From 708c2d95c14829e0acbe7f40d9bea39e7bb03450 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Sat, 1 Oct 2022 15:58:10 +0200
Subject: [PATCH 01/16] feat: add and implement unchecked_duration_subtraction
lint
---
CHANGELOG.md | 1 +
clippy_lints/src/lib.rs | 2 +
.../src/unchecked_duration_subtraction.rs | 107 ++++++++++++++++++
clippy_lints/src/utils/conf.rs | 2 +-
4 files changed, 111 insertions(+), 1 deletion(-)
create mode 100644 clippy_lints/src/unchecked_duration_subtraction.rs
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9bd67617f5b..eb4ca980143 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4428,6 +4428,7 @@ Released 2018-09-13
[`try_err`]: https://rust-lang.github.io/rust-clippy/master/index.html#try_err
[`type_complexity`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_complexity
[`type_repetition_in_bounds`]: https://rust-lang.github.io/rust-clippy/master/index.html#type_repetition_in_bounds
+[`unchecked_duration_subtraction`]: https://rust-lang.github.io/rust-clippy/master/index.html#unchecked_duration_subtraction
[`undocumented_unsafe_blocks`]: https://rust-lang.github.io/rust-clippy/master/index.html#undocumented_unsafe_blocks
[`undropped_manually_drops`]: https://rust-lang.github.io/rust-clippy/master/index.html#undropped_manually_drops
[`unicode_not_nfc`]: https://rust-lang.github.io/rust-clippy/master/index.html#unicode_not_nfc
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index a4bacb78034..a5407b65b88 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -279,6 +279,7 @@ mod trailing_empty_array;
mod trait_bounds;
mod transmute;
mod types;
+mod unchecked_duration_subtraction;
mod undocumented_unsafe_blocks;
mod unicode;
mod uninit_vec;
@@ -921,6 +922,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_late_pass(|_| Box::new(from_raw_with_void_ptr::FromRawWithVoidPtr));
store.register_late_pass(|_| Box::new(suspicious_xor_used_as_pow::ConfusingXorAndPow));
store.register_late_pass(move |_| Box::new(manual_is_ascii_check::ManualIsAsciiCheck::new(msrv)));
+ store.register_late_pass(move || Box::new(unchecked_duration_subtraction::UncheckedDurationSubtraction::new(msrv)));
// add lints here, do not remove this comment, it's used in `new_lint`
}
diff --git a/clippy_lints/src/unchecked_duration_subtraction.rs b/clippy_lints/src/unchecked_duration_subtraction.rs
new file mode 100644
index 00000000000..fb08067de8d
--- /dev/null
+++ b/clippy_lints/src/unchecked_duration_subtraction.rs
@@ -0,0 +1,107 @@
+use clippy_utils::{diagnostics, meets_msrv, msrvs, source, ty};
+use rustc_errors::Applicability;
+use rustc_hir::*;
+use rustc_lint::{LateContext, LateLintPass};
+use rustc_semver::RustcVersion;
+use rustc_session::{declare_tool_lint, impl_lint_pass};
+use rustc_span::symbol::sym;
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Finds patterns of unchecked subtraction of [`Duration`] from [`Instant::now()`].
+ ///
+ /// ### Why is this bad?
+ /// Unchecked subtraction could cause underflow on certain platforms, leading to bugs and/or
+ /// unintentional panics.
+ ///
+ /// ### Example
+ /// ```rust
+ /// let time_passed = Instant::now() - Duration::from_secs(5);
+ /// ```
+ ///
+ /// Use instead:
+ /// ```rust
+ /// let time_passed = Instant::now().checked_sub(Duration::from_secs(5));
+ /// ```
+ ///
+ /// [`Duration`]: std::time::Duration
+ /// [`Instant::now()`]: std::time::Instant::now;
+ #[clippy::version = "1.65.0"]
+ pub UNCHECKED_DURATION_SUBTRACTION,
+ suspicious,
+ "finds unchecked subtraction of a 'Duration' from an 'Instant'"
+}
+
+pub struct UncheckedDurationSubtraction {
+ msrv: Option<RustcVersion>,
+}
+
+impl UncheckedDurationSubtraction {
+ #[must_use]
+ pub fn new(msrv: Option<RustcVersion>) -> Self {
+ Self { msrv }
+ }
+}
+
+impl_lint_pass!(UncheckedDurationSubtraction => [UNCHECKED_DURATION_SUBTRACTION]);
+
+impl<'tcx> LateLintPass<'tcx> for UncheckedDurationSubtraction {
+ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
+ if expr.span.from_expansion() || !meets_msrv(self.msrv, msrvs::TRY_FROM) {
+ return;
+ }
+
+ if_chain! {
+ if let ExprKind::Binary(op, lhs, rhs) = expr.kind;
+
+ if let BinOpKind::Sub = op.node;
+
+ // get types of left and right side
+ if is_an_instant(cx, lhs);
+ if is_a_duration(cx, rhs);
+
+ then {
+ print_lint_and_sugg(cx, lhs, rhs, expr)
+ }
+ }
+ }
+}
+
+fn is_an_instant(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ let expr_ty = cx.typeck_results().expr_ty(expr);
+
+ match expr_ty.kind() {
+ rustc_middle::ty::Adt(def, _) => {
+ clippy_utils::match_def_path(cx, dbg!(def).did(), &clippy_utils::paths::INSTANT)
+ },
+ _ => false,
+ }
+}
+
+fn is_a_duration(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
+ let expr_ty = cx.typeck_results().expr_ty(expr);
+ ty::is_type_diagnostic_item(cx, expr_ty, sym::Duration)
+}
+
+fn print_lint_and_sugg(cx: &LateContext<'_>, left_expr: &Expr<'_>, right_expr: &Expr<'_>, expr: &Expr<'_>) {
+ let mut applicability = Applicability::MachineApplicable;
+
+ let left_expr =
+ source::snippet_with_applicability(cx, left_expr.span, "std::time::Instant::now()", &mut applicability);
+ let right_expr = source::snippet_with_applicability(
+ cx,
+ right_expr.span,
+ "std::time::Duration::from_secs(1)",
+ &mut applicability,
+ );
+
+ diagnostics::span_lint_and_sugg(
+ cx,
+ UNCHECKED_DURATION_SUBTRACTION,
+ expr.span,
+ "unchecked subtraction of a 'Duration' from an 'Instant'",
+ "try",
+ format!("{}.checked_sub({}).unwrap();", left_expr, right_expr),
+ applicability,
+ );
+}
diff --git a/clippy_lints/src/utils/conf.rs b/clippy_lints/src/utils/conf.rs
index 0cf49ca6d42..ab58e9b8b68 100644
--- a/clippy_lints/src/utils/conf.rs
+++ b/clippy_lints/src/utils/conf.rs
@@ -213,7 +213,7 @@ define_Conf! {
///
/// Suppress lints whenever the suggested change would cause breakage for other crates.
