From eed466281c8d0e3a920a2cde01a5b4b5c0df5f0e Mon Sep 17 00:00:00 2001
From: Centri3 <114838443+Centri3@users.noreply.github.com>
Date: Thu, 1 Jun 2023 14:29:56 -0500
Subject: [PATCH] ignore `Foo::deref` altogether
---
clippy_lints/src/dereference.rs | 47 ++++++++++----------------
tests/ui/explicit_deref_methods.fixed | 15 ++++----
tests/ui/explicit_deref_methods.rs | 3 +-
tests/ui/explicit_deref_methods.stderr | 40 ++--------------------
4 files changed, 30 insertions(+), 75 deletions(-)
diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs
index 96d1bcea6e5..93b6e2083b5 100644
--- a/clippy_lints/src/dereference.rs
+++ b/clippy_lints/src/dereference.rs
@@ -56,9 +56,11 @@ declare_clippy_lint! {
/// let b = &*a;
/// ```
///
- /// This lint excludes:
+ /// This lint excludes all of:
/// ```rust,ignore
/// let _ = d.unwrap().deref();
+ /// let _ = Foo::deref(&foo);
+ /// let _ = <Foo as Deref>::deref(&foo);
/// ```
#[clippy::version = "1.44.0"]
pub EXPLICIT_DEREF_METHODS,
@@ -155,7 +157,7 @@ impl_lint_pass!(Dereferencing<'_> => [
#[derive(Default)]
pub struct Dereferencing<'tcx> {
- state: Option<(State<'tcx>, StateData)>,
+ state: Option<(State, StateData)>,
// While parsing a `deref` method call in ufcs form, the path to the function is itself an
// expression. This is to store the id of that expression so it can be skipped when
@@ -210,13 +212,12 @@ struct DerefedBorrow {
}
#[derive(Debug)]
-enum State<'tcx> {
+enum State {
// Any number of deref method calls.
DerefMethod {
// The number of calls in a sequence which changed the referenced type
ty_changed_count: usize,
is_final_ufcs: bool,
- call_args: Option<&'tcx [Expr<'tcx>]>,
/// The required mutability
target_mut: Mutability,
},
@@ -313,16 +314,10 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
&& position.lint_explicit_deref() =>
{
let ty_changed_count = usize::from(!deref_method_same_type(expr_ty, typeck.expr_ty(sub_expr)));
- let (is_final_ufcs, call_args) = if let ExprKind::Call(_, args) = expr.kind {
- (true, Some(args))
- } else {
- (false, None)
- };
self.state = Some((
State::DerefMethod {
ty_changed_count,
- is_final_ufcs,
- call_args,
+ is_final_ufcs: matches!(expr.kind, ExprKind::Call(..)),
target_mut,
},
StateData {
@@ -445,7 +440,6 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> {
ty_changed_count + 1
},
is_final_ufcs: matches!(expr.kind, ExprKind::Call(..)),
- call_args: None,
target_mut,
},
data,
@@ -1480,16 +1474,15 @@ fn ty_contains_field(ty: Ty<'_>, name: Symbol) -> bool {
}
#[expect(clippy::needless_pass_by_value, clippy::too_many_lines)]
-fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State<'_>, data: StateData) {
+fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data: StateData) {
match state {
State::DerefMethod {
ty_changed_count,
is_final_ufcs,
- call_args,
target_mut,
} => {
let mut app = Applicability::MachineApplicable;
- let (expr_str, expr_is_macro_call) = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app);
+ let (expr_str, _expr_is_macro_call) = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app);
let ty = cx.typeck_results().expr_ty(expr);
let (_, ref_count) = peel_mid_ty_refs(ty);
let deref_str = if ty_changed_count >= ref_count && ref_count != 0 {
@@ -1512,23 +1505,19 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State<'_>,
"&"
};
- let mut expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence().order() < PREC_PREFIX {
- format!("({expr_str})")
+ // expr_str (the suggestion) is never shown if is_final_ufcs is true, since it's
+ // `expr.kind == ExprKind::Call`. Therefore, this is, afaik, always unnecessary.
+ /*
+ expr_str = if !expr_is_macro_call && is_final_ufcs && expr.precedence().order() < PREC_PREFIX {
+ Cow::Owned(format!("({expr_str})"))
} else {
- expr_str.into_owned()
+ expr_str
};
+ */
- // Fix #10850, changes suggestion if it's `Foo::deref` instead of `foo.deref`. Since `Foo::deref` is
- // a `Call` instead of a `MethodCall` this should catch all instances of this, even if it's fully
- // qualified or whatnot.
