` with a reference
+ /// ### What it does
+ /// Checks for calls to `std::mem::forget` with a reference
/// instead of an owned value.
///
- /// **Why is this bad?** Calling `forget` on a reference will only forget the
+ /// ### Why is this bad?
+ /// Calling `forget` on a reference will only forget the
/// reference itself, which is a no-op. It will not forget the underlying
/// referenced
/// value, which is likely what was intended.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let x = Box::new(1);
/// std::mem::forget(&x) // Should have been forget(x), x will still be dropped
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub FORGET_REF,
correctness,
"calls to `std::mem::forget` with a reference instead of an owned value"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `std::mem::drop` with a value
+ /// ### What it does
+ /// Checks for calls to `std::mem::drop` with a value
/// that derives the Copy trait
///
- /// **Why is this bad?** Calling `std::mem::drop` [does nothing for types that
+ /// ### Why is this bad?
+ /// Calling `std::mem::drop` [does nothing for types that
/// implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html), since the
/// value will be copied and moved into the function on invocation.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let x: i32 = 42; // i32 implements Copy
/// std::mem::drop(x) // A copy of x is passed to the function, leaving the
/// // original unaffected
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub DROP_COPY,
correctness,
"calls to `std::mem::drop` with a value that implements Copy"
}
declare_clippy_lint! {
- /// **What it does:** Checks for calls to `std::mem::forget` with a value that
+ /// ### What it does
+ /// Checks for calls to `std::mem::forget` with a value that
/// derives the Copy trait
///
- /// **Why is this bad?** Calling `std::mem::forget` [does nothing for types that
+ /// ### Why is this bad?
+ /// Calling `std::mem::forget` [does nothing for types that
/// implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the
/// value will be copied and moved into the function on invocation.
///
/// there
/// is nothing for `std::mem::forget` to ignore.
///
- /// **Known problems:** None.
- ///
- /// **Example:**
+ /// ### Example
/// ```rust
/// let x: i32 = 42; // i32 implements Copy
/// std::mem::forget(x) // A copy of x is passed to the function, leaving the
/// // original unaffected
/// ```
+ #[clippy::version = "pre 1.29.0"]
pub FORGET_COPY,
correctness,
"calls to `std::mem::forget` with a value that implements Copy"
}
const DROP_REF_SUMMARY: &str = "calls to `std::mem::drop` with a reference instead of an owned value. \
- Dropping a reference does nothing.";
+ Dropping a reference does nothing";
const FORGET_REF_SUMMARY: &str = "calls to `std::mem::forget` with a reference instead of an owned value. \
- Forgetting a reference does nothing.";
+ Forgetting a reference does nothing";
const DROP_COPY_SUMMARY: &str = "calls to `std::mem::drop` with a value that implements `Copy`. \
- Dropping a copy leaves the original intact.";
+ Dropping a copy leaves the original intact";
const FORGET_COPY_SUMMARY: &str = "calls to `std::mem::forget` with a value that implements `Copy`. \
- Forgetting a copy leaves the original intact.";
+ Forgetting a copy leaves the original intact";
declare_lint_pass!(DropForgetRef => [DROP_REF, FORGET_REF, DROP_COPY, FORGET_COPY]);
impl<'tcx> LateLintPass<'tcx> for DropForgetRef {
fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
if_chain! {
- if let ExprKind::Call(ref path, ref args) = expr.kind;
+ if let ExprKind::Call(path, args) = expr.kind;
if let ExprKind::Path(ref qpath) = path.kind;
if args.len() == 1;
if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id();
projects / rust.git / blobdiff