(avoid_breaking_exported_api: bool = true),
- /// Lint: MANUAL_SPLIT_ONCE, MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE, APPROX_CONSTANT, DEPRECATED_CFG_ATTR, INDEX_REFUTABLE_SLICE, MAP_CLONE, BORROW_AS_PTR, MANUAL_BITS, ERR_EXPECT, CAST_ABS_TO_UNSIGNED, UNINLINED_FORMAT_ARGS, MANUAL_CLAMP, MANUAL_LET_ELSE.
+ /// Lint: MANUAL_SPLIT_ONCE, MANUAL_STR_REPEAT, CLONED_INSTEAD_OF_COPIED, REDUNDANT_FIELD_NAMES, REDUNDANT_STATIC_LIFETIMES, FILTER_MAP_NEXT, CHECKED_CONVERSIONS, MANUAL_RANGE_CONTAINS, USE_SELF, MEM_REPLACE_WITH_DEFAULT, MANUAL_NON_EXHAUSTIVE, OPTION_AS_REF_DEREF, MAP_UNWRAP_OR, MATCH_LIKE_MATCHES_MACRO, MANUAL_STRIP, MISSING_CONST_FOR_FN, UNNESTED_OR_PATTERNS, FROM_OVER_INTO, PTR_AS_PTR, IF_THEN_SOME_ELSE_NONE, APPROX_CONSTANT, DEPRECATED_CFG_ATTR, INDEX_REFUTABLE_SLICE, MAP_CLONE, BORROW_AS_PTR, MANUAL_BITS, ERR_EXPECT, CAST_ABS_TO_UNSIGNED, UNINLINED_FORMAT_ARGS, MANUAL_CLAMP, MANUAL_LET_ELSE, UNCHECKED_DURATION_SUBTRACTION.
///
/// The minimum rust version that the project supports
(msrv: Option<String> = None),
From 3b4e42b91b0df11c43983c6fe67bb971f472aa3f Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Sat, 1 Oct 2022 16:02:57 +0200
Subject: [PATCH 02/16] test: add tests for 'unchecked_duration_subtraction'
lint
---
tests/ui/unchecked_duration_subtraction.rs | 16 ++++++++++
.../ui/unchecked_duration_subtraction.stderr | 32 +++++++++++++++++++
2 files changed, 48 insertions(+)
create mode 100644 tests/ui/unchecked_duration_subtraction.rs
create mode 100644 tests/ui/unchecked_duration_subtraction.stderr
diff --git a/tests/ui/unchecked_duration_subtraction.rs b/tests/ui/unchecked_duration_subtraction.rs
new file mode 100644
index 00000000000..fff1d13720d
--- /dev/null
+++ b/tests/ui/unchecked_duration_subtraction.rs
@@ -0,0 +1,16 @@
+#![warn(clippy::unchecked_duration_subtraction)]
+
+use std::time::{Duration, Instant};
+
+fn main() {
+ let _first = Instant::now();
+ let second = Duration::from_secs(3);
+
+ let _ = _first - second;
+
+ let _ = Instant::now() - Duration::from_secs(5);
+
+ let _ = _first - Duration::from_secs(5);
+
+ let _ = Instant::now() - second;
+}
diff --git a/tests/ui/unchecked_duration_subtraction.stderr b/tests/ui/unchecked_duration_subtraction.stderr
new file mode 100644
index 00000000000..827b18a5a09
--- /dev/null
+++ b/tests/ui/unchecked_duration_subtraction.stderr
@@ -0,0 +1,32 @@
+[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
+error: unchecked subtraction of a 'Duration' from an 'Instant'
+ --> $DIR/unchecked_duration_subtraction.rs:9:13
+ |
+LL | let _ = _first - second;
+ | ^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(second).unwrap();`
+ |
+ = note: `-D clippy::unchecked-duration-subtraction` implied by `-D warnings`
+
+[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
+error: unchecked subtraction of a 'Duration' from an 'Instant'
+ --> $DIR/unchecked_duration_subtraction.rs:11:13
+ |
+LL | let _ = Instant::now() - Duration::from_secs(5);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(Duration::from_secs(5)).unwrap();`
+
+[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
+error: unchecked subtraction of a 'Duration' from an 'Instant'
+ --> $DIR/unchecked_duration_subtraction.rs:13:13
+ |
+LL | let _ = _first - Duration::from_secs(5);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(Duration::from_secs(5)).unwrap();`
+
+[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
+error: unchecked subtraction of a 'Duration' from an 'Instant'
+ --> $DIR/unchecked_duration_subtraction.rs:15:13
+ |
+LL | let _ = Instant::now() - second;
+ | ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(second).unwrap();`
+
+error: aborting due to 4 previous errors
+
From b280dbe5f73286a3f2a02e93c6c3e42181ec8aca Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Sat, 1 Oct 2022 16:50:45 +0200
Subject: [PATCH 03/16] docs: add docs for `unchecked_duration_subtraction`
lint
---
src/docs/unchecked_duration_subtraction.txt | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
create mode 100644 src/docs/unchecked_duration_subtraction.txt
diff --git a/src/docs/unchecked_duration_subtraction.txt b/src/docs/unchecked_duration_subtraction.txt
new file mode 100644
index 00000000000..6b9c9308c87
--- /dev/null
+++ b/src/docs/unchecked_duration_subtraction.txt
@@ -0,0 +1,19 @@
+### What it does
+Finds patterns of unchecked subtraction of [`Duration`] from [`Instant::now()`].