- if is_final_ufcs && let Some(args) = call_args {
- // Remove ref if it's there
- let arg = if let ExprKind::AddrOf(.., arg) = args[0].kind {
- arg
- } else {
- &args[0]
- };
- expr_str = snippet_with_applicability(cx, arg.span, "{ .. }", &mut app).to_string();
+ // Fix #10850, do not lint if it's `Foo::deref` instead of `foo.deref()`.
+ if is_final_ufcs {
+ return;
}
span_lint_and_sugg(
diff --git a/tests/ui/explicit_deref_methods.fixed b/tests/ui/explicit_deref_methods.fixed
index 6cf7a28cafa..1710b170fb8 100644
--- a/tests/ui/explicit_deref_methods.fixed
+++ b/tests/ui/explicit_deref_methods.fixed
@@ -75,15 +75,16 @@ fn main() {
let opt_a = Some(a.clone());
let b = &*opt_a.unwrap();
- // make sure `Aaa::deref` instead of `aaa.deref()` works as well as fully qualified syntax
+ // make sure `Aaa::deref` instead of `aaa.deref()` is not linted, as well as fully qualified
+ // syntax
- &*Aaa;
- &mut *Aaa;
- &*Aaa;
- &mut *Aaa;
+ Aaa::deref(&Aaa);
+ Aaa::deref_mut(&mut Aaa);
+ <Aaa as Deref>::deref(&Aaa);
+ <Aaa as DerefMut>::deref_mut(&mut Aaa);
let mut aaa = Aaa;
- &*aaa;
- &mut *aaa;
+ Aaa::deref(&aaa);
+ Aaa::deref_mut(&mut aaa);
// following should not require linting
diff --git a/tests/ui/explicit_deref_methods.rs b/tests/ui/explicit_deref_methods.rs
index 77501fa6b6e..85147e1cb69 100644
--- a/tests/ui/explicit_deref_methods.rs
+++ b/tests/ui/explicit_deref_methods.rs
@@ -75,7 +75,8 @@ fn main() {
let opt_a = Some(a.clone());
let b = opt_a.unwrap().deref();
- // make sure `Aaa::deref` instead of `aaa.deref()` works as well as fully qualified syntax
+ // make sure `Aaa::deref` instead of `aaa.deref()` is not linted, as well as fully qualified
+ // syntax
Aaa::deref(&Aaa);
Aaa::deref_mut(&mut Aaa);
diff --git a/tests/ui/explicit_deref_methods.stderr b/tests/ui/explicit_deref_methods.stderr
index 30ebcd47b2b..592563ffa8c 100644
--- a/tests/ui/explicit_deref_methods.stderr
+++ b/tests/ui/explicit_deref_methods.stderr
@@ -67,46 +67,10 @@ LL | let b = opt_a.unwrap().deref();
| ^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&*opt_a.unwrap()`
error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:80:5
- |
-LL | Aaa::deref(&Aaa);
- | ^^^^^^^^^^^^^^^^ help: try this: `&*Aaa`
-
-error: explicit `deref_mut` method call
- --> $DIR/explicit_deref_methods.rs:81:5
- |
-LL | Aaa::deref_mut(&mut Aaa);
- | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut *Aaa`
-
-error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:82:5
- |
-LL | <Aaa as Deref>::deref(&Aaa);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&*Aaa`
-
-error: explicit `deref_mut` method call
- --> $DIR/explicit_deref_methods.rs:83:5
- |
-LL | <Aaa as DerefMut>::deref_mut(&mut Aaa);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut *Aaa`
-
-error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:85:5
- |
-LL | Aaa::deref(&aaa);
- | ^^^^^^^^^^^^^^^^ help: try this: `&*aaa`
-
-error: explicit `deref_mut` method call
- --> $DIR/explicit_deref_methods.rs:86:5
- |
-LL | Aaa::deref_mut(&mut aaa);
- | ^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&mut *aaa`
-
-error: explicit `deref` method call
- --> $DIR/explicit_deref_methods.rs:112:31
+ --> $DIR/explicit_deref_methods.rs:113:31
|
LL | let b: &str = expr_deref!(a.deref());
| ^^^^^^^^^ help: try this: `&*a`
-error: aborting due to 18 previous errors
+error: aborting due to 12 previous errors