-use crate::utils::{is_copy, match_def_path, opt_def_id, paths, span_note_and_lint};
+use crate::utils::{is_copy, match_def_path, paths, span_lint_and_note};
use if_chain::if_chain;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::ty;
-use rustc::{declare_tool_lint, lint_array};
+use rustc_hir::{Expr, ExprKind};
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_middle::ty;
+use rustc_session::{declare_lint_pass, declare_tool_lint};
-/// **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
-/// 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:**
-/// ```rust
-/// 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();
-/// ```
declare_clippy_lint! {
+ /// **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
+ /// 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:**
+ /// ```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();
+ /// ```
pub DROP_REF,
correctness,
"calls to `std::mem::drop` with a reference instead of an owned value"
}
-/// **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
-/// 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:**
-/// ```rust
-/// let x = Box::new(1);
-/// std::mem::forget(&x) // Should have been forget(x), x will still be dropped
-/// ```
declare_clippy_lint! {
+ /// **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
+ /// 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:**
+ /// ```rust
+ /// let x = Box::new(1);
+ /// std::mem::forget(&x) // Should have been forget(x), x will still be dropped
+ /// ```
pub FORGET_REF,
correctness,
"calls to `std::mem::forget` with a reference instead of an owned 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
-/// 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:**
-/// ```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
-/// ```
declare_clippy_lint! {
+ /// **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
+ /// 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:**
+ /// ```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
+ /// ```
pub DROP_COPY,
correctness,
"calls to `std::mem::drop` with a value that implements Copy"
}
-/// **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
-/// 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.
-///
-/// An alternative, but also valid, explanation is that Copy types do not
-/// implement
-/// the Drop trait, which means they have no destructors. Without a destructor,
-/// there
-/// is nothing for `std::mem::forget` to ignore.
-///
-/// **Known problems:** None.
-///
-/// **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
-/// ```
declare_clippy_lint! {
+ /// **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
+ /// 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.
+ ///
+ /// An alternative, but also valid, explanation is that Copy types do not
+ /// implement
+ /// the Drop trait, which means they have no destructors. Without a destructor,
+ /// there
+ /// is nothing for `std::mem::forget` to ignore.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **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
+ /// ```
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.";
-const DROP_COPY_SUMMARY: &str = "calls to `std::mem::drop` with a value that implements Copy. \
- 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 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";
+const FORGET_COPY_SUMMARY: &str = "calls to `std::mem::forget` with a value that implements `Copy`. \
+ Forgetting a copy leaves the original intact";
-pub struct Pass;
+declare_lint_pass!(DropForgetRef => [DROP_REF, FORGET_REF, DROP_COPY, FORGET_COPY]);
-impl LintPass for Pass {
- fn get_lints(&self) -> LintArray {
- lint_array!(DROP_REF, FORGET_REF, DROP_COPY, FORGET_COPY)
- }
-}
-
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
+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.node;
- if let ExprKind::Path(ref qpath) = path.node;
+ if let ExprKind::Call(ref path, ref args) = expr.kind;
+ if let ExprKind::Path(ref qpath) = path.kind;
if args.len() == 1;
- if let Some(def_id) = opt_def_id(cx.tables.qpath_def(qpath, path.hir_id));
+ if let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id();
then {
let lint;
let msg;
let arg = &args[0];
- let arg_ty = cx.tables.expr_ty(arg);
+ let arg_ty = cx.typeck_results().expr_ty(arg);
- if let ty::Ref(..) = arg_ty.sty {
- if match_def_path(cx.tcx, def_id, &paths::DROP) {
+ if let ty::Ref(..) = arg_ty.kind() {
+ if match_def_path(cx, def_id, &paths::DROP) {
lint = DROP_REF;
msg = DROP_REF_SUMMARY.to_string();
- } else if match_def_path(cx.tcx, def_id, &paths::MEM_FORGET) {
+ } else if match_def_path(cx, def_id, &paths::MEM_FORGET) {
lint = FORGET_REF;
msg = FORGET_REF_SUMMARY.to_string();
} else {
return;
}
- span_note_and_lint(cx,
+ span_lint_and_note(cx,
lint,
expr.span,
&msg,
- arg.span,
- &format!("argument has type {}", arg_ty));
+ Some(arg.span),
+ &format!("argument has type `{}`", arg_ty));
} else if is_copy(cx, arg_ty) {
- if match_def_path(cx.tcx, def_id, &paths::DROP) {
+ if match_def_path(cx, def_id, &paths::DROP) {
lint = DROP_COPY;
msg = DROP_COPY_SUMMARY.to_string();
- } else if match_def_path(cx.tcx, def_id, &paths::MEM_FORGET) {
+ } else if match_def_path(cx, def_id, &paths::MEM_FORGET) {
lint = FORGET_COPY;
msg = FORGET_COPY_SUMMARY.to_string();
} else {
return;
}
- span_note_and_lint(cx,
+ span_lint_and_note(cx,
lint,
expr.span,
&msg,
- arg.span,
+ Some(arg.span),
&format!("argument has type {}", arg_ty));
}
}
projects / rust.git / blobdiff