+
+### Why is this bad?
+Unchecked subtraction could cause underflow on certain platforms, leading to bugs and/or
+unintentional panics.
+
+### Example
+```
+let time_passed = Instant::now() - Duration::from_secs(5);
+```
+
+Use instead:
+```
+let time_passed = Instant::now().checked_sub(Duration::from_secs(5));
+```
+
+[`Duration`]: std::time::Duration
+[`Instant::now()`]: std::time::Instant::now;
\ No newline at end of file
From b485832b16a388dbcfd3c42030356959e7662a3d Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Sat, 1 Oct 2022 16:50:56 +0200
Subject: [PATCH 04/16] style: remove `dbg!` call
---
clippy_lints/src/unchecked_duration_subtraction.rs | 4 +---
tests/ui/unchecked_duration_subtraction.stderr | 4 ----
2 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/clippy_lints/src/unchecked_duration_subtraction.rs b/clippy_lints/src/unchecked_duration_subtraction.rs
index fb08067de8d..ae796000662 100644
--- a/clippy_lints/src/unchecked_duration_subtraction.rs
+++ b/clippy_lints/src/unchecked_duration_subtraction.rs
@@ -71,9 +71,7 @@ fn is_an_instant(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let expr_ty = cx.typeck_results().expr_ty(expr);
match expr_ty.kind() {
- rustc_middle::ty::Adt(def, _) => {
- clippy_utils::match_def_path(cx, dbg!(def).did(), &clippy_utils::paths::INSTANT)
- },
+ rustc_middle::ty::Adt(def, _) => clippy_utils::match_def_path(cx, def.did(), &clippy_utils::paths::INSTANT),
_ => false,
}
}
diff --git a/tests/ui/unchecked_duration_subtraction.stderr b/tests/ui/unchecked_duration_subtraction.stderr
index 827b18a5a09..6b297a01c7b 100644
--- a/tests/ui/unchecked_duration_subtraction.stderr
+++ b/tests/ui/unchecked_duration_subtraction.stderr
@@ -1,4 +1,3 @@
-[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:9:13
|
@@ -7,21 +6,18 @@ LL | let _ = _first - second;
|
= note: `-D clippy::unchecked-duration-subtraction` implied by `-D warnings`
-[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:11:13
|
LL | let _ = Instant::now() - Duration::from_secs(5);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(Duration::from_secs(5)).unwrap();`
-[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:13:13
|
LL | let _ = _first - Duration::from_secs(5);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(Duration::from_secs(5)).unwrap();`
-[clippy_lints/src/unchecked_duration_subtraction.rs:75] def = std::time::Instant
error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:15:13
|
From 2f2eb2e4baace68868af2f4ac3ec7aed073139ad Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 7 Nov 2022 20:58:49 +0100
Subject: [PATCH 05/16] refactor: lint man. instant elapsed and unch. dur.
subtr. in single pass
---
..._subtraction.rs => instant_subtraction.rs} | 78 ++++++++++++++++---
clippy_lints/src/lib.rs | 5 +-
clippy_lints/src/manual_instant_elapsed.rs | 69 ----------------
3 files changed, 71 insertions(+), 81 deletions(-)
rename clippy_lints/src/{unchecked_duration_subtraction.rs => instant_subtraction.rs} (52%)
delete mode 100644 clippy_lints/src/manual_instant_elapsed.rs
diff --git a/clippy_lints/src/unchecked_duration_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
similarity index 52%
rename from clippy_lints/src/unchecked_duration_subtraction.rs
rename to clippy_lints/src/instant_subtraction.rs
index ae796000662..8cc5643c9a7 100644
--- a/clippy_lints/src/unchecked_duration_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -1,17 +1,48 @@
-use clippy_utils::{diagnostics, meets_msrv, msrvs, source, ty};
+use clippy_utils::{
+ diagnostics::{self, span_lint_and_sugg},
+ meets_msrv, msrvs, source, ty,
+};
use rustc_errors::Applicability;
-use rustc_hir::*;
+use rustc_hir::{BinOpKind, Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_semver::RustcVersion;
use rustc_session::{declare_tool_lint, impl_lint_pass};
-use rustc_span::symbol::sym;
+use rustc_span::{source_map::Spanned, sym};
+
+declare_clippy_lint! {
+ /// ### What it does
+ /// Lints subtraction between `Instant::now()` and another `Instant`.
+ ///
+ /// ### Why is this bad?
+ /// It is easy to accidentally write `prev_instant - Instant::now()`, which will always be 0ns
+ /// as `Instant` subtraction saturates.
+ ///
+ /// `prev_instant.elapsed()` also more clearly signals intention.
+ ///
+ /// ### Example
+ /// ```rust
+ /// use std::time::Instant;
+ /// let prev_instant = Instant::now();
+ /// let duration = Instant::now() - prev_instant;
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// use std::time::Instant;
+ /// let prev_instant = Instant::now();
+ /// let duration = prev_instant.elapsed();
+ /// ```
+ #[clippy::version = "1.64.0"]
+ pub MANUAL_INSTANT_ELAPSED,
+ pedantic,
+ "subtraction between `Instant::now()` and previous `Instant`"
+}
declare_clippy_lint! {
/// ### What it does
/// Finds patterns of unchecked subtraction of [`Duration`] from [`Instant::now()`].
///
/// ### Why is this bad?
- /// Unchecked subtraction could cause underflow on certain platforms, leading to bugs and/or
+ /// Unchecked subtraction could cause underflow on certain platforms, leading to
/// unintentional panics.
///
/// ### Example
@@ -32,21 +63,39 @@ declare_clippy_lint! {
"finds unchecked subtraction of a 'Duration' from an 'Instant'"
}
-pub struct UncheckedDurationSubtraction {
+pub struct InstantSubtraction {
msrv: Option<RustcVersion>,
}
-impl UncheckedDurationSubtraction {
+impl InstantSubtraction {
#[must_use]
pub fn new(msrv: Option<RustcVersion>) -> Self {
Self { msrv }
}
}
-impl_lint_pass!(UncheckedDurationSubtraction => [UNCHECKED_DURATION_SUBTRACTION]);
+impl_lint_pass!(InstantSubtraction => [MANUAL_INSTANT_ELAPSED, UNCHECKED_DURATION_SUBTRACTION]);
+
+impl LateLintPass<'_> for InstantSubtraction {
+ fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
+ if let ExprKind::Binary(Spanned {node: BinOpKind::Sub, ..}, lhs, rhs) = expr.kind
+ && check_instant_now_call(cx, lhs)
+ && let ty_resolved = cx.typeck_results().expr_ty(rhs)
+ && let rustc_middle::ty::Adt(def, _) = ty_resolved.kind()
+ && clippy_utils::match_def_path(cx, def.did(), &clippy_utils::paths::INSTANT)
+ && let Some(sugg) = clippy_utils::sugg::Sugg::hir_opt(cx, rhs)
+ {
+ span_lint_and_sugg(
+ cx,
+ MANUAL_INSTANT_ELAPSED,
+ expr.span,
+ "manual implementation of `Instant::elapsed`",
+ "try",
+ format!("{}.elapsed()", sugg.maybe_par()),
+ Applicability::MachineApplicable,
+ );
+ }
-impl<'tcx> LateLintPass<'tcx> for UncheckedDurationSubtraction {
- fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
if expr.span.from_expansion() || !meets_msrv(self.msrv, msrvs::TRY_FROM) {
return;
}
@@ -67,6 +116,17 @@ impl<'tcx> LateLintPass<'tcx> for UncheckedDurationSubtraction {
}
}
+fn check_instant_now_call(cx: &LateContext<'_>, expr_block: &'_ Expr<'_>) -> bool {
+ if let ExprKind::Call(fn_expr, []) = expr_block.kind
+ && let Some(fn_id) = clippy_utils::path_def_id(cx, fn_expr)
+ && clippy_utils::match_def_path(cx, fn_id, &clippy_utils::paths::INSTANT_NOW)
+ {
+ true
+ } else {
+ false
+ }
+}
+
fn is_an_instant(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
let expr_ty = cx.typeck_results().expr_ty(expr);
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index a5407b65b88..ce0e7ebfbf1 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -151,6 +151,7 @@ mod inherent_impl;
mod inherent_to_string;
mod init_numbered_fields;
mod inline_fn_without_body;
+mod instant_subtraction;
mod int_plus_one;
mod invalid_upcast_comparisons;
mod invalid_utf8_in_unchecked;
@@ -172,7 +173,6 @@ mod manual_assert;
mod manual_async_fn;
mod manual_bits;
mod manual_clamp;
-mod manual_instant_elapsed;
mod manual_is_ascii_check;
mod manual_let_else;
mod manual_non_exhaustive;
@@ -279,7 +279,6 @@ mod trailing_empty_array;
mod trait_bounds;
mod transmute;
mod types;
-mod unchecked_duration_subtraction;
mod undocumented_unsafe_blocks;
mod unicode;
mod uninit_vec;
@@ -908,7 +907,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_late_pass(move |_| Box::new(operators::Operators::new(verbose_bit_mask_threshold)));
store.register_late_pass(|_| Box::new(invalid_utf8_in_unchecked::InvalidUtf8InUnchecked));
store.register_late_pass(|_| Box::<std_instead_of_core::StdReexports>::default());
- store.register_late_pass(|_| Box::new(manual_instant_elapsed::ManualInstantElapsed));
+ store.register_late_pass(move |_| Box::new(instant_subtraction::InstantSubtraction::new(msrv)));
store.register_late_pass(|_| Box::new(partialeq_to_none::PartialeqToNone));
store.register_late_pass(move |_| Box::new(manual_clamp::ManualClamp::new(msrv)));
store.register_late_pass(|_| Box::new(manual_string_new::ManualStringNew));
diff --git a/clippy_lints/src/manual_instant_elapsed.rs b/clippy_lints/src/manual_instant_elapsed.rs
deleted file mode 100644
index 1e60aa02d3c..00000000000
--- a/clippy_lints/src/manual_instant_elapsed.rs
+++ /dev/null
@@ -1,69 +0,0 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
-use rustc_errors::Applicability;
-use rustc_hir::{BinOpKind, Expr, ExprKind};
-use rustc_lint::{LateContext, LateLintPass};
-use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::source_map::Spanned;
-
-declare_clippy_lint! {
- /// ### What it does
- /// Lints subtraction between `Instant::now()` and another `Instant`.
- ///
- /// ### Why is this bad?
- /// It is easy to accidentally write `prev_instant - Instant::now()`, which will always be 0ns
- /// as `Instant` subtraction saturates.
- ///
- /// `prev_instant.elapsed()` also more clearly signals intention.
- ///
- /// ### Example
- /// ```rust
- /// use std::time::Instant;
- /// let prev_instant = Instant::now();
- /// let duration = Instant::now() - prev_instant;
- /// ```
- /// Use instead:
- /// ```rust
- /// use std::time::Instant;
- /// let prev_instant = Instant::now();
- /// let duration = prev_instant.elapsed();
- /// ```
- #[clippy::version = "1.65.0"]
- pub MANUAL_INSTANT_ELAPSED,
- pedantic,
- "subtraction between `Instant::now()` and previous `Instant`"
-}
-
-declare_lint_pass!(ManualInstantElapsed => [MANUAL_INSTANT_ELAPSED]);
-
-impl LateLintPass<'_> for ManualInstantElapsed {
- fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
- if let ExprKind::Binary(Spanned {node: BinOpKind::Sub, ..}, lhs, rhs) = expr.kind
- && check_instant_now_call(cx, lhs)
- && let ty_resolved = cx.typeck_results().expr_ty(rhs)
- && let rustc_middle::ty::Adt(def, _) = ty_resolved.kind()
- && clippy_utils::match_def_path(cx, def.did(), &clippy_utils::paths::INSTANT)
- && let Some(sugg) = clippy_utils::sugg::Sugg::hir_opt(cx, rhs)
- {
- span_lint_and_sugg(
- cx,
- MANUAL_INSTANT_ELAPSED,
- expr.span,
- "manual implementation of `Instant::elapsed`",
- "try",
- format!("{}.elapsed()", sugg.maybe_par()),
- Applicability::MachineApplicable,
- );
- }
- }
-}
-
-fn check_instant_now_call(cx: &LateContext<'_>, expr_block: &'_ Expr<'_>) -> bool {
- if let ExprKind::Call(fn_expr, []) = expr_block.kind
- && let Some(fn_id) = clippy_utils::path_def_id(cx, fn_expr)
- && clippy_utils::match_def_path(cx, fn_id, &clippy_utils::paths::INSTANT_NOW)
- {
- true
- } else {
- false
- }
-}
From a566eb37659ecbdcfe1403f8ccab753714dbec60 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 7 Nov 2022 20:59:55 +0100
Subject: [PATCH 06/16] docs: update docs for unchecked duration subtr. lint
---
src/docs/unchecked_duration_subtraction.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/docs/unchecked_duration_subtraction.txt b/src/docs/unchecked_duration_subtraction.txt
index 6b9c9308c87..15a4c02c606 100644
--- a/src/docs/unchecked_duration_subtraction.txt
+++ b/src/docs/unchecked_duration_subtraction.txt
@@ -2,7 +2,7 @@
Finds patterns of unchecked subtraction of [`Duration`] from [`Instant::now()`].
### Why is this bad?
-Unchecked subtraction could cause underflow on certain platforms, leading to bugs and/or
+Unchecked subtraction could cause underflow on certain platforms, leading to
unintentional panics.
### Example
From 80e3553f290cd252646c61086e9461fc7618b694 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 7 Nov 2022 21:34:24 +0100
Subject: [PATCH 07/16] refactor: improve code re-use in InstantSubtraction
lint pass
---
clippy_lints/src/instant_subtraction.rs | 77 +++++++++++++++----------
1 file changed, 46 insertions(+), 31 deletions(-)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index 8cc5643c9a7..3166c62dad4 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -1,6 +1,8 @@
use clippy_utils::{
diagnostics::{self, span_lint_and_sugg},
- meets_msrv, msrvs, source, ty,
+ meets_msrv, msrvs, source,
+ sugg::Sugg,
+ ty,
};
use rustc_errors::Applicability;
use rustc_hir::{BinOpKind, Expr, ExprKind};
@@ -78,45 +80,41 @@ impl_lint_pass!(InstantSubtraction => [MANUAL_INSTANT_ELAPSED, UNCHECKED_DURATIO
impl LateLintPass<'_> for InstantSubtraction {
fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ Expr<'_>) {
- if let ExprKind::Binary(Spanned {node: BinOpKind::Sub, ..}, lhs, rhs) = expr.kind
- && check_instant_now_call(cx, lhs)
- && let ty_resolved = cx.typeck_results().expr_ty(rhs)
- && let rustc_middle::ty::Adt(def, _) = ty_resolved.kind()
- && clippy_utils::match_def_path(cx, def.did(), &clippy_utils::paths::INSTANT)
- && let Some(sugg) = clippy_utils::sugg::Sugg::hir_opt(cx, rhs)
+ if let ExprKind::Binary(
+ Spanned {
+ node: BinOpKind::Sub, ..
+ },
+ lhs,
+ rhs,
+ ) = expr.kind
{
- span_lint_and_sugg(
- cx,
- MANUAL_INSTANT_ELAPSED,
- expr.span,
- "manual implementation of `Instant::elapsed`",
- "try",
- format!("{}.elapsed()", sugg.maybe_par()),
- Applicability::MachineApplicable,
- );
- }
+ if_chain! {
+ if is_instant_now_call(cx, lhs);
- if expr.span.from_expansion() || !meets_msrv(self.msrv, msrvs::TRY_FROM) {
- return;
- }
+ if is_an_instant(cx, rhs);
+ if let Some(sugg) = Sugg::hir_opt(cx, rhs);
- if_chain! {
- if let ExprKind::Binary(op, lhs, rhs) = expr.kind;
+ then {
+ print_manual_instant_elapsed_sugg(cx, expr, sugg)
+ } else {
+ if_chain! {
+ if !expr.span.from_expansion();
+ if meets_msrv(self.msrv, msrvs::TRY_FROM);
- if let BinOpKind::Sub = op.node;
+ if is_an_instant(cx, lhs);
+ if is_a_duration(cx, rhs);
- // get types of left and right side
- if is_an_instant(cx, lhs);
- if is_a_duration(cx, rhs);
-
- then {
- print_lint_and_sugg(cx, lhs, rhs, expr)
+ then {
+ print_unchecked_duration_subtraction_sugg(cx, lhs, rhs, expr)
+ }
+ }
+ }
}
}
}
}
-fn check_instant_now_call(cx: &LateContext<'_>, expr_block: &'_ Expr<'_>) -> bool {
+fn is_instant_now_call(cx: &LateContext<'_>, expr_block: &'_ Expr<'_>) -> bool {
if let ExprKind::Call(fn_expr, []) = expr_block.kind
&& let Some(fn_id) = clippy_utils::path_def_id(cx, fn_expr)
&& clippy_utils::match_def_path(cx, fn_id, &clippy_utils::paths::INSTANT_NOW)
@@ -141,7 +139,24 @@ fn is_a_duration(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool {
ty::is_type_diagnostic_item(cx, expr_ty, sym::Duration)
}
-fn print_lint_and_sugg(cx: &LateContext<'_>, left_expr: &Expr<'_>, right_expr: &Expr<'_>, expr: &Expr<'_>) {
+fn print_manual_instant_elapsed_sugg(cx: &LateContext<'_>, expr: &Expr<'_>, sugg: Sugg<'_>) {
+ span_lint_and_sugg(
+ cx,
+ MANUAL_INSTANT_ELAPSED,
+ expr.span,
+ "manual implementation of `Instant::elapsed`",
+ "try",
+ format!("{}.elapsed()", sugg.maybe_par()),
+ Applicability::MachineApplicable,
+ );
+}
+
+fn print_unchecked_duration_subtraction_sugg(
+ cx: &LateContext<'_>,
+ left_expr: &Expr<'_>,
+ right_expr: &Expr<'_>,
+ expr: &Expr<'_>,
+) {
let mut applicability = Applicability::MachineApplicable;
let left_expr =
From 4bd6d0beb0ef8ad72ad8ce6a28eb25a48f9cbc4b Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 7 Nov 2022 21:37:04 +0100
Subject: [PATCH 08/16] test: update tests for manual_instant_elapsed lint
---
tests/ui/manual_instant_elapsed.fixed | 1 +
tests/ui/manual_instant_elapsed.rs | 1 +
tests/ui/manual_instant_elapsed.stderr | 4 ++--
3 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/tests/ui/manual_instant_elapsed.fixed b/tests/ui/manual_instant_elapsed.fixed
index 0fa776b7b2e..85a91543c89 100644
--- a/tests/ui/manual_instant_elapsed.fixed
+++ b/tests/ui/manual_instant_elapsed.fixed
@@ -1,6 +1,7 @@
// run-rustfix
#![warn(clippy::manual_instant_elapsed)]
#![allow(clippy::unnecessary_operation)]
+#![allow(clippy::unchecked_duration_subtraction)]
#![allow(unused_variables)]
#![allow(unused_must_use)]
diff --git a/tests/ui/manual_instant_elapsed.rs b/tests/ui/manual_instant_elapsed.rs
index 5b11b84535d..c98cb15b916 100644
--- a/tests/ui/manual_instant_elapsed.rs
+++ b/tests/ui/manual_instant_elapsed.rs
@@ -1,6 +1,7 @@
// run-rustfix
#![warn(clippy::manual_instant_elapsed)]
#![allow(clippy::unnecessary_operation)]
+#![allow(clippy::unchecked_duration_subtraction)]
#![allow(unused_variables)]
#![allow(unused_must_use)]
diff --git a/tests/ui/manual_instant_elapsed.stderr b/tests/ui/manual_instant_elapsed.stderr
index 5537f5642a2..4ce1f689107 100644
--- a/tests/ui/manual_instant_elapsed.stderr
+++ b/tests/ui/manual_instant_elapsed.stderr
@@ -1,5 +1,5 @@
error: manual implementation of `Instant::elapsed`
- --> $DIR/manual_instant_elapsed.rs:17:20
+ --> $DIR/manual_instant_elapsed.rs:18:20
|
LL | let duration = Instant::now() - prev_instant;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `prev_instant.elapsed()`
@@ -7,7 +7,7 @@ LL | let duration = Instant::now() - prev_instant;
= note: `-D clippy::manual-instant-elapsed` implied by `-D warnings`
error: manual implementation of `Instant::elapsed`
- --> $DIR/manual_instant_elapsed.rs:26:5
+ --> $DIR/manual_instant_elapsed.rs:27:5
|
LL | Instant::now() - *ref_to_instant; // to ensure parens are added correctly
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `(*ref_to_instant).elapsed()`
From 852d80245148cdd23c5516bea015b0f3bf277ed4 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 7 Nov 2022 22:21:32 +0100
Subject: [PATCH 09/16] style: inline variables in `format!`
---
clippy_lints/src/instant_subtraction.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index 3166c62dad4..c039f1b5c6a 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -174,7 +174,7 @@ fn print_unchecked_duration_subtraction_sugg(
expr.span,
"unchecked subtraction of a 'Duration' from an 'Instant'",
"try",
- format!("{}.checked_sub({}).unwrap();", left_expr, right_expr),
+ format!("{left_expr}.checked_sub({right_expr}).unwrap();"),
applicability,
);
}
From 62ab4fb9c265b9e25d61c99511cd26de0260f435 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Tue, 8 Nov 2022 10:22:58 +0100
Subject: [PATCH 10/16] fix: add rust-fix annotation to unckd. duration subtr.
lint test
---
tests/ui/unchecked_duration_subtraction.fixed | 17 +++++++++++++++++
tests/ui/unchecked_duration_subtraction.rs | 1 +
tests/ui/unchecked_duration_subtraction.stderr | 8 ++++----
3 files changed, 22 insertions(+), 4 deletions(-)
create mode 100644 tests/ui/unchecked_duration_subtraction.fixed
diff --git a/tests/ui/unchecked_duration_subtraction.fixed b/tests/ui/unchecked_duration_subtraction.fixed
new file mode 100644
index 00000000000..bcc231d93b1
--- /dev/null
+++ b/tests/ui/unchecked_duration_subtraction.fixed
@@ -0,0 +1,17 @@
+// run-rustfix
+#![warn(clippy::unchecked_duration_subtraction)]
+
+use std::time::{Duration, Instant};
+
+fn main() {
+ let _first = Instant::now();
+ let second = Duration::from_secs(3);
+
+ let _ = _first.checked_sub(second).unwrap();;
+
+ let _ = Instant::now().checked_sub(Duration::from_secs(5)).unwrap();;
+
+ let _ = _first.checked_sub(Duration::from_secs(5)).unwrap();;
+
+ let _ = Instant::now().checked_sub(second).unwrap();;
+}
diff --git a/tests/ui/unchecked_duration_subtraction.rs b/tests/ui/unchecked_duration_subtraction.rs
index fff1d13720d..a14a7ea57cc 100644
--- a/tests/ui/unchecked_duration_subtraction.rs
+++ b/tests/ui/unchecked_duration_subtraction.rs
@@ -1,3 +1,4 @@
+// run-rustfix
#![warn(clippy::unchecked_duration_subtraction)]
use std::time::{Duration, Instant};
diff --git a/tests/ui/unchecked_duration_subtraction.stderr b/tests/ui/unchecked_duration_subtraction.stderr
index 6b297a01c7b..b949dbf701a 100644
--- a/tests/ui/unchecked_duration_subtraction.stderr
+++ b/tests/ui/unchecked_duration_subtraction.stderr
@@ -1,5 +1,5 @@
error: unchecked subtraction of a 'Duration' from an 'Instant'
- --> $DIR/unchecked_duration_subtraction.rs:9:13
+ --> $DIR/unchecked_duration_subtraction.rs:10:13
|
LL | let _ = _first - second;
| ^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(second).unwrap();`
@@ -7,19 +7,19 @@ LL | let _ = _first - second;
= note: `-D clippy::unchecked-duration-subtraction` implied by `-D warnings`
error: unchecked subtraction of a 'Duration' from an 'Instant'
- --> $DIR/unchecked_duration_subtraction.rs:11:13
+ --> $DIR/unchecked_duration_subtraction.rs:12:13
|
LL | let _ = Instant::now() - Duration::from_secs(5);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(Duration::from_secs(5)).unwrap();`
error: unchecked subtraction of a 'Duration' from an 'Instant'
- --> $DIR/unchecked_duration_subtraction.rs:13:13
+ --> $DIR/unchecked_duration_subtraction.rs:14:13
|
LL | let _ = _first - Duration::from_secs(5);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(Duration::from_secs(5)).unwrap();`
error: unchecked subtraction of a 'Duration' from an 'Instant'
- --> $DIR/unchecked_duration_subtraction.rs:15:13
+ --> $DIR/unchecked_duration_subtraction.rs:16:13
|
LL | let _ = Instant::now() - second;
| ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(second).unwrap();`
From 862ac29192bd4e2c9db04e9763dfd1a35a00a9cb Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Tue, 8 Nov 2022 15:04:32 +0100
Subject: [PATCH 11/16] fix: remove (redundant) semicolon in lint suggestion
---
clippy_lints/src/instant_subtraction.rs | 2 +-
tests/ui/unchecked_duration_subtraction.fixed | 8 ++++----
tests/ui/unchecked_duration_subtraction.stderr | 8 ++++----
3 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index c039f1b5c6a..d83beb622cf 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -174,7 +174,7 @@ fn print_unchecked_duration_subtraction_sugg(
expr.span,
"unchecked subtraction of a 'Duration' from an 'Instant'",
"try",
- format!("{left_expr}.checked_sub({right_expr}).unwrap();"),
+ format!("{left_expr}.checked_sub({right_expr}).unwrap()"),
applicability,
);
}
diff --git a/tests/ui/unchecked_duration_subtraction.fixed b/tests/ui/unchecked_duration_subtraction.fixed
index bcc231d93b1..a0e49a8beb1 100644
--- a/tests/ui/unchecked_duration_subtraction.fixed
+++ b/tests/ui/unchecked_duration_subtraction.fixed
@@ -7,11 +7,11 @@ fn main() {
let _first = Instant::now();
let second = Duration::from_secs(3);
- let _ = _first.checked_sub(second).unwrap();;
+ let _ = _first.checked_sub(second).unwrap();
- let _ = Instant::now().checked_sub(Duration::from_secs(5)).unwrap();;
+ let _ = Instant::now().checked_sub(Duration::from_secs(5)).unwrap();
- let _ = _first.checked_sub(Duration::from_secs(5)).unwrap();;
+ let _ = _first.checked_sub(Duration::from_secs(5)).unwrap();
- let _ = Instant::now().checked_sub(second).unwrap();;
+ let _ = Instant::now().checked_sub(second).unwrap();
}
diff --git a/tests/ui/unchecked_duration_subtraction.stderr b/tests/ui/unchecked_duration_subtraction.stderr
index b949dbf701a..a2e0aa1d7c0 100644
--- a/tests/ui/unchecked_duration_subtraction.stderr
+++ b/tests/ui/unchecked_duration_subtraction.stderr
@@ -2,7 +2,7 @@ error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:10:13
|
LL | let _ = _first - second;
- | ^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(second).unwrap();`
+ | ^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(second).unwrap()`
|
= note: `-D clippy::unchecked-duration-subtraction` implied by `-D warnings`
@@ -10,19 +10,19 @@ error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:12:13
|
LL | let _ = Instant::now() - Duration::from_secs(5);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(Duration::from_secs(5)).unwrap();`
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(Duration::from_secs(5)).unwrap()`
error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:14:13
|
LL | let _ = _first - Duration::from_secs(5);
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(Duration::from_secs(5)).unwrap();`
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `_first.checked_sub(Duration::from_secs(5)).unwrap()`
error: unchecked subtraction of a 'Duration' from an 'Instant'
--> $DIR/unchecked_duration_subtraction.rs:16:13
|
LL | let _ = Instant::now() - second;
- | ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(second).unwrap();`
+ | ^^^^^^^^^^^^^^^^^^^^^^^ help: try: `Instant::now().checked_sub(second).unwrap()`
error: aborting due to 4 previous errors
From 36eac0cb4ae2e372193f73c3181d5290431d3ae4 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Thu, 10 Nov 2022 15:55:45 +0100
Subject: [PATCH 12/16] fix: update lints
---
clippy_lints/src/declared_lints.rs | 3 ++-
clippy_lints/src/lib.rs | 1 -
src/docs/unchecked_duration_subtraction.txt | 19 -------------------
3 files changed, 2 insertions(+), 21 deletions(-)
delete mode 100644 src/docs/unchecked_duration_subtraction.txt
diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs
index 98265410e84..7a705e563fc 100644
--- a/clippy_lints/src/declared_lints.rs
+++ b/clippy_lints/src/declared_lints.rs
@@ -202,6 +202,8 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
crate::inherent_to_string::INHERENT_TO_STRING_SHADOW_DISPLAY_INFO,
crate::init_numbered_fields::INIT_NUMBERED_FIELDS_INFO,
crate::inline_fn_without_body::INLINE_FN_WITHOUT_BODY_INFO,
+ crate::instant_subtraction::MANUAL_INSTANT_ELAPSED_INFO,
+ crate::instant_subtraction::UNCHECKED_DURATION_SUBTRACTION_INFO,
crate::int_plus_one::INT_PLUS_ONE_INFO,
crate::invalid_upcast_comparisons::INVALID_UPCAST_COMPARISONS_INFO,
crate::invalid_utf8_in_unchecked::INVALID_UTF8_IN_UNCHECKED_INFO,
@@ -250,7 +252,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[
crate::manual_async_fn::MANUAL_ASYNC_FN_INFO,
crate::manual_bits::MANUAL_BITS_INFO,
crate::manual_clamp::MANUAL_CLAMP_INFO,
- crate::manual_instant_elapsed::MANUAL_INSTANT_ELAPSED_INFO,
crate::manual_is_ascii_check::MANUAL_IS_ASCII_CHECK_INFO,
crate::manual_let_else::MANUAL_LET_ELSE_INFO,
crate::manual_non_exhaustive::MANUAL_NON_EXHAUSTIVE_INFO,
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index ce0e7ebfbf1..3cfb2f491bc 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -921,7 +921,6 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_late_pass(|_| Box::new(from_raw_with_void_ptr::FromRawWithVoidPtr));
store.register_late_pass(|_| Box::new(suspicious_xor_used_as_pow::ConfusingXorAndPow));
store.register_late_pass(move |_| Box::new(manual_is_ascii_check::ManualIsAsciiCheck::new(msrv)));
- store.register_late_pass(move || Box::new(unchecked_duration_subtraction::UncheckedDurationSubtraction::new(msrv)));
// add lints here, do not remove this comment, it's used in `new_lint`
}
diff --git a/src/docs/unchecked_duration_subtraction.txt b/src/docs/unchecked_duration_subtraction.txt
deleted file mode 100644
index 15a4c02c606..00000000000
--- a/src/docs/unchecked_duration_subtraction.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-### What it does
-Finds patterns of unchecked subtraction of [`Duration`] from [`Instant::now()`].
-
-### Why is this bad?
-Unchecked subtraction could cause underflow on certain platforms, leading to
-unintentional panics.
-
-### Example
-```
-let time_passed = Instant::now() - Duration::from_secs(5);
-```
-
-Use instead:
-```
-let time_passed = Instant::now().checked_sub(Duration::from_secs(5));
-```
-
-[`Duration`]: std::time::Duration
-[`Instant::now()`]: std::time::Instant::now;
\ No newline at end of file
From 3f89ab0618a1075f0c53c47d405c0f6e9bf43953 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 14 Nov 2022 22:00:09 +0100
Subject: [PATCH 13/16] chore: update lint version of MANUAL_INSTAN_ELAPSED to
1.65
---
clippy_lints/src/instant_subtraction.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index d83beb622cf..6d23a672856 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -33,7 +33,7 @@ declare_clippy_lint! {
/// let prev_instant = Instant::now();
/// let duration = prev_instant.elapsed();
/// ```
- #[clippy::version = "1.64.0"]
+ #[clippy::version = "1.65.0"]
pub MANUAL_INSTANT_ELAPSED,
pedantic,
"subtraction between `Instant::now()` and previous `Instant`"
From 912dc919af03427288b64921bb4aea0010d071bf Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 14 Nov 2022 22:08:11 +0100
Subject: [PATCH 14/16] docs: update unchecked duration subtraction lint doc
---
clippy_lints/src/instant_subtraction.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index 6d23a672856..3f72222f31b 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -41,7 +41,7 @@ declare_clippy_lint! {
declare_clippy_lint! {
/// ### What it does
- /// Finds patterns of unchecked subtraction of [`Duration`] from [`Instant::now()`].
+ /// Lints subtraction between an [`Instant`] and a [`Duration`].
///
/// ### Why is this bad?
/// Unchecked subtraction could cause underflow on certain platforms, leading to
From 72ab91d8066ee399cff3e3c8293bf4dbccfb6358 Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 14 Nov 2022 22:25:56 +0100
Subject: [PATCH 15/16] fix: add extract_msrv_attr call to instan_subtraction
lint pass
---
clippy_lints/src/instant_subtraction.rs | 2 ++
1 file changed, 2 insertions(+)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index 3f72222f31b..716c11becd9 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -112,6 +112,8 @@ impl LateLintPass<'_> for InstantSubtraction {
}
}
}
+
+ extract_msrv_attr!(LateContext);
}
fn is_instant_now_call(cx: &LateContext<'_>, expr_block: &'_ Expr<'_>) -> bool {
From 0dd6ce0b1931e3e5c274daf4bbf50e96a322befd Mon Sep 17 00:00:00 2001
From: Nadir Fejzic <nadirfejzo@gmail.com>
Date: Mon, 14 Nov 2022 22:37:25 +0100
Subject: [PATCH 16/16] docs: import Instant and Duration in doctests
---
clippy_lints/src/instant_subtraction.rs | 2 ++
1 file changed, 2 insertions(+)
diff --git a/clippy_lints/src/instant_subtraction.rs b/clippy_lints/src/instant_subtraction.rs
index 716c11becd9..60754b224fc 100644
--- a/clippy_lints/src/instant_subtraction.rs
+++ b/clippy_lints/src/instant_subtraction.rs
@@ -49,11 +49,13 @@ declare_clippy_lint! {
///
/// ### Example
/// ```rust
+ /// # use std::time::{Instant, Duration};
/// let time_passed = Instant::now() - Duration::from_secs(5);
/// ```
///
/// Use instead:
/// ```rust
+ /// # use std::time::{Instant, Duration};
/// let time_passed = Instant::now().checked_sub(Duration::from_secs(5));
/// ```